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1971 E Drive shaft knocking

Hi. Fully restored 1971 E is back on the road but I now have a very loud knocking coming from one side CV joint. It comes on quietly but soon gets louder, takes about 20 minutes before it starts and sometimes dissapears whist driving. I have now removed and fully inspected all components and they all look in good condition with only little scoring to carriers etc. I'm thinking of reassembleing and making sure that all joints are clocked and shafts to joints are square. It is possible that this wasn't done first time around but could this be the cause of a very loud knock from the rear end, possibly replace both shafts with new ones but I'm unsure of what is considered worn on CVs
Old 09-05-2017, 08:29 AM
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not sure what you mean by clocked and square but it does not matter. (unless there is a big angle from the shaft to CV, then a bad CV will make noise)

the CV's are pretty robust and aren't likely to make a lot of noise, not like a front wheel drive car.
when the car is sitting, if the shafts to CV is pretty straight, IE not much of an angle on the CV;'s then there is even less chance for noise which should be the case.

if the shafts are still off, move the CV's around, if they are smooth and not binding then they are not the noise.

could be a wheel bearing but WB's usually sound more like a dry kind of grinding sound.
with the CV's off you have a great opp to spin the wheel and listen, remove pads if you need to.
also wiggle the hub and see if it moves. if it is a heat issue you may not hear anything

when it is making the noise try pushing in the clutch and coasting.
put it in neutral and let the clutch out and coast.
see if the noise is speed related. does it change with speed.
see if it is engine RPM related
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86 930 42kmiles [__] RUNNING:[__] NOT RUNNING: ____77 911S widebody: SOLD
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Old 09-05-2017, 10:19 AM
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Foot on the clutch knocking is still there, coast downhill with foot on the clutch knocking gets quicker, rev engine with can stationary no knocking, had car up at the back and checked all wheels for issues and can't find a thing. It sounds exactly like someone is hitting the gearbox with a hammer. Gearbox input shaft bearings are all new and gearbox is good. Definitely speed related. Not clutch related.
Old 09-05-2017, 10:57 AM
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One thing to check: Length of each CV bolt. If too long, could interfere with parts on the other side (suspension hub/gearbox).

You could also swap drive axles side-to-side to help isolate the noise source.

Nothing out of kilter in the emergency brake drum?

Lift car onto stands, block front wheels and run car in gear. If open differential (non LSD), only one rear wheel may rotate. In that case, block that wheel to direct torque to the other side. Be careful.

If noise is apparent, try to locate noise source with a mechanic's stethoscope.

Sherwood
Old 09-05-2017, 11:26 AM
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yes, I did that with my 930.
run it on stands.

someone has been in the gearbox?
that was my next suggestion. gearbox.
__________________
86 930 42kmiles [__] RUNNING:[__] NOT RUNNING: ____77 911S widebody: SOLD
88 BMW 325is 200K+ [__] RUNNING: [__] NOT RUNNING:
05 BMW 330CI 130K:: [__] RUNNING: [__] NOT RUNNING:
08 VOLVO V70 190K:: [__] RUNNING: [__] NOT RUNNING:
90 B2200[] RUNNING:[_] NOT RUNNING:__2000 MER E320 WAGON [_] WRECKED:[]RUNNING:
Old 09-05-2017, 11:36 AM
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That's worth a go. Thanks guys.
Old 09-05-2017, 12:26 PM
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