Sierra 7 inch diff leaks

[leegav]

So over the past few hundred miles my diff seals have started leaking, So I took it to a local garage to refit some new seals.

My drive home reveals the two output shafts are leaking even more now. I have no idea why 5 seals would fail. I have taken the back plate off and inspected the breather hole, it's not blocked as this could cause some pressure to push through shafts. I am now in the process of taking the shafts out and the seals to see if they seal over the drive shaft..

Has anyone else got any ideas why they would leak like this?

[DJ.]

Really sorry to hear you're having more trouble. I don't know why the seals should be leaking, you've checked the breather and I assume it wouldn't have been over filled.

I'll tell you a story to try and make you feel better, my almost new Caterham started dripping from the pinion of the whining original diff. Rather than be mucked about by Caterham and their dodgy reconditioned parts, I bought an old Ford diff from Ebay and got it rebuilt by Phil at Road and Race (£1000 as I got carried away and had a Titan LSD installed). Once back in the car, it whined in the same way at the same speed . At least I have the LSD and it doesn't leak I thought............a few weeks later the drips from the pinion started . Anyway, it's now been in there eight years and I have to top it up every 1500 miles, and I can't park on posh driveways without putting paper under the back of the car. Still brilliant fun to drive though

[b33fy]

Really sorry to hear you're having more trouble. I don't know why the seals should be leaking, you've checked the breather and I assume it wouldn't have been over filled.

I'll tell you a story to try and make you feel better, my almost new Caterham started dripping from the pinion of the whining original diff. Rather than be mucked about by Caterham and their dodgy reconditioned parts, I bought an old Ford diff from Ebay and got it rebuilt by Phil at Road and Race (£1000 as I got carried away and had a Titan LSD installed). Once back in the car, it whined in the same way at the same speed . At least I have the LSD and it doesn't leak I thought............a few weeks later the drips from the pinion started . Anyway, it's now been in there eight years and I have to top it up every 1500 miles, and I can't park on posh driveways without putting paper under the back of the car. Still brilliant fun to drive though

Funnily enough, I had mine rebuilt as well with a new 3.14 crown wheel and pinion and quaife atb for a not inconsiderable sum. They went to great pains to ensure it clonked like 200,000 mile old Sierra 1.6 rep mobile. If it was running today it would still be clonking.. In fairness they did offer to sort it (with an old newspaper.. ) but I never got round to removing from the car... yet again.

[leegav]

That does make me feel better.
My worry is that something more sinister is going on internally and I don't want that to ruin my quaife ATB.
There hasn't been a drip yet on this set of seals but it's close and they are weeping more now.
I worked out when I drained it last time I'd lost about 150ml in about 400 miles from the pinion side, the carbos sealed underneath with a rear diffuser and a mass of Aly sheet so only noticed it when it started running down the centre console onto my feet.
As for more issues .... This is one of many many problems I'm encountering

[kenton]

As it happens I picked up my spare diff from road and race last Friday. Had it rebuilt with a new 3.14 CWP as the old was foobared. On the pinion nut they put a smear of sealant as the oil can weep through the threads, had this too on the Luego before I changed the seal and sealed the threads. Maybe yours is not the seal but weeping along the threads through the pinion nut?

[SteveRST]

Sounds sh1t mate.
No experience with leaks from the output shaft, but as Kenton said above, they can leak from the diff nose.
I went to change the input shaft seal last year and when I took the flange off the end of the diff nose, it was clear that my oil leak was not due to oil leaking past the oil seal, but oil travelling down the splines in the shaft and then leaking out at the nut at the end of that shaft.



I used some silicone gasket sealant on the splines and on the far end of the flange so that it should create a nice seal when reassembled and has been ok since.

[leegav]

Oooh ok. That's sounds like result.

What about the two rear outputs. Could they do the same and leak down the threads on the bearing housing and not through the seals?

[Rob E]

:lol:
That does make me feel better.
My worry is that something more sinister is going on internally and I don't want that to ruin my quaife ATB.
There hasn't been a drip yet on this set of seals but it's close and they are weeping more now.
I worked out when I drained it last time I'd lost about 150ml in about 400 miles from the pinion side, the carbos sealed underneath with a rear diffuser and a mass of Aly sheet so only noticed it when it started running down the centre console onto my feet.
As for more issues .... This is one of many many problems I'm encountering

Lee
Sounds like way too much pain for such a new car, can you not take the car back to them, give them the keys and say I want it perfect and until it is I don’t want it back or we start the legal route ? Seems you’ve been fobbed of a bit too much.

[leegav]

It's been back twice Rob, and it's 10 hours driving to take it then ten hours driving to collect it plus fuel, accomodation for overnight stay and rental of a trailer. And if I wanted to send it back on a trailer without me driving it's 350 quid.

I figured it's easier to take local.

Can the diff leak through the bearing housing down the threads...

[Matth93]

The threads on the bearing housing have a o ring at the end so if that’s no good then it could leak there