11 BMW 1973 R75/5 Replace Front Crankshaft Seal

I had replaced the rear crankshaft seal, oil pump cover, bolts and oil pump cover o-ring.  I also replaced the camshaft seal as it was leaking. You can read how I did that here.

Parts List

This is the parts list.

Part # Description Qty
11 14 1 337 654 Front Crankshaft Seal 1

Remove the Stator

I replaced the alternator brushes which requires removing the stator. You can read about how to remove the stator here.

Remove the Rotor

When I purchased the brushes from Euro Motoelectrics, I also picked up a hardened bolt to remove the alternator rotor from the crankshaft.

Rotor Puller Bolt and New Brushes

Rotor Puller Bolt and New Brushes

With the stator removed, the rotor is exposed.

Rotor

Rotor

It is secured to the crankshaft with an Allan bolt and is pressed onto the tapered nose of the crankshaft. Since my engine was out of the frame, I installed the tranmission and put it into first gear to provide some extra drag so I could loosen the alternator bolt.

Loosening Rotor Bolt

Loosening Rotor Bolt

Then I removed the bolt and washer.

Backing our Rotor Bolt

Backing our Rotor Bolt

I threaded the rotor removal bolt and had to block the rotor from turning to get the rotor to back off from the tapered crankshaft nose. I used a 1 inch steel strap carefully inserted between the steel casing avoiding contact with the coil windings.

Inserting Puller Bolt

Inserting Alternator Rotor Puller Bolt

Torquing the Stator Bolt

Blocking the Rotor with Steel Bar

It popped off the crankshaft exposing the front main crankshaft seal.

Removing Rotor with Puller Bolt

Alternator Rotor Removed from Crankshaft Nose

Rotor with Puller Bolt

Rotor with Puller Bolt

I had recently purchased a Lisle shaft seal puller, #584030, and used it to remove the old seal.

Lisle Shaft Seal  Puller

Lisle #58430 Shaft Seal Puller

The hook slips beside the shaft and the extends under the shoulder of the seal.

Hook on Shaft Seal Puller

Hook on Shaft Seal Puller Goes Under the Edge of the Seal

How Shaft Seal Puller is Used

How Shaft Seal Puller is Used

There is an adjustable pivot bar so it can be placed on the housing and then you lever the seal out of the hole.

Shaft Seal Puller Installed

Shaft Seal Puller Installed With Adjustable Pivot Pin Resting on Engine Housing

I heated the engine housing with a heat gun to make it easier to remove the seal. It popped out the seal in quickly.

Heating Seal Bore

Heating Engine Housnig Around Shaft Seal Bore

Removing Oil Seal

Old Crankshaft Seal Removed

Installing the New Front Crankshaft Seal

I used metal polish to clean the tapered nose of the crankshaft and the tapered bore in the rotor. Then I used brake cleaner to get any oil off them.

Cleaned Crankshaft Nose

Cleaned Crankshaft Nose

Clean Bore of Rotor

Clean Bore of Rotor

I put a little oil on the outside of the new seal and then heated the engine casing around the seal bore.

Oiling Outside of the Seal

Oiling Outside of the Seal

I pushed the seal into the hole evenly and used a 30 mm deep socket and a rubber mallet to tap it home.

Deep Socket to Drive Front Crankshaft Seal

30 mm Deep Socket to Drive Front Crankshaft Seal

Installing the Rotor

I put the rotor back on the crankshaft nose and threaded the alternator bolt into the rotor. I used the 1 inch metal bar to carefully brace the rotor and tightened the rotor bolt to 17 FOOT/pounds.

Torquing the Stator Bolt

Carefully Bracing Rotor to Torquing the Stator Bolt

Installing the Stator Housing

You can see how I installed the stator housing in the write-up on replacing the alternator brushes.

I put the timing cover back on the engine and then polished it.  Here is the engine ready for installation in the frame.

Polished Engine

Polished Engine

Polished Engine

Polished Engine

2 thoughts on “11 BMW 1973 R75/5 Replace Front Crankshaft Seal

  1. Hello Brook.
    I am glad to have found your site I am just starting on a wonderful 73 R/75. Please, your process for polishing the engine.
    Thanks in advance,

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