firesine

i believe my tcc is slipping in lock up, but would like some confirmation. 1st of all, when in lock up should it ever slip? i started noticing rpm increases to maintain speed when pulling my 6k travel trailer up a grade. it's varying from 100 to 250 rpms if i have a headwind. i'm sure the lockup isn't disengaging when this happens. once when lockedup in 3rd i was pulling up a hill and my speed dropped from 52 to 40 while my rpms stayed at 2k.
all of this is after i took it back to the tranny shop because it was slipping after my last trip in november. there was fine aluminum in the pan, so they pulled the unit, did some work to the tcc, cleaned out the valve body, and replaced the filter.
also, now after the r/r my lockup doesent want to engage if it becomes disengaged while drivin down the road. sometimes it takes miles and i have to jack w/the accelerator to help it l/u.

note.. i rode w/the tech and he showed me on the comp that the lockup is showing "on" so he thinks it's engaged, but but i can tell it isn't.

any feedback appreciated.

john, 95 slt l/b auto w/256k. low stall billet tc, hvy dty tranny, kdp dead, ground stock plate, timin advanced, 235/85/bfg commercials.

dieselfuelonly

Your TC shouldn't be slipping at all when its locked up. Do you get a shudder when the RPMs increase but your speed doesn't really change?

firesine

haven't had any shudder.
john

gmctd

When TCC is not locked, engine rpm will vary when accel pedal is varied, and will drop to near idle rpm when pedal is released - engine rpm will remain steady when pedal is pressed or released, until TCC unlocks - TCC lock is controlled by brake pedal via the PCM, so maybe the brake switch is bad, or the connector or wiring is bad - also effects cruise, so if having cruise problems it's the brake switch or wiring - if only the TCC, check the main trans connector for dirty\oxidized\corrosion, or loose wires - then check the connectors\wiring on the ECM, over on the passenger-side firewall

infidel

Try using a cheap and easy to install lock up switch and see if things change.
Instructions> http://www.tstproducts.com/Torque%20...p%20Switch.pdf

firesine

tcc isn't unlocking under load. to maintain speed rpms increase under load, but doesn't unlock. i confirmed this by tapping the brake, then it unlocks and rpms jump higher. i keep my grounds and terminals clean. also turned up my tps to 1.15 . didn't seem to affect when it locks up or hold any better.

yeah, i didn't put it on my bi line cuzz i disconnected my manual switch. seems like i would accidently turn it on or forget it was on when comin to a stop. i'll reconnect it and see if it helps. on my 1st tranny when the lockup wouldn't want to kick in it didn't help. but i didn't have a slippin issue. i'll reconnect it and see if it helps hold better and report back.

the valve body was supposed to have been upgraded givin more line pressure and whatever else they do to beef it up. but not by these folks. they're more used to doin hondas and the like. this al started one day when sittin in the drive way and was curious how many rpms the engine made just in park. so it gets up to 2800, i back off the accelerator to idle. then put it in reverse and back out on the street. well, i noticed a trail of fluid DUMPED down the drive and in the street. i pulled most of the way back in and hve to push it the rest of the way. the return line blew off the tranny. so i had it towed to the loal shop that had a great guy for a manager, w/some savy, thats now gone. so here i is.

thanks for the help guys.
john, 95 slt l/b auto w/256k. low stall billet tc, hvy dty tranny, kdp dead, ground stock plate, timin advanced, 235/85/bfg commercials, disconnected tc l/u switch

Iron Pony

Get ready to spend some money. It sounds like the tranny is slipping. JMHO

firesine

tranny's still under warranty, but the hassle is hassle.

i hooked up my l/u switch again. took it for a long dive and it's still slippin under a load. switch wouldn't help it go into l/u either. before my trip it wouldn't slip w/out towing something. now i can make it to slip on an overpass. i'll see what other input i get from members and approach the shop monday or tuesday.
if i understand correctly the l/u can slip and not shudder. but it could be the tranny itself? when they pulled the pan last go around, at my insistance and i got to see, there wasn't any type of clutch material, just fine aluminum.

john, 95 slt l/b auto w/256k. low stall billet tc, hvy dty tranny, kdp dead, ground stock plate, timin advanced, 235/85/bfg commercials, tc l/u switch

Iron Pony

Don't do like I did. I had a local shop rebuild mine. They used a Banks Converter and a TCI valve body kit. So far it's holding up, with about 8,000 miles on it. But for about 1,200.00 more I could of had a Gorend. Now I've started to mod the truck. So I have started to save for a Gorend. I hope it holds up until then. Good luck

firesine

was able to get hold of G.M at shop and speak to him at length. they're going to put a new V.B(Lockup not holding and not engaging after disengaging), and adjust the cables and governer?(downshifting to 2nd too soon when stopping)
if the pan looks clean should i be concerned about wear of the L.U. clutch or clutch packs?



john, 95 slt l/b auto w/256k. low stall billet tc, hvy dty tranny, kdp dead, ground stock plate, timin advanced, 235/85/bfg commercials, tc l/u switch

firesine

got my truck in on wed and back from the shop sat mornin. peterson bros in houston built me a new low stall billet tc and the tranny shop put in a new
vb and did some work to it to hold LU better. now the LU works great. haven't pulled the trailer to see how it holds yet. but will du that soon.

john, 95 slt l/b auto w/256k. low stall billet tc, hvy dty tranny, kdp dead, ground stock plate, timin advanced, 235/85/bfg commercials, tc l/u switch