Aux. Spin on Transmission Filters

[kd5byb]

Yep - I used the cST = SSU / 4.55.

I didn't catch the limitation where it only worked above 50 SSU. I now retract my comment about how the 4.55 factor seemed simplistic - that's because it is!

3.3 PSI is still very low. Low enough that I'm really beginning to think that a 15 or 25 PSI bypass may be too high. By the time it hits 15 or 25 PSI differential, the filter is extremely plugged.

May not even need a bypass if the filter has a lot of surface area or is of large enough micron size that it just won't plug between changes. I did buy some Fleetguard/Cummins heads that don't have a bypass. Some of the filters that fit this mount are huge - like a Wix 51202 - 3.6" by 7.8" - that I just don't see the thing ever plugging even with a beta 2/20 = 2/11.

Perhaps instead of a 15/25 PSI bypass head, I'll use one without a bypass and use an element that will have no chance of plugging in between element changes???

later,
ben

 

[Gary Allan]

They do offer some with 3 and 5 psi bypasses. But I think that you're correct that the bypass will never be needed. Schultz (look back around page 4 or 5) kinda confirms that with his very fine filter that's not of too exceptional size. I think an annual (or longer) change out would work well. Convenient time to swap out a quart or two. Assuming that you're not over heating anything, you may just have the sump in stasis ..so to speak.

 

[Gary Allan]

Here's another hydraulic filter. This one has an internal bypass (not common) ..but it's pretty far up there by our engine standards of perception.

There is no Wix xref for this. It's available in LuberFiner (Champ, iirc) LFH8596

P550229 (Donaldson)


HYDRAULIC ELEMENT SPIN-ON





Hydraulic Filters Product Attributes
A - OD (Inches): 3.82
B - Thread Size (Inches): 1-12
C - Length (Inches): 7.01
D - Gasket OD (Inches): 2.8
E - Gasket ID (Inches): 2.4
Product Type Description: HYDRAULIC SPIN-ON
Primary Application: LINDE 009830615
Media Type: Cellulose
Efficiency Beta 2 (Micron): 20
Relief Valve Setting (PSI): 30-42

 

[kd5byb]

Hi Gary and gang,

I took apart one of my PTI filter heads the other evening to see if perhaps I could cut off a coil or two of the spring to lower the bypass setting.

With the PTI head, you insert a socket into the input line of the filter to compress the spring. Using an Allen key that fits the socket on the bypass valve, you then unhook the spring from the bypass valve poppet. Very easy. I just took a look at the Northern Tool filter head and it can be disassembled the same way. Looks like you could very easily clip off one or two turns of the spring and lower the bypass setting.

Yet, Schultz's posts scream to me that even with a very fine filter, you really won't ever hit the bypass in ATF use. His filter seems to be much finer than a 10 micron nominal Northern Tool filter, or even a 5 micron nominal hydraulic filter - yet, he's never tripped his 15 psi warning light!

Certainly, a once a year filter change won't allow for much yuck-build up in the filter.

The only thing a skeptic could say is perhaps auto trannys can't source in excess of 15 psi - but yet, I seem to recall either in this thread or another thread that a smallish Saturn tranny could put out near 100 psi at the test port, where I do believe this owner had supplied oil to a tranny filter.

Or, perhaps 100 psi at a test port is appropriate, but perhaps a tranny can't source 15 psi in a cooler line?

Anyone here know what sort of pressure an auto tranny can push into a cooler? I may just need to tee into the supply line of my Tundra's cooler to get an idea what sort of pressure it's pushing.

Perhaps a bypass filter across the ATF cooler is the way to go? Then there really can't be an issue with the amount of pressure the tranny can source?

thanks,
ben

 

[Gary Allan]

I haven't confirmed it personal testing but I believe that there's no limit the pressure that can be produced by the cooler line. That is, it's the limit of the pump. There just isn't anything to restrict the flow normally. When one member used a Permacool sandwich to drive a Motor Guard, he heard it buzzing. It was the sound of the poppet slamming open and closed when the tranny pump hit relief. He needed to drill a VERY small hole to allow enough flow.

