Thanks Poser. I just did my pan gasket per your instructions, but with even more RTV. It was several hours of work to get the old cork off, and I hear using RTV on the flats, while not needed for sealing, will probably make it easier to disassemble later since the cork might not embed itself into the metal surface so much.
If you're on this thread, you're probably also doing the rear main seal, which I'm doing for the 2nd time in a year. On mine, I went through a tremendous amount of water last year, not deep, just fairly fast, maybe 70 of the 500 miles we did off-road was really wet trails. I think I got more water in the clutch area than could drain out. And there was oil in there too. So if you're in that far, let me tell you that this can cause a lot of damage. The release bearing had over 0.5mm slop after only 1500 miles due to dirt, water, and oil intrusion. The clutch spring plate had dirt and oil collecting on the area where the plate goes under the wire rings that hold it in place. This grime smelled like GL5, the rest was engine oil and dirt.
I'm changing transmission & transfer again this year (had a bad output shaft spline on transmission last year, and didn't have time to fix an out-of-spec high speed gear wobble in the transfer before I put it all together last year). I also didn't like the H41 I got by mistake. Great for crawling, which I really needed for about 4 minutes of that trip, but way too low for the usual driving in my area. I've never had an issue with climbing stuff around here with an H42.
Anyway... What I did to prevent this was:
1) If you're using an unknown transmission like I did, make sure to change the input shaft seal on the transmission, no matter how good it looks. It looked perfect, but it leaked. For that matter, replace every seal you can get to. I did every one but that one since it seemed fine. Big mistake.
2) Really inspect the oil pan seal before doing a clutch. If in doubt, now is the time to change it. Mine did have a slow leak. Spray everything down, wipe it off, start the engine (with the flywheel still attached), and if it weeps at all, change it.
3) The rear main seal goes with the garter spring to the inside toward the engine. This was evidently done backwards before I bought the vehicle. I replaced it the same way. It worked fine until I started it after having it sitting in the garage for 6 months, I heard a funny noise, it ran fine, but then it started leaking like before. Probably spun it or it gripped the