Citizen Kane

Well-Known Member
I've had nothing but trouble with my pinion seal on my rear diff. When I originally got the vehicle there was a lot of play in the pinion and I discovered that the nut was loose. The seal was replaced a new Corteco one but this only lasted a couple of months but this was long enough for me to acquire a replacement second hand diff for rebuilding.

The rebuilt diff was fitted and ever since I seem to be replacing seals, sometimes they only lasted a year, some have gone for two years but eventually they all seem to leak. After the first one went I put it down to bad luck, when the second one went a decided to replace the comedy mud shield with a plastic unit that created a basic labyrinth to better protect the seal but the problem still persisted.

I did a bit of digging around and found a website that specialises in rebuilding and upgrading Land Rover diffs, seems I'm not the only one to suffer this problem and its quite common and the death of many units.

So it seems there is an alternative more modern seal, a Corteco FTC5258 fitted to some later Land Rovers. The seal appears to be a completely different design with more sealing lips and a different material, they also sell a new upgraded alloy mud shield as well. The pic shows both seals side by side with the later seal on the left.

IMG_2398.JPG


The original seal has some kind of raised flange on the outer surface, I've always knocked these seals in so they were flush with the diff case. When I was reading about fitting this newer seal to Defender diffs the advise was to drive the seal into the housing until it bottomed out, when I took a few measurements on the Series I thought this was a bit too deep and the first lip of the seal wouldn't engage with the sealing face of the drive flange so I made a simple seal driver to locate the seal 6mm under flush.

Here's a few pics of the old seal and the new one being fitted.

Old Seal fitted flush to diff case.
IMG_2407.JPG


New seal being fitted.
IMG_2408.JPG


New seal in position.
IMG_2409.JPG


Drive flange with plastic mud shield.
IMG_2406.JPG


Only time will tell if this new seal solves the problem but I'm ever hopeful.
 
I've had nothing but trouble with my pinion seal on my rear diff. When I originally got the vehicle there was a lot of play in the pinion and I discovered that the nut was loose. The seal was replaced a new Corteco one but this only lasted a couple of months but this was long enough for me to acquire a replacement second hand diff for rebuilding.

The rebuilt diff was fitted and ever since I seem to be replacing seals, sometimes they only lasted a year, some have gone for two years but eventually they all seem to leak. After the first one went I put it down to bad luck, when the second one went a decided to replace the comedy mud shield with a plastic unit that created a basic labyrinth to better protect the seal but the problem still persisted.

I did a bit of digging around and found a website that specialises in rebuilding and upgrading Land Rover diffs, seems I'm not the only one to suffer this problem and its quite common and the death of many units.

So it seems there is an alternative more modern seal, a Corteco FTC5258 fitted to some later Land Rovers. The seal appears to be a completely different design with more sealing lips and a different material, they also sell a new upgraded alloy mud shield as well. The pic shows both seals side by side with the later seal on the left.

View attachment 196852

The original seal has some kind of raised flange on the outer surface, I've always knocked these seals in so they were flush with the diff case. When I was reading about fitting this newer seal to Defender diffs the advise was to drive the seal into the housing until it bottomed out, when I took a few measurements on the Series I thought this was a bit too deep and the first lip of the seal wouldn't engage with the sealing face of the drive flange so I made a simple seal driver to locate the seal 6mm under flush.

Here's a few pics of the old seal and the new one being fitted.

Old Seal fitted flush to diff case.
View attachment 196854

New seal being fitted.
View attachment 196856

New seal in position.View attachment 196857

Drive flange with plastic mud shield.
View attachment 196858

Only time will tell if this new seal solves the problem but I'm ever hopeful.

We await the trial of the winter roads ...
 
Fingers crossed it solves the problem. Will keep an interested eye on your thread and how it progresses.
 
Get a gallon of EP90 in the garage, keep it topped up and regard the spillage as rustproofing for the back chassis.

Usually looks worse than it is. I always think a few drops hanging under the diff nose is a sign there is still oil in it.
Whereas actual pools forming on the ground every night is a sign something needs doing.
There is a lot of oil in those diffs, about a litre and half from memory, takes a lot of drips before that gets to a level that will be damaging.
 
More worried about what can get in, it got dipped yesterday on a local green lane.

Dipped won't give it a problem. If you go in so the diff stays well under water for some time, enough to cool it, you might get some sucked in.
But if that happens, it is likely that you will get some in though the hub seals anyway.
Land Rovers are not waterproof.
 
Hub seals are next on the list, there must be a modern twin lip seal to replace the existing ones. If I can find the correct OD and thickness then It should be easy enough to machine up suitable lands if the ID is wrong.
 
Usually looks worse than it is. I always think a few drops hanging under the diff nose is a sign there is still oil in it.
Whereas actual pools forming on the ground every night is a sign something needs doing.
There is a lot of oil in those diffs, about a litre and half from memory, takes a lot of drips before that gets to a level that will be damaging.
exactly
 
I've had nothing but trouble with my pinion seal on my rear diff. When I originally got the vehicle there was a lot of play in the pinion and I discovered that the nut was loose. The seal was replaced a new Corteco one but this only lasted a couple of months but this was long enough for me to acquire a replacement second hand diff for rebuilding.

The rebuilt diff was fitted and ever since I seem to be replacing seals, sometimes they only lasted a year, some have gone for two years but eventually they all seem to leak. After the first one went I put it down to bad luck, when the second one went a decided to replace the comedy mud shield with a plastic unit that created a basic labyrinth to better protect the seal but the problem still persisted.

I did a bit of digging around and found a website that specialises in rebuilding and upgrading Land Rover diffs, seems I'm not the only one to suffer this problem and its quite common and the death of many units.

So it seems there is an alternative more modern seal, a Corteco FTC5258 fitted to some later Land Rovers. The seal appears to be a completely different design with more sealing lips and a different material, they also sell a new upgraded alloy mud shield as well. The pic shows both seals side by side with the later seal on the left.

View attachment 196852

The original seal has some kind of raised flange on the outer surface, I've always knocked these seals in so they were flush with the diff case. When I was reading about fitting this newer seal to Defender diffs the advise was to drive the seal into the housing until it bottomed out, when I took a few measurements on the Series I thought this was a bit too deep and the first lip of the seal wouldn't engage with the sealing face of the drive flange so I made a simple seal driver to locate the seal 6mm under flush.

Here's a few pics of the old seal and the new one being fitted.

Old Seal fitted flush to diff case.
View attachment 196854

New seal being fitted.
View attachment 196856

New seal in position.View attachment 196857

Drive flange with plastic mud shield.
View attachment 196858

Only time will tell if this new seal solves the problem but I'm ever hopeful.
Citizen Kane,
I'll be replacing this seal myself for the for the first time, its now failed 3 times, had the diff nose bearing replaced but the seal failed again.is it simply pull out and press in, any Specialist tools required. Btw what was the website for the alternative seal?
 
Last edited:
Have you checked condition of the land the seal run's on on the drive flange? Fit a Corteco seal. A seal remover tool is handy [Ebay] and a simple press in tool is easy to make as in post above.
 

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