Renewing the differential front oil seal

[Klaus Schlueter]

Hi all and a happy New Year,
the front oil seal that runs on the quill shaft is leaking and needs to be renewed. I did the job in 2016, so before I start it now I read the paragrafs in the ROM Haynes and Autobooks. The content is more or less the same and is shown in my pictures 1 and 2 taken from the ROM. Only Haynes mentions to disconnect the prop shaft from the diff extension.
My question: based on your experience is that the correct procedure? Is there no need to loosen/undo the bolt # 1 in picture 3?
Has anyone published the procedure to do the job?
Looking forward to hearing from you.
Klaus

[NeilR]

No need to touch subframe mountings or propshaft, just remove diff mounting plate & diff will drop low enough.
Best to support rear of car on swing arms, that will force the subframe to tilt in the right direction.

[Rigid]

Only ever done it on a Herald.
Getting the old one out was not pretty (lots of twisted metal) but replacing was simple.
Good luck, you'll spend an age lying on your back with all the blood draining from your arms if my experience is anything to go by.

[Klaus Schlueter]

Many thanks to both of you. Has anyone further ideas or experiences from carrying out this job?

Klaus

[JeffW]

Many thanks to both of you. Has anyone further ideas or experiences from carrying out this job?

Klaus

Hi Klaus

I did it on my Mk1. It was ok, but the diff is wobbly on a trolley jack and in the words of Richard the Stag, don't try and stop it if it rolls off as it will crush your finger(s). I know some have used a much better transmission (gearbox) jack to lower it and raise it back up.

The only issue I had is the diff has to come out towards the rear of the car as well as down from the nose extension, so be aware that a little jiggling is necessary. It was easier for me to come out then put back in as whilst carefully jacking it up it would roll off the jack. I did have a soft camping mat laying down under the car to soften the blow!

Hope this helps.

Jeff

[Lingen]

Klaus.
It is fairly straightforward as described by NeilR. I would suggest though that once the diff. is removed you also change the quill shaft bearing. This is normally lubricated with grease when it is manufactured. However, if it has been fed with oil due to the leaking seal, this may have thinned the grease, and you are now going to stop it being lubricated by oil as well! To be on the safe side, replace it.
To do this you will have to disconnect the rear of the propshaft, push it out of the way, and then remove the flange by removing the big nut inside it and pulling it off. It is not on a taper.
(You will need to stop the flange turning). Then you will be able to remove the quill shaft by tapping it out backwards.
Having done that, you will be able to get at, and remove, the rear circlip that holds the bearing in place. Then with a "Suitable tool" you will be able to tap the bearing out backwards (side to side) as well .
"Reverse the process to Reassemble" as they say.
Mike.

[Goldstar]

Hi Klaus. If you have a leather pinion seal fitted you might find it something of a wrestle (metal case and leather seal needed hammer and punch in my last attempt) so definitely worth taking the diff off the car and on the bench to do the job rather than do it from below. As Mike (Lingen) mentions you should also do the quill shaft bearing at the same time.

A pleasing pair of jobs once done as it will definitely make your car run quieter

[Sculthorpe]

I carried out this task about a year ago and replaced the diff extension bearing at the same time, and removed the diff and extension as separate tasks. I used a trolley jack and the removal of the diff was a wobbly affair, so I resolved to make some kind of fixture to hold it steady for the replacement task. The result is from some scrap lumber and is crude, but it provided enough stability for a smooth installation. The step on the front added some tilt to make the shaft engagement easier.

For the flange removal on the extension, a chain locking pliers worked great to hold the flange in place while removing/replacing the nut.

[JeffW]

Klaus.
It is fairly straightforward as described by NeilR. I would suggest though that once the diff. is removed you also change the quill shaft bearing. This is normally lubricated with grease when it is manufactured. However, if it has been fed with oil due to the leaking seal, this may have thinned the grease, and you are now going to stop it being lubricated by oil as well! To be on the safe side, replace it.
To do this you will have to disconnect the rear of the propshaft, push it out of the way, and then remove the flange by removing the big nut inside it and pulling it off. It is not on a taper.
(You will need to stop the flange turning). Then you will be able to remove the quill shaft by tapping it out backwards.
Having done that, you will be able to get at, and remove, the rear circlip that holds the bearing in place. Then with a "Suitable tool" you will be able to tap the bearing out backwards (side to side) as well .
"Reverse the process to Reassemble" as they say.
Mike.

Hi again Klaus

Just to add to this, I also replaced my quill shaft bearing when I had the diff out, but I took the nose extension off the arms as I noticed the nose was cracked (a common problem). I had the fins welded on as many have done on here and then replaced the bearing with a good Timken one.

As Paul (Goldstar) said, a very pleasing result when done.

