does "T-Tech" system really work

[kmrcstintn]

I have a 1999 Subaru Forester with 21,000 miles; the trans fluid is factory OEM and I want to have it changed; some people have been recommending "T-Tech" that completely drains and refills the system and torque convertor without changing the filter/pan gasket;

is this a good way to do a transmission service over the old way of draining by gravity?

 

[The Critic]

The concept of a transmission fluid exchange service has both its positives and negatives. When used in conjunction with an actual filter cleaning or replacement at every other service, a transmission fluid exchange, if done only with fluid (no additives), can be beneficial to a transmission. Instead, many transmission fluid exchanges are done by quick lube operators who hoped for this service to be a rapid profit maker as it requires minimal time and skill to complete. Sadly, quick lube operators recommend the transmission fluid exchange service, but neglect servicing the filter.

However, you generally need to pump through 1.5x the capacity of the transmission to adequately replace all of the old fluid. This is because a transmission fluid exchange is a rapid dilution of the old fluid, you need to run through more than the transmission's total fluid capacity, generally 1.5x the amount, to completely dilute most of the old fluid.

As a final note, I'd like to add that a transmission fluid exchange, when used in conjunction with periodic filter changes, is not mandatory for proper maintenance of a transmission. Draining the fluid every 30,000 miles (or 20,000 miles if you wish to be extra conservative) via either a pan removal, pan drain plug, or dipstick extraction, and refilling with fresh, good quality fluid, combined with a filter change at every other service (or 60,000 miles), will be more than enough for 95% of the transmissions on the road today.

For your transmission, draining the pan should remove about 5 quarts of fluid. The specified fluid is Dexron-III, so you have many fluid choices avaliable. I would stick with a mineral Dexron-III(H)/Mercon or Dexron-VI fluid and change the fluid every 20,000 miles and the filter every 60,000 miles. Pennzoil or Chevron Dexron-III(H)/Mercon fluids are a very good value and are obtainable from any local auto parts store for $2.50/qt or less. Full synthetic transmission fluids are not a bad idea, but given your financial situation and no known issues with this transmission, draining and refilling frequently with a good conventional fluid will be more than adequate.

[ May 25, 2006, 12:04 AM: Message edited by: The Critic ]

 

[muddawgs]

nicely said and good advice.. follow a maint routine and stick with it. the only thing that will extend its life is decent fluid and to keep it cool. people often try to make things better or try to improve upon things. in your case i dont think a easily driven forester would be any concern unless you think there is a concern? bad fluid smell? crummy shifting??

 

[unDummy]

If you have an ATF drain plug, you can't beat the simplicity or cost savings of the 'old way'.

With 21k miles, I wouldn't worry about the ATF filter(if inside the pan). If you have a screw on ATF filter, you could probably change that yourself pretty easily and cheaply.

I have nothing against the T-tech. But, way too many shops are cutting corners which would not be a good way. Without knowing shop specifics, I don't recommend a T-tech flush.

 

[Iain]

The Critic wrote:

quote:

---

However, you generally need to pump through 1.5x the capacity of the transmission to adequately replace all of the old fluid. This is because a transmission fluid exchange is a rapid dilution of the old fluid, you need to run through more than the transmission's total fluid capacity, generally 1.5x the amount, to completely dilute most of the old fluid

---

With the exception of the above paragraph, I totally agree with your post.

The efficiency of the machine used in ATF exchange is the determining factor here. Some are simply more efficient in the transfer procedure and are able to completely exchange fluid with less waste than others.

 

[ewetho]

Most of the machines I ave seen separate the fluids "in to" and "out of" the trans from a given point so the dilution and forcing the fluid from the pump through the Torque Converter I would have to agree that the estimate of 1.5X would be better than 1X fluid because while the machine is 100% efficiant the trans is not!

 

[kmrcstintn]

thank you for the thorough feedback; the local Subaru dealer uses "BG" system and wants @ $150.00 just to change fluid since they feel that the factory OEM spin-on filter is a lifetime component that only requires replacement if damaged; I got this directly from the parts dept and the service dept and they stated that the filter is there only to filter metal shavings during the break-in period...this policy erodes my faith intheir care for Subaru vehicles

There is a service shop called CJ's in my area; they use T-Tech and with a coupon the price is $69.95 and they stated a 1:1 exchange; I think this would remove more aged fluid than opening the drain plug and gravity draining; I can buy an aftermarket spin-on filter (Pro-King brand) for @ $12 at Advanced Auto Parts that offers a 1 year warranty; I'll see if they can change out the filter before they begin the T-Tech (I can't fit under the car and I don't have the proper filter wrench to remove the spin-on filter)...

anyone have feedback about my plan?

 

[The Critic]

Sounds good. My instinct would be to change the filter AFTER the T-Tech though.

