3rd Gen Clutch needs replacement?

[BretMann]

I parked my 107k miles truck 14 months ago w/ the transmission shifting fine and no slippage. After waiting for parts, distractions and finding the time to finish the job at hand, it's now back together and running. But the shifter wouldn't shift either with the engine on or off.

I installed a new Aisin clutch master cylinder a couple k miles ago and is essentially new and no drips as well as for the slave cylinder. I then rotated the master plunger rod to extend it about 1/4" more and it's now on the last threads. Doing that got the shifter working again.

1 -Did it sitting for a year create the issue of it not shifting? If so why?
2- About how many miles do you think are left on the factory clutch?
3- Would adding a plunger rod extending coupling extend the life of the clutch or is doing that a bad idea?

Thanks.

 

[RandyBobandy]

I’d replace the slave cylinder first, they have a higher failure rate than the master and a bad clutch shouldn’t cause you to not be able to shift unless there was something wrong with the pressure plate and in that case adjusting the master cylinder push rod wouldn’t have done anything

Also 200k+ on a factory clutch isn’t out of the ordinary, it should have plenty of life left

 

[BretMann]

That's all good news. I'll try that even though the slave isn't dripping. I wondered if the slave and master wear out at about the same time. I hope it's just the salve cylinder. I don't tow much at all, drive hard or ride the clutch so I hope I get all those miles more out of it.

Thanks!

 

[brillo_76]

Mostly they don't wear out unless they are leaking. However, I have seen o rings start to fail in master cylinders and leak fluid past thus not work properly.

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[4Reak Show]

I’m not understanding, what did you replace already? The clutch assembly? If so I have an idea

 

[BretMann]

Interesting.

I just ordered the Aisin slave (CRT029) from RockAuto (w/ Tx + Ship = $35.29).

I'll try it out and and report back. I saw on YouTube to grease the rings. Is that a good idea and if so, what grease - white lithium, silicone?

 

[BretMann]

I already replaced the master cylinder relatively recently - and the fluid. Hmmm, could the fluid have water in it already? I'll test for that.

 

[Sparky 97Runner]

But the shifter wouldn't shift either with the engine on or off.

Your clutch, master and slave will have nothing to do with not being able to shift with the engine off. You should normally be able to smoothly shift through all gears without touching the clutch with the engine off. Any chance that something on top of the transmission is physically blocking your shifter from moving?

 

[BretMann]

Not that I know of. The very first startup attempt, clutch pedal down, the truck lurched forward without engine starting. Never had that happen before but fortunately the hand brake was on. It was in 1st gear. I managed to get it into neutral and tried again and it started ok but then couldn't get it into gear. Turned engine off, got it into gear, clutch pedal down, start again then lurched again without engine starting. Then there it stayed in 1st gear and couldn't get it out of that gear. I pushed and pulled on the shifter with some effort but didn't want to force it. When I extended the master's pushrod the next day, it shifted into all gears normally.

 

[Sparky 97Runner]

Turned engine off, got it into gear, clutch pedal down, start again then lurched again without engine starting. Then there it stayed in 1st gear and couldn't get it out of that gear. I pushed and pulled on the shifter with some effort but didn't want to force it.

Okay, that makes sense. Your transmission was under pressure against the parking brake which made it difficult to get out of gear with the engine off. Does it shift through all gears now with the engine off? If so, I agree this does sound like a master/slave issue. Most likely your new Aisin master needs to be bleed properly considering you don't have any leaks.

 

[BretMann]

Good point. What I'll also try is to back the plunger rod to where it was. And with no pressure on the parking brake, try the starting sequence again outside where there's space - see was happens and report back.

 

[Sparky 97Runner]

Good point. What I'll also try is to back the plunger rod to where it was. And with no pressure on the parking brake, try the starting sequence again outside where there's space - see was happens and report back.

First try bleeding your master with plunger in original location. That's the easiest thing to do but you need two people. Or use a russell speed bleeder.

 

[Pyral]

The original clutches last a very long time, you could get another 100k or more out of it depending on how you drive.