Jeff

[staggering]

Klaus.
It is fairly straightforward as described by NeilR. I would suggest though that once the diff. is removed you also change the quill shaft bearing. This is normally lubricated with grease when it is manufactured. However, if it has been fed with oil due to the leaking seal, this may have thinned the grease, and you are now going to stop it being lubricated by oil as well! To be on the safe side, replace it.
To do this you will have to disconnect the rear of the propshaft, push it out of the way, and then remove the flange by removing the big nut inside it and pulling it off. It is not on a taper.
(You will need to stop the flange turning). Then you will be able to remove the quill shaft by tapping it out backwards.
Having done that, you will be able to get at, and remove, the rear circlip that holds the bearing in place. Then with a "Suitable tool" you will be able to tap the bearing out backwards (side to side) as well .
"Reverse the process to Reassemble" as they say.
Mike.

+1 to Mikes advise above. Can I also suggest that when you have this all apart to make a small drill hole in the bottom of the diff nose extension tube (as well as reinforce the tube - mine failed badly at 40 mph). This hole serves two purposes - it will drip oil onto floor if / when the new diff seal goes again and also lessens the chance of the quill bearing from getting washed out as Mike explains above.

Good luck
Ian

[Klaus Schlueter]

Hi all,
the diff is almost out, but I had to stop the job as I was out of town. Will continue tomorrow. Thanks for all your answers and tipps.

Jeff: I have the advantage of a four post car lift in my garage and many years ago I bought a hydraulic gearbox lift. I have made a special 4-arms diff holder which works fine. I reinforced the extention already many years ago.

Mike and Goldstar: I have changed the bearing in the diff extension three times. in 2009 I developed a method to avoid this procedure and it seems that it works. Watch out, I'l post the details during the next days.

Goldstar: I use a modern radial oil seal from SKF.

Ian: that was the "development" I made in 2014

Klaus

[JeffW]

Jeff: I have the advantage of a four post car lift in my garage and many years ago I bought a hydraulic gearbox lift. I have made a special 4-arms diff holder which works fine. I reinforced the extention already many years ago.

Very nice! That would have save 3 of my fingers!

[staggering]

Hi all,
the diff is almost out, but I had to stop the job as I was out of town. Will continue tomorrow. Thanks for all your answers and tipps.

Jeff: I have the advantage of a four post car lift in my garage and many years ago I bought a hydraulic gearbox lift. I have made a special 4-arms diff holder which works fine. I reinforced the extention already many years ago.

Mike and Goldstar: I have changed the bearing in the diff extension three times. in 2009 I developed a method to avoid this procedure and it seems that it works. Watch out, I'l post the details during the next days.

Goldstar: I use a modern radial oil seal from SKF.

Ian: that was the "development" I made in 2014

Klaus

Wow Klaus - thanks - I did wonder were I got that from (and you've reinforced the diff nose as well - mine collapsed on a busy road so this mod alone is essential in my view)

Cheers
Ian

[Klaus Schlueter]

The diff is now back in the Stag.

1. When I drained the oil in the beginning, there was a lack of approx. 60 to 80 ml. This amount escaped through the drain hole in the diff extension within one year of leaking.
The outer end of the quill shaft was dust dry. So there was no need to change the RHP-bearing.
2. My hydraulic lift worked fine again, especially the cradle I made to secure the diff against falling down.
3. First time I dismantled the wide mounting plate at the rear of the diff. So I was able to change the seal under the car.
4. The speedy sleve did not show any groove from the seal's lip, only a black shadow after eight years running and 32000 km. To be on the safe side I placed the new seal approx. 2 mm further in.
The black 2 mm wide shadow is the result of the special design of the lip. SKF calls it "wave type", i. e. the lip "wanders" slightly to both sides.

Thanks to all who answered and tried to help me in this awkward work.
Klaus

[jbuckl]

https://www.facebook.com/reel/866098878855456/?s=single_unit&__cft__%5B0%5D=AZUqyLl_2FKo0GmoSZ4v _8t9yxokfUPT169Fwa9gtZ1mRlDXaWBqIixrsMTEm9Tn_X0-rMFEwWYhaPW5JkdRDqq3ZKdqXy00xRJ2p976o5s8qE4moIHmDw 39PXijEPwAXQDrD45Yosy-4NHsPrTBHE7aQ6MeNF3WxOPoeBfwvKc8euDlyQUhMZ36DKm7vy O7VorgbDhwR_3F0rfC3e7jHAPF&__tn__=H-R

Mostly, these reels are awful….. this one seems great.

Air chisel adaptor for removing oil seals.

Proper job for diff seal removal possibly… if you’ve ever tried removing an original?

texas twister!

maybe not enough space for it?

I have had to put serious effort into diff seal removal though.