It may be different in some automatics ..but the cooler flow typically comes from the converter (hottest point) and then lubricates/cools the rotating parts before hitting the pan again.

The line is typically low pressure ..but it's not limited to low pressure. It's just that there's nothing typically in the way.

In reverse pump pressures can be over 250 lbs in some automatics. That was in the 70's ..so some may be higher now.

A test port may work out for a bypass filter with a restrictor in it. I prefer plumbing it across the cooler circuit. I think that technique is an Allan original. Not really much different then returning it to the stick except that no flow is lost from the circuit. It obviously doesn't matter either way.

Check your mounts. There are some that are adjustable and they're the identical castings. Just a screw type action sends it one way or the other.

 

[kd5byb]

The more I think about it, the more I think that a parallel (bypass) type of setup is the way to go. Some small amount of flow will go through the filter with the main amount of the flow going through the cooler.

I started thinking last night about what effects plumbing in-line with the cooler might have:

* Reduced oil flow through the cooler.

I'm not certain as to the effect on the transmission here. Depending on how the cooler is sized/engineered, less flow through the cooler may yield cooler fluid coming out of it. Or, it may yield higher transmission temperatures as the amount of fluid being cooled is lowered. Now, in my Tundra and I expect some other vehicles, the cooler circuit has a thermostat. When the fluid is cold, no ATF is sent to the cooler. I'd expect that if the transmission temperature were to increase above where the thermostat wanted it, it would open further allowing more flow. But this assumes that the thermostat isn't an on/off or "bang-bang" type that is either full open or full closed. I expect that since it is a wax-pellet type per the service manual, it has some regulation and isn't on/off.

I need to think about this more.

* Flow becomes a function of the amount of filter clogging - the more clogged the filter is, the less flow you get until you hit the bypass. My first thoughts on this subject is that I'm worrying over nothing, as the filter won't plug anyways, unless something is very goofy with the transmission, and flow, while it will fall off over time, will drop so slowly that it doesn't really matter.

* There are others that I cannot remember at the moment.

A compromise approach may be like you mention - take a non-bypassing filter housing and putting a small hole (maybe 1/4") in it between the input/output ports. Most flow goes right though, some gets filtered. It's like a bypass filter now.

I need to see if I can find some technical data on the Tundra tranny to see what the pressure is and how it releives...

thanks much,
ben

 

[Gary Allan]

Quote:
I'm not certain as to the effect on the transmission here. Depending on how the cooler is sized/engineered, less flow through the cooler may yield cooler fluid coming out of it. Or, it may yield higher transmission temperatures as the amount of fluid being cooled is lowered. Now, in my Tundra and I expect some other vehicles, the cooler circuit has a thermostat. When the fluid is cold, no ATF is sent to the cooler. I'd expect that if the transmission temperature were to increase above where the thermostat wanted it, it would open further allowing more flow. But this assumes that the thermostat isn't an on/off or "bang-bang" type that is either full open or full closed. I expect that since it is a wax-pellet type per the service manual, it has some regulation and isn't on/off.


If the filter you're proposing (the ones mentioned) is a conventional pleated paper/synthetic media ...then I wouldn't be too concerned about plumbing it full flow. I'd have a trans temp gauge installed just to assure adequate cooling. The only potential problem is if there was some mass introduction of debris (let's say a converter let go). So, while you many save the trans internals from all that debris festering in the rotating parts and passageways ...you'll fry them instead. This is naturally a situation where the trans was in for major service anyway ..so . This is when a bypass mechanism would be needed.

If it was an MG or any mechanically restricted filter (Frantz, etc.) then it's a bad idea. They make "biasing blocks" for the Frantz setups that will induce some flow to the dense filter.

Quote:
Flow becomes a function of the amount of filter clogging - the more clogged the filter is, the less flow you get until you hit the bypass.


