Board logo

knocking in the running gear - but where?
Steve Lovelock - 14/4/12 at 05:21 AM

I am running a type-9 and Sierra XR4x4 LSD and drive shafts and am experiencing a few knocking noises. Essentially when I pull away and often if I roll off the power then back on again I get a knocking noise coming from the drive train and I don't know where. It sounds like something is loose but I know that it is isn't.

Any ideas?

jollygreengiant - 14/4/12 at 07:22 AM

Rear drive shaft CV joint(s).????????



Best description I can come up with of this noise would be, two heavy hammers being banged together (head to head) repeatedly and very, very quickly.
HTH

Another possibility (IF bolt on drive shafts) is that of the outer CV to drive stub bolt heads making contact with the upper wishbones where the adjuster tube is for the upper adjuster.

[Edited on 14/4/12 by jollygreengiant]

mookaloid - 14/4/12 at 07:53 AM

diff mounting bolts?

franky - 14/4/12 at 08:37 AM

quote:
Originally posted by mookaloid
diff mounting bolts?


This. Seems like a torque reaction so something around the diff.

Chippy - 14/4/12 at 10:09 AM

I had similar, and it turned out to be the UJ's on the drive shafts. Although they didn't appear to be worn, when i changed them the knocking had gone. HTH Ray

britishtrident - 14/4/12 at 10:42 AM

First port of call is to check the propshaft UJ flange bolts are tight, they tend to slacken off.

rusty nuts - 14/4/12 at 02:19 PM

If you haven't managed to fix it before we can have a look at Stoneleigh Steve.

Steve Lovelock - 14/4/12 at 09:00 PM

Thanks for the tips, I had a new drive shaft made when I built the car and as I have only done 5,000 miles I'd be disappointed if it was the uj joints. How would I check that? I'll certainly look at the bolts on the diff though. The car was out for its annual MOT which it passed so I'll definitely be at Stoneleigh now.