Series 3 Rear drive train - diff, prop etc

Evening all

Upon investigating a leaking diff pinion seal, I have found a few other problems that may well be addressed while at it.

1. Prop shaft UJ's knackered. After getting some prices, it seems a case of replacing the propshaft as the slide is worn as well as both UJs. Any advice one who makes fair quality ones?

2. Diff pinion backlash. There is about a 16th of a turn backlash in the diff pinion. There is no fore/ aft play as such. Having not had a proper look in the manual yet, I don't know how to set, or how much backlash there should be. I'm thinking it might be easier to buy a new or recon diff and simply swap it out. Any ideas who can supply a good condition replacement diff? Standard Rover diff, not a salisbury.

This has made me think about not bothering to replace the seal and just starting to collect parts to overhaul the entire rear axle but that seems a bit drastic. The other option is to replace the seal, oil and propshaft then just drive the S3 and see what happens.

New to all this so any advice appreciated.

Cheers
Ben

The play might not be in the diff could be worn halfshaft or drive flange 1/16 of a turn is acceptable in my opinion. If the oil leak is large worth renewing the oil seal whilst you have the propshaft offbeware the seal ruuning surface on drive pinion might be worn you can fit a speedi sleeve or buy a new flange.

http://baileymorris.co.uk/ are often talked of as being good at strong propshafts, and having had a chat with them, they're making some custom length ones for me.

1/16 of a turn play certainly indicates some play, but I've driven a few that are about 1/8th of a turn, and they don't feel that bad. I'd sort your propshafts out first, then go for a drive and see what you think. Don't forget that you've got two gearboxes worth of backlashes to factor in - 'tight' drivetrains and Landies aren't ever going to bedfellows for very long.

But you sound like a capable chap, re-building a standard diff isn't a big deal if you do it with the good book and measure carefully. If you'd rather leave it to a pro, then our own @jamesmartin has done more diffs than he'd probably care to admit.

Cheers Blackburn. I'm beginning to think I'm reading too much into the diff. No noise on driving and no nasty graunching. I have a new flange and seal so will bung them in along with a new prop and see what happens.

Cheers Boguing for the propshaft heads up. I'll give em a bell tomorrow. Currently going on what Keith Gott have on the shelf, an Allmakes one for £67......seems a bit cheap if you ask me....

btiratsoo said:

......seems a bit cheap if you ask me....

Click to expand...

Yep, I said that you sounded sensible.

Well after driving all the way to the parts dept that was selling the propshaft only to find out it was a Britpart part after they had assured me it wasn’t, I decided to overhaul my prop. New set of UJs and a battle to get the thing out after all the seized nuts and bolts.

Assembled new bits into prop without too much drama. Not as much play in splines as I thought. Happy days.

Time to do the diff seal. Diff pinion castle nut loose....ok, what other horrors? Aaah, ok the seal had worn a groove in the flange. Tidy. New flange, new seal, tighten nut to correct torque. Hylomar on outside of seal, ep80/90 on running surface of flange to lubricate. Tighten up. Top up diff till it just runs out. Check breather is clear. Happy days. Put prop in. Run up on axle stands. No leaks. Yippee.

Decide to go for a drive...........after 5 minutes stop to buy cider as a celebratory/ medicinal reason and check for leaks. Oil everywhere. Bugger. Back to the drawing board. Consume cider.

Any ideas? Seal knocked in square and to the right depth. Pinion was a bit loose I have to admit.....bearing came out with the old flange.....but was by no means knackered.

Cheers
Ben

Spray it all with brake cleaner or jet wash it exactly where its comming out before you wade in. If its the oil seal then I can only think it got a nick, its in the wrong way or the shaft is moving and knocking the seal away from the flange. Is it possible the flange didn't pull right in then moved once you drove it? (Seems unlikely I know)

Nice one Rob. I’m going to calm down now and have a look with a fresh head tomorrow. The flange may well have moved so will check the measurements I took before disassembly.

The red mist had descended.....

If the bearing came out was the washer/ spacer item 539745 in place. Who's make was the oil seal and new flange. Post some pics when you pull it back off. There is a line of thought that filling it to top is not necesary just check it more often.

Spacer went back in as per the drawing. In hindsight, either the flange is too far in and the seal is running on the ridge rather than the running surface or the seal isn’t quite seated.

I like the train of thought about over filling diffs. It’s just splash lubrication so no need to have loads I suppose. Calm head later in the week and some photos.

I’m assuming that 539707 is a taper roller bearing?

it is

Cheers James. That means that at least it’s the right bearing in there. I’m assuming as the flange tightens on the shaft, it preloads the bearing with the spacer and the shims? No for an aft movement so bearing must be ok.

The castle nut was loose when I started the job.

No split pin in the castle nut?

boguing said:

No split pin in the castle nut?

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Oh yeah. Just not torqued up. Finger tight - probably 1 or 1.5 threads out! I’m thinking now I may not have put the new seal in deep enough. I put the main body of the seal flush with the diff housing. I’ve now read it should be recessed a bit and the lip sea should be level with the housing.

Was it cleanish or grubby and full of grass etc?

Just thinking that the play might be a sign of failing pinion bearings, not a lack of torquing. (It would be very odd to not tighten and then put the split pin back).

Can't help thinking that you might find it loose again when you get under there tomorrow.

But maybe I'm just being pessimistic and it was just a nick in the seal as rob said.

Fairly clean to be fair. Just years of muck and grimes combined with the recent diff oil leak due to worn flange running surface. I must admit I’m beginning to think knackered diff bearings but who knows. Will get the seal sorted and go from there.

Plus point is the squeak and noises from propshaft have gone!

For those who are interested, the leak was the installers fault, me. I didn’t put the seal in far enough. Simple as that. I took a photo but it’s hard to see.

Old new seal out, new seal in. This time much further. Test fit flange. Not quite enough. Remove flange and knock in so the lip that is proud is just below diff casting. Refit everything. Torque to 85ft lbs and spilt pin lines up. Happy days. Road test. Leak fixed. Diff whining like a bastard. Castle nut was still tight for those interested.

Happy though as the total loss oil problem has been cured.