300 tdi Defender 90 Rear Diff Pinion Seal Replaced now leaking horrifically

Had a bit of a weap on my rear diff pinion seal thought best get that sorted. Got the part and we swapped it out last night.

Part number we used was a FTC5258G. However after the replacement the leak is now sadly 10 times worse.

This was a pic before replacement after about 6 weeks since I first noticed the leak


Then this was after the replacement last night and driving about 8 miles back home




I honestly don’t know how its gone so catastrophically wrong. I added a brand new extended axle breather a few weeks back in the hopes that would cure the slow leak it but nope, then was advised to swap the pinion seal out.

I actually have another seal called an FRC8220 which is 14mm wide and not 13mm wide like FTC5258G. Don’t know if that will help in anyway?

Is there a certain orientation that the seal needs to be?

My friend did it for me and it all seemed to go fine until the drive home lol. He has done hundreds before. Just a bit worried there is something more wrong with the differential in someway but i just don’t know enough about them.

Its now made quite a bit of a mess on the drive

Likely nicked or bent the seal going in.

Double check the part number and do it again. Make sure the diff mating face clean of debris and its full seated. Check for play in the pinion as well

Check for a wear groove in the flange where the seal runs,if you have an obvious groove you can fit the new seal a couple of millimetres either way so the seal runs on fresh metal,

Different mud shields need compatible seal.
OEM seal and put some grease in the back of the seal and on the edge.
As mentioned the flange wears out, been there done it and eventually changed the flange.
I always buy two seals when I change one so have a spare for mistakes or next time I need one.

I put a bit of sealant on the outer circumference of the seal when I do mine so the oil can't ooze out between the seal and the casing.

Occasionally you get a seal that doesn't work. Maybe just the way it's made or maybe it got scratched going in. Another thing I've seen happen is a bit of debris get between the shaft of the flange and the seal. Or some seals have a garter spring on the inside which comes off in the assembly process or is separate in the packaging and people forget to put it on.

Have you had a chance to look at the problem?

Anaconda said:

Have you had a chance to look at the problem?

Click to expand...

Yes spring had failed new seal again fixed it