Rear main oil seal replacement

[arcturus]

If you have access to hoist its much easier to lift the whole unit and do the work on the bench.It also gives you a chance to clean and inspect everything including the engine bay.Less chance of giving yourself a hernia!

[Army]

Originally Posted by arcturus

If you have access to hoist its much easier to lift the whole unit and do the work on the bench.It also gives you a chance to clean and inspect everything including the engine bay.Less chance of giving yourself a hernia!

Indeed.

I feel compelled to add that if you are of a particular character who thinks "now the engine is out I could..." or "oh look that needs a bit of help..." or " cor wouldn't it be good if..." you are in danger of ending up with a large boxes full of bits!

This has happened to me on numerous occasions - I just can't help myself. In the end of course I'm sure "you do the best thing for the car" but you might not be taking nice trips this summer in a leak free classic Volvo (!) - may be next summer...

...or the one after...

[packers1712]

Having just read a previous thread on here regarding rear main seal leaks my first job is to be absolutely sure that its the rear main leaking and not just oil from somewhere else finding its way to the lowest point and dripping from there!
A real good clean of the engine and run it up again to be 100% sure! Thanks for all of your advice.

Doug.

[Army]

Originally Posted by packers1712

Having just read a previous thread on here regarding rear main seal leaks my first job is to be absolutely sure that its the rear main leaking and not just oil from somewhere else finding its way to the lowest point and dripping from there!
A real good clean of the engine and run it up again to be 100% sure! Thanks for all of your advice.

Doug.

Sorry I'm a bit bored today - I don't usually post on here this much (!)

On my M41 (?) gearbox there's a cover for the clutch arm that looks like it can be moved out of the way to enable inspection inside the bell housing. A cheapo USB camera for a mobile phone is ideal for this type of investigation.

Lots of engines suffer from leaks from the valve cover gasket that more often than not is not replaced as frequently as subcribed - funny thing really - people often seem obsessed about adjusting valves but not so keen on replacing valve cover gaskets.

My B20 has a gauze filled canister on the side of the engine that was pretty grotty before I became the owner - I guess the distributor could leak too (as well as the obvious oil filter housing / mating surface)

Enjoy!

[Derek UK]

I may not be right here but I think that with B20 cars the box has to be unbolted from inside the bell housing. This may or may not be of any concern but it would mean that you can't remove the box to make it easier to remove the bell housing. Dropping out as a pair is best.

[powen1]

Originally Posted by 68jackh

Where abouts in Herts are you.
I'm HP4

Sg6 North Herts :-)

[powen1]

Originally Posted by Derek UK

I may not be right here but I think that with B20 cars the box has to be unbolted from inside the bell housing. This may or may not be of any concern but it would mean that you can't remove the box to make it easier to remove the bell housing. Dropping out as a pair is best.

Hi Derek, Mine is a 1971 M41 gearbox with overdrive with a B20 engine - had the 9mm Allen bolts - Doug could have a quick look underneath to check.

[powen1]

Originally Posted by packers1712

Having just read a previous thread on here regarding rear main seal leaks my first job is to be absolutely sure that its the rear main leaking and not just oil from somewhere else finding its way to the lowest point and dripping from there!
A real good clean of the engine and run it up again to be 100% sure! Thanks for all of your advice.

Doug.

Doug if your not sure where the oil is coming from first check the valve cover gasket common leak area - have a look at the back of engine where the heater fan is check for oil on top of bell housing.
Also I found that removing the alloy bracket that holds the engine to gearbox (6 bolts) you can see the back of the flywheel and maybe work out where the oil is coming from. I assume you have the same as me and oil is dripping from bottom of bell housing ? Also someone mentioned about removing Philips screws on clutch arm you can look inside bell housing but you would need a flexible camera :-)

[packers1712]

It’s this Wednesdays job to check (I have a day off) but i will let you all know what I find, I’ll be well impressed if it’s just a rocker cover gasket but I’m not holding my breath!

Doug.

[packers1712]

Good evening all,
So today’s investigation revealed that the rear main oil seal isn’t leaking but the housing that it is fitted to is, it’s definitely running down from above the crank.
The best that I can see is oil running from one of the housings fixings, I’m hoping it’s the gasket but I’ve ordered a housing, gasket and a seal from Brookhouse to try and cover every eventuality! Is there anything else behind the flywheel that can leak oil I could see a core plug but guessed that was water jacket?
The website says I need a sump gasket too but if I leave the engine in situ I can’t remove the sump so has anyone changed this housing successfully without taking the sump off and replacing the gasket with the gearbox removed?

Doug.