Perkins 4108 oil pan / sump removal question

[Warby12]

Hi, I am chasing down leaks in our 4108 (surprise!) and I have done the front oil seal and rear one (great fun but made zero difference). That can only leave the oil pan gasket.

I think I have room below the engine to remove it but am wondering if there are any tricks?

Can I ask anyone clever, with experience, is it just the bolts down either side, and the two in the back from the bell housing holding it in place?

[jpendoley]

I just rebuilt my Westerbeke 40/Perkins 4-108. No leaks yet, but its early....
I can speak to the pan issue though, if you have the light steel tank it is prone to distorting under pressure from the silly inch long washers Perkins provided. I fabricated two rails that run the length of the pan and wrap around the front and back corners. They sandwhich the pan lip between the block and the rails. That and some sealant has dont the trick so far. I did the same thing for the cover, fabricating a ring that covers the lip of the timing cover 360 degrees. Really hard to see how that will leak.

Dropping the pan in place was impossible in my configuration, but I can raise the engine with a hanging bracket that slides over the bridge deck. I removed my engine for the rebuild, but I could do the pan in the main cabin if I had to.

[model 10]

There is a gasket surface at the front of the pan and the timing cover that will be a problem. You can do it, but use lots of glue.

[artisanmach]

my 4108 front cover and oil pan had pinholes in them. I did the seal and gasket thing as well.. and it still leaked. that's when I discovered the pinholes. right below the sea water pump dripping from the weep hole.

[artisanmach]

p.s. I found a new timing cover and pan at a place called Farmland Tractor in Albany Oregon. I did have to machine the cover to fit the sea water pump.

[Warby12]

Thanks all! Ours is a cast aluminium pan, pretty solid and has two threaded holes for bolts going in horizontally under the bell housing. I'm sure it's seal is the culprit.

What kind of sealant do you recommend? I have the red RTV silicone sealant but I'm a bit worried that if it fails and I have to remove the old silicon it will become a nightmare.

[jpendoley]

I heard the aluminum pans are much sturdier and less prone to warping-you are lucky. I used Permatex Ultra Black gasket material....so far so good.

[Scubaseas]

Optimum black would be the best choice. Ultra Grey as a second. While ultra black has the best oil resistance you are joining two dissimilar metals and need a high torque and flex gasket.



https://www.permatex.com/gasket-maker-comparsion-chart/

[bongo]

When using a sealant one needs to be aware of the gasket material itself. Most of these gaskets are NOT impregnated with cloth or other fiber that prevent it from distorting under pressure. If the sealant is put on and the gasket is immediately torqued up you will see the gasket squish out at the pressure points. (Probably not as bad with a cast aluminum pan, especially if it has a channel for the gasket). What I do is put a thin film of sealant on both surfaces, and carefully set the gasket on one surface. After the sealant sets, then I put the two together.
I’m debating going for my sump gasket myself. I have the
Westerbeke 40-108 engine hoisted and good access on one side. At the moment I’m trying to get the last two bolts that hold the Paragon transmission in place, (attempting to renew the rear crankshaft seal, which is leaking about 3 drops/minute). Because it is a close coupled V-drive, with the shaft about an inch below the tranny/bell housing/engine, thre is no room for a Kings Point Gasket, (engineered drip pan).

[Warby12]

Permatex Black it is! Previously I tried making a rocker cover gasket with Permatex Red but failed miserably. True, I didn't clean the head surface well. First I built up a thick bead on the cleaned rocker cover, lay it on the head, let it set for a while then tightened it. Leake like mad. Ended up buying a nitrile ( I think ) from perts4engines.com which worked perfectly.
Thanks for all of your advice!

[PineyWoodsPete]

For a totally unconventional repair in a low-pressure application if you can't drop the pan enough for a Perm. Black clean bead full round the flange, consider the repair I did on one of the two two Yanny 2QM's on my Antiqua 37, about 25yrs ago for a high-pressure fuel pump oil leak.

First side, on the leg from BC to San Diego, I had a Yanmar mechanic repair it. I'll attempt about anything else but with shims, etc, no go... He found a gasket defect at one mounting hole, and his $500 poultice cured that one.

