04 CV8 - Knocking noises from the Back Axle / Diff

[ozonejunky]

Has anyone ever heard, and felt, a knocking noise from the rear diff / axle when setting off from a standstill, and when the oil is really hot ? But then it goes as soon as you get over 10 mph ?

This has happened to me twice in the last 14 months. I had to drive from Manchester to Reading yesterday, so a long stint on the motorway - oils all nice and warm. When I left the M40 at Junc 4 I got stuck in a horrendous traffic jam for about 50 minutes on the roundabout. As I edged forward over the 50 minutes the car began to make a knocking noise, and shuddered. Hard to say for sure, but it seemed to be OK if I steered straight, but any lock whatsoever would induce the noise. Finally I cleared the roundabout and hoofed it off down the A404. No problem. And it didn't re occur again. Same circumstances as the first time it happened last year, i.e. long motorway drive + extreme traffic jam = knocking noise. My father in law had a similar issue on a Chimera a while ago, never caused any problem and he put it down to the limited slip diff.

Any idea's anyone ?

Edited by ozonejunky on Wednesday 14th March 12:54

[monkfish1]

You need an oil change! Decent oil with friction modifier (in the correct quantity) will resolve this.

[Checkitoot]

also m40 jct 4 for reading? Are you into pain?!? Come off at J7 through Little Milton pop over the fantastic A329 road to Benson down the main stretch to reading via Dorchester (A4074)

Or J6 and go via Walington - oooh or go via j7 then postcombe to j5 on the A40

much nicer and less congested

[ozonejunky]

Checkitoot said:

also m40 jct 4 for reading? Are you into pain?!? Come off at J7 through Little Milton pop over the fantastic A329 road to Benson down the main stretch to reading via Dorchester (A4074)

Or J6 and go via Walington - oooh or go via j7 then postcombe to j5 on the A40

much nicer and less congested

Absolutely !! Might try the A329. Went back on the B481 - Nettlebed, Watlington. Scenic, traffic free, but lot of 30 limits. Thanks for the tip.

Monkfish1 said:

You need an oil change! Decent oil with friction modifier (in the correct quantity) will resolve this.

Roger, I'm going to do this trip a few times in the next couple of months. Which means I'm driving right past your door (ish). How long to change the oil ? Can it be done reasonably swiftly if I'm there early enough ?

[monkfish1]

Can be done within the hour, no problem. Just let me know when.

[ozonejunky]

OK, will do. Thanks Roger.

[Checkitoot]

ozonejunky said:

Checkitoot said:

also m40 jct 4 for reading? Are you into pain?!? Come off at J7 through Little Milton pop over the fantastic A329 road to Benson down the main stretch to reading via Dorchester (A4074)

Or J6 and go via Walington - oooh or go via j7 then postcombe to j5 on the A40

much nicer and less congested

Absolutely !! Might try the A329. Went back on the B481 - Nettlebed, Watlington. Scenic, traffic free, but lot of 30 limits. Thanks for the tip.

Monkfish1 said:

You need an oil change! Decent oil with friction modifier (in the correct quantity) will resolve this.

word of warning on a329 (not driven it in 4 years)

half way through there is a blind and I mean BLIND hair pin

very fast entry is misleading in both directions



Roger, I'm going to do this trip a few times in the next couple of months. Which means I'm driving right past your door (ish). How long to change the oil ? Can it be done reasonably swiftly if I'm there early enough ?

[ozonejunky]

Thanks. I'd hate to spill any of that new oil that Roger's putting in

[mackie1]

Actually on this subject I had it locking up backing out of a parking space at the weekend. It's only done it once or twice since I had the change done but do you think I could do with bobbing the rest of the modifier in to quell this? I guess it's a combination of the warmer weather and having been on a longish drive before parking up.

[ozonejunky]

mackie1 said:

Actually on this subject I had it locking up backing out of a parking space at the weekend. It's only done it once or twice since I had the change done but do you think I could do with bobbing the rest of the modifier in to quell this? I guess it's a combination of the warmer weather and having been on a longish drive before parking up.

That sounds scary. What change have you had (whole diff or just the oil & modifier) and how did you manage to get out of the parking space in the end ?

[mackie1]

Just the lube to with redline stuff. It was just felt as resistance to turning, you can still do it but it makes noises while doing so. I suspect it does just need a tad more friction modifier adding.

[ozonejunky]

Ah - OK. Met a chap the other day with a Cerbera that had locked it's diff and sent him through a hedge. But I think your issue is very similar to mine - still works but noisey.

[Boyce]

Yeah mine made a similar noise in exactly the same circumstances as you described. Had the level check and it was fine, also I have given the diff a thorough work out since and its been fine.

I was tempted to change the fluid anyway, but am concerned this may cause more problems. Think I'll wait a while and see if it re-occurs, so far only once in about six months.

[darren_r1]

adding friction modifier cured mine.

[ozonejunky]

Thanks Darren. I think that should alleviate any fears that Boyce has and certainly encourages me to go and see Roger, pronto.

BTW - nice photographs on your profile Looking forward to the one of your 'Ro !