Replacing Rear Crankshaft Seal on Volvo Penta MD22L

[daga]

I have a 20 year old Volvo Penta MD22L in a 12m aluminium van de Stadt Norman. I have had the boat 4 years and it has always leaked oil into the bilge. This is now getting much worse and is about 20ml/hr. I am not sure but I strongly suspect the Rear Crankshaft Seal is leaking.

Can anyone advise whether it is possible to replace the seal without lifting the engine?

Also, while I have a 'Workshop Manual' it does not describe this part of the engine at all, and provides no diagrams, procedures or part numbers. Any of these details would be enormously useful.

I am currently in Tanga Tanzania.

[DougR]

The MD22L engine is based on a Perkins block that VP used for many years, and was also sold by Perkins as the M50,60,80, etc. It was also used in numerous on highway applications.

In the VP version there’s a 10mm thick plate which bolts to the back of the block, and the rear seal sits in this plate. The plate also is sealed to the block surface by a gasket, and this gasket could also be causing leaks.

The process of replacing this seal is described very completely in the VP workshop manual (publication #7738684-5 April 1999) on page 47. This is actually a Perkins manual that was adopted by VP, and like most Perkins manuals it is very complete. Maybe you can find it on line.

To replace the seal you will have to remove the transmission, the flywheel housing, the damper plate, and the flywheel, and that will expose the seal. The manual describes the removal and replacement process and the use of three special tools to do it. I would guess that a technician of moderate skills can do the job with normal shop tools and could get by without all these special bits and pieces...

In the VP version of the engine the rear motor mounts are situated on the flywheel housing, so to replace the seal you will have to block up or otherwise support the rear of the engine as the flywheel housing will be removed.

The VP part numbers for the seal and gasket are 859718-9 and 861404-2 respectively, but of course they may have been superseded to different numbers over the years.
I am also sure you can find these same parts from Perkins or other sources as well.

Good luck.

[Reefmagnet]

Don't naturally assume it is the rear seal. Leaking oil will always appear to leak at the lowest point of the engine which is in the proximity of the rear seal. For example, my leaking rear seal turned out to be a leaking front seal. Another issue is splitting the gearbox from the engine. If the spline has locked itself with corrosion to the damper plate, it may prove impossible to remove the gearbox in situ with limited access so have a contingency plan in case this eventuates. At the very least, make up some wood wedge "dogs" to help separate the bell housing from the engine. Good luck!

[daga]

Thanks deeply for your detailed reply. I have located a workshop manual as you suggested (dunno how I missed it in my prior search) and the job looks doable.

A few days back I cleaned the sump breather, not really expecting any effect. It did not appear particularly dirty but the effect has been dramatic: in 14hrs of engine time so far there has been no detectable oil loss.

So it is watch and wait for now.

[a64pilot]

Originally Posted by daga

Thanks deeply for your detailed reply. I have located a workshop manual as you suggested (dunno how I missed it in my prior search) and the job looks doable.

A few days back I cleaned the sump breather, not really expecting any effect. It did not appear particularly dirty but the effect has been dramatic: in 14hrs of engine time so far there has been no detectable oil loss.

So it is watch and wait for now.

That makes you smarter than the average bear, it doesn’t take much as you discovered, too bad we can’t really fit a PCV system, some have using a pump, but I’m not suggesting that, but keep that vent clean