syn ATF runs hotter??

[flynavydiesel]

I have seen a more than few posts about synthetic atf running hotter vice regular atf while towing under very similar conditions. I thought the syn atf would handle the heat and run cooler? Any thoughts on why this might be?

The post which stated the atf ran hotter was also running a bigger transmission pan and a larger capacity cooler than stock. So now I am baffled. The truck was running Mobil 1 syn atf, he seemed pretty miffed about putting $100.00 atf in which ran hotter than the stock fluid. I would be too if this is the case.

 

[MolaKule]

Just so we can frame this discussion in the right context, to which links are you referring?

 

[Drew]

I quit using Synthetic ATF after my transmission failed six months into using it.

The rebuilt transmission runs as well with Quaker State as it did with Mobil 1 and the temps are slightly lower according to my temp guage that is attached to my permacool inline filter.

 

[flynavydiesel]

Molakule, these are discussions on a Ford forum, the diesel stop. This is the first I had heard of something like this and it has me confussed.

 

[MolaKule]

Here is what I was getting to:
1. What type Type of driving and conditions under which equipment was operated,
2. Condition of equipment at time of installation
- was the synthetic fluid introduced to cure or MASK some type of pre-existing
problem?
3. Preventive and ongoing Maintence - how was it done or WAS it done?
4. Were temps real or inferred, i.e., guessed at or guaged with accurate guages
placed in the correct areas?
5. Did the operators assume that since they had synthetic fluid that would be a cure all,
and did they operate the equipment under more severe conditions and at higher
loads than they would normally do?

Just some of the context questions.

 

[Bio-T]

flynavydiesel,
The particular transmission (4R100) has a bypass valve and the flow of fluid to the cooler may be restricted causing an over heat problem. A larger transmission pan will just take the fluid longer to heat up and also to cool off. By itself it will not prevent an over heat problem.

1. The owner needs to ensure flow through the trans cooler eliminating any bypass restriction in the CBV. (cooler bypass valve) This is a common problem and many transmissions are scrapped because of this valve. The trans. fluid temp must be at operating temp for this test.

2. If no flow is impeded at this point a flow test must be performed. The Ford 4R100 needs to flow at 32 ounces (1Quart) in 15 seconds. This test is preformed at the return line at the rear of the transmission on the passenger side.

Just for information the Ford E40D from 89-94 will flow 24 ounces in 15 seconds and the E40D from 95-98 will flow the same as the 4R100 which is 32 ounces in 1 Minute.

 

[JohnBrowning]

GM has research showing that ester based ATF loweres the operateing temp under harsh dyno-trailer work in the desert up steep grade. THe ester ATF was custom blended just for the testing. It effective held the temps under the max recomended operateing temps 230F max it ran something like 221F. The non-ester based regualr Dex III ran up to some insane number just under 400F like 371F. Now I doubt that any one can buy a 100% ester based ATF!! I think that Redline is something like 30-40% ester based from what I have heard!

 

[flynavydiesel]

Molakule,
here this might help.

As far as I can tell, the transmission and cooler were all operating normally. The situations were apparantly similar, towing in summer heat same Travel Trailer each time. The only difference in the scenarios were the addition of synthetic Mobile ATF. The temperatures were observed on a transmission temp gauge. I think he was just trying to keep his temps lower and figured synthetic would help in addition to the larger transmission cooler. The one installed is for a 20,000 gvwr so way big enough for anything a F250-350 can tow.

Vetteman, I have to assume that the CBV and flow rates were the ok, if they saw the increase only with synthetic.

Could it be that batch of mobile was just not functioning properly?

 

[MolaKule]

From what Vetteman said, I can only speculate that the M1 may have disloged some crud that restricted proper operation of the CBV.

 

[flynavydiesel]

I hope this is isolated but he mentioned that other threads on that board had revealed similar instances of the transmission temps going up with snythetic. I could not find them, and everyone running amsoil has not had a complaint.
Who knows just though I would find out if this was something that might happen.