But the 2nd, in the same place other side some thousand miles further south, I attacked with a slightly thickened epoxy bead around pump periphery in two application after acetone cleaning and a light sanding. No problem over the ensuing 1500 hours of a 20,000nm + voyage. I used the same on the recurring slow fuel leakage at the steel banjo fuel line fittings that wouldn't stay tightened on the aluminum on-engine fuel filter housings. Again a seemingly permanent cure of an unpleasant leak under the queen berths. These days I'd probably use the very handy G-Flex.

[Warby12]

Originally Posted by PineyWoodsPete

For a totally unconventional repair in a low-pressure application if you can't drop the pan enough for a Perm. Black clean bead full round the flange, consider the repair I did on one of the two two Yanny 2QM's on my Antiqua 37, about 25yrs ago for a high-pressure fuel pump oil leak.

First side, on the leg from BC to San Diego, I had a Yanmar mechanic repair it. I'll attempt about anything else but with shims, etc, no go... He found a gasket defect at one mounting hole, and his $500 poultice cured that one.

But the 2nd, in the same place other side some thousand miles further south, I attacked with a slightly thickened epoxy bead around pump periphery in two application after acetone cleaning and a light sanding. No problem over the ensuing 1500 hours of a 20,000nm + voyage. I used the same on the recurring slow fuel leakage at the steel banjo fuel line fittings that wouldn't stay tightened on the aluminum on-engine fuel filter housings. Again a seemingly permanent cure of an unpleasant leak under the queen berths. These days I'd probably use the very handy G-Flex.

I love a good work around. Thanks!

[SVGreatPerhaps]

Following this thread.

Also tracking down the cause of oil leak. After replacing the rear main seal (front seal seems to be fine), we are still leaking from the bellhousing (flywheel housing)- picture attached. We realized its the cork gasket on the oil pan - see picture of engine, missing the cork seal.

Following for more advice on removing the oil/sump pan while the engine is in the boat and how now to tear anything up in the process!

[Warby12]

Originally Posted by SVGreatPerhaps

Following this thread.

Also tracking down the cause of oil leak. After replacing the rear main seal (front seal seems to be fine), we are still leaking from the bellhousing (flywheel housing)- picture attached. We realized its the cork gasket on the oil pan - see picture of engine, missing the cork seal.

Following for more advice on removing the oil/sump pan while the engine is in the boat and how now to tear anything up in the process!

Well yes, indeedy, this has turned into a saga. I was going to update this thread when the saga was over. SVGreatPerhaps you are right on the money I think. My theory is, the famous Perkins 4108 rear main seal oil leak is often..... the not quite as famous, Perkins 4108 sump / oil pan leak! The gasket, is a nasty four piece mess doomed to failure in my opinion.

Anyway, I dropped the oil pan successfully, cleaned up the pan surfaces and put silicone sealant on. I didn't or couldn't access the surface on the block. Maybe with a dentists mirror and a lot of patience.... Made no difference. Getting at the old seal at the back end of the oil pan join on the block is really really hard. I am sure this is where it is coming out.

I regretted not attacking it with sealant while I had the flywheel off.

Bad news is good news though! In preparation for putting our beautiful, rebuilt gearbox back on, I broke one of the old drive plate bolts off in the flywheel

So now I have to take that off again. While off, I will also take that big backing plate off again and attack the back of the seal as best I can in some kind of bodgy, sealant festival (thanks PineyWoodsPete). The trouble is you can't have the bell-housing and oil pan off at the same time unless the engine is out of the boat.

Stay tuned, there will be photos and either tears or champagne! Then again maybe just a cup of tea (or champagne (or tears)(or champagne anyway!)).

[SVGreatPerhaps]

Bummer Warby12 about the broken drive plate bolt. Nothing like repeatedly removing the transmission! The reason we starting taking our engine apart this time around was that we sheared the flywheel bolts, holding the flywheel to the crankshaft hub! Thankfully three of the 5 came out easily, and the other 2 required patient and careful drilling and extraction with an Easy-out. Warby12, can you tell me if your flywheel has a place for a drive pin or alignment pin? My crankshaft hub has the 5 threads for the 5 flywheel bolts, but also has a smooth bore 6th hole. I was thinking it was for a set pin or drive pin for the flywheel. However, the flywheel has no such hole, just the 5 holes for mounting. Thoughts?