front crankcase oil seal

can someone tell me which oil seal I need for the front crank case of my 1974 Eldorado the one in the timing cover its listed in the manual as 90 40 32 51 is this the size or what ? mines leaking a little and its annoying need to replace it A S A P ! thanks :question:

According to my parts list the front crank oil seal in the timing cover is part no 90 40 38 51 and is shown as 38.50.7 in the specifications. That’s 38mm ID, 50mm OD and 7mm thick.

It’s very easy to do. But much less messy if you drop the oil out of the engine first. Guess how I know…

Thank you ranton rambler seal ordered AND I will drop out the oil first …less messy !

should not make a differance to messy as casing stays on the engine and oil level is well below the crank level

Come to think of it yes! Crankshaft is not submerged…

Different on a loop Mike…front cover has to come off.


Never dropped oil but jacked bike up a bit!! I also found that double lip seals gave a little extra security! If there is any wear on crank, double lips also “touch” in different place to single lip.

ok chap and chappesses I would like to fit the new front crankcase seal do I remove the large nut on the front of the crank driven pulley OR do I have to take the three ten mm bolts from the pulley first ? then …after draining the oil remove all the 10 mm bolts around the second casing that hold s the seal and fit new seal and reverse the process any help would be appreciated

From memory, I took the pulley off (3 bolts), then the drive flange, then the timing cover.

ok fitted new seal and all went well however can I just fit the generator pulley back on the way it came off OR do I have to re time and adjust the shims ect first ie left cylinder to tdc then adjust ?

You’ll need to make sure the timing marks are in the right place, but should be able to put the shims back as they were if you’re putting the same belt back on. If you adjust the belt tension, keep it as loose as you can. Too tight is bad for the belt and generator.

Thank you ranton rambler my 850 eldorado does not leak anymore and is all i hoped it would be :smiley:

Good one…yes Ian is a very helpful chap…in General Banter we have a dedicated thread called ‘in the Loop’…they are smashing old bikes arent they…

Glad it’s sorted. Now you can get out and do a few thousand miles over the summer. See you about maybe…Ian