clutch issue
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- Posts: 620
- Joined: Fri Aug 26, 2011 10:01 am
clutch issue
Hi Guys.
I have done a rebuild on a CU 2 ltr engine. The engine is in a Vanagon.
Been driving round and clocked up 1 k miles so far.
The problem I'm having is I'm starting to struggle changing gear.
I did fit a new clutch including the throw out bearing.
This van has a slave cylinder for the clutch.
The way that I'm getting the van to go into gear is to double the clutch.
Any ideas as to why this is happening.
I think the slave cylinder behind number 3 cylinder has some trapped air and needs to be bled due to the fact that after 2 clutch pumps the gear change is ok.
I have done a rebuild on a CU 2 ltr engine. The engine is in a Vanagon.
Been driving round and clocked up 1 k miles so far.
The problem I'm having is I'm starting to struggle changing gear.
I did fit a new clutch including the throw out bearing.
This van has a slave cylinder for the clutch.
The way that I'm getting the van to go into gear is to double the clutch.
Any ideas as to why this is happening.
I think the slave cylinder behind number 3 cylinder has some trapped air and needs to be bled due to the fact that after 2 clutch pumps the gear change is ok.
- Marc
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Re: clutch issue
Bleeding would be the first thing to try. If you can never get bubble-free fluid out, one of the cylinders has a bad seal and is drawing air into the system when you let up on the pedal.GARRICK.CLARK wrote:...after 2 clutch pumps the gear change is ok.
Here's how to do it using a hand-operated vacuum pump: http://www.vanagonauts.com/index.phtml?catid=183
But if you have a helper it can be done manually, you may want to try that before spending $40 on a MightyVac.
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- Joined: Fri Aug 26, 2011 10:01 am
Re: clutch issue
Hey thanks Marc I will bleed system , hopefully its full of air and not the box.
- raygreenwood
- Posts: 11895
- Joined: Wed Jan 22, 2003 12:01 am
Re: clutch issue
If the clutch slave "was" working....and now has air in it...either it or the master is shot. Just like brakes...they dont mysteriously get air in them over time. Its bypassing somewhere and is usually on the slave seal end. Just pull it and rebuild it. Ray
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Re: clutch issue
Not had time to bleed the slave cylinder yet , BUT gear oil is leaking out the bottom of the bell housing. how is this possible.The input shaft oil seal must be split pretty bad. . clutch pedal is good. it has pressure behind it like a normal operating clutch. cant get any gears at all. With motor running ,when I try to select any gear it just grinds the gears. Does the clutch fluid have the same smell as gear oil , and can the fluid from the slave cylinder get into the bell housing.
- Marc
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Re: clutch issue
Check the clutch fluid reservoir level, if it's not low you're not losing hydraulic fluid.
Gear lube has a distinctive odor due to the sulfur compounds in the the extreme-pressure additives in it. Smells like rotten eggs and cat piss.
Flywheel seal (or O-ring) leakage will allow engine oil to get into the bellhousing area too; the latter gets oil all over the clutch disk on its way out...oil-contaminated clutch linings can exhibit a few different symptoms which may change as it heats up, but failure to disengage isn't one of them until the lining starts to disintegrate and the pieces stack up.
Another thing that can cause the same symptom as a dragging clutch is a bad pilot bearing in the end of the crank - if it's messed up it can transmit enough power to the trans mainshaft to make it hard to get into gear even if the clutch is disengaging as it should.
Gear lube has a distinctive odor due to the sulfur compounds in the the extreme-pressure additives in it. Smells like rotten eggs and cat piss.
Flywheel seal (or O-ring) leakage will allow engine oil to get into the bellhousing area too; the latter gets oil all over the clutch disk on its way out...oil-contaminated clutch linings can exhibit a few different symptoms which may change as it heats up, but failure to disengage isn't one of them until the lining starts to disintegrate and the pieces stack up.
Another thing that can cause the same symptom as a dragging clutch is a bad pilot bearing in the end of the crank - if it's messed up it can transmit enough power to the trans mainshaft to make it hard to get into gear even if the clutch is disengaging as it should.
