Auto tranny slips at low speeds

[suprarx7nut]

Hey guys, my 88 turbo auto project car is having some trouble.

CLIFFS: Auto tranny slips in 2nd gear from 2k~3.2k rpm.

Car is drivable, just doesn't catch in 2nd at those rpms.

Any adjustments that I should check? New to auto's so I'm kinda clueless...

The tranny slips intermittently, mostly at low speeds. Once it's going over about 30 mph, it doesnt seem to slip at all. Sometimes it grabs fully even at low rpms and holds all the way, even at full boost.

The car had not been run in many years, and about half the fluid has been changed. I know bad fluid can make a difference, but I wouldn't think that it would cause such bad slipping. The fluid will get flushed eventually, but it'd be a waste to get new fluid in a tranny that might be dead.

The throttle cable seems to be adjusted per tsrm spec. Are there any other adjustments I should be looking out for? The tranny might be toast, but it seems odd for it to go bad just from sitting.

THANKS!!!
-Andy

 

[Koenigturbo]

I'm not by any means an tranny guy so this just a "wild swing" Check tranny fluids, If I were to guess I would be a stuck valve or servo. If it's been sitting, it probaly has tranish build up from sitting, it's intermitant because the valve or servo is trying to work it self free from the build up of tranish. Seals go bad from sitting. clogged filter?

 

[jdub]

Flush the fluid and change the filter (screen) in the pan. Fluid does make a difference - I have had success using Castrol Import Dex III. It's a semi-synthetic - I tried Amsoil synthetic universal ATF and got some slip in my tranny. Replaced with the Castrol and no more problem. There's a 'how to' complete ATF change sticky in the Lube Section.

 

[Joe]

Been trough this I drive auto fixed (Kaizen: Jose Valle and A to the J)
They replaced the lock up celenoid, that is what causes tha tranny to slip.Mine started intermitently and then it sliped every time, untill the lock up celenoid
was replaced. Sould cost about 80 to 100 bucks.

Dude It was you who Inspired me and gave me a clue for my blue Led cluster(superbright leds rocks). Thanks Hope My info helps.

 

[suprarx7nut]

Thank you guys. I'll replace the fluid and filter and go from there. If thats fails ill look into the solenoid.

Jdub, thanks for the fluid change reference, I was just going to drain it and dilute one quart at a time.

 

[ZoomZoomZoom]

Tranny pump. Didn't cost an arm-and-a-leg, and it shifts MUCH smoother now. This is the third auto supra I've had, and looking back I think they all needed to have the pump at least checked.

 

[suprarx7nut]

Well I changed out the filter and fluid. The fluid is now very fresh looking. After 20 miles, the car still slips just about the same.

How can I narrow down whether it's the locking solenoid or maybe the pump or if the tranny is just dead?

OH, and the car only has 128k and had plenty of oil and very little metal shavings in the pan so I find it hard to believe the transmission is completely worn out. Gears 3 and 4 dont seem to slip at all, but 1 and 2 have a hard time.

 

[Koenigturbo]

Well I changed out the filter and fluid. The fluid is now very fresh looking. After 20 miles, the car still slips just about the same.

How can I narrow down whether it's the locking solenoid or maybe the pump or if the tranny is just dead?

OH, and the car only has 128k and had plenty of oil and very little metal shavings in the pan so I find it hard to believe the transmission is completely worn out. Gears 3 and 4 dont seem to slip at all, but 1 and 2 have a hard time.

Question: Don't you have a place where they can dianose it for free, like Ammaco?
Question: "very little metal shaving? Isn't that an indication that some thing could be wrong? Just because theres "little" doesn't mean that it's not a major problem, maybe the filter has a lot more shaving. not being an ass, I just throwing out ideas...or suggestions, just trying to help. I'm willing to bet that gears three and four are the same clutch and is different clutch pack for first and second gear... just a guess.

 

[MA702Tone]

It may be low line pressure, if this is the case the pump may need to be crossed referenced to the TRSM for the line pressure, and the clearances for the trans pump. If this was driven for a while with it slipping and boosted often it may have burnt the clutches, and friction plates. In turn time for a rebuild/replacement. A question that I think that may lead to a pump failure is: Dose it make a whining sound much like a Power steering pump on a old Ford? That’s when I noticed when my tranny went sour and fast. Did you notice a slight burnt smell on the old fluid before you refreshed with new? What was the color? Light pink, foamy, dark brown, dark red, metallic color?

 

[suprarx7nut]

Question: Don't you have a place where they can dianose it for free, like Ammaco?
Question: "very little metal shaving? Isn't that an indication that some thing could be wrong? Just because theres "little" doesn't mean that it's not a major problem, maybe the filter has a lot more shaving. not being an ass, I just throwing out ideas...or suggestions, just trying to help. I'm willing to bet that gears three and four are the same clutch and is different clutch pack for first and second gear... just a guess.

I could take it to aamco, havent really considered that, but I could try.
Its perfectly normal for there to be some indications of wear on a car with 128k miles. They put magnets in the pan for a reason. As for the clutch packs, that could be, but I haven't a clue.

It may be low line pressure, if this is the case the pump may need to be crossed referenced to the TRSM for the line pressure, and the clearances for the trans pump. If this was driven for a while with it slipping and boosted often it may have burnt the clutches, and friction plates. In turn time for a rebuild/replacement. A question that I think that may lead to a pump failure is: Dose it make a whining sound much like a Power steering pump on a old Ford? That’s when I noticed when my tranny went sour and fast. Did you notice a slight burnt smell on the old fluid before you refreshed with new? What was the color? Light pink, foamy, dark brown, dark red, metallic color?

There is no whining sound at all. The old fluid didn't smell burnt or anything and it was brown for sure. Not foamy, not metallic. It was a medium brown. :dunno:

 

[Poodles]

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=AT&P=9

Start there. You might have tranny codes and not know it. It also can step you through the troubleshooting process. Same thing some shop is going to do (or they'll just rebuild it and charge you a ton).

 

[suprarx7nut]

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=AT&P=9

Start there. You might have tranny codes and not know it. It also can step you through the troubleshooting process. Same thing some shop is going to do (or they'll just rebuild it and charge you a ton).

Ya, I checked for codes first thing. I should have included that in my earlier posts. No codes, so it must be mechanical. I'll start running through the TSRM steps for troubleshooting.

OH**** so this may be important.

The transmission was full when I started to drain it using the cooler line in a bucket method. Only about 3 quarts actually came out while the engine was running. :dunno: I coaxed the rest out by adding a little more new fluid until the fluid coming out was pretty much new. Altogether, maybe 5 quarts came out at most. Should all the ATF been drained by this method? The dipstick indicated the tranny was full numerous times. I know it was full.

Could that indicate a bad pump? This was before changing the filter, but after pulling the filter the screen looked just fine. Zero blockage that I could see. :dunno:

 

[suprarx7nut]

UPDATE:

Did some driving in the car today. Here's the scoop:

Only slips for ~2k-3.2k rpms in 2nd gear. All other gears and ranges seem perfectly fine.

Does that indicate bad bands? Need a rebuild/new tranny?