TurboKH

92 4x4 3.0 5speed truck.. recently installed a rebuilt transmission, new clutch/pressure plate/throwout bearing/flywheel. Also replaced the clutch master and slave cylinder (OEM parts). It still doesn't feel right! I've bled the clutch hydraulics a few times, adjusted the pushrod to spec, yet it still feels like I'm not pushing the clutch in all the way. Gears grind internittantly. Sometimes while stopped in gear with the clutch down, it starts to engage as if I'm letting the pedal up.. losing pressure? But not always. I've also checked the firewall and brackets for cracks and/or flex. Maximum free play at the bottom of pedal travel is 1 inch. Of my 106 cars and trucks, most have been standard gearboxes, so I'm not new to this, but this is the first time I've had these kind of erratic problems... It's such a simple system, I must be missing something stupid. ANY ideas??

coryc85

Could be a longshot here, but did you also change the pilot bearing? I guess if it were freezing up, it would spin your tranny input shaft as if the clutch were engaged.

TurboKH

yep.. did the pilot bearing, too. The symptoms kind of point to something like that, dbn't they? Main shaft still spinning?

coryc85

Sounds like you know what you're doing. The other obvious thing could just be that the system needs to be bled more. I don't know if you bench bled your new MC or not, but then again you probably would have mentioned it if your clutch pedal felt mushy. I know you bought OEM parts for the MC, but maybe the seal on the piston is not holding the pressure.

TurboKH

Yeah.. I bought all Toyota stuff, new master and slave. Bled the MC before attaching the line down to the slave. I keep going back to the possibility that there's a pressure drop.. is the fliexble rubber line expanding? That would be weird. Most of my standard shift cars have had enough play at the bottom of the pedal that it wouldn't matter. I don't know what kind of pressure is IN that system. What's odd is the inconsistancy.. sometimes it shifts like a new trans should, then all of a sudden I'll pull a gear and it's like I haven't even depressed the clutch.

All good ideas, though.. what else ya got??

coryc85

Marlin doesn't show a different slave cylinder for the 3.0 vs 22re, so I don't imagine that there would be a mixup and somehow you ended up with a slave cylinder that has too short of a shaft. Perhaps you could jack the rear end up, put the tranny in gear and have someone push the clutch while you try to spin the driveshaft, if it sticks then you have duplicated the problem and then see if you can push the lever on the side of the tranny back more to fully release the pressure plate (may have to use a rachet strap to do this). If the lever is not moving back far enough with the hydraulics then you know the problem is slave or master, if the lever absolutely won't move back any more then the problem is inside. Could be wrong throwout bearing (could be too narrow I suppose).

drew303

Forget the book and adjust the pedal so it the bracket that attaches to the piston rod on the Master Clutch cylinder is as far out on that as possible. In other words so when you push in the pedal its pushing that rod in as far as it can.

Other than that, I find it highly unlikely a pilot bearing could sieze and spin the drivetrain.

Only other culprit that comes to mind is that short flex line. Any kind of pressure absorbtion taking place in that line is enough to make the system not work as you describe.

TurboKH

I had the pedal rod adjusted at extremes in both directions and it didn't make much difference, up to the point that it wouldn't work at all. So I went back to spec. If you go too far one direction the pedal gets stuck in the down position, so I knew that was too far.

The pilot bearing is new and greased, so it didn't seem likely but at this point I question everything. One of the few things I haven't replaced yet is the rubber line.. maybe? I still can't imagine that it bloats enough to absorb that much pressure. I ordered one from the dealer today anyway.

I appreciate the feedback from you guys.. I'm sure it's fixable I just have to stumble on the right thing.

TurboKH

It wasn't the flexible line, either. Replaced it over the weekend. Now what? Clutch fork bent or cracked? Demons?? Another couple weeks of this aggrevation and it'll be another V8/automatic swap.