Page 1 of 1

#1 Diff noise

Posted: Fri Nov 02, 2012 4:23 am
by Downunda
I have a 1970 series 2+2 E Type.

Can anyone please let me know how much backlash (rotation free play), there should be on the pinion shaft when the back wheels are locked up?

When coasting there is a slight knocking noise coming from the back, I have checked the UJ?s and they look to be ok, I recently replaced the pinion seal.

Does it sound like I will need to overhaul the diff unit?
Ian

#2

Posted: Sat Nov 03, 2012 4:31 pm
by mgcjag
Hi Ian,,,,,When replacing the seal the position of the nut should be marked to the thread so that it can be retightened to exactly the same position as before it was removed. I know that this does not help you now but you may be able to tighten a bit......Steve

#3

Posted: Sat Nov 03, 2012 5:33 pm
by Downunda
Hi Steve, thanks for the reply, I realise I probably made a mistake with the seal but at the time I thought the best way was to retighten it as to the workshop manual.

Since then I now realise, as you rightly say I should have marked the nut first. I just wondered if the damage has been done, and if this could be the reason for the noise.

Thanks
Ian

#4

Posted: Sun Nov 04, 2012 2:31 pm
by mgcjag
Hi Ian.....The diffs are quite robust & agricultural & there are numerous out there that have not been rebuilt & have play in them I would eliminate everything else first unless the noise started straight after you replaced the seal in which case i would slightly tighten the nut to see if the noise goes......All the best Steve

#5

Posted: Mon Nov 05, 2012 12:36 am
by Downunda
Hi Steve, I am not sure if I the noise was there before I changed the seal, I had hardly driven the car before I changed it. Long story short, I had a number of other problems I was concentrating on and probably would not have noticed the noise prior to replacing the seal.

While I was checking the UJ?s, I again checked the pinion nut at 125lb.ft. torque setting. I also have recepts for 3 UJ?s to confirm they are ok.

If it is not the UJ?s then I am not sure if there is anything else apart from the diff. The noise only happens on no load and its frequency is relative to the speed.

If you have any suggestions of anything else I should check I would be keen to hear.

Many thanks
Ian

#6

Posted: Mon Nov 05, 2012 8:17 am
by JEP41
Just a thought on the noise. Many years ago my E-Type developed a noise from the rear and it turned out to be a simple fix. I had not tightened one of the wire wheel spinners tight enough. Has your car wire wheels and are they torqued to 220 ft/lbs?

#7

Posted: Mon Nov 05, 2012 10:19 am
by Downunda
Hi Steve, yes I have wire wheels, is there an adapter or something for the spinners, I just used a leather head hammer.

Ian

#8

Posted: Mon Nov 05, 2012 10:48 am
by SESH
I recently had a noise coming from the rear of my S3 OTS only whilst coasting along and not under acceleration, it turned out to be the rear brakes. Took them out cleaned them up and noise has gone. Mike.

#9 Diff Noise

Posted: Mon Nov 05, 2012 12:22 pm
by norman m. macleod
Hi Ian,
John's comment (JEP41....) re the rear wheels reminded me of an identical problem I had when I took delivery of my new 1969 FHC......a light knocking noise on the over-run (speed proportional....). Turned out the wheel spinners were not tightened sufficiently on the rear (both wheels...) despite a supposed Pre-Delivery Check by the agent (!!) Mmmmmmm........Worth a check.....
Regards,
Norman.

#10

Posted: Mon Nov 05, 2012 11:09 pm
by Downunda
Sorry about the mix up in the names :oops: but it looks like I still have a couple of things to check before I pull out the diff.

Cheers
Ian