Diff again

[Kevin Garrod]

Some of you may remember I ran my diff dry earlier this year which resulted in a nasty screeching noise from the back end.

I've had the diff out and replaced the bearing in the extension housing, fitted a new seal and quill shaft (courtesy of Stustag), put oil in it and I painted the casing too but it still makes the same noise.

So I've just received a good used diff via ebay and hopefully it will be OK, there's a lot less back lash than my one.

The thing is after I'dwon the auction I got talking to someone who has a pal who rebuilds Stag diffs using BMW parts... I must admit to being somewhat sceptical, can you really put BMW parts into a Stag diff case? I probably should talk to the guy first hand, as the price should be well undera Weslake diff except I won't need one now (if my ebay one holds up!)

If anyone else is interested I'll see if I can find out some more.

[V Mad]

imported post

I know quite a few that would love to hear about that!!

[singapore stag]

imported post

Hi Kevin,

I will be more then interested, I just don't trust the standard Stag diff, sooner or later yhey start to whine like a Banshee giving birth.

Please find out more regarding the BMW/ Stag diff mod.

Cheers Sukh.

[peter f]

imported post

Would be grateful if you could print some details.
cheers

[Kevin Garrod]

imported post

No news on the BMW diff, but I'll report back if I can find out some more.

In the meantime I've whipped the old diff out this evening (getting quite good at it now!) and removed the output shafts (I failed to notice when I was bidding that the 'new' diff came without them) It seems that the problem is with the bearing on the right, rough as a badgers arse!

Paddocks do exchange shafts for £35, is this the best option? No-one seems to sell just the bearing, but I could probably pick one up locally from Kent Bearings.

The dilemma now is, do I put my old diff back in on the basis that it was just this bearing causing the noise or try out the replacement?

[adieturner]

imported post

Kev,

Whip the rear cover off each and try to get a photo of the crownwheel teeth on the drive side. It may be possible to recommend which may be quieter having seen the two contact patterns.

Adie

[adieturner]

imported post

Oh and that bearing damage is water ingress in case you didn't realise it..........not sure how or where from (tank?, boot drain/hole? etc.)

[adieturner]

imported post

On second thoughts, it's been drowned......it can't have got in from a drip!

[Kevin Garrod]

imported post

adieturner wrote:

Kev,

Whip the rear cover off each and try to get a photo of the crownwheel teeth on the drive side. It may be possible to recommend which may be quieter having seen the two contact patterns.

Adie

Hi Adie,

Here's the original, I haven't got a pic of the 'new' one yet but it feels a lot taughter.

[sjm]

imported post

Kevin Garrod wrote:

Paddocks do exchange shafts for £35, is this the best option? No-one seems to sell just the bearing, but I could probably pick one up locally from Kent Bearings.

Hi Kevin,

I used this service from Paddocks two years ago, and I have had no problems with them, I had trouble trying to remove the old bearings and this seemed the best way to go.

Regards

Steve

[adieturner]

imported post

I'd say there's something wrong with that mate. The contact pattern is very light and too far towards the heel. It also looks like there's been some heat at the toe of the teeth that shouldn't have been there. That sounds contradictory I know but the heat could be on the overun. Is the Pinion tail bearing (nearest the flange) OK? I'd say at some point it's been run dry and with poor pinion bearing support.

[Kevin Garrod]

imported post

adieturner wrote:

I'd say there's something wrong with that mate. The contact pattern is very light and too far towards the heel. It also looks like there's been some heat at the toe of the teeth that shouldn't have been there. That sounds contradictory I know but the heat could be on the overun. Is the Pinion tail bearing (nearest the flange) OK? I'd say at some point it's been run dry and with poor pinion bearing support.

Run dry? yep! See top of thread!

[adieturner]

imported post

Dah!.....sorry mate didn't read that.........and now I think about it didn't I comment on this photo then too?

Try this for what it should look like:

http://books.google.co.uk/books?id=FXGBaLtPWHYC&pg=PA407&lpg=PA407&dq=crownwheel+contact+pattern&source=bl&ots=n91jMUuO4B&sig=0QSV30QBq4VTCJDzllUxy2DtD1k&hl=en&ei=CbYBS6lj1f3gBrHE1PAL&sa=X&oi=book_result&ct=result&resnum=2&ved=0CBIQ6AEwAQ#v=onepage&q=&f=false

[Westfaling]

imported post

Guys
Great information here. Given me confidence to pull my diff apart and take a look at it!
Thanks
Nick

[Kevin Garrod]

imported post

I visited Kent Bearings today and they will have the bearing for me in the morning.

Getting the shaft apart is a bit of a job! I was directed to an engineering firm called Qualiturn across the road from KB and the nice man there stuck it in his press and....no joy so tried another press that was so big they had to keep it outside! He went medievel on it and here it is in bits.



Here's a close up of my new diff and to my newly trained eye it looks a lot better.



Compared to the now obvious to me wear on the old one.






I clumsily managed to split the rubber gaiter on my nearly new Datsun driveshafts:X, so I've got that to sort out now too.