Topic: Clutch problem. (Solved)

[Hawk Thor]

My truck almost killed me today. I had been wheeling it up steep hills, slick ice and on some bumpy roads in 4LO. I put it in 2HI and headed home. On the first downhill I tried to downshift and it would not go into second gear. I finally got it to engage after I had revved it up. I just barely managed to stop before going thru an intersection and in the way of a E350.

I can not get it into first from a standstill unless I turn the motor off and then shift. When I start it the clutch slips and the motor does not idle at normal revs.

I know the clutch is not disengaging and the tranny is fine, there are no strange sounds coming from it and its not hot, just the normal warmth that is to be expected.

I checked the clutch mastercylinder and slave and I found no leaks or loose bolts. The master is full of fluid and the pedal is not loose or crooked.

I tried to pump the pedal to no avail.

What do you think this could be? Where should I start looking? Its cold outside and I can´t get the truck inside for a few days, so I´d rather not lay on my back in the cold for too long.

[79coyotefrg]

adjust the slave cylinder push rod,  mine is a  13mm and a flat screw driver, loosen the lock nut,  then  rotate the "bolt" with the screw driver till there is a small amount of slack (make the distance between the slave and the clutch fork shorter)

[84pickup]

my 84 pickup was doing that too a while back ago and when i changed the clutch i sort of tested my pressure plate on a 20 ton press and when i pushed down on the springs, the plate didn't move so i'm guessing the problem is the pressure plate.

[JD]

If the clutch had been engaging very close to the floor, then the slave cylinder push rod adjustment should work. You would want to raise the pedal higher off the floor by backing out the rod after the lock nut is loosened.

[Hawk Thor [OP]]

Thanks for the tips guys. I´m gonna check out the pushrod today and report back.

[Hawk Thor [OP]]

The slave cylinder pushrod is not adjustable, its just a solid rod thats held in place by a seal that snaps to the cylinderbody.

I´m just gonna roll it next week into the garage I´m waiting to get into. I´ll tear into it and let you guys know.

[JD]

Yes, but the clutch pedal height is adjustable, that's what I was talking about. You adjust it from inside the cab, and it allows you to control the clutch engagement point. My theory is that yours might set be too low.

[Hawk Thor [OP]]

So you´re talking about a rod that connects to the master cylinder? The one that goes thru the firewall and connects to the pedal?

[JD]

Yes! I have no idea if this is your problem or not, but it's an easy thing to try out without getting your hands dirty.

[Hawk Thor [OP]]

I tried adjusting the pedal and the rod and no luck. I did notice though that the bracket that holds the pedal is cracked and is flexing. I forced the bracket to its original form and it still does not work. I´m just gonna take the transmission out when I get a chance and have a look at the fork, throw out bearing and the pressure plate. I´m sure one of those is the problem.

[JD]

I think you are probably correct, but it never hurts to rule out the easy fixes first.

[84pickup]

definetly. i had a friend that replaced everything in his clutch system except the slave and it still didn't work so when he did replace it, the system was fixed.

[Hawk Thor [OP]]

Yeah, its sometimes like that.

I have a spare slave that I will try before I drop the tranny. I recently flushed the clutch and brake systems and bled them, the clutch and brakes were fantastic after that. Now my precious Motul fluid will be spillt.

[joey0712]

If the clutch bracket is cracked its flexing and your not getting your full throw outta the pedal. I have welded a few before. Have somone push the clutch in and see if its flexin.

[miks85yota]

check the rivets or welds that mount the clutch pedal itself . ive had them break loos and didnt know it, but it wouldnt let the clutch engage right, and i didnt find it till after id already swapped the clutch, master, and slave cylinder. put another weld on it and presto! worked fine.

[boggerunner]

ive used a longer rod in the slave, a 12mm headed bolt works great

[Hawk Thor [OP]]

I saw the cracked bracket and forced it into the right position with a long screwdriver and 2 big zip ties. I pushed it by hand and kept and eye on the crack while holding the stick against first gear. It didn´t work. I will put some spotwelds on that bracket or maybe a small plate and rivets, or both.

[Hawk Thor [OP]]

I haven´t mentioned that I have a ´90 3rd gen with ´89 motor and tranny.

[miks85yota]

when mine cracked, it barely moved when i hit the pedal, but it was just enough to not let it go into gear.

[Hawk Thor [OP]]

check the rivets or welds that mount the clutch pedal itself . ive had them break loos and didnt know it, but it wouldnt let the clutch engage right..

I took the pedal out and checked the bushings in it, those are fine. I fully extended the rod and pushed the pedal, that did not work. I looked at the bracket and looked for more cracks, there is only one crack. Its facing the brake pedal so the clutch pedal flexes towards the kickpanel.

I greased the pedal bolt to silence the squeak thats been there for months and fixed the stop for the pedal so it won´t rattle.

[Hawk Thor [OP]]

I pulled the tranny and clutch yesterday and checked things. The throwout bearing is beginning to make a sound and the pivot for the fork is worn.

I also checked the clutch disk and it measured 7.5 mm in thickness, I have two discs measuring 8.3 and 9 mm, so I will change that out.

I checked the springs in the pressure plate and those are worn down to 3 mm where the throw out bearing contacts them, I have a plate that measures 3.5mm in the same place so that will go in.

The inputshaft bearing was toast, grinded pretty bad and was stiff. We had to dremel the bearing out since we didn´t have a bearing puller and we were a long way from a tool store.

So far I have spaced out the fork pivot rod by putting a shim behind it, we polished the flywheel with a flap disc, it didn´t need resurfacing. I also cleaned my thickest clutch disc with brakecleaner. Tomorrow I´m gonna buy the bearings and get the inputshaft bearing in the flywheel. I´ll post up when I finish.

[85toyextcab]

Mine is doin the same thing but my bracket looks fine, i just installed a new slaycylender today and still at the floor, and my adjuster is all the way out. . But the guy i got the truck from said the clutch is just a few months old, and i dont think he a bull shitter. What should i check next?

[84pickup]

air in the lines?

[85toyextcab]

I bled and bled, about half bottle of fluid. Ne more ideas

[85toyextcab]

Well update on my clutch problem, Installed the clutch master today and that seemed to be my problem. 

[84pickup]

cool! i'm glad you figured the problem out.

[Hawk Thor [OP]]

We´re putting the clutch and tranny in tomorrow. Then I´ll be removing the clutch and brake pedals so the pedalbracket can be welded.

Does anyone have a diagram of the 4x4 and reverse sensor wiring? It would help me since one connector is broken and the wiring loom has melted after coming into contact with the exhaust pipe.

[Hawk Thor [OP]]

I drove the truck home today. It went together easily thanks to the shops freezer and a can of anti-seize. 

The pilot bearing went into the freezer on thursday so it almost fell into its seat went I installed it. All bolts were coated in anti-seize except for the ones that had thread lock on them. I almost look forward to tearing it apart again just to se how much difference the anti-seize makes.

The clutch is smoother now and I also adjusted the pedal travel so there is no slop in it anymore.