Search found 801 matches

by ndevans
Fri Nov 01, 2019 10:34 pm
Forum: Mechanical
Topic: Differential overhaul
Replies: 198
Views: 7227

Re: Differential overhaul

Reading back through the posts, I understand now that a pinion with a crush spacer does not need shims. So in the next few days, I am going to tap out the pinion on my 4.22:1 diff, see what sort of spacer it has, and renew it if it's a crush spacer, or adjust the shims if it's a solid spacer. Hopefu...
by ndevans
Fri Nov 01, 2019 4:26 pm
Forum: Mechanical
Topic: Differential overhaul
Replies: 198
Views: 7227

Re: Differential overhaul

It's annoying that the BMC manual only covers the solid spacer type. Well mine does, anyway.
by ndevans
Fri Nov 01, 2019 4:16 pm
Forum: Mechanical
Topic: Differential overhaul
Replies: 198
Views: 7227

Re: Differential overhaul

Ok thanks. So, the question is, am I missing a shim, or do crush spacers not need shims?
by ndevans
Fri Nov 01, 2019 3:19 pm
Forum: Mechanical
Topic: Differential overhaul
Replies: 198
Views: 7227

Re: Differential overhaul

Where was it fitted? Did you have a solid spacer?
by ndevans
Thu Oct 31, 2019 10:57 pm
Forum: Mechanical
Topic: Differential overhaul
Replies: 198
Views: 7227

Re: Differential overhaul

Right, I see now. Confusingly, my hardcopy of the manual shows the shim between spacer and outer bearing as item 27, but my electronic copy shows it as item 29! Back to the spacers. I am a little unsure now. What I thought was a 21mm spacer and a shim between the crush washer and the pinion head, no...
by ndevans
Thu Oct 31, 2019 4:00 pm
Forum: Mechanical
Topic: Differential overhaul
Replies: 198
Views: 7227

Re: Differential overhaul

Interestingly, the diagram in the the BMC manual, section HH, page 2, suggests that there is no shim between the solid spacer and the inner bearing, only a thrust washer between the inner bearing and the pinion head. Which is right?

Cheers N
by ndevans
Thu Oct 31, 2019 12:29 pm
Forum: Mechanical
Topic: Differential overhaul
Replies: 198
Views: 7227

Re: Differential overhaul

The BMC manual does talk about using a washer of "known thickness" when reassembling. You then use the dial indicator reading & the markings on the pinion head to increase or decrease the washer thickness, in order to set the pinion height correctly.
by ndevans
Thu Oct 31, 2019 10:09 am
Forum: Mechanical
Topic: Differential overhaul
Replies: 198
Views: 7227

Re: Differential overhaul

PoolGuy wrote:
Thu Oct 31, 2019 9:47 am
Edit. Mr Evans may have solved it.
That'll be a first!

I haven't actually had them apart yet, but it looks like there may be a shim under the solid spacer. Will report later today.

cheers N
by ndevans
Thu Oct 31, 2019 9:42 am
Forum: Mechanical
Topic: Differential overhaul
Replies: 198
Views: 7227

Re: Differential overhaul

There is. Think this photo may explain. IMG_20191031_090317~2.jpg This is the pinion from my 3.9:1 diff. Between the crush spacer and the pinion inner bearing is another spacer. The crush spacer has been crushed to approx.19mm, and the two combined measure just under 41mm. The solid spacer is marked...
by ndevans
Thu Oct 31, 2019 8:34 am
Forum: Mechanical
Topic: Differential overhaul
Replies: 198
Views: 7227

Re: Differential overhaul

Wow. That's no small difference.
by ndevans
Wed Oct 30, 2019 4:56 pm
Forum: Mechanical
Topic: Differential overhaul
Replies: 198
Views: 7227

Re: Differential overhaul

Ok thanks Phil. I'm prepared to buy another oil seal if necessary, I'd just like to avoid it.

So does the inner race just tap out?

And, if I have a crush spacer fitted, is it ok to fit a solid spacer and shims instead? I have a new crush spacer, just out of interest would like to know.

Cheers N
by ndevans
Wed Oct 30, 2019 1:59 pm
Forum: Mechanical
Topic: Differential overhaul
Replies: 198
Views: 7227

Re: Differential overhaul

If/when I get that far, I'll let you know!
by ndevans
Wed Oct 30, 2019 10:49 am
Forum: Mechanical
Topic: Differential overhaul
Replies: 198
Views: 7227

Re: Differential overhaul

Ok, thanks Phil & Declan. Since it looks like I am committed now to getting the pinion bearing off, I guess I might as well replace it. Do I need a bearing puller to remove the outer bearing inner race? Also, will I be able to remove the new oil seal that I fitted a couple of weeks ago, without dama...
by ndevans
Wed Oct 30, 2019 7:10 am
Forum: Mechanical
Topic: Differential overhaul
Replies: 198
Views: 7227

Re: Differential overhaul

Last night I managed to get the flange nut up to 140ftlb. The bench held firm, which is pleasing, but the pinion bearing pre-load is still not significantly higher-it's around 1/4 of what it should be. I've tried two different torque wrenches, so I'm fairly sure it's not a wrench calibration issue. ...
by ndevans
Mon Oct 28, 2019 12:26 am
Forum: Mechanical
Topic: Differential overhaul
Replies: 198
Views: 7227

Re: Differential overhaul

And here is the new, improved, extra brilliant white work surface and vice setup. Not much to see actually, but underneath I have reinforced the surface with 50x50mm timber, screwed to the wall in about 15 places. It's much stronger and more rigid now, and barely moves even with 120ftlb on the torqu...
by ndevans
Fri Oct 25, 2019 7:32 pm
Forum: Mechanical
Topic: Differential overhaul
Replies: 198
Views: 7227

Re: Differential overhaul

Quick question, I received two new cage planet wheel shaft pegs today. The BMC manual says they should be tapped home, then the hole peened over with a punch. How do I do this? And is it ok to use a bit of threadlock or bearing lock on the peg, will that hold it in place just as well as peening? che...
by ndevans
Tue Oct 22, 2019 12:22 am
Forum: Mechanical
Topic: Differential overhaul
Replies: 198
Views: 7227

Re: Differential overhaul

Thanks for the replies and informative link. Nothing to report for now, nor will there be for a few days at least, I have to reinforce the workshop table. The vic,e is going to rip through the work surface if I apply much more torque to the flange nut. I've got to 132ft-lb, and daren't go any furthe...
by ndevans
Fri Oct 18, 2019 7:44 am
Forum: Mechanical
Topic: Differential overhaul
Replies: 198
Views: 7227

Re: Differential overhaul

I've got a length of light aluminium angle with two holes drilled for the flange bolts. I then balance weights on at 12" until it just starts to move. So far it's got to just under 100g, which is about 1/4lb. Taking into account the weight of the angle itself, 260g/m, or about 130g for the 50cm leng...
by ndevans
Fri Oct 18, 2019 12:25 am
Forum: Mechanical
Topic: Differential overhaul
Replies: 198
Views: 7227

Re: Differential overhaul

Got it up to 132lbft this evening, no real change in pinion preload torque though.
I'm going to have to strengthen the bench that the vice sits on before I go any further. Either the vice is going to rip through the wood, or it'll pull the bench off the floor and away from the wall.

Cheers N
by ndevans
Thu Oct 17, 2019 11:16 am
Forum: Mechanical
Topic: Differential overhaul
Replies: 198
Views: 7227

Re: Differential overhaul

Thanks Dec. My bearings will be fairly dry, it's been cleaned with gunk.
My vice is ok-it's the table that's the weak point!

Cheers N