ajginth

1991 Pickup 3VZE manual 170K.

Having some trans issues that I have mostly worked out thanks to this forum: New shift bushings,clutch pedal adjustment,bled cylinders, trans oil change.

When I did all this it was late and I had already dropped the trans oil. It was....ugly, real dark. The only thing open was Advance Auto, so I picked up what they had (Coastal 80W-90 rated for GL-3,4,5) and used it to replace the drained oil. I know I'm supposed to use 75W but I figured it is only about 1/3 the total oil in the trans, and at least it's clean, right?

I wan't to switch the trans over to Redline MT90 or possibly the Amsoil equivalent, but I'm afraid of having a machine flush done cause of the higher miles. Heard some horror stories. Would it be a good idea to do a couple of maintenance changes with some cheap stuff to get the trans a little cleaner before I do the MT90? Will I get any of the benefits without doing a full fluid change? Or should I not bother and just use a cheaper GL-4 75W? Like I said, the oil is pretty nasty, and I don't wanna just dump good/expensive gear oil over bad. How about those drain plug magnets...any benefit to installing one of those, or just a gimmick?

RustBucket

iTrader: (1)

Since it's a manual trans you don't need to do any "flushing." What came out when you pulled the plug was all the oil in the trans. If you've filled it to the top (that is, oil is running back out of the fill plug hole) then drive it around and drain it when the oil is nice and hot. Then pump the synth oil that you want to use into it and you're good to go!

ajginth

Ohh...hehe, yeah, I knew that....

Ok...Shifting great now with the cheapo stuff. But my clutch pedal is adjusted almost all the way out on the rod thread (the one that goes through the firewall) so the clutch will disengage. Doesn't release till I'm within a couple inches of the floor. Any way to know if the clutch master/slave are bad for sure?

blake.nemitz

your clutch disk is probably getting a little thin, the thinner it gets the farther forward the throw out bearing has to move forward to disengage the pressure plate

DeathCougar

iTrader: (23)

You also should check your clutch pedal bracket for cracks/broken. If you have to push it out that far, the pedal assy might be going bad. Its a very very common problem in these trucks.

UKMyers

I believe the 91's had a hydraulic clutch. If that's the case they are self adjusting and as it wears should not effect pedal movement. It sounds like your hydraulic components are about shot.

ajginth

Been there done that on the clutch pedal bracket, all welded up and solid. Clutch disk? never thought of that...only replaced the clutch once though.

If the hydraulics self adjusting then why the adjustable clutch pedal assembly?

Clutch pedal FEELS solid, lots of pressure, not spongy, which is what confused me. Just has to go so far down to floor before disengaging and no more room to adjust on the pedal bracket.

Thanks for the help guys.

ajginth

Should I just replace the master/slave and assume it's bad? Clutch was replaced 40K ago.

UKMyers

The adjustment is only to adjust the clutch pedal freeplay as shown in this procedure

http://personal.utulsa.edu/~nathan-b.../2checkand.pdf

ajginth

Gotcha, thanks.

So, how do I tell if the slave/master is bad? Like I said, lots of pressure in the pedal feel

blake.nemitz

wouldnt be a bad idea to rebuild them too, advanced auto parts sells rebuild kits for hella cheap, same thing in the end as a reman for alot of money

ajginth

Thanks, I think the general consensus on here is just buy new and buy OEM/Aisin lotsa issues with the rebuilds, and no guarantee.

Have you had good luck with the rebuilds?

I just wish I knew if mine was bad or not for sure... No leaks I can see, and good pedal pressure. But my clutch pedal adjustment rod is adjusted way out so the clutch will engage properly.

RustBucket

iTrader: (1)

You could check for internal leaks by holding the pedal down, maybe with a brick or have a friend help, and see if the slave cylinder retracts. I had that trouble once - If you pushed in the clutch, put it in gear, and waited (like at a red light) the clutch would slowly engage as the system lost pressure.

If it holds pressure I can't imagine there's anything wrong with it. I don't think the system is "self-adjusting"; it's just two simple pistons. The adjustment rod is there to let you compensate for the clutch wear and decide where you like the clutch to engage.

ajginth

Yeah...kinda what I thought, system IS holding pressure, thats why I'm a bit confused

Here is my original post about the clutch.

https://www.yotatech.com/forums/f116...es-216832-new/