Diff oil leak

[Jono]

Late last year I thought I'd resolved an oil leak from the seal at the differential/drive shaft exit point - to centre section. The oil loss is very apparent again because it is flung at high velocity up to the exhaust manifold and hot water rail, and burns off. With the car up we can see there's too much play in that shaft section. Could this be the result of a worn bearing? Any thoughts will be gratefully received... Jono.

[Nigel]

Hi Jono,
The play you mention: is that up/down or rotational?

It sounds like you had the seal at the right-hand diff end replaced previously for a similar
issue (?) and that its now leaking from the same place.

Yes it's possible the diff bearing is worn but these are usually quite robust. Is there
similar play on the left-hand flange? If not maybe the r/h spline is worn. Or maybe
the support bearing that's in the carrier bolted to the engine block.

Lots of maybe's and questions! Hard to diagnose.

Regards, Nigel

[SanRemo78]

It’s also easy to damage the seal when inserting the shaft or drive flange. I note the seals for the similar Alfa 166 boxes have a plastic ring to help prevent this. But they may not fit the Beta seal flanges. Just a thought?

[Jono]

Hello Nigel, yup, the oil seal was replaced last Oct so we thought that was all wrapped up. Not so it seems.

I seem to recall my technician claiming the seal he removed wasn't seated correctly, a size issue possibly. Anyhow I bought two seals : 35 x 50 x 8. One was fitted to the defective side.

I watched him move the shaft, it was up and down movement he noted not in and out. I could just recognise the splined section. Must go and top up the oil today, I find that dipstick hard to read. I painted mine red, so at least it's easier to find!

Car going in to workshop on the 12th so more clarity will be apparent hopefully. J

[Neil-yaj396]

Exactly the same thing has happened with my MGTF. The equivalent seal was replaced last July and started leaking again in May. The previous seals were badly butchered for reasons unknown and I fear that the actual flange on the diff itself is damaged, leading to rapid wear of the seal.

Certainly worth checking that all is clean and straight round the edge to which the seal mounts when the seal is removed.

[Nigel]

Jono,
A point to note is that the seals are different, left and right, but
it's hard to tell just by looking.
Also, behind each flange is an 'O' ring. This goes rock hard over time.
Both Betaboyz and Monte Hospital sell the seals in pairs for that reason.
I can't say which is which right now as my garage is inaccessible due to
wet floor paint!

I'll measure my spare flanges and report back tomorrow evening.

Nigel

 

[Nigel]

Jono,

The seals can't be incorrectly fitted, the smaller of the two goes
to the engine side. It does need to seat firmly in its recess.
If you haven't got a new O ring, use the existing but use some sealant.

Nigel

[WestonE]

If you have access to a spare un molested gearbox with care you can read off the seal size from the rear of the seals. Bearing suppliers both on trading estates and online sell them along with every kind of O ring. Given the history I would start again with seal plates from another gearbox. You want sockets that just loose fit the seal recess to tap down the seals evenly. Note Tap down not smash down with a large hammer!

If you can borrow or buy a seal seating kit even better.

Enjoy
Eric 

[Jono]

Thanks Nigel, and others, this is all crucial info to be relayed to my technician, stuff that's inevitably been discussed previously I'm sure. I've ordered the pair of seals that Mark supplies to kick things off. Take it from there... J

[peteracs]

Hi

If you feel you need anything off of a n other gearbox, I have a couple going spare.

Peter

[Jono]

Peter, thank you for that offer. I will see how things progress from Monday when my Beta is up on the ramp, always hoping that this play in the drive-shaft isn't too bad, and we can achieve a good seal this time...

Of course we're taking about 45 year old components and 100k miles, but these cars are mechanically pretty tough I reckon...

[Jono]

Peter, do either or both your gearboxes have the output drive -shaft on them? The side that links to the centre bearing... Just thinking ahead. Car at garage awaiting attention. Still waiting for correct seals too, so no panic. J

[peteracs]

Hi

They can have as I have drive shafts as well.

Peter