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Discussion Starter #1
Last week I first noticed a strange rumbling sound/vibration when coming off throttle and slowing down. It seems most pronounced in the lower gears (3rd and 2nd) between something like 2000 and 2500 RPM. If I dip the clutch the sound/vibration doesn't seem to occur.
Does anyone have an idea what this could possibly be?
 

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Discussion Starter #3
The center bearing has already been replaced 40k. kilometers ago so I believe this is fine. Put the car on the lift and noticed excessive play in the cv joint so I expect this to be the issue. It seems to be getting worse (it's daily driver doing 115 km a day) so I hope my spare shaft gets back from balancing soon so I can exchange it and hopefully cure my issue.
 

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Discussion Starter #4
Replaced the prop shaft today for my spare one which just has been rebalanced all joints are fine. The rumbling still isn't cured so it must be something else, symptons are the same. I've noticed it doesn't occur after a spirited drive. Any suggestions what might be the issue?
 

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Yes, you'll need the wheels of the ground and if it is the half shaft you'll want to have an idea of what side.

Whilst rocking the wheel put your hand on the shaft, you should be able to feel it. At our cars age/mileage they'll have play but you want to feel where it's gone a bit beyond that.
 

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Discussion Starter #10 (Edited)
Whilst driving home from work today I noticed severe vibrating at 65 km/h, didn't detect it yesterday because I didn't test at that speed. This is the exact same symptom as when I purchased the car (2 years ago). Swapping the shaft with a secondhand one on which I replaced the center bearing, cured this issue, although it had some very slight play in the CV joint.

The problematic shaft that came of the car looked recently rebuild and all joints were free of slack so I kept it as a spare and would have the balancing checked when the occasion should arrise I would need it again. So I had it rebalanced the guy over there reported very minor inbalance.

Fitted It and the vibration at 65 km/h is back :(

Decided to swap the shafts again, when I removed the exhaust and heat shield I noticed that the shafts curved at a strange angle after the u-joint. Hmmm

Decided the remove the CV-joint from the problematic shaft and fit it to the one which didn't cause the 65 km/h vibration. This left me with a example with all joints good.

Fitted it and inspected it, no strange angle after the u-joint, refitted the exhaust and shield and went for a test drive. No more 65 km/h vibration and the rumbling at 2100 RPM whilst deccelaration seems gones as well.

So it seems the u-joint hasn't been rebuild correct on one shaft, and the cv-joint might have been the cause for the 2100 RPM rumble on the other. Will report back after some more driving if this really was the cause.

Also inspected both drive shaft and they seem in pretty good nick, no excessive amounts of slack.
 

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Discussion Starter #11
After driving a bit more it seems like it's solely rpm related just a tad above 2000 rpm it occurs, it doesn't matter which gear. Did notice that the casing around the cats was loose maybe this could cause the noise?
 
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