ok as seen in https://www.thirdgen.org/techbb2/sho...hreadid=121789

my tranny slips going into 3rd gear ONLY at about half throttle or more. and it DOESN"T slip when downshifting into 3rd..
it feels like it hooks up for a second and then it slips. so i put some lucas tranny additive in, and took it for a test drive. the first 3\4 throttle run it slipped. but i did it 4 more times and it shifted just fine. so today it was 1 out of 5 times it slipped.

so its weird that it only happens some times.. what could be causing this? coud it be possible that i didn't have enough tranny fluid in? also the tranny only has about 20,000 miles since rebuild and is SUPPOSIVLY pretty much a corvette tranny, with vett servo and planatary gears or whatever.. im not tranny expert, thats just what my uncle told me..

any clues? anything i can do to test?

 

someone!!! im begging!!!

 

It's hard to say for sure. The lucas transmission additive is supposed to coat and renew the friction surface of bands, clutches and free a stickey valve body. My guess would be you have some cluches burnt. The 3/4 shift is done by the 3/4 cluch pack I cant recall if the band is applied durring this shift but I fairly sure its not. My guess would be the 3/4 clutch pack is going.

Strang though, I put some of the Lucas transmission additive in my car and it actually changed the shift chariteristics. My tranny has a TransGo kit and it used to chirp the tires shifting from 1st to second, second to third. The odd thing is since I put this stuff in my transmission it wont chirp the tires but it did reduce lag between shifts a noticeable amount. I guess its better not to chirp em but I wonder what the additive has in it to make the transmission do this??

 

one more update.. today it slipped at like 50 mph at like 1/4 throttle. but i noticed something.. it felt like it shifted into 3rd, cause i felt what seemed like a hard shift, and imediatly afterwards the RPMS jump up and it goes no where..

but it seems that the cars pulls harder up till 3rd when it slips, then it does when it doesn't slip. maybe a t.q. lockup problem?

 

Sounds more like a 3-4 clutch pack problem.

 

is this something i can adjust? or should it be replaced?

 

Prolly rebuild time. Sorry

 

the tranny only has 20,000 miles on it or less!!!!!!!!

one more thing, it ALWAYS feels like it shifts into 3rd, even when it sleep i feel what seems like a hard shift, like it engages for half a second, and then it slips, so it is shifting, its hard to explain.. maybe like its trying to shift into 3rd but its not quite ALL the way in or something, kinda weird..

 

My old tranny did the exact same thing. the 3-4 band was burnt up. $1200 to rebuild with all new clutches and bands. Sorry if thats your problem. it really sucks to have a cool car and not be able to drive it very fast.

 

screw that, im not gonna risk having it rebuilt to crap again.... im gonna go with a T-56 swap... when i have the money and time that is..

is there any temporary fixes i can do just to keep it from getting worse? just something to keep it from dying on me? besides being gentle on it



also, can i bring it to a tranny shop to have them diagnose it just to be sure without ripping to much out/

 

A shop might look at it for free it just depends.
As far as fixes just drain the fluid and put 2 bottles of the Lucas in and see if that will keep it going. Who knows it might keep it going untill you get the cash for a 5speed.

 

5 speed!!! im getting a 6 speed

but i have one more question for you guys about the 2-3 clutch pack.. 4-3 downshifts are just fine at wot, and 2-3 upshifts at light throttle are fine.


are 4-3 downshifts controlled by the 3-4 clutchpack?

 

3-4 pack is on in... 3rd and 4th!

 

It can still shift hard, yet slip. Its one thing to slam clutches together, its another for those clutches to hold Torque. Good chance that the 3-4 clutches are burnt. If it pulls good in first, then the foward clutch is probably OK. Second uses the 2-4 band, which 3rd gear does not. The only difference between 1st and 3rd is the application of the 3-4 clutches, so you be the judge... Anyhow, its not like these trannies are notorious for the 3-4 clutches...

 

ok, i appreciate all you guys help ALOT. it sucks that my tranny is having problems, but im glad u guys could help explain it to me.:hail: