4th gear gone, why?

[Lowizle]

i have a 2000 GP GT, recently the car decided it no longer wanted to shift into 4th gear, i have checked the fluid, shift linkage, all sensors connections, just about everything i can think of, ive taken it to 3 different shops, and ive been given three different answers,

1st shop said spline shaft was shot
2nd shop said torgue converter was gone
3rd shop said it needed a total rebuild

thing is, they all report it making a mechanical noise when driven, ive driven this car for 2 years, so i know how its supposed to sound, and when driving, it makes no noises that are abnormal, still rides quite, and shifts 1-3 smooth as ever.

anyone have any ideas? im at a loss and id really hate to sell this car...
thanks,
lowizle.

[gtpinsc]

4th gear is common to go out on GP's... start saving for rebuild or get a used trans.

[blueguy]

The 4th shaft is a common failure on the transmissions...

[JJ91284]

Shop 1 and 3 are right. If you don't replace the shaft yourself, the repair will run yourself upwards at a minimum of $700 for them to replace the shaft. The actual part part can be replaced without taking the trans out, but its a real pain in the ass. Most shops won't even try to replace the shaft with the trans in the car because it can take longer than actually pulling the trans out.

The actual part cost is less than $50, its all in the labor. You have to ask yourself if its work spending the $700+ to get it fixed so you haev 4th gear but still have a tired transmission. Or have it rebuilt and have it last you a long while. Your best bet would be to buy a transmission from one of our vendors and either have your shop or theirs put it in. Most transmission shops don't do thorough rebuilds and you run into problems down the road.

[dagger]

Its true, sounds like your 4th gear shaft stripped. You best bet now is to searched the used car parts and try to pick up a built trans and have that rebuilt and thrown in. Then you'll have a transmission that isn't going to leave you stranded.

[Lowizle]

how big of a job is it to put a new 4th clutch in with the trans still in the car?

[JJ91284]

how big of a job is it to put a new 4th clutch in with the trans still in the car?

how big of a job is it to put a new 4th clutch in with the trans still in the car?

Basically you have to lower the engine/trans cradle so the transmission cover can be pulled off without interfering with side chassis. You really should support the engine and transmission some way or another. I use a transverse engine support. Bascially it holds the engine and trans from the top of the car. Once you can pull the trans side over cover you'll have to pull the valve body and channel plate. You'll need to channel plate gaskets as well as valve body gaskets.

Here's some pictures to give you an idea of what to do. If you decide to tackle the job, then we'll have to tell you how to lower the trans/engine assembly safely.

Engine Support




Side cover removed



Valve body/pump/channel plate removed



4th cluch friction and plates on right side need to be removed



4th clutch is the metal hub on the right side and goes through the chain gear assembly. All you do is lift up on it and it comes out. The teeth that get stripped you can't see until you pull the hub out.

[Lowizle]

kinda looks like more of a PiTA than anything else, leaning towards just having it completly rebuilt, having a hardened 4th clutch put in, and maybe a shift kit tossed into it, not really sure what im going to do as of yet though

*edit* i really apreciate the info btw, id love to do this job my self and save the coin, but i am the type of person who likes to have a good idea of whats up before i dive into stuff.

[RustedOutBuick]

Where are you guys getting these 4th hubs at? I tore my trans apart tonight and mine is ready to go!! (250k on it, razor thin splines)

[99prixgt]

Where are you guys getting these 4th hubs at? I tore my trans apart tonight and mine is ready to go!! (250k on it, razor thin splines)

www.tripleedgeperformance.com


he does sexy rebuilds too

[Lowizle]

going to have my trans completly rebuilt, any after market parts i should have tossed in there while im at it?

[GR8racingfool]

I was inside my transmission because I sheered the pins off the input speed sensor reluctor wheel. While I was in there, I had to replace the chain anyway, so changed the gearing, and replaced my 4th gear clutch shaft as well as a precaution because it was not a heat treated/hardened one. But mine did show sines of wear for sure.

Once inside the transmission...its plug and play with that thing. Just make sure you get a hardened 4th gear clutch shaft, the splines on the end of the shaft should be heat treated, and you should see clearly some burning left over.

Hardened/heat treated one is on the left in this picture.


I cant remember where I bought my parts from, either ZZP or Intense. But Dave walked me through what I needed to do and what to look for, and look out for. Basically what to expect. Hes a good teacher over the phone.













~F~

[TheOtherNick]

I would say you got the parts from zzp judging by the box in the background of pic 5.

[Lowizle]

what gearing did you end up going with?

[RustedOutBuick]

Heres what my 4th splines looked like when I pulled it apart a few days ago...



I just picked up the hardened version to replace it.

Anyone know the best place/cheapest place to get a new stock style (093) chain?

[GR8racingfool]

Ya, I think I went with ZZP too. I know I ordered the VSS reluctor wheel from them for the Diff. when I changed gearing, maybe the chain and new gears too, and at that time some new 105# springs I believe.

But I always have ZZP box's laying around the garage for other people at any given moment. LOL, you should see my work bench now, or lack of a work bench.

~F~

[GTPJOE90]

hahaha mine didnt have any splines left ha im putting the my trans after some beefing up and rebuilding shes going in tomarrow hehee