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Engine Specific Info and Questions => IDI Engine => Topic started by: jb86 on April 19, 2012, 09:06:57 am
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Friend has 85 turbo diesel jetta
Clutch was slipping in february
We replaced the clutch
Pressure plate
All oem Sachs for the car
Flywheel machined
New rear main seal
Steel pcs washed with alcohol as being assembled
Oem new bolts pressure plate and flywheel
All torqued as Bentley specs
Red thread locker on flywheel bolts
Torqued to 15 lb ft as specd
Tranny was pressure washed
New seals on tranny - input shaft and push rod shaft
New throw out bearing
Everything was clean and assembled with light white lithium grease
New cable - manual adjust, lots of free play
After 2k it's now slipping on the highway
Is it possible that something is hanging up in the pressure plate or the pushrod?
Jon
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Define "lots" of free play. Iirc the gap at the throttle cable 2 carrier gromet on the granny is 12mm. I actually set mine to 8 or so
Did you replace the "finger" when you did the TO bearing if it has a crack in it that could be the problem
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did they machine BOTH areas of the flywheel?? not only the clutch surface gotta machine the area that touches the pressure plate.. else gap too big
cracked finger = no clutch release...
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He did not machine both surfaces
Only the mating surface
Maybe that comes too close to the flywheel now?
Finger looked good
Jon
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cracked finger = no clutch release...
you are correct, not too sure what my thought process there ::)
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probably the lack of proper machining on the flywheel?
over in the toyota world, we actually have them machine the portion that touches the pressure plate more then the surface that touches the disc to get a tighter grip.
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probably the lack of proper machining on the flywheel?
over in the toyota world, we actually have them machine the portion that touches the pressure plate more then the surface that touches the disc to get a tighter grip.
because toyota pressure plates will lose pressure when theres still quite a few miles of friction material left on the clutch..
once, my dads friend had a toyota pickup, and we were all over hunting, 600 miles from home, and his clutch started slipping BAD.. so we dropped the trans, pulled the pressure plate, and took a GRINDER to the mating surfaces of the pressure plate, basically making the actual plate sit closer to the flywheel, so it would have some pressure left to grab the clutch disk again..
anyways, we ground down the 3 flat surfaces where it bolts up to the flywheel (removed about half of the thickness of the material) then put it back together with all the old parts, and IT WORKED for the time being. got us around for those 2 weeks we were there, and made it back home also..
but yes, i too, have the mating surfaces machined more than the actual flywheel friction surface.. actually makes the pressure plate bite the disk harder..
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I understand
I mocked it up with a flywheel and old pressure plate
With no disk there's maybe a light 1/4" gap between them
The disk is about 5/16"
I saw where they mate
We'll watch it and if it needs it we'll pull it next week
Thanks for the replies
Jon
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Also you can use a 16v pressure plate for a little more clamping force.
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It's possible they incorrectly machined the step on the flywheel too. I just replaced my clutch twice this week (first because I had a bad disc, then I replaced the fancy high clamping race clutch with a stock one because burning out whenever I pulled away from a stop got old) and the machinist was surprised at how many steps there were for MK2's. He told me had I not told him the year it was from, he wouldn't know what step to put on it. With that said, I think all the Jettas and Golfs (diesel) had the same step, so as long as they stepped it to a diesel, and not an 8v gasser, you should be in good shape. If you pull it apart, you could measure the step yourself with calipers, then compare it to what it should be. Just a thought.
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I know of a local mechanic (for 50 yrs) that just seems to know a lot about everything
I stopped in to see him
In the way, on the highway the clutch slipped in 5th 4 times on a hill in a 10 mile drive
The last time was on flat highway coming from 4th to 5th
He looked everything over
All looks good
Started it
In 2nd at a stop slipped the clutch while revving
Didn't say anything but I just heard him revving and slipping the clutch
when smoke started coming out of the clutch
He said it should, I'm burning it
He drove it around his backyard a bit
Said - I think you're all set now
It was slipping in 2nd when he first got in
After "working it" it didn't slip
That's been a few days
Hasn't slipped since
He thought maybe something was hung up or got in there
Darned if I know
I figured we had nothing to loose
So far so good
Thanks for responses to try to narrow things down
Jon
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Interesting.. so you msut have had some kind of petroleum product on your clutch disk.. ?
