Diff noise

[adam quantrill]

Seems like the SX noise is the diff - it's related to road speed rather than engine speed.

Apart from checking and topping up the oil - is there anything else that can be done in situ?

How long before it goes bang - or do they just go on forever quite noisy???

- Adam

[adam quantrill]

An update - checked the oil level - it seems plenty in there, and it's clean.

There is a little oil visible on the outside of the diff - I wonder if it's starting to leak?

Also - it seems to get worse after it's warmed up. Of course, it might be a bearing instead, but I've never heard one make this sort of noise.

[rev-erend]

Adam - YHM.

[leorest]

adam quantrill said:

There is a little oil visible on the outside of the diff - I wonder if it's starting to leak?

IIRC the Bible says something about the length of the breather pipe thingy. Oil vapour can flow out and condense giving the appearence of a leak. The fix is to lengthen it. But it could be leaking
L

[adam quantrill]

Yes - good point, I'll check the breather. THere is certainly plenty of oil in.

So - if it's the diff on the way out, my options are:

a) drive it anyway and live with the noise until it goes

or

b) have it reconned now

Would it be significantly more expensive to have it reconned after it has expired?

One more thought - given that the noise seems to appear/get worse after it has warmed up, I reckon there might be some crud settled in the bottom that has been stirred up. After all this car has been sitting around doing hardly any mileage for 15 years.

So I'm going to let out some oil from the bottom and see what emerges....

[rev-erend]

Just do it before it breaks..

Don't want to skid off into a ditch..

[adam quantrill]

Well there was loads of crud in the oil at the bottom, so I let it all out, and have put fresh back in.

A quick test drive and the noise is still there, but then again that may not be surprising. What has probably happened is that the crud had settled nicely to the bottom, and then been stirred up by my vigorous antics. It has now caused the gearing or LSD components to be scored, resulting in the noise.

I'm fairly confident that the diff will survive now, so I intend to give it a few hundred miles and re-check the oil.

The only other possibility is that the noise is coming from the gearbox final drive, as its pitch is proportional to the road speed, but then again I have a spare box, and as Steve Heath says, they are consumables. It won't be the first time I've broken a gearbox!!!

Thanks Rev for the suggestions, I think I'm going to rig up a magnetic microphone so I can test drive and pinpoint the noise more easily.

- Adam

[gsx600]

Adam

There is a guy on ebay selling jag diffs at the moment, has a whole load of them different ratios, and lsd as well, for not that bad a price.

Might be worth an investment as a spare just in case ?

[The colonel]

Adam - at the last MOT how did your rear wheel brakes get tested? I told my MOT tester the wedge had non-switchable LSD and he set the rollers to run in unison

(he is a good guy - had a chuckle when I mentioned Taply Meter)

[adam quantrill]

Ahhh - we did it the old way. Bloke in passenger seat with device on the floor, me driving and slamming on the anchors. He asked about the LSD and insisted we did it that way.

[The colonel]

adam quantrill said:

Ahhh - we did it the old way. Bloke in passenger seat with device on the floor, me driving and slamming on the anchors. He asked about the LSD and insisted we did it that way.

Thats alright then.

Unfortunate for the diff to go at that mileage, maybe one of the bearings each side of the diff at driveshafts dried up through lack of use, or other bearing eleswhere in drive train.

Good luck with that and I look forward to seeing your Wedge at BBWF

[jasper gilder]

I had to have the driveshaft oil seals on my diff done at about 40,000 miles, but no trouble since - it could just be lack of use - my SX has done 79,000 miles....

[andy390]

Guys, since having my roll bar fitted, I can now hear the diff bearings whirring. which has promped me to think about getting it rebuilt... Any suggestions as to who to get to do it??i had heard that GKN can do it?
thanks

[paul gotts]

andy390 said:

Guys, since having my roll bar fitted, I can now hear the diff bearings whirring. which has promped me to think about getting it rebuilt... Any suggestions as to who to get to do it??i had heard that GKN can do it? thanks

I think CTS do diffs. (as well as gearboxes) and have a good reputation, so are usually well backed up with work - I assume you'll be taking the diff out yourself?
I used an outfit in Surrey last year for my diff rebuild - it's the place that Austec would take it to if you wanted them to do the job. Will look for the invoice later and post their name.

Paul.

[paul gotts]

Now found the bill for my diff. rebuild last year. It was done by Hardy Engineering, Leatherhead 01372 378927. Cost was £455 including all seals, bearings and a couple of other broken/worn parts. They didn't change the friction plates - were ok. This was me supplying the removed diff. to them. Comes with 12k mile / 12 month gtee.

Paul.