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- Joined: Fri Aug 26, 2011 10:01 am
Re: clutch issue
Dropped the engine tonight. Bell housing covered in gear oil. The input seal has failed.
How much oil it has lost I'm not sure till I remove the box. So due to this seal failing it has damaged the box. Cant get gears. So Is it a case of getting a recon unit and giving this box in as the exchange unit or is it possible that a gear box specialist can replace only the damaged items to get this bus back on the road. Which parts have failed.
How much oil it has lost I'm not sure till I remove the box. So due to this seal failing it has damaged the box. Cant get gears. So Is it a case of getting a recon unit and giving this box in as the exchange unit or is it possible that a gear box specialist can replace only the damaged items to get this bus back on the road. Which parts have failed.
- Marc
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Re: clutch issue
It's a rare failure that makes all 5 gears quit working. Does the shifter feel normal, as though it's going into each position? (with the engine off you may find that it's reluctant to go into one or two of them unless you roll the car a little or have a helper rotate the input shaft - that's normal).
Pull on the input shaft; does it move? Some radial motion is normal, I mean endwise.
If the trans does need major surgery, the first question's going to be the condition of the ring & pinion - if they've been damaged from lack of lube it's not likely to be cost-effective to rebuild this trans.
Pull on the input shaft; does it move? Some radial motion is normal, I mean endwise.
If the trans does need major surgery, the first question's going to be the condition of the ring & pinion - if they've been damaged from lack of lube it's not likely to be cost-effective to rebuild this trans.
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Re: clutch issue
the input shaft does have a small amount of end play. looks like the spring ring in the input shaft oil seal has failed as the inner seal doesn't touch the input shafts surface. I can also turn the input shaft and 1 drive shaft flange turns with no resistance (grinding) when the input shaft is turned by hand
- Marc
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Re: clutch issue
Was this making noise when last on the road? The only endplay that should be discernible would be the tiny bit of slop in the threads of the coupling stud that holds the input shaft to the mainshaft, If there's more than that the mainshaft bearing at the nosecone end of the trans would be suspect - that characteristically makes noise most noticeable in 3rd & 4th. It can be replaced without tearing the whole trans apart using a special puller.
Sometimes the splined coupling slips off (it's only held in place by a small snapring) but the fact that turning the input shaft results in motion of the F.D. flange tells us that hasn't happened. It's normal for only one side to turn; if you hold that one, the other side should turn. Rotating one F.D. flange makes the other one turn in the opposite direction, that's the differential in action.
Buses have a relay lever setup for the shift linkage inside the nosecone that's prone to troubles - but a problem there would cause the shifter to act strangely...does it?
The input seal can be replaced without dismantling anything (removing it's the hardest part) or you can unbolt the bellhousing and do it on the bench - that'd let you inspect the condition of the ring & pinion gear teeth for the price of a gasket. There's a magnet on the drainplug, if it's caught any big chunks of steel the need for major surgery is indicated.
Sometimes the splined coupling slips off (it's only held in place by a small snapring) but the fact that turning the input shaft results in motion of the F.D. flange tells us that hasn't happened. It's normal for only one side to turn; if you hold that one, the other side should turn. Rotating one F.D. flange makes the other one turn in the opposite direction, that's the differential in action.
Buses have a relay lever setup for the shift linkage inside the nosecone that's prone to troubles - but a problem there would cause the shifter to act strangely...does it?
The input seal can be replaced without dismantling anything (removing it's the hardest part) or you can unbolt the bellhousing and do it on the bench - that'd let you inspect the condition of the ring & pinion gear teeth for the price of a gasket. There's a magnet on the drainplug, if it's caught any big chunks of steel the need for major surgery is indicated.
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- Posts: 620
- Joined: Fri Aug 26, 2011 10:01 am
Re: clutch issue
fixed. Not driven it yet but I'm confident its ok. Took the box to be checked. input shaft were the crank needle runs was worn, needle was worn too. I had the input shaft machined down and a sleeve fitted to the same inner i.d as a new needle bearing. New seals fitted etc.