I don't believe that this is the case. I believe that increased pressure is the result of the filter clogging. If you look back at the Ford 450xx (whatever) transmission that undummy linked to, they have a "viscosity sensitive" (aka: pressure) flow regulator to the cooler circuit. If the trans has no such shunt installed and is truly temp regulated, then, in the absence of a localized pressure relief, it would just go to whatever limits the supply has in pumping what it is going to pump. I would assume, in the absence of any counter information, that this would be the tran pump's limit, which is rather high (200lb+)

Also remember that the post cooler flow doesn't just return to the pan i any automatic that I've seen the fluid schematic for. It does other stuff entering the trans again. Lubing and cooling. Any loss in flow can damage the trans ..at least eventually. In the aforementioned Ford HD 4xxx trans ..no flow was reduced to the trans itself. Just the flow through the cooling circuit due to THAT transmissions cooler regulation modality.

Quote:
I need to see if I can find some technical data on the Tundra tranny to see what the pressure is and how it releives...


I highly recommend it.


Have a good holiday!

 

[kd5byb]

Good morning Gary and all!

I hope everyone is getting ready to have a nice Thanksgiving. I took today and Friday off from work. It feels odd to me - other than our week-long Summer vacation I don't take off much time from work. But, it gives me time to think about filters and transmissions.

I've got the temp gauge covered - the Tunda towing package comes standard with a transmission temperature gauge. Yes, it's little more than an idiot light as it has no scale nor calibration, but its better than no temperature information at all. I will able to see gross fluctuations.

The failure discussion is very interesting. I agree - if there is no bypass feature, a mass clogging event becomes a tranny killer as there is no cooling. But, in either case, the tranny is probably doomed to be rebuilt so it may be six of one, half dozen of another.

Interestingly, I've read a story where a guy with a 2006 Tundra installed a Magnefine tranny filter in his ATF cooler lines backwards, preventing ANY flow through the cooler because of the built-in check-valve. He drove 20,000 miles with no cooler without any problems and no apparent cooking or degradation of the fluid. I can believe this, as there are Tundra trucks without the towing package that don't have an external air to ATF cooler. (They all have a coolant to ATF warmer/cooler.) It may be that the tranny may have an internal bypass to protect itself in the case of a plugged cooler.

I've rethought my flow/pressure/clogging comments below. My comments are correct if the flow to the cooler is pressure regulated - any increase in filter delta P is going to decrease flow.

But, if the flow to the cooler is flow regulated, an increase in filter delta P only increases pressure in the pump to filter lines as the pressure rises to get proper flow.

Electrical engineers (which I play at work sometimes even though I'm a mechanical/aerospace engineer) would explain the flow/pressure differences in terms of source impedance.

The Tundra tranny (at least the new six speed I own) gets even more complicated. I did some poking around in the service manual and while I don't yet have the full picture, I've concluded a few things:

* The tranny regulates "pressure" based on fluid temperature. I've put pressure in quotes as it isn't clear where the pressure is regulated - is it regulated only into the valve body / solenoid stacks? Is it the whole flow? Parts of it?

* The temperature regulation on the ATF cooler/warmer circuit isn't bang-bang, it's proportional. Increased tranny temp will increase flow to the cooler to help cool off the tranny. This strongly suggests to me that the pump has lots of extra capacity, and that any restriction in the cooler circuit will be overcome by the pump increasing output pressure. Or, better said, flow is what is important, not pressure.

Interestingly, Dr. Haas and others (myself included!) have lobbied here that flow is more important than pressure - as long as you have enough pressure to get the minimum required flow, more pressure won't help anything.

Still left to determine:

* ATF flow path and the pressure in the flow path.
* Where the fluid is returned to in the transmission.

thanks much,
ben

 

[Gary Allan]

Quote:
This strongly suggests to me that the pump has lots of extra capacity, and that any restriction in the cooler circuit will be overcome by the pump increasing output pressure. Or, better said, flow is what is important, not pressure.


If it's like most, it's a crescent pump with minor losses and will produce volume based on its' speed. Pressure will develop based on how much of that volume is moved through a respective conduit. It has some limiting mechanism for pressure, and hence a max volume that can/will be pushed through a given conduit.

