Help - Strange clunking/clacking - I'm stumped

Yep, as Nachaluva has said, it's the centre bearing - and I agree. Mine had the same sort of noise but a louder thudding that what I can hear on the video.

Turned out I managed to snap the metal plate that holds the centre bearing in place so that the top hoop was doing its own thing - mainly under very heavy loads. On road there has not been an issue.

Cheers

Bennie
 
So after all this the centre bearing was fine.... I swapped the complete tailshaft for a second hand one and the problem did not go away. When I got the tailshaft I checked the 5 foresters at the wrecking yard and they all had the same large amount of play which was suggested by many of the SF owners previously.

There is no question that the centre bearing moving around is what is causing the noise but the movement is not caused by a faulty bearing mount but something else inducing radial vibrations into the system.

Today I changed my last guess component, the transmission X member and what do you know problem gone. On the trip that this problem got worse I did manage to put a big dent in the X member on a rock however this damage was AFTER the problem got worse and the impact with the rock did not make the problem noticeably worse so I thought that it must have been something else.

It looks to me like the X member has slowly been deforming upwards over time each time the car bottoms out and this last trip was just the straw that really broke the camels back. With the gearbox higher than it should be the tailshaft goes from almost perfectly straight through the centre bearing to kinked downwards in the middle slightly. I can only assume that this slight deviation from a straight line between gearbox and diff is prone to inducing a wobble at certain resonate frequencies...

Anyway seems all good now but definitely something for others to keep in mind if experiencing similar symptoms.

Picture time.

Damage X member on the car
15898432769_94252bd403_z.jpg


New and old side by side
15898374569_c8cd80e4f4_c.jpg
 
Well well, there ya go. Good discovery!
 
Glad you found the problem, DM.

It was the tail shaft/centre bearing making the noise, just caused by something else! Diagnosing these things can sometimes be pretty tricky.

A good thing to find that bent cross member. Who knows what long term damage it could have caused having the gearbox and drive train out of alignment like that. Potentially very ugly long term, IMO.

I'll bet you are pleased to be rid of the problem ... :poke: :biggrin:.
 
wow that's quite interesting. While it looks quite damaged, it doesn't look to have pushed the gearbox up really that much but maybe it's deceptive looking at them next to each other on the ground at that angle in the picture. Do you think it pushed the gearbox up a huge amount? Interesting to me because I've made a few custom crossmembers up by combining various bits of Forester/Liberty/L series crossmembers to fit EJ gearboxes into L series and not followed any particular formula as far as positioning the gearbox - just put the back of it it at a height that sortof looks right.
 
Yeah that is why I didn't pick up on it earlier, I would not have thought it made that much difference being a few cm out.
I stupidly didn't measure the before and after height but before I swapped it I did notice that the tail shaft had virtually no clearance on the bottom of the gearstick when in 1st,3rd or 5th. Now it has 1.5ish cm of clearance. I would estimate that translates to a similar amount of vertical movement at the trans mount location considering where everything can pivot.
I also used the rubber trans mount from the bent x-member as it is a more heavy duty one so that can't be blamed for the fix either. Can only be the position of the trans that fixed it, nothing else changed that I am aware of.
 
When I've been messing around with lift kits, first the 2" then 1" body lift, I had to keep changing the height of the centre bearing blocks. if its the wrong size, the tailshaft is put on an angle & creates a bad drumming type vibration. Took me a while to get it right
 
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