maidenracing1984

Hey guys, so after I did my cam swap my 93 TA tore out second gear, which has been slipping between shifts for a while. So I took the trans out and rebuilt it myself with a kit from advance. However, I decided to go with a Transgo 2&3 reprogramming kit for the 700r4/4L60 as well as a .500 boost valve and new vette servos for it as well to help it perform better. Well got the car back together and no reverse. first gear worked and sevond but 2-3 shift slipped like crazy and 4th as well. Well, pulled the trans and found the boost valve clip had fallen out. Put it back together, double, triple, and quadruple checked that the shift kit was installed as the instructions said. and it was, no valves stuck, nothing. so with the new 3-4 clutches, the car works like a charm in reverse, 1st and 2nd. however, the 2-3 shift still slipped after all the work. and 4th was even worse. So it burnt out the 3-4 clutches again in under a mile. So, the programming kit is installed exactly as the instructions said, trans was freshly rebuilt and then all the seals checked after it burnt the clutches. So essentially a new trans and no 3-4. and it isnt the clutches burning out, TV cable is adajusted so at WOT the tv valve is depressed completely. theres a lack of pressure to the clutches, any clues to the cause? Thank you all.

hrcslam

What Trans Go kit? Was it the SK4L60E?

The 4L60/4L60e in ALL gen 4 F-bodies with the LT1/LS1 came from the factory with the "Corvette" servo.

maidenracing1984

It was the 700-2&3 for the 700r4/4l60 trans.

http://www.transgo.com/products.php?...product_id=169

hrcslam

What did you gap your 3/4 clutch pack to? Burning up a clutch pack in 1 mile is excessive and tells me your trans is fighting it's self.

Why did you do that shift kit?

maidenracing1984

The 3-4 clutches had about .075" of clearance between the backing plate and first friction plate. I went with that kit because its the most performance oriented one they made for my trans. I read reviews and forums and everyone said the transgo was the one to go with. So that's the one i went with.

hrcslam

Did you air check it? Also, what is it reading for line pressures? And you also soaked your clutches for a few hours first right?

If I remember right, the 4L60 and 4L60e have different 3/4 pack set ups (slightly), but I set mine up at .030" clearance (4L60e in my Suburban).

I think the 4L60 calls for a little more clearance, allowing up to .075", but I'd lean toward going to the tighter end of the tolerances, .060".

In any case, stepping up to the 7 disc clutch pack for the newer 4L60e would be an improvement; these are not stock, but an aftermarket improvement. Then gap it closer, some go as close as .010".

Did you upgrade the Sunshell while you were in there?

maidenracing1984

Yeah, i upgraded all the weak points i could. but my book called for .06-.09 clerance for the 3-4 clutches. the first time the trans was put together i had them at .035 and i figured that may have been the reason they burnt so i added some space the second time. still no luck though. but i was doing research and did find something interesting. i installed the 7-cs spring kit in the trans as well which replaces the 3-4 apply springs and the other springs in the 3-4 drum. They are much higher pressure probably triple the stock ones and are used for high reving engine above 5500 rpm. so im thinking that the added spring pressure is causing the 3-4 clutch pack to not apply quickly, and also is putting too much force on it causing it to basically fight the line pressure and not hold well. When i drove the car and did WOT pulls the car shifted ok from 2-3. wayyyyy better than part throttle shifts, although i do understand the trans will have more pressure when the pedal is depressed, you would think the trans would tear out way faster that way. so im thinking im going to reinstall the stock springs in the drum and add new clutches and try it one more time. And i did air check the clutches, they seemed to apply or at least moved. you could see the 3-4 clutches apply and the piece that applies them compress the clutch pack. it worked fine with the air pressure check. so my theory is that although the 3-4 springs are important for making the trans downshift from 3/4-2 well (which it does fantastically) they also make a less firm 2-3 shift because they have more force. Also, if im not mistaken the 4L60 trans in 93 had stronger springs than the past 700r4s. but to know for sure i don't. i do know people used to remove springs from the old thm350 and 400 trans to make the 2-3 shift firmer. If this doesn't help i really have no idea what could be wrong.

Thanks for your help, ill check back in when i get that done, which may be a while, i move to college in a couple days. Also, here is the link to the 7-cs spring kit i was talking about.

http://www.transgo.com/products.php?...dcountview=Yes

maidenracing1984