To alter Dr. Haas view just a tad ..pressure is a byproduct of flow that varies with viscosity. In almost any other commonly observed event (electricity, water, etc.) pressure is the driver of flow with resistance being a static component in most cases. There are instances of reactive components when the pump is in relief. Oil filters respond this way when the pump is in relief. If the pump isn't in relief, the filter's "resistance" is trumped BIG TIME by the massive resistance to flow that the engine represents. When in relief, the engine produces less back pressure due to reduced flow ..but the upstream side of the filter sees the attenuated pump pressure. No relief? The flow just changes in intermediate velocity as it encounters restrictions. Just like rapids in a river. Same gpm ..higher speed.

There are some limitations to the fine doctor's feelings on pressure. There has to be an "equivalency" of flow @ pressure in the processed oil flow. I guess it would work out much like wattage to some extent. In real terms you just can't get as thin a fluid as you please in any old engine and say it will work (although I'm working on finding the edge of this envelope as we speak).

Quote:
nterestingly, I've read a story where a guy with a 2006 Tundra installed a Magnefine tranny filter in his ATF cooler lines backwards,


Unless he cut it open, we would have no way of knowing whether or not the media collapsed allowing full flow. I don't recall a check valve in the Magnefine that I cut open. It appeared to be a bypass valve. I could be wrong. It does have a bypass valve which may also be a ADBV ..but that would be odd to include it as a feature in a system that could care less whether or not the flow was reverse during shut down.

I'll stop here ...it's a holiday.

I'll try for shorter posts

Enjoy the long weekend. Spend time with family and friends ... for they are the true blessings of life.

 

[kd5byb]

Hi Gary and gang,

Spent some free time yesterday and today looking for Toyota transmission information. There's nothing specific to the AB60E tranny that's in my Tundra, but I did find some good general information.

I paid $10 for a day and a half access to Toyota's Technical Information Service - did some heavy duty looking and printing of pages of interesting. The Service Manual for the Tundra was pretty worthless. Lots of "if this, replace this" instructions, but no schematic of fluid circulation.

However, I hit gold on the training information section. Found two manuals that covered Toyota tranny theory of operation (although not specifically the AB60E) in detail. I think these will give me the information I need.

First, ATF fluid flow:

1) Pump is a gerotator type pump that provides PRIMARY line pressure. It's got a spring-poppet valve to prevent over-pressurization, as well as a Primary Regulator Valve.

2) Primary line pressure provides hydraulic pressure for the "hydraulic circuits" in the transmission - or, more succinctly, the solenoids in the tranny.

I found documentation that shows the line pressure (primary pressure) can be about 60 psi at idle, going up to 190 psi at stall.

3) Primary line pressure is then dropped down to Secondary Pressure, and this goes to the Torque Converter and tranny lubrication.

4) Fluid from the Torque Converter, if it's not locked up, is sent to the cooler if the ATF temperature is high enough. If too cold, it gets dumped back into the pan.

4.5) If the Torque Converter is locked up, it appears that there isn't any fluid circulation inside the Torque Converter and therefore no flow to the cooler. I find this interesting. I can understand that if the Torque Converter is locked up, it's not churning fluid and heating it. Yet, what about the hot ATF in the tranny from other tranny parts? Perhaps the heat load from other parts is insignificant compared to the heat load of the Torque Converter.

5) The line to the cooler has a By-Pass Valve on it. Toyota notes that it is a low pressure system, but never quantifies the amount of pressure. If the feed pressure to the cooler becomes too high, fluid bypasses back into the input side of the pump. I don't know at what pressure this By-Pass valve actuates.

This cooler bypass is probably what kept the guy with the backwards Magnefine from starving his tranny for oil.

6) It appears that the fluid from the cooler gets dumped back into the pan.

It looks like I've got a few on-vehicle tests to do. I can warm up the truck, add a pressure gauge to the cooler input line and restrict the cooler output line and see what sort of pressure I get.

If it's high, say I can get 10 or 15 psi when I constrict the hose, I can plumb the filter as a full-flow. I'm betting this will be the case.

If it's low, say 3 or 4 psi, I can plumb the filter as a cooler-bypass filter. I'm not filtering a lot of fluid, but still better than nothing. I'm betting that this won't be the case, as it means just a little restriction in the cooler circuit negates any benefit to having the cooler.

thanks much!
ben

 

[Gary Allan]

Quote:
4) Fluid from the Torque Converter, if it's not locked up, is sent to the cooler if the ATF temperature is high enough. If too cold, it gets dumped back into the pan.


