noisey diff

[delwin]

Have just got the car back on the road having recommissioned it. changed all fluids and pipework and brakes.

Diff oil looked poor and smelt bad when changed, suspect it was original as car has only covered 18K from new.

Prior to buying, when I originally drove it the diff wasn't particularly noisey.

Now I've put in clean new EP80/90 it is noisey. I currently reckon it's best to drive it for a while but want any experts thoughts.

Also does it have a crushable washer or how can I tell, and who would be able to supply me 1 as I want to change the pinion oil seal as it weeps

Car is 1098 4 door saloon all standard.

Appreciate help
Thanks
Dave

[bmcecosse]

Does the final drive have any significant backlash? The 'diff' only comes in to play when one wheel is turning faster than the other (corners/slippery surface etc) . Washer etc from all the usual suspects - at a price. You sure it has only done 18k miles? That would be exceptional for a minor these days - sure it's not 118k miles? The old oil may have been 'doctored' (sawdust/banana skins/STP) to keep the gears quiet..hence the smell you report. Check MOSS for the part you need http://www.moss-europe.co.uk/Shop/ViewP ... exID=17078

[philthehill]

Attached is the BMC wksp manual instruction extract for replacing the pinion oil seal.
You do not need the compressible spacer which if you did want to renew it would result in much more work than you may imagine. You do not need the special tool to hold the diff flange just use what you have.
If the diff is noisy you cannot make it any worse by just replacing the seal.
Whether it has the compression spacer or not so long as you do not tighten the pinion nut any higher than the specified amount you will be tightening to the same spec as original so you will not compress the spacer any more.
Job done
I drove my Minor for over 10k with a noisy diff which was so bad you could hardly hear yourself speak [frame][/frame]
Plenty of S/H 4.22-1 diffs out there if you need one.

[delwin]

Thanks to both of you for advice, and Yes definately 18K - i have all the records and the relevant MOT's - bit frustrating really as the rest of the car is great. I suspect that some corrosion has got into/on the pinion/pinion bearing due to lack of use.

I've got a workshop manual Phil so will re-read what it says, I reckon my impact gun would rattle that nut off as 140NM is pretty loose compared to modern car wheel nuts but not sure the shock would do any good to the rest of the axle! I will also check for pinion endfloat as a small nip of the nut may make all the difference.

Thanks Again
Dave

[philthehill]

The details above are from the BMC wksp manual.
You must use a torque wrench when re-fitting the pinion nut.
There should be NO end float as regards the pinion.
Taking up the nut a 'small nip' may make things worse.
Do not do it up any tighter than the specified torque.
Note;- NM is different from lb/ft (ft/lbs).
140NM = 103 ft/lbs so it will be loose.
140 ft/lb = 170NM.

[bmcecosse]

It's far from 'loose' compared to car wheel nuts! If you tighten wheel nuts to that level you will certainly strip/break something..... Truck wheel nuts are a different matter of course. I expect if you remove the prop shaft - you will find the nut loose... and as Phil says - just tightening it up a bit may make matters worse - but worth a try ! You could also add STP to the axle - never used it myself -but many on other forums 'swear by it' !

[katy]

Suggest you get a piece of flat or angle iron or daxion, 2 or 3 foot or longer, drill a couple of holes in it so you can bolt it to the pinion flange and brace it against the floor when loosening or tightening the pinion nut.
Personally I wouldn't use an impact gun to loosen (or tighten) that nut.

[philthehill]

The attached diagram of the Minor Bevel Pinion Flange Wrench. This is the type of tool you should aim for.
When I did the diff pinion seal on my Landrover I just used a flat piece of bar with just two holes drilled in it to accommodate the two flange bolts and it worked a treat.[frame][/frame]

I have to agree with Katy - keep that impact gun well away from the pinion nut. Use a socket and breaker bar to undo and a torque wrench and socket to tighten.

[delwin]

Thanks to you all, looks like I need to make me a tool!! Have now got the seal.

FYi most medium sized people carriers wheel bolts are IRO 140 to 170@NM Insignias are IRO 170NM and the dreaded transits are 200NM. Most modern (last 3 years) cars wheels bolts/nuts are IRO 120 to 140NM

So all are extremely tight compared to most parts on a minor!! But i will leave my impact gun in my van.

Thanks again
Dave