squiffy Posted January 21, 2019 Share Posted January 21, 2019 I have a knocking noise when coming on and off throttle when in gear. (Diff and gearbox mounts have been changed, clutch and flywheel has been changed from solid to a dual mass) And a new noise when I'm accelerating at full throttle from the back end. I thought it may have been the exhaust rubbing against something but it isn't. It's a constant fast knocking. I had the car on the ramp and there seems to be a lot of play in the diff. Ive shown it best I can in the video with the car on a drive on ramp in neutral. I have had the output shaft seals and bearings changed (due to oil leak) and i found paperwork to say the front diff seal has been changed. (But no crush washer receipt) Could someone of not set the backlash / preload correctly? Any info / advice would be appreciated. I don't want to drive it to destruction Car is a 93 j spec TT6 so is a B03B Quote Link to comment Share on other sites More sharing options...
Ric Posted January 21, 2019 Share Posted January 21, 2019 The rubber donut which joins the propshaft is known to fail and causes these types of problems on/off throttle creating a thunk. Quote Link to comment Share on other sites More sharing options...
Jellybean Posted January 21, 2019 Share Posted January 21, 2019 Most likely used the Crush waster again I had knocking noise when coming on and off throttle , it was the center Bearing assembly on the propshaft Part Number 37230-24090 I would take the prop-off and check the Bearing assembly , give it a once over ; check your Diff oil for metal filings , I cannot comment if it is excessive play in your diff Quote Link to comment Share on other sites More sharing options...
squiffy Posted January 22, 2019 Author Share Posted January 22, 2019 Cheers guys, We've had the prop off and the doughnut looks in good shape. The centre bearing has been looked at in the past and also looked to be in good shape Quote Link to comment Share on other sites More sharing options...
Scooter Posted January 22, 2019 Share Posted January 22, 2019 I not 100% sure why but I don't like/remember the movement outward (seemingly) of the flanges when you rotate the driveshafts 14-15 22-23 seconds. I have been under the car and rotated the prop and had the slack on rotation you have with zero running issues/noises. Quote Link to comment Share on other sites More sharing options...
squiffy Posted January 22, 2019 Author Share Posted January 22, 2019 Yeah that didn't look right to me either! Quote Link to comment Share on other sites More sharing options...
rider Posted January 22, 2019 Share Posted January 22, 2019 You maybe need to check out your rear diff to subframe two mounting bushes. If the go spongy then it can cause transmission hop. If you can, rig a camera underneath and drive then you'd be able to see if there is a lot of flex in the bushes power on to power off. I replaced all my rear end for new just over a year ago and the only components that looked like they could really benefit from the change were the diff frame bushes that had gone really soft, much softer than the new OE ones. Keep you fingers crossed it isn't the diff mounts as getting the old bushes out and new bushes in isn't easy with the frame mounted on the car and isn't particularly easy with the frame off either. Quote Link to comment Share on other sites More sharing options...
squiffy Posted January 22, 2019 Author Share Posted January 22, 2019 You maybe need to check out your rear diff to subframe two mounting bushes. If the go spongy then it can cause transmission hop. If you can, rig a camera underneath and drive then you'd be able to see if there is a lot of flex in the bushes power on to power off. I replaced all my rear end for new just over a year ago and the only components that looked like they could really benefit from the change were the diff frame bushes that had gone really soft, much softer than the new OE ones. Keep you fingers crossed it isn't the diff mounts as getting the old bushes out and new bushes in isn't easy with the frame mounted on the car and isn't particularly easy with the frame off either. thanks Rider, this was my first go to. I have changed the front and rear diff bushes within the last year to stongflex ones and it still makes the noise Quote Link to comment Share on other sites More sharing options...
Hissig Posted January 23, 2019 Share Posted January 23, 2019 im going thru exactly the same thing now. taking the diff out to get it inspected and probably shimmed. The problem seems like there is too much play in the diff? ring pinion? Quote Link to comment Share on other sites More sharing options...
squiffy Posted January 23, 2019 Author Share Posted January 23, 2019 im going thru exactly the same thing now. taking the diff out to get it inspected and probably shimmed. The problem seems like there is too much play in the diff? ring pinion? yes i agree, can you let me know if you find anything? thanks I think i'll keep an eye out for a 2nd hand diff to see if the problem is still there, then probably get mine looked at Quote Link to comment Share on other sites More sharing options...
Hissig Posted January 23, 2019 Share Posted January 23, 2019 Sure. will do! hopefully the diff will be on its way to an expert next week Quote Link to comment Share on other sites More sharing options...
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