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I replaced the rear main seal
Cleaned everything with alcohol
I used a 2 pc bell housing cover plate - it has the remove able cover at the bottom
That way I could see if oil was leaking
Its all dry
I'll just see what happens
So far so good
Jon
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that or maybe just a slick surface on the new disc?
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if you think something got on the disc you could always try soaking it in brake keen a couple times and let dry I've heard of that curing the problem before.
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Right now he says it's doing good after a heavy break in
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Sounds like the clutch needed "bedding", like when you replace your brake pads and rotors and you make some hard stops to promote contact between the brake parts. That's what your mechanic friend did; slipped the clutch until either any protectant coating on the parts was burned off or until the clutch friction material wore into the flywheel and pressure plate's contact surfaces. A clutch is basically a large brake after all, designed to match speed between tour flywheel and trans input shaft.
You should be fine now as long as the clutch engagement is smooth and progressive.
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I usually try to break in brakes that way...maybe the clutch could benefit? Get it hot once and call it good? Not the way I usually break in a clutch, but I never had one slipping like that either.
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that or maybe just a slick surface on the new disc?
new disks grab very well..
if your NEW disk doesnt grab very well, then something is wrong..
ive never had a disk slip because it wasnt broken in..
ive had a disk slip because it wasnt broken in PROPERLY tho..
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he admitted the flywheel was not machined properly... its just time till it really bites him in the bumb.. gotta machine both sections.. not just 1..
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I gave it to a local auto machine shop to resurface
I expected it would be done correctly
I expect that they only took off a small amount of material
I mocked up an old pressure plate and flywheel to see how much space is between them
Without machining there's about a light 1/4" with the flywheel tight to the pressure plate on the surface
The disk is about 5/16"
Not much room for wear since the outer edge of the flywheel wasn't machined
I didn't know to ask
Eventually I'll have to pull the tranny and do it again
What sucks is I did my car the same way
So
Eventually I'll have to do my car too
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yep sadly this is where some machine shops suck.. LOL.. knowledge is key.. now you know.. its also why my inital post in this thread asked as ive seen it done wrong a few times..
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I personally have had a NEW clutch slip pretty bad. gotta figure if it is just 1/32" wider on the inside then the outside, its not getting 100% grab at first
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Just spoke to machine shop
The "old timer" really knows vws
He built my engine
I questioned everything
Because of the idiosyncrasies of the Vw diesel
He did everything right
Far as I could tell
He said he did machine both surfaces
Jon
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Forgot to add
He said he took off .003"
To his recollection
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Could there be any loose bits in there for what ever reason jamming the pressure plate? When my clutch fell apart one of the springs was jamming the pressure plate from closing tightly.
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With help, it is possible to pull the trans and block apart from each other without too much grief. Jack the car up and remove the trans towards the wheel.
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With help, it is possible to pull the trans and block apart from each other without too much grief. Jack the car up and remove the trans towards the wheel.
support the ENGINE with the jack, and then pick the trans off the engine, and lower it to the ground.. put the car up on jack stands, because you MAY need to pull the pinch bolts for the ball joints to get the axles out of the drive flanges on the trans..
i can drop an 020 trans by myself no problem. lean over the trans from above it, slide it off the engine, and then carefully set it on the ground, or a TIRE that you set under it before removing, or whatever..
leave the passenger motor mount connected, so the engine is KINDA connected to something, and remove the other 2 mounts.. then lower the trans end down, un bolt, and remove. you can get the trans out EASILY without removing the engine..
ive tried bench pressing the trans back up in the car before, and its NO FUN..
so i set the trans under the car, stand up, reach down thru the engine bay, pick up the trans, and slide it on the engine. works out great, and its much easier on your body. its much easier to LIFT the trans into place, rather than try and hold the trans still on your chest, then get a good enough grip on it to get it of your chest, then maintain enough strength to actually put it where it needs to be..
