Oil seal treatment

[CAPP0]

I have a leaking differential pinion oil seal on my motorhome, which I'll replace soon, but I need to use the MH next week.

Are these oil seal treatments, such as this type of thing worth any sort of consideration, as a very temporary option to slow the leak down, or are they just the snakiest of snake oils (pun intended)?

[GreenV8S]

I imagine the seal will have hardened and worn over many years and it's hard to imagine a bit of goop is going to make any difference to the state of the rubber over a few days, even if it does what it claims.

But - what do you have to lose?

[CAPP0]

Good point yes, although I guess the alternative is just to carry an extra litre of oil and top it up! I might try some though just in case it gets worse next week before I can change it properly.

[paintman]

What ever you put in will affect ALL the seals it comes into contact with not just the problem one.
Which may or may not be a good thing.

[CAPP0]

I hadn't thought about that. It's a standard solid axle but there will be seals at both hubs of course. I don't need to do much more than about 150 miles before I can replace the pinion seal so I think I'll just top it up and monitor until I can change it.

Edited by CAPP0 on Wednesday 1st September 22:48

[Evoluzione]

That's how they make their money, from selling to the 'It's only a few quid, i'll give it a go' crowd.

[23.7]

If it's leaking that badly no amount of goop will help.

[Ivan stewart]

23.7 said:

If it's leaking that badly no amount of goop will help.

This ,
It could be the axle breather is blocked causing pressure to build up,
I would also check to see if there is any play in the bearings which could destroy the diff if you keep running it !!

[Old Merc]

CAPP0 said:

I have a leaking differential pinion oil seal on my motorhome, which I'll replace soon, but I need to use the MH next week.

Are these oil seal treatments, such as this type of thing worth any sort of consideration, as a very temporary option to slow the leak down, or are they just the snakiest of snake oils (pun intended)?

All I can add is that I used Forte products professionally for years. I found their stuff very good, it does what it says on the tin.

[CAPP0]

I'm running up against a more fundamental issue now, which is to identify the axle type itself and thus the oil type and capacity! I dipped a finger in the filling hole (the oil level is about half an inch below currently, hence the loss through the seal) and what came out on my finger was thin and red - doesn't look, or smell, like any diff oil I've ever seen before! Very difficult to find comprehensive info.

[23.7]

CAPP0 said:

I'm running up against a more fundamental issue now, which is to identify the axle type itself and thus the oil type and capacity! I dipped a finger in the filling hole (the oil level is about half an inch below currently, hence the loss through the seal) and what came out on my finger was thin and red - doesn't look, or smell, like any diff oil I've ever seen before! Very difficult to find comprehensive info.

Could it be automatic trans fluid?

[CAPP0]

23.7 said:

CAPP0 said:

I'm running up against a more fundamental issue now, which is to identify the axle type itself and thus the oil type and capacity! I dipped a finger in the filling hole (the oil level is about half an inch below currently, hence the loss through the seal) and what came out on my finger was thin and red - doesn't look, or smell, like any diff oil I've ever seen before! Very difficult to find comprehensive info.

Could it be automatic trans fluid?

Well yes, it could well be, but all the suggestions I’ve seen so far online go for different versions of hypoid oil. Doesn’t mean someone hasn’t put ATF in of course! I’ve never come across an axle which specifies ATF before though?

[23.7]

CAPP0 said:

23.7 said:

CAPP0 said:

I'm running up against a more fundamental issue now, which is to identify the axle type itself and thus the oil type and capacity! I dipped a finger in the filling hole (the oil level is about half an inch below currently, hence the loss through the seal) and what came out on my finger was thin and red - doesn't look, or smell, like any diff oil I've ever seen before! Very difficult to find comprehensive info.

Could it be automatic trans fluid?

Well yes, it could well be, but all the suggestions I’ve seen so far online go for different versions of hypoid oil. Doesn’t mean someone hasn’t put ATF in of course! I’ve never come across an axle which specifies ATF before though?

I think I'd be tempted to drain it.

[paintman]

What do the manufacturers recommend for the axle on the vehicle?

[Skyedriver]

T5 gearboxes in the Chimaera/Griffith range use ATF. Info may or may not be of use...

[CAPP0]

paintman said:

What do the manufacturers recommend for the axle on the vehicle?

This is the problem - I just can’t find a definitive answer to that anywhere. Surely a diff has to run a hypoid oil? I might try calling a Ford truck branch and ask them. I’m 99% sure it’s a Dana S80 axle, which is very widely used in American trucks, but I still keep finding different answers.

Re the comment about draining it - me too! But I have to confirm what goes back in!

[GreenV8S]

CAPP0 said:

Surely a diff has to run a hypoid oil?

I know there are at least a few truck diffs that are non-hypoid, but every car diff I've seen has a hypoid pinion and needs hypoid oil.

[CAPP0]

Mostly sorted now, I managed to speak to the mechanic who looked after it before I bought it. He's confirmed that the oil is 75W140, and that it's red, so that covers that part, and I also talked through changing the pinion seal with him, it's a pretty straightforward job so I'll be having a go at that in the next week or two. Thanks everyone for the input, much appreciated

[Skyedriver]

I've not looked at these "magic potions" before, which one, there are a number, would you recommend for a leaking output seal on a Jaguar diff?
Thanks