 

[Titanium_Alloy]

quote:

---

Originally posted by JohnBrowning:
GM has research showing that ester based ATF loweres the operateing temp under harsh dyno-trailer work in the desert up steep grade. THe ester ATF was custom blended just for the testing. It effective held the temps under the max recomended operateing temps 230F max it ran something like 221F. The non-ester based regualr Dex III ran up to some insane number just under 400F like 371F. Now I doubt that any one can buy a 100% ester based ATF!! I think that Redline is something like 30-40% ester based from what I have heard!

---

John can you give me a link or a paper title or number (if it's a SAE paper). I know that MoleKule also mentioned that paper but I didn't ask for specific title of the paper or detailed information on tests performed and ATFs used. If anyone can provide any additional info on these GM tests I would be very grateful.

Regards,

 

[therion]

quote:

---

Originally posted by Drew:
I quit using Synthetic ATF after my transmission failed six months into using it.

The rebuilt transmission runs as well with Quaker State as it did with Mobil 1 and the temps are slightly lower according to my temp guage that is attached to my permacool inline filter.

---

How many miles when you switched it to Mobil 1 Synthetic ATF?

 

[heyjay]

This is the first I've heard of a synthetic ATF running HOTTER than a regular Dex III.

However, I have heard of a synthetic ATF causing problems with an older transmission. Like mentioned above, the higher detergents in synthetic ATF can knock crud loose that plugs valve bodies, and makes check valves and shift solenoids stick.

I was also under the impression that Ford has had a LOT of trouble with that transmission, and probably the CBV is one reason why. Why not just remove that CBV? If it's winter, run a winter front.

Regarding this GM test in the desert, was it performed using the Allison 1000 5spd autobox and Allison TranSynd synthetic ATF??

Allison got Castrol to specially blend a synthetic ATF called TranSynd for extreme HD use, like heavy towing, city transit buses, refuse packers, etc.

Apparently, TranSynd lowers operating temps and allows extended drain intervals for Allison automatics. Under severe use, the drain interval is 12 months or 12,000 miles. With TranSynd, 48 months or 48,000 miles.

This new spec oil is beyond the older Allison C3 and Allison C4 oils for HD powershift and automatics. Which is a shame because Esso and Mobil now have a wide range of arctic, seasonal, and high temp synthetic Allison C4-approved oils.

Neither GM or Allison recommends the use of TranSynd in a non-Allison transmission. You could experience shift problems.

If you want more info on TranSynd, take a peek at:

http://www.allisontransmission.com

Jerry

 

[Titanium_Alloy]

heyjay if I'm not mistaken TranSynd as well as Amsoil's replacement for it are both rated Dexron III. I once had a crazy idea of trying these fluids due to their supposed "superiority" to other synthetics. I quickly changed my mind and have never done so. Do you know if there would be any problems running TranSynd or Amsoil's TorqueDrive instead of Dexron III? Some parameters of these fluids look by far superior to other Dexron III rated ATFs, while other factors look OK (better than most, worse than some). Both JohnBrowning and MoleKule said that GM tested synthetic fluid was ester based. Isn't the TranSynd a PAO or GIII based oil?

Regards,

 

[heyjay]

Well, I think Amsoil regular synthetic ATF and Mobil 1 ATF provide the high temp protection as well. They're both DexIII and Allison C4.

If you carefully read the Allison web site, they state that TranSynd was developed for use in the Allison transmissions. This is for a new TES295 supplement.

If you're not familiar with Allison heavy duty automatics, keep in mind they have some unique frictional requirements. Although they seem compatible with Dexron, Allison has always suggested an Allison C3, C4, and now TES295 oil for heavy duty use.

Allison probably wanted to cash in on the oil servicing. The 3,000 and 4,000 series Allison's are factory-fill with TranSynd and Allison warns you void the warranty if you use Dexron. Allison only recognizes Castrol TranSynd as meeting TES295, despite the fact Amsoil has a similar oil.

I would contact Allison directly to verify their TranSynd fluid is good to use in other automatic transmissions.

Again, I think you would have great results in high-temp use running Amsoil or Mobil 1 ATF.

Jerry