knocking noise from the rear
Discussion
I have a knocking noise coming from the rear of the 3000ml. It sounds like a cross between a noisey drive shaft UJ and the exhaust banging on the chassis, it's only there when you are accelerating you can hear it in any gear, it's not overly loud so once you get going it's hard to tel if it's still there. Setting of you can hear a knock knock knock, if you on a quiet road in say 4th if you put your foot on the loud pedal you can hear it but as soon as the foot is of the gas it's gone. So today I pulled the drive shafts and checked the UJ's even though they are all new also checked the prop and made sure the exhaust is not catching anywhere. All checked out OK with no issues. The diff which is the TR6 type is also fully recoditioned and seems to be OK I do have a bit of play if I hold the prop and one wheel I can turn the other maybe 3 or 4 minutes if think of the whhel as a clock but I would expect that is due to the internal spiders.
I have only done about a 100 miles in the car since its rebuild, I did have to swap the engine that was noisey but don't remember having this clunking knocking noise so maybe I've done something while swapping the engines?
Any ideas would be great of what to look at next .
I have only done about a 100 miles in the car since its rebuild, I did have to swap the engine that was noisey but don't remember having this clunking knocking noise so maybe I've done something while swapping the engines?
Any ideas would be great of what to look at next .
Well this one has got me baffled, checked everything was nice and tight. Checked all the UJ's checked the diff hanger made sure the brakes were all OK. Took it out for another spin and knock knock knock. So got the car back jacked it up removed the wheels lowered the car on to blocks under the rear hub carrier so the suspension was at normal ride height and Started her up. With the car in gear I got a mechanics stethoscope on the differential no noise I know that there was no load but if there was a problem I'm sure you would have heard something.checked the oil and all good listened at the hubs and the same all quiet. Checked the exhaust and nothing loose or close to catching. Not been out in the car since as it started raining but as I haven't actually found or repaired anything I'm guessing it will be the same.
No idea what to look at next.
Chris
No idea what to look at next.
Chris
TVRMs said:
Diff on its way out?
Diff is fully rebuilt and have checked it. It will end up being something daft. The main problem in finding it is it's hard to know if it's always there as its not very loud and the car is pretty noisy anyway. You can hear it best when your driving on a very smooth road. Take you foot of the gas and it disappears back on and there it is again it doesn't matter what gear your in and you can also hear it when setting off. I can't quite decide if it speeds up the faster you go as when you accelerate the noise of the engine drowns it out. Would just like to find it damn annoying more than anything. I thought it may have been coming from in the fuel tank area but have had it all out and nothing in there that can knock. I will try get it down to work over the next week or two and get it on a ramp and just check everything underneath.
Thanks for the suggestions
Chris
Cheers John yes did check it and couldn't see any cracks movement or problems with it. It is something of concern as I should have had strengthened while it was off. Schoolboy error on my part as they are a pain to get off once the body is back on. I could do with getting a spare really to have welded up and ready to put on so I can do it in one go.
Chris
Chris
Well it's coming from the rear, the only thing that I haven't removed and checked is the diff so I guess it's time to pull it out, a job that I really didn't want to have to do with the body back on hence having the diff rebuilt to try and stop this happening. Anyway a mate is coming over in the morning for a second opinion before I start the job. Well p@@@ed of at the moment. Won't be ready for BHP season opener.
Diff removal isn't a pain, it's a maze of tubes but it comes out nicely sideways. I had a nightmare with a badly rebuilt diff and had mine on and off 5 times and got it down to under 2 hours. The pain is the dive shaft flange bolts there's a lot of them and the flange has to be rotated right left and centre to get a spanner on them.
You'll be fine.
You'll be fine.
chris52 said:
Well it's coming from the rear, the only thing that I haven't removed and checked is the diff so I guess it's time to pull it out, a job that I really didn't want to have to do with the body back on hence having the diff rebuilt to try and stop this happening. Anyway a mate is coming over in the morning for a second opinion before I start the job. Well p@@@ed of at the moment. Won't be ready for BHP season opener.
Any progress?Diff is out and can't find anything wrong with it. Very smooth no damaged teeth no play. The carrier has no cracks But where the rear bush mounts was a bit misshaped and the bushes inner sleave can slot through the bolt hole. Had a chat with Adrian and he will be sending me a recon heavy duty carrier and new rear bushes. Fingers crossed this sorts it all out.
Thanks for all the help
Chris
Thanks for all the help
Chris
Edited by chris52 on Sunday 3rd April 20:36
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