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With help, it is possible to pull the trans and block apart from each other without too much grief. Jack the car up and remove the trans towards the wheel.
support the ENGINE with the jack, and then pick the trans off the engine, and lower it to the ground.. put the car up on jack stands, because you MAY need to pull the pinch bolts for the ball joints to get the axles out of the drive flanges on the trans..
i can drop an 020 trans by myself no problem. lean over the trans from above it, slide it off the engine, and then carefully set it on the ground, or a TIRE that you set under it before removing, or whatever..
leave the passenger motor mount connected, so the engine is KINDA connected to something, and remove the other 2 mounts.. then lower the trans end down, un bolt, and remove. you can get the trans out EASILY without removing the engine..
ive tried bench pressing the trans back up in the car before, and its NO FUN..
so i set the trans under the car, stand up, reach down thru the engine bay, pick up the trans, and slide it on the engine. works out great, and its much easier on your body. its much easier to LIFT the trans into place, rather than try and hold the trans still on your chest, then get a good enough grip on it to get it of your chest, then maintain enough strength to actually put it where it needs to be..
Did the bench press method myself while working on my brother's 98 civic, like lifting a miniature fully-loaded fridge. He was calling one of our bigger friends to help us with that, but I just did it while he was calling him. Next thing, I tell him "run a bolt in" while straining to hold the trans on the engine, and he just stops and says ". . . uh never mind dude". LOL, but yes the banch press method is NOT FUN especially as I learned the 98 civic trans is heavier than an 020. :P
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When we replaced the clutch in the 85
Set car on jack stands maybe 1 foot or so higher than normal height
I built a wood frame with 2x6
It's a beam about 1 foot above the engine and supported on the fenders
I used 2 nylon ratchet straps to hang engine and a 3rd that I wrapped around the tranny
Removed 2 engine mounts and loosened pass side mount
Unbolted cv's at tranny, pushed them as far back as I could and down on the cross member
Lowered the drivers side a couple inches so the butt end of tranny would fit toward the wheel well
I was under it on a creeper
Helper removed the last bolt while I balanced it, hanging from the strap
Then I swung it out and helper lowered by ratchet
Only issue
I laid it on my stomache but it was too high to get out
Had to reposition a bit
Went back in the same way
Jon
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I had to do my clutch and I just pulled it, not the 2 together. If I did it again I would probably pull them both as the only difference was a couple wires and hoses. I could have got to the bolts quicker and easier and I think that would have more than made up the time. For me I could bench the trans with my right arm and twist it with my left as I had to rotate IIRC diff side up a bit and then slide it in. Getting all the bolts in the trans on the ground was the hard part for me...if I had a lift and could walk under the car, then yes, I would pull just the trans everytime. Working in the driveway, I will probably pull both. Being bigger and stronger helps in lifting the trans, but not so much getting the bolts everywhere they need to be on your back on the ground.
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I had to do my clutch and I just pulled it, not the 2 together. If I did it again I would probably pull them both as the only difference was a couple wires and hoses. I could have got to the bolts quicker and easier and I think that would have more than made up the time. For me I could bench the trans with my right arm and twist it with my left as I had to rotate IIRC diff side up a bit and then slide it in. Getting all the bolts in the trans on the ground was the hard part for me...if I had a lift and could walk under the car, then yes, I would pull just the trans everytime. Working in the driveway, I will probably pull both. Being bigger and stronger helps in lifting the trans, but not so much getting the bolts everywhere they need to be on your back on the ground.
im probably one of the biggest, and strongest here, and i still do it the easy method..
gotta remember, us big/tall guys usually have back issues that we have to watch out for..
sure, lifting a trans isnt fun, but neither is bench pressing it. believe it or not, the only times i messed up my back on a trans job, was using the bench press, because i had to struggle..
its literally a cake walk to set the trans under the car, reach down thru the engine bay, and lift it on to the engine.. its easier pulling it on from above, then pushing it on from below.. dunno wether its the increased grip on the trans, grip in better places, but whatever it is, i only drop 020 trannies in the method i described..
and the way i do it, is way quicker than lifting the whole engine/trans as a unit.. i dont have time to drain the coolant, disconnect all the hoses, un hook all the wires, fuel lines, yadda yadda..
ill leave the engine in, unless i have a GOOD reason to pull it..
almost every time i pull them as one piece, i seem to mess something up..
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Yeah you should never do this solo. Sure you could but its a dumb idea.
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Yeah you should never do this solo. Sure you could but its a dumb idea.
i ALWAYS do anything on the 020 solo.. its no big deal. helpers just get in the way and make the process take longer. haha.