 

[kmrcstintn]

good point...guess I wouldn't want any older fluid back filling the new filter; I'll find out what brand of ATF they use (I think it'll be bulk Pennzoil mineral base since they use Pennzoil bulk motor oil) and top off whatever is lost from the filter change

 

[Steelers]

Had a T-Tech service performed on a Ranger several years ago for $59.95 at a tire joint. Used a total of 14 quarts of Castrol Mercon V and took about 45 minutes. You can see the old fluid go out and the new go in. Not a bad deal considering the Castrol ATF is over $3 a quart and you get almost all of the old stuff out. No filter change, tire shop won't touch that. Either have to do it yourself or find a shop or dealership that will for a good price. Many folks alternate services. Pan drop, new filter, refill. Drive 15-30K then T-Tech. Repeat. I guess it depends on how often you want to change your filter. Many "coupon cutter" transmission services use only Mercon/Dextron fluid, that's how they keep it cheap. They may tell you its ok or offer to sell you some Lubegard to bring it up to specs. I prefer to use a fluid that meets the manurfacture's recommendation. If you drive a GM car and Mercon/Dextron works you're in luck, if you drive a Honda, Toyota, DC that may not work. Ask before they take your car into the bay what type and brand of fluid they will refill the the transmission with. That's one plus to have services done at the dealership, they use the correct fluids and filters etc.

 

[RF Overlord]

quote:

---

Originally posted by kmrcstintn:
they feel that the factory OEM spin-on filter is a lifetime component that only requires replacement if damaged; I got this directly from the parts dept and the service dept and they stated that the filter is there only to filter metal shavings during the break-in period...this policy erodes my faith intheir care for Subaru vehicles

---

Maybe this will help restore your faith...the FSM for my car (a Ford product) states that the transmission filter needs to be changed only if the transmission requires an actual repair; it doesn't need changing during a routine service. So there may be some truth to what the Subaru dealer told you.

I installed an upgraded pan (one with a drain plug) and a new filter at approx 15,000 miles. I drain the pan every 10,000 miles (car has an aftermarket supercharger) and plan on replacing the filter again at 50,000.

 

[Ken2]

Any of the fluid replacement machines, T-Tech brand or others, work alike...they're just a pair of connected reservoirs. 1:1 is not adequate...the new fluid goes into the transmission sump where it mixes with old fluid; that just the way things are. I'd do 1:1.5.

Instead of expensive transmission fluid service, how about spending $20 or so on an analysis of the ATF? If it is good, leave it alone and save money. Synthetic ATF plus a Magnefine filter greatly extends the life of the fluid, and likely the transmission.


Ken

 

[Kestas]

Critic's advice is very reasonable. I've done too many fluid changes where I included a filter change, only to find the filter was clean, or was simply a fine mesh screen.

It is wasteful to change the filter every time. Screen filters should never be changed, and if needed, cleaned. Media filters maybe should be changed (or checked) early in the transmission's life for break-in contamination, then maybe changed (or checked) every 60K per Critic's advice.

 

[dkcase]

quote:

---

....change the filter AFTER the T-Tech though.

---

The pan should be dropped and the filter changed before the machine to get the crud cleaned out of the pan so it is not circulated up into the trans.

 

[olympic]

^^ Exactly!! Any wear material, sludge, etc that is in the trans will be in the pan, attached to the magnet or in the filter. A T-Tech service can't remove this stuff even if they dump in some fancy cleaning/flushing chemical beforehand. I wish I had taken pics of my Montanas tranny pan after 250,000km and 50,000km T-Tech services. It was filled with a 1/4" layer of sludge and wear material.

DKcase's method(pan drop, refill, then T-Tech) would be the correct way but none of the quicky lube places will do it.

 

[BlazerLT]

T-Tech, then change the filter after.

Worked great and gets all the fluid refreshed instead of just the 40% in the pan.

 

[Louie's gone fishing]

I've done some poking around to get some info on auto trans service. Today I looked inside a transmission that has 30k fluid exchanges with a flush chemical, that power flushed the transmission. No filter added. At 175k there was alayer of grey gunk in the pan. The transmission was shot. Another transmission had a filter added in the cooler line, a Magnefine. This unit saw 30k pan drains and annual filter changes. At 10 years old with 155k miles the pan looked clean and the transmission was working just fine. I know that this does not prove anything, but it makes me feel better about my plan to do 30k pan drains, and change an add on filter once a year. I think the power flush changes the fluid, but a good filter, with draining just the pan, helps keep the transmission clean, too.

 

[1sttruck]

"DKcase's method(pan drop, refill, then T-Tech) would be the correct way but none of the quicky lube places will do it."

Local Jiffy lube offers a T-Tech flush or a drop the pan and filter change, so I suppose you could ask for both.

 

[BlazerLT]

quote:

---

Originally posted by Louie's gone fishing:
I've done some poking around to get some info on auto trans service. Today I looked inside a transmission that has 30k fluid exchanges with a flush chemical, that power flushed the transmission. No filter added. At 175k there was alayer of grey gunk in the pan. The transmission was shot. Another transmission had a filter added in the cooler line, a Magnefine. This unit saw 30k pan drains and annual filter changes. At 10 years old with 155k miles the pan looked clean and the transmission was working just fine. I know that this does not prove anything, but it makes me feel better about my plan to do 30k pan drains, and change an add on filter once a year. I think the power flush changes the fluid, but a good filter, with draining just the pan, helps keep the transmission clean, too.

---

The power flush was your problem with a chemical.

T-Tech is passive and uses the transmission pump to draw in the new fluid and push out the old.

There is no power assist nor is there any chemical needed. Works great.

Not changing the filter after is what probably killed the transmission, not the service itself. The damage was already there.