Front crankshaft oil seal

[Impromptu]

Being in the process of adjusting the valve clearances on a 1972 twin cam, I put a timing disk on the front crankshaft pulley. While down there, i noticed also some oil leak, either from the water pump pulley area or from the front crankshaft seal. Just a few questions for my understanding:
- should there be a belt tensioner between the front crankshaft pulley and the water pump? Mine doesn't seem to have one, so how is it tensioned?
- can one remove the front crank oil seal and replace it with removing the front plate or even the engine from the car? Any particular precautions to take?
Thanks in advance for your feedback.

[4129R]

No belt tensioner. The water pump does not need much belt grip to rotate it.

The whole water pump assembly needs taking off to change the oil seal, which is a bitch to do with the engine in, and the head on.

If the oil leak is not bad, leave it, and check the oil level in the sump regularly.

[jbcollier]

Are you sure?

The workshop manual says to just take off the front pulley and hook the seal out.

http://www.lotus-europa.com/manuals/tcwork/e/index.htm#23

[Pfreen]

The water pump has no tensioner.
I hate to disagree, but I have replaced the front seal 2 or 3 times.
The water pump pulley bolts and the crankshaft pulley bolt are removed.
The belt is then removed.
The seal is then removed with a seal remover or screw driver.
To replace the seal, I use a piece of aluminum or steel and pull the seal squarely into the front cover with the crankshaft bolt.  It is a bitch to hammer it in squarely while lying on your back.

I seal the od of the seal with aircraft gasket sealer.

The belt and pulleys are then installed.  I use a cut off wood broom handle through the middle of the water pump pulley to jack it into place and tension the belt while pushing the crank pulley in.
It's not easy, but you will get it.

[jbcollier]

Also, check the seal run on the front pulley.  Fit a speedi-sleeve if there is a groove.

[4129R]

Are you sure?

The workshop manual says to just take off the front pulley and hook the seal out.

http://www.lotus-europa.com/manuals/tcwork/e/index.htm#23

Mea culpa.

I thought it was pressed in from the inside.

I must have been thinking about another oil seal I have replaced recently.

I just remembered where I got that from. I had to replace a leaking water pump, and the oil seal on the bell housing of the gearbox in consecutive weeks, and the oil seal on the gearbox goes in from behind, so you have to take the bell housing off the gearbox to get to it. Apologies.

[Impromptu]

Thank you all for your speedy and valid suggestions. With one problem I learned so much from your answers. I wasn't aware of speedi-sleeves and I certainly pay careful attention if this is needed. Also the tensioning trick with a wooden broom stick is one to remember.
Thanks again for sharing your valuable knowledge.
Jan

[Pfreen]

The broomstick is a special tool😊
If the pulley is not too worn, you can clean it up with crocus cloth or fine sandpaper.  I never needed a speedy sleeve.

[jbcollier]

The DGL* is always standing by!

* Distinguished Gentlepeople of Lotus

or, more accurately:

Deranged Geriatric Lunatics

[4129R]

The broomstick is a special tool😊
If the pulley is not too worn, you can clean it up with crocus cloth or fine sandpaper.  I never needed a speedy sleeve.

On my cement mixer, I used string wound around the pulley to make it bigger to tension the drive belt. It worked well.