Hey gents,

Puzzled staring at the backside of the engine trying to figure out how I replace the rear main seal.

On the steel-outside-cup there's an arrow, is the seal itself underneath? Do these just twist out? I wonder if there's sealant holding mine because it's stiff as a brick - no pun intended :suspect:

This is the seal, the arrow indicates the shaft turning direction in this specific seal.

Inge K. wrote:This is the seal, the arrow indicates the shaft turning direction in this specific seal.

Thanks Inge. Maybe I ordered the wrong part because it doesn't have the lettering/arrow, or steely look to it. Roughly the same size though but it's black this is why i thought it was underneath this.

The metal you see on the outside on your old seal, is molded into your new black seal.
This seal (and all others) have been changed a lot of times during the years
(BMW don`t make their own shaft seals).


Which colour (or non sealing surface material) doesn`t matter, what`s important is the correct measurements.
And it don`t necessarily got a arrow, even if made for running in a specific direction.

Here is a rear main seal which is black/metal/red, and without a arrow, but a closer look at the sealing lip shows thats it made for a anticlockwise running shaft.

Thanks for the picture Inge. I now have my Shaft Seal as well as Main Seal, want to replace both. Even my front Seal (shaft seal) looks different from the one that's in there, is this because it's the old style ones are plastic/Steel and these are both Teflon?

Should i tap the Main Seal with a block of wood and a hammer a few times to get it out? It's really being difficult.

Also the Shaft Seal comes out from the rear of the Timing plate correct?

The 'shaft seal' is not seated in a pocket/recess. Easiest is to get it out towards the rear of the bike/engine.

With regards to the other seal, how far is the engine dismantled? I would try with some hooks or selftapper screws and pull it out. There is a BMW instruction to leave this new seal .5 mm out from flush.

Use a seal puller to get the main seal out:


To re-seat the main seal, refer to this URL for instructions on making a seal setting tool really cheap out of wood and which guarantees the 0.5mm proud seating:

http://www.motobrick.com/index.php/topic,1350.msg6322.html#msg6322

Personally, I used a mallet and block of wood. Carefully tapped the seal in, taking measurements continuously as I approached 0.5mm. Took a while but I was not in a rush.

Leaving the seal out by .5mm is so that the seal lip runs on a fresh part of the sealing surface.
Clean the surface with a bit of fine emery and run your fingernail across the surface and if you feel a groove then leave the seal out a bit but if all ok then put the seal in the usual place ie level with the surrounding surface.

I pulled, smacked, torched, cursed and threw a fit - I get my hands on a Seal puller tomorrow maybe that'll yeild results. This SOB will not cooperate wishing I had left it in there in the first place as others had cautioned me keep you posted on my trip to Seal Removal Hell

it can be difficult removing seals but as mentioned in previous posts by some it is often down to being carefull. utry using a couple of thick self tappers and or a slide hammer that has a screw end. it has worked for me often

if you screw a self tapper in and grab it with a set of vice grips and gently tap in the correct direction (toward yourself) it should be an easy out job. so good luck whatever method you choose to use

Thanks everyone for the insights I appreciate it. Can't turn back now, got my seal puller today, some self tapping screws, if this doesn't work I'm getting the Slide Hammer tomorrow

Look at this, http://k100rt.aforumfree.com/t444-any-tips-on-replacing-the-rear-eng-seal#1897

Update on mine,

I tried with the screws and failed.

Used this tool with arms face outwards, put nut back on output shaft, a metal flat edge across the nut to avoid damaging the hole, screwed down centre bolt, ........ 3 mins later, no effort, no apparent damage to shaft end................

whoa!!!! out it came.



I'm hoping what I've done is OK, I know its too late now but I cant believe how easy it was.
Does anybody want to share their views on it?

glad you finaly had sucsess in your endevor to remove the seal

and there is nothing wrong with using a puller if you can gain access with the legs of it and no damage is caused. those of us who posted the idea of using screws have done this probably more than once with good results the reason for using screws is the access problem. but if you have managed to get the puller inside then good on you mate and just be careful when putting new seal in. plwnty lube and carful hammer tapping should do it but make sure you get it in the right way round:)