Is this determined by actual thermal properties or viscosity? Either are functional cooling determining factors in how it effects shifting and whatnot. I think that you eluded to a wax bulb (like a CTO) type switch somewhere back in your posts.

Quote:
4.5) If the Torque Converter is locked up, it appears that there isn't any fluid circulation inside the Torque Converter and therefore no flow to the cooler. I find this interesting. I can understand that if the Torque Converter is locked up, it's not churning fluid and heating it. Yet, what about the hot ATF in the tranny from other tranny parts? Perhaps the heat load from other parts is insignificant compared to the heat load of the Torque Converter.


Unless there is some co-acting mechanism that closes the inlet to the converter when the lockup occurs ..just what stops the flow in and out from occurring? That is, the lock up itself should be independent of the ingress:egress of fluid.

Quote:
6) It appears that the fluid from the cooler gets dumped back into the pan.


Although not a usual configuration ..there's nothing that prevents the cooler circuit from being an "kidney loop" auxiliary circuit ...totally independent from other functions. It has its pluses and minuses. It could just be a matter of the cooler being put in line with the normal lubrication circuit as well. AFT is primarily a power transmission (pressure actuation and motion transmsission) modality and a coolant. Real lubrication isn't one of its strong suits.


Quote:
Good morning Gary and all!

 

[kd5byb]

Hi Gary and all,

I forgot to mention the wax-plug thermostat - if the thermostat is open, fluid is sent from the torque converter to the cooler. If closed, fluid is returned into the transmission. It's purely temperature.

Regarding lockup, it appears that the fluid flow into the torque converter when not locked up is through the lock-up clutch of the converter. It flows out when not locked-up through the center of the converter.

Here are the two graphics from the TM:

When locked up, the fluid direction reverses. It flows in thru the center section and the pressure pushes the lock-up clutch into the front cover, both locking up the converter and preventing egress of fluid from the converter. The fluid that was in between the front cover and the lock-up clutch is simply drained into the pan.

I'm very skeptical that something isn't missing here! It seems very odd that there is no flow of hot fluid to the cooler once the converter is locked up. Seems counterintuitive to not be cooling ATF with the cooler just because the converter is locked up.

Regardless of the exact plumbing of the cooler circuit, I'm pretty confident I can do my pressure test to determine if to plumb full-flow vs. bypass.

Only problem after that is to find a place on the truck to mount it! I have one open space under the hood right by the cooler that would be perfect, but it somewhat blocks access to the power steering fluid reservoir...

thanks much,
ben

 

[Gary Allan]

Quote:
I'm very skeptical that something isn't missing here! It seems very odd that there is no flow of hot fluid to the cooler once the converter is locked up. Seems counterintuitive to not be cooling ATF with the cooler just because the converter is locked up.


Well, and this is just speculation, I think that the schematic shows your wax bulb as the closed thingie that would lead to the cooler. The alteration to the drawing has no purpose ..yet has a conduit and a partition depicted. I would say that valving routes fluid to the cooler regardless of temp when the convert clutch is not locked up. When locked up the temp must open the wax bulb (the depicted partition w/its own conduit) to access the cooler circuit.

 

[kd5byb]

Hi Gary and all,

Well, one problem with the diagrams I posted is that they don't show the ATF warmer / cooler circuit on that schematic. They were pretty general, being from a Toyota course that focused on general Toyota auto tranny theory.

I also think it is a bit dated.

Here's a section of the AB60E manual showing the cooler/warmer functions:

(If the photos don't show, my webpage may be down - give it a few minutes and try again. The links to the photos are in here and correct, just not showing up right now!)

Another problem is that the diagrams I posted earlier nor the above diagram show the cooler by-pass valve.

