zapp168

iTrader: (7)

1998 Camaro Stock, rebuilt the transmission added a 3600 RPM YANK stall converter. 2000 miles later I noticed the converter would slip in and out of lock on the highway a little, I upped the misfire table using EFIlive. It continued to happen, then the transmission slipped and was toast.
Rebuilt it again, turned off the misfire tables, Same thing, same time frame. Unlocked converter....then slipped, then junk, burned 3-4 again. Any tuning issue I have missed maybe?
Thanks

Yank

iTrader: (181)

Who is the trans builder I would look to them for cause of the failure.
Slipping 3/4 clutch pack has the same feel as the converter clutch would if it was slipping.
You might look to one of the transbuilders listed here --------------->

SS SLP2

iTrader: (8)

Over heat ?? had like problem, 3 times, one rebuild last 200 miles,
my problems= hot lapping
Johnny

Jays_SSZ28

iTrader: (2)

P0751, P0757. Will false set and disable lock up.

What 3-4 clutch are you using? What clearance are you setting it up at?
When it's fresh rebuilt does it slide into 3rd? Does it tie up on the 2-3 shift?

zapp168

iTrader: (7)

The Builder has 20 years experience, has built many performance transmissions for us. When it is fresh it shifts perfect, nice firm shifts. The day that it will lose third it will still shift hard into 3rd. It seems like a heat problem, but I am using the same trans cooler, the same converter (and same builder) as other car in shop with a 415 Stroker that runs 11's no problems with that transmission going on two years now. I have no codes engine or transmission. I had originally made the misfire tables higher (cause of the smaller converter), the second time I shut them off. Starts to have problems after long highway trips

Jays_SSZ28

iTrader: (2)

You have to disable P0751 and P0757.
I've given this advice before, I've had the problem myself, I've tuned a few other cars with this problem.
Do as you will, I'm not going to beg you or try to convince you.

swaynoo

Is there a Clutch pack(brand) you would recommend?

zapp168

iTrader: (7)

The same issue? Drives for an hour then starts to slip, then burns out the transmission?
P0757 P0751
"What happens is the PCM comands a gear then compares the ENGINE RPM to the OUT PUT SPEED. Because of the high stall of the cam the PCM sees the RPM are to high and assumes the shift did not occur and set a code for the solenoid being faulty when it actually is not"

I cannot see this being an issue when on the highway for an hour, the car has not shifted in an hour, the codes do not come up in the PCM ever, not even in history, but I will delete them anyway.

jimmyblue

iTrader: (11)

You should be looking closer at how the trans shifts
and whether you are getting slip in the frictions (not
TCC). Stock pressure profiles are meant for base torque
levels (1.8 STR stock converter) and fuel economy.
You go downshifting into the shift extension at high
torque multiplication, you could overwhelm the friction
torque capacity and scrub them real good.

At cruise especially, the applied pressure is low. Add to
this any cleverness like a MAF or speed density tune
that reads low on airflow -> "load", and you starve the
line at mid throttle too. Take a look at Delivered Torque
- Trans. If it seems lower than you think is realistic, that
could indicate an airflow accuracy problem that can lead
to line pressure shortage.

So anyway you should be looking at input and output
shaft RPM, and criticize that ratio against the trans current
gear ratio. You can watch how it pulls in to 1:1 across a
shift, to gauge whether it's getting done quick or not (too
long and slow, increases heat dumped inside the clutch
pack or the band) and you sure do not want to see anything
but straight-up gear ratio when in gear (anything else says
hard slip).

I massaged my force motor table long ago to up the 0% line
column (bring current down) and pressure is all in by 300 lb-ft.

That Force Motor table also is indexed by trans fluid temp.
If the problem comes in after long running, have you checked
the reported temp? Need more cooling? I flattened that dimension
in the force motor table too, because I didn't understand or trust
the GM profile and sure did not want any more blowoff at hot,
than cold.

zapp168

iTrader: (7)

I have not gotten the trans back in yet, the first time the builder thought he found a reason for the first failure, so I disregarded it. Now that it failed again, I am going to start looking more into it.
The thing is we have done this same set up a dozen times, same trans, same converter, same tune, same cooler. Of course my wifes car is giving me a headache (better than a customer I guess) Funny thing is, she is so short I don't even think that she car floor it....LMAO. When i get it back in, I will drive it myself and start digging I guess....thanks for the replies!

zapp168

iTrader: (7)

I understand why your response would be to blame the builder, but honestly you sell the product and offer no support on tuning it to properly work in the vehicle. You should at least take the time to learn the basics of how to make your product work properly, not tell people to "call this guy at this shop, he does tuning"

Jays_SSZ28

iTrader: (2)

Last car I tuned was a guy that lived an hour or so away. His complaint was that after the Yank 3600 install it would blow fluid out of the breather tube on the highway.

When he got to my house he had three DTC's that would disable lock up.
Misfire, 751, 757.
I did some standard transmission tuning and he replied back that the problem went away.

In your case you seem to have tuning equipment, why don't you set it up to log at the least tcc lock up and drive it. Whats your trans temp?

I've been through the same thing, blame the converter manufacturer, why don't you supply tuning instructions, etc.
97% of my posts and reading on this site are in the transmission section. I see the same thing over and over with torque converter tuning and I've learned that it's not very difficult to do.

I realize it's dificult for me to be 100% correct not having the car in my possesion, but your problem sounds very familiar.

zapp168

iTrader: (7)

I am assuming that you mean P0751 AND P0756 NOT P0757? I disabled them although they show up no place in a scan. I lowered the force motor current POS and NEG ten percent. Before making any changes I noted that even with the Yank All the shifts feel firm, I lowered the desired shift time in all gears by ten percent to keep temps down, will start monitoring now.

Jays_SSZ28

iTrader: (2)

I mean P0757.

zapp168

iTrader: (7)

I cannot find any P0757 I believe in 98 it is P0756

P0751 Shift solenoid valve A stuck off
P0756 Shift solenoid valve B stuck off

Jays_SSZ28

iTrader: (2)

You're right, it would be 756 for a 1998.

Teakwo23

My car just started doing that with my 4000 yank. Thanks for the info. Im taking it back to my tuner in the AM.

DRIVER456

I had the same problem,TC locking,unlocking,Then not locking at all.I have EFILive and what I did was Change {D2901} TCC MIN. PRESS. To 0psi(zero) and {D2902} TCC MAX PRESS. to 255psi and {D2903} TCC SOLENOID MIN. PWM to 0%(zero) and {D2904} TCC SOLENOID MAX. PWM to 100% And the TC has been working with out a problem and I have a YANK SS4000 that I beat the snot out of.I don't know if thats your problem,But you can try it........Paul

w3s1c0a5t

iTrader: (3)

Wow... Such lazyness its unreal.

Yank builds converters. Damn good ones. He built mine. He doesn't tune. TUNERS tune cars. Either learn to tune, as setting up the tune for a converter is very easy. I own hpt pro and do my own tuning. Or take it to a tuner and let them.

Would you tell your engine builder you want a start up tune?

You want to build cars? Learn how. You want someone else to build it for you? Pay them to.

zapp168

iTrader: (7)

Thanks for the NON-information....Too bad this wasn't an opinion based thread, otherwise you would have made some contribution.