Have you tried to lower the shift rpm just to see if it will take it? Just curious... You might want to give Frank a call to see what he has to say.

Go easy on it until you resolve this issue. You can take out the 3/4 clutches in no time if they are partially applied but not holding during that 2/3 shift!

g

 

We tried at 62% throttle and shifted at 3908rpm and 50mph, still slipped. It works fine when not in boost but any time it is making a couple #'s it will not shift 2-3

 

Wow, that's saying a mouthfull there! Talk about short shifting a hot rod!

I would suggest getting a pressure gauge on it and see what's going on with line pressure when this happens. If it will take a hard pull after the shift then mechanically the rotating assembly is cool for now.

But, there is a reason for it to miss the 2/3 under a load and I'd bet it's in the tune... but I don't know what's inside that tranny either. That being said, if you are commanding that shift as early as you mentioned then that is pretty damned conservative and just about any 60e will make the shift. Therefore after thinking about it a while if that unit is equipped with an EPC Solenoid then I'll bet you're going to find the line pressure drops at the 2/3 shift under a load.

The trick is to figure out if it's being commanded or not.

g

 

I'm pretty sure the shift is being commanded. I logged the run and the log showed the shift being commanded and thats when it flashes to the rev limiter and it will not engage 3rd until I release the throttle.

 

Changed a couple more things still nothing... Until I thought WTF and tried it in D instead of 3. Well it atleast shifted. It flashed about 1000 rpms under part throttle and 500 under WOT, but it did shift. What would cause it to act like neutral during the 2-3 shift if the lever is in 3 and flash 500 rpm's if the shift lever is in D. I always thought that you wanted to run these in 3?

Anybody??

 

I've read D for drag racing and 3 for a lot of kick down driving.

So it will drive in third after the shift?

 

Yup once it finally engages it will pull like it should. The 500 rpm flash was still a slip by looking at the log but it atleast engaged.

 

Dumb ? How's the fluid level?


Also what did frank say?

 

Fluid level is fine and clean. Frank just told me to increase the line pressure for the 2-3 shift, which I have done. It hasn't helped yet. I had ended up making so many changes to the tranny settings that I took it back to stock yesterday and only increased the line pressure for the 2-3 shift. It still does the same thing. I tried small line pressure increases and big line pressure increases... no difference. What I don't understand is the difference in it not shifting at all if the shifter is in 3 and it flaring 500-800 Rpms if I leave it in D. I am going to hook up a mechanical line pressure gauge this weekend and look for pressure drop. That's all I have left to check before I take it out.

 

Well, I sent the tranny back to the builder. He says it looks new inside just like the day he sent it out. No sign of slippage or wear. He is dynoing it and sending it back. What else do I need to look at? I have tried everything in the tune I could think of and eventually put it all back to stock since nothing helped.