The slave cylinder last until they start leaking, my 4runner likely sat for a very long time before I bought it and it didn't have any issues internally.

You should bleed the clutch fluid, this is often neglected and theoretically shortens the life. Your more likely to have problems with master cylinder.

 

[octanejunkie]

A bad master cylinder will allow fluid past the plunger, meaning the pressure plate won't be held by the clutch. It won't leak like the slave cylinder does.

A few tricks and things to consider

If you didn't bench bleed the clutch master crack the hardline connection at the master and have a helper pump the clutch pedal slowly until it weeps from the hard line connection, then tighten it down and wipe it well.

When you bleed the hydraulic clutch (master and slave) it's best to have a helper on the pedal and you working the bleeder screw/wrench while holding the plunger on the slave in, that way the full stroke of the master can go to bleeding the circuit.

2-3 pumps like that and you will be properly bled.



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[brillo_76]

Can you use a speed bleeder on the clutch slave cylinder to bleed it yourself?

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[JohnMc]

First try bleeding your master with plunger in original location. That's the easiest thing to do but you need two people. Or use a russell speed bleeder.

/\ /\ /\ If the push rod is set too long, which it sounds like was done here, then the master cylinder can't pull more fluid in from the reservoir. There is a small opening from the reservoir into the master cylinder bore that is opened only when the piston comes all the way out, as far as it can go. If the rod is too long, it won't let the piston come out far enough, and that hole stays covered, and the system can only use the fluid that's currently in it, sort of the same thing as having an empty reservoir.

Shorten the rod until it barely comes off the piston with the pedal all the way up. No need for a large gap, just a tiny bit of pedal travel needed before the rod hits the piston in the master cylinder.

 

[mtbtim]

I suspect you didn't properly bleed the system. Bleeding the clutch hydraulic system can be a pain.

This video helped us get the system bled when we were doing a 3.0 to 3.4 Swap on a 2nd Gen 4runner.

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[BretMann]

Thanks very much. I adjusted the pedal back to how it was and rolled the truck back and forth a bit. That seems to have released any pressure on the clutch and is ok now.

I'm getting a shuddering though, sometimes when I'm in 1st gear and launching from a stop. It may be that I'm out of practice and I just need to drive it more. Maybe I'm just missing the sweet engagement spot because it's been usually very smooth to launch from a stop for me. However, although there's no slippage yet, maybe it's a tell tale sign the clutch spring is weakening because the clutch pad is getting worn down, now with 107k miles on it.

What do you think?

 

[Pyral]

Thanks very much. I adjusted the pedal back to how it was and rolled the truck back and forth a bit. That seems to have released any pressure on the clutch and is ok now.

I'm getting a shuddering though, sometimes when I'm in 1st gear and launching from a stop. It may be that I'm out of practice and I just need to drive it more. Maybe I'm just missing the sweet engagement spot because it's been usually very smooth to launch from a stop for me. However, although there's no slippage yet, maybe it's a tell tale sign the clutch spring is weakening because the clutch pad is getting worn down, now with 107k miles on it.

What do you think?

It could be a worn spring. When mine was worn it felt like a clutch, it had a very narrow feeling engagement.

You could be out of practice, but replacing the clutch spring with a linear spring would be a good mod anyway because the stock ones are known to start squeaking.

 

[Rushthezeppelin]

Thanks very much. I adjusted the pedal back to how it was and rolled the truck back and forth a bit. That seems to have released any pressure on the clutch and is ok now.

I'm getting a shuddering though, sometimes when I'm in 1st gear and launching from a stop. It may be that I'm out of practice and I just need to drive it more. Maybe I'm just missing the sweet engagement spot because it's been usually very smooth to launch from a stop for me. However, although there's no slippage yet, maybe it's a tell tale sign the clutch spring is weakening because the clutch pad is getting worn down, now with 107k miles on it.

What do you think?

I'm leaning towards the shuddering just you being out of practice. The engagement spot on these clutches isn't huge and I've had a few times where I'm careless and get that shuddering like the clutch is just skipping on the flywheel.