I know I'm doing something somewhat risky - combining information from one section of a generic manual, with another section of the same generic manual, with a section from a specific AB60E manual. But, it would seem to me that if Toyota followed an evolutionary design process, and I think they do, that the AB60E is nothing more than a generic Toyota auto tranny, albeit computer controlled, with a cooler/warmed scabbed onto the exterior of the tranny:

To me, the cooler/warmer thermostat business looks pretty scabbed on. I think it's more scabbed on because if you don't have the towing package, you don't ever have a cooler!

All that said, the little bulb-like thingy in the full-color schematics is troubling. What is it? What does it do? Why even have it there if it doesn't pass fluid?

It's very strange.

In the good news column, I hope to order parts for my little pressure test setup sometime this week. HOPEFULLY I'll get to do the test before it gets too Wintry here.

later,
b

 

[Gary Allan]

Quote:
To me, the cooler/warmer thermostat business looks pretty scabbed on. I think it's more scabbed on because if you don't have the towing package, you don't ever have a cooler!


Hmmm ...scabbed? This is a laminar heat exchanger. As long as the cooling system is of adequate capacity, the trans should have a very stable temp all the time. The engine coolant flow probably trumps the trans fluid flow by a decent amount ...so the added btu load, again, assuming enough capacity in the cooling system, should be transparent in use from an engine temp perspective.

The best heat exchangers are laminar coolers. They're the most compact design and allow one thermostat to govern everything. It may slightly delay your engine warm up.

This just allowed them cheaper (not saying lower quality) radiators as opposed to cheaper transmissions (not saying lower quality either).

It would complicate auxiliary cooling and filtration and would frustrate anyone who wants lower then 190-195 trans temps.

 

[kd5byb]

You know Gary, the more I think about the warmer/cooler setup on the Tundra the more I like it.

The warmer helps get the transmission fluid up to temperature quickly, which per Toyota, saves gas. I've also noticed that the shift logic in the AB60E delays lock-up until the tranny reaches a minimum temperature. I noticed this behavior this morning, which was about 36 deg F here.

I pulled out of my short driveway, went down the 1 mile road to the state highway. Pulled out and got to 55 / 60 MPH, and noticed I was turning 2000 rpm, which is rather high for my truck. It's a six speed auto, and it usually turns about 2k at 75 MPH. Well, I let off the gas and I noticed the RPMS drop down to 1500 or so with my foot off the gas. About two miles down the road, lock-up occurred and the RPMS were at about 1500 or so - much more in line with where I'm used to seeing them on Highway 53 in warmer weather.

So it's a good thing for me, gas mileage-wise, to get the tranny up to temp quickly.

Now, the other neat thing is that if the tranny starts getting really hot (higher than engine temp!) the warmer acts like a cooler, transferring ATF heat to the coolant. Then, the hot fluid goes to the tranny cooler, to dump more heat directly to the air.

Not sure I see how this complicates filtration? Sure, I'm not filtering when the oil is cold if I'm plumbed into the cooler lines, but assuming I'm getting at least partial cooler flow when the engine is hot (and I am, as I've felt the cooler after driving and its definitely warm to hot). Yes, I'm not filtering 100% of the tranny's flow 100% of the time, but certainly over my 25 mile commute I'm going to filter all the fluid at least once, perhaps multiple times? Not as good as a filter doing 100%/100% of the time, but still a vast improvement.

I need to digest the other part of that same sentence more. I can both see, yet not see, where coolant temp would be a lower limit for coolant temp.

Let me run a test case (thinking out loud here in writing):

CONDITIONS:
Let's say - Tranny fluid is 150 deg F. Coolant is 190 deg F. Outside air temp and flow over the cooler is sufficient to drop cooler output to 100 deg F. Tranny oil thermostat cracks at 120 deg F, full open at 150 deg F.

Okay, so 150 deg F fluid comes out of the tranny. Into the warmer it goes, where it absorbs coolant heat and reaches 180 degrees. Tranny oil t-stat is full open as 180 > 150. Fluid sent to cooler and comes out of the cooler at 100 deg F.

COMMENT - this seems dumb, as the warmer is adding heat to be removed by the cooler. Why do this? It's nonsense.

And this will occur as long as the tranny oil thermostat opens fully at a lower temp than the coolant.

So, it only seems logical that engine coolant temp is the tranny temp's lower limit.

