1st gen new clutch slipping

Okay backstory:

I have a 1996 single cab SX v6 manual truck with over 300k on it. Drive fine when I picked it up but when I drove home on long steeper hills clutch would slip in 5th and 4th. Basically couldn't maintain speed all the way to the top, even though it should.

I drove it like that for 3 years babying the clutch and finally decided to get a new one.

I installed an Aisan stock clutch kit and LUK fly wheel and rebuilt the master cylinder and slave.

And it still slipped just like before. Plus the clutch I pulled was an Exedy stage 1 I think and honestly didn't look bad at all. I think I could put it in another truck and it would be fine for years.

So then I bought an LCE clutch performance kit with a stronger pressure plate and then put the OEM fly wheel on after getting it resurfaced.

Still slips.

I've bled the system a lot to make sure it is good.


I'm tired of lipping around in this small what should be fun and a bit quick truck.

Someone tell me what stupid thing I'm overlooking.

Only other thing I'm fixing to do is flat out replace all the hydraulics.

 

Yeah you're kind of making me wonder if the hydraulics don't fully release. Most other broken stuff causes the clutch to not disengage rather than slip.

 

Yeah which to be fair, not like they are new. Almost 30 years old at this point.

I'd still be a bit peeved if that was the case since I did rebuild them. But could be something so bad a rebuild ain't gonna fix it?

 

That’s my thought as well.
I haven’t been under a 1st Gen in years.

Can one take a look at the clutch fork and “see” if it’s releasing fully?
Maybe crack the bleeder on the slave and see if the fork moves?

 

Can check for sure.

 

Sounds like something isn't going as far as it should. If you replaced with a heavier pressure plate and are still getting slippage seems like the fork isn't moving far enough.
If you check the master and slave and those look like they are in proper working condition, I wonder if there could be any chance the fork got bent somehow the wrong way causing it not to return to the right position.

 

Yeah that could make sense. I seem to remember checking before and the fork was not under pressure. Will double check that.

But yeah, something is not happy but it's not clear what it is. Not sure you can bend the fork though?

 

Yeah not likely, but somewhere to also look. It sounds like you did the other clutches yourself so you probably were careful, but say if a shop did it (or pulled the trans at one point) and the trans rolled or flopped onto the side and tweaked the geometry just slightly it could do something.
Have you verified that the master and slave are OEM?

 

I am pretty sure they are OEM. Slave is for sure. Master not 100% certain. Will poke around today and see. Suppose that could be a factor though. The rebuild kits were OEM.

 

Looks like everything is OEM.

The slave is keeping pressure on the fork which it's supposed to do and there is no play in the fork when it's all the way out.

However!

My valve cover gaskets are leaking. Been on my to do list a while. The bottom of the bell housing does have oil on it. I don't see how oil could get in there but maybe it's possible?

Wouldn't explain it over long term or when I changed clutches though.

 

99.9% would have seen oil on your old clutch if that was the case. How did the pivot ball look on your housing?

 

Check your clutch pedal freeplay, if it's not adjusted right it will keep pressure on the hydraulics. Around 1/4"-3/8" play is typical. Make sure you see the play on the pushrod and not just the pedal itself. Most likely will need a 12mm and 14mm wrench.

 

^^^

https://www.tacomaworld.com/threads/clutch-pedal-truffle-shuffle.499079/

 

Hell idk. Been a year or more since i swapped in the new clutch. Nothing looked bad though. Cleaned it all up good.

I've read about this and have messed with it. To no avail. Not sure if I just am doing it wrong but there is some pedal play before the rod moves.

 

there should be no free play, but you should be able to give a heavy handed wiggle. I suggest (trying) to forcing your slave to return all the way, it can absolutely lip and prevent full return if it spent 20+ years on a thin plate before going to a new thicker plate. You should be able to fully compress that boi by hand easily enough.

Your hydraulic replacement plan is the right next step tho.

 

It’s not impossible for the clutch fork to bend as they’re pretty thin material and I’ve seen at least one guy saying it broke (not bent though) on him.

 

Wouldn't that typically cause the clutch not to fully disengage though, rather than stick partially engaged? Although yes, you can absolutely bend these forks

 

Yeah it would most likely bend towards the trans.

 

Did you handle the friction disk with bare hands and/or over lube the input shaft

 

I mean it's very very little play. It was a lot before and then I adjusted it. It's pretty tight now to engaging the rod soon as you push it.

I can easily push it with my hand to the floor.

Or you mean pushing the slave all the way in and letting it come out?

gloves. And no signs of grease on the 2 i removed before the 3rd clutch disk.