ssstreetcar

iTrader: (4)

As stated,99 z28 4l60e started slipping in 4th and tcc lock up.At first i thought it was just 3/4 clutches.i freshend up trans clutches,band,ect...put it back in car and the same thing.the best way to explain it is you have to drive it about 10-15 minutes at say 70mph and if you slightly speed up it slips.if you pull it back down to 3rd and then to 4th it wont slip again for about 10-15 minutes,and the tq is locked up the whole time.the only thing i can think of is a pressure issue.Could the 2/4 band slipping cause this? Also,the 3/4 clutches were burnt(not bad) and the 2/4 band was also burnt and the hub was turned blue.

ssstreetcar

iTrader: (4)

anyone?HELP!Thanks

ls10

Mine is doing the same thing. It's very intermittent, and only happens when cruising in 4th for a while, but the car will still accelerate well, just slip in doing so.

maro_mullet

Same problem!!!!

joecar

Might have a leak at the 4th apply piston in the 2/4 servo, or a leak at the 3-4 accumulator.

ls10

Mine is very intermittent. It won't usually happen in the morning when it's cooler or on cool days, but when it does it does seem to be warmer, and could happen after 5 mins, 30 mins, stop and go or cruising. Theres really no rhyme other than heat it seems. Wouldn't a leak show itself consistently?

rdrage728

I had this same problem, turned out to be the billet tci 4th gear servo. it was leaking around the pin. I put the factory servo in and was like new again.

ssstreetcar

iTrader: (4)

thanks for the replys.im going to try changing the 2/4 servo seals and check the band adjustment.also going to change the boost valve to .500 valve.as soon as i get a chance to work on it,ill update and let you know if it works.

ls10

I replaced the 4th servo this past weekend, and it didn't change a thing except 3rd is starting to slip, so looks like I was just slowly loosing the trans all together.

shortdog

iTrader: (1)

AFTER my tranny and converter rebuild, I'm having lockup slippage also. Post up if you find the culprit.

lt170chevelle

iTrader: (2)

Im having similar issue and found out my new band had stretched. I lengthened my servo pin and going to take it for a drive in a few to see if it fixed it.

ssstreetcar

iTrader: (4)

UPDATE;tried stepping on the b-pedal to unlock converter and it still slipped.As stated before i can pull it down in 3rd and back to 4th and it quits slipping for a while,so i tried wot while slipping to see if it would kick down in 3rd.Just slipped worse.

lt170chevelle

iTrader: (2)

Mine so far looks like my servo pin length was wrong and now doesnt seem to be slipping at all on my fresh trans , now that i lengthened the pin.

ssstreetcar

iTrader: (4)

(UPDATE)checked servo end play,it was ok.replaced servos and seals(all new)replaced sevo pin just for good measure.same results.Next step is pinless 3/4 accumalator.ALso going to try shift solenoids,and .500 boost valve.Any input would be welcome.thanks

ssstreetcar

iTrader: (4)

UPDATEreplaced 3/4 accumalator piston with pinless unit,relaced solenoids,and boost valve.problem fixed.3/4 piston seal was worn and 3/4 pin had excessive wear.i believe this was the cause,replaced the solenoids and boost valve to cover all my bases.hope this helps.EDIT=i thought it was fixed.it has not slipped for 3 days and all the sudden today it did it again.when i came to a stop,i found that it will not shift into 3rd auto.i can manually go to 3rd.if you put it into OD it skips 3rd.if you put it into D it will shift to 3rd.also found you can be in OD 4th and pull it down to 3rd.(WTF)HELP

jshadx

Same problem in 2000Z. If anyone finds or has found the fix please post...