Now it makes a lot of sense if:

CONDITIONS:
Tranny fluid is 250 deg F. Coolant is 190 deg F. Outside air temp and flow over the cooler is sufficient to drop cooler output to 100 deg F. Tranny oil thermostat cracks at 175 deg F, full open at 190 deg F.

Fluid bops out of the tranny at 250. The warmer actually cools this hot fluid down some. Let's say it goes down to 210, a little hotter than the coolant. Tranny oil t-stat is full open, 210 degree fluid goes to the cooler and pops out at 100 deg F. Tranny heats it back up to 250 deg F and lather, rinse, repeat.

This makes sense. Now the question becomes how do you define "tranny temp?" Even though the fluid coming out may be at 250 deg F, some parts will be hotter (to get the fluid to 250) and others much cooler, as 100 deg F fluid is going into the tranny from the cooler.

It's like asking me what is the temperature of a turboshaft jet engine? Well, T4.5 may be 1350 deg F, but it's cooler in the compressor, and hotter inside the combustor.

Perhaps the term "tranny temp" is really misleading?

VERY INTERESTING DISCUSSION.

later,
b

 

[Gary Allan]

Quote:
Not sure I see how this complicates filtration?


In your case it doesn't. You've got the towing package.

The rest is a little hard for me to follow ...too many numbers heading in too many directions.

..but it would seem that you would be bleeding engine heat out via the trans cooler 24/7 if you are elevating the trans fluid temp above the thermostat's threshold ..which one would normally think it will surely reach. I'm sure that they've engineered it well ..but there may be an element or two that we're not privy to in the illustrations that you've posted.

Quote:
Now the question becomes how do you define "tranny temp?" Even though the fluid coming out may be at 250 deg F, some parts will be hotter (to get the fluid to 250) and others much cooler, as 100 deg F fluid is going into the tranny from the cooler.


We know from your diagrams that the flow comes from the converter to the cooler/warmer plumbing. This is typically the hottest point in any trans.

 

[kd5byb]

Originally Posted By: Gary Allan

The rest is a little hard for me to follow ...too many numbers heading in too many directions.

Yeah, it was a little hard to follow. When I get latched on to something like that, I just type and as long as it makes sense to me, I'm good! Problem is that I don't stop and think that perhaps someone else won't understand it.

That said, I think you're right when you say we're probably missing an element or two.

One those elements may be that this is a brand new transmission using Toyota WS fluid. It may be designed to operate in a temperature range of the engine's coolant and dropping the temperature far below this may not be good for it.

It also may be that the tranny fluid does come out of the tranny at a far hotter temp than the coolant. Some heat is lost to the coolant, but most is lost in the tranny cooler. The warmer may be very thermally small. Tranny temp does lag engine temp per my temp gages.

I just don't know. Had hoped to do some work on it this weekend, but found out Wednesday that I'm being sent to California on Sunday afternoon for all of next week. Ugh. Feels like 12 hour days...

later,
b

 

[Gary Allan]

Quote:
Yeah, it was a little hard to follow. When I get latched on to something like that, I just type and as long as it makes sense to me, I'm good! Problem is that I don't stop and think that perhaps someone else won't understand it.

I don't know how good I am ...but the same thing happens to me all the time. It's more in the way I organize and regurgitate information. So, I don't even know if I could understand myself if I wasn't the guy writing it.

Quote:
The warmer may be very thermally small. Tranny temp does lag engine temp per my temp gages.


Well, it is compact. Even an Audi/VW or Modine/Long sandwich oil:coolant exchanger shortens a normal 13-15 mile normalization of oil temp to about 9 miles ..and that's with a 4-5 quart sump.

 

[TheLoneRanger]

After a search, I turned up this very informative thread on
aux spin-on trans filters. My plans are to install a B&M
spin-on mount (which I suspect is actually a rebranded Permacool), along with a good filter to a 3.0 Ford Ranger.
It looks to be a 3/4" by 16 thread size.

The question is, what is a good brand of filter for these
mounts, and is a 20 micron filter or thereabouts, good
eniough filtration.

Thanks,
TLR