Developed a strange problem over the last week or so. The first couple of times i take off in the car the trans acts normally, but off and on much after that the trans begins to act very strange. When coming to a stop it feels as though the car is going into nuetral and will stop much shorter than i'm used to. Then when its time to take off the car feels like its out of gear and will rev freely. When it does finally take off it will do one of two things, it will gradually pull away and first gear will gradually engage. The other thing it does is it will bang into first very hard with a clunk and take off normally after that. It also does this hard bang/clunk into first gear and lurching forward when braking (decel) gradually in stop and go traffic mostly.

Usually I dont allow it to slip or bang into first gear. I have the pcm set up to manually shift into whatever gear is selected and i usually take it down to 2 (lowest selectable havent removed tab yet) and it will take off then.

There are no ses lights or pending codes i've scanned the car about every day this week trying to figure it out, trans fluid looks fine and level is fine as well. The car is a 96 t/a with 140k on it. Stock stall with 3.23 gearing. Car shifts just fine and 3rd gear is also fine. Everything is as normal except off and on getting moving or coming to a stop. I dont manually shift the car ever unless its snowing or i'm keeping it in 3rd to run on the dyno. I'm the only one who drives it, its my daily driver. Recently replaced shift solenoids 10k ago when solenoid a failed.

Need ideas on where to look or somebody to tell me its cooked or not. I really dont think it is because everything else is fine. Problem does seem to be getting worse daily though. Appreciate all help sorry for the length but I wanted to describe the problem as well as possible.

 

aluminum forward piston is cracked.

Frank
CPT

 

So basicly what you're saying is its rebuild or m6 swap time. What kind of turn around time am I looking at if I send it to you Frank.

Is it going to crap out completely on me soon or? I need it to last about another week for me then I will have time to rip it apart.

 

2 week turn around, right now.

You'll probably lose all forward soon.

Frank
CPT

 

Frank what rebuild should I be looking at. Car is 100% street driven with about 50/50 city and highway. I put about 500 miles a week on it. Engine is really nothing special ported heads 222/230 cam 11.5 compression, makes 380-390rwhp depending on which dyno its on at the time. The rear gears are 3.23 and will probably remain so until the car becomes a toy. Of course it will see some spirited driving but most of the time its just some stop and go followed by me setting the cruise and holding the wheel for 40 minutes.

I'll also be looking for a converter obviously so i'll need a rec there too. I dont mind a pretty decent stall rpm i've driven many cars with them, but I dont need a track killer either because I never race my driver. Just looking for something thats pretty efficient and will make the car more fun to drive and easier to deal with the 800rpm idle, although the car drove just fine with the stock stall for the most part.

I would appreciate pricing for everything so I can start getting the money together to get things going.

 

$1000 + "hard parts" (if any) for our "Race" rebuild. I'd also suggest our $50 steel input piston option. For a DD, I'd go with a 2800 stall 12" converter, which will run you $300.
Give me a call to discuss specifics. 302-250-1202

Frank
CPT

 

Frank the forward piston you're talking about, is that the low/reverse piston at the output shaft end of the trans?

Reason i'm asking is money situation is looking a bit like crap atm (need summer tuition), so I may end up just fixing whats broken and praying, yeah i know . I have the tool to compress the springs to get to the pistons I just dont want to take anything more apart than i have to. So I just thought i would check and see if you thought it was the one in with the 3-4 clutch pack, or if it was the low-rev piston at the tailshaft end. So far everything looks in pretty good shape but i've only gotten as far as the 3-4 clutch pack.

If i find whats busted i'll be giving you a call on parts, and if i cant get it figured out i guess i'll have to send it to you and figure something out. Appreciate all the help so far.

 

It's the forward clutch apply piston, in the input drum (the drum the input shaft is attatched to).
If the piston is cracked, just pay shipping. These aluminum pistons aren't anything but "scrap aluminum" to me. I've got stacks of them.

Frank
CPT

 

Well, sorry to say its not the forward piston, got it out just now and its not cracked at all that I can see. So i need more ideas on where to look, or what to do.

Heres a shot of the piston.

 

what does the input sprag look like?

Frank
CPT

 

I'll check that out tonite and post back. Other things that i have come up with is the spring for the 1-2 shift valve, or the 2nd accumulator piston.

 

Well I think I found the problem. With eyes that havent been through three engineering finals, after washing and drying the clutches and cleaning the steels off they are all smoked. At least the smallerpack closest to the front of the trans when the input drum is installed. Some of them are worn so badly you can see the steel under the friction surface it looks a little less worn as you get farther away from the input shaft but random flakes are missing and some pretty bad hot spots on the steels. I guess i'm going to have to have it rebuilt or do it myself, gonna have to think it over.

The sprag looked great and felt smooth too working it by hand, and the 1-2 shift valve spring was fine too, didnt get to the accumulator, just kinda stopped. I think maybe the stock stall and higher than factory idle probably hurt it along with lots of stop and go driving 14xK miles didnt help it either. If I should decide to do it myself, what kinda cost am I looking at here for parts, assuming no hard parts are broken.

 

bump

 

350-400$ including some upgrades pinless accumulator pistons beast sunshell borg warner sprag high engergy frictions, zpack, o ringed boost valve etc etc.

Take the lip seals off(inside and outside) the piston and lightly strike it with something(screwdriver, i use a seal pick) while holding it from the center with one finger. It should ring like a bell, if not there is a crack that you did not see.

 

We use in excess of $700 for our "Pro Race" units. That's OUR prices. Retail would be closer to $900-$1000. Retail for parts for our "Performance" build would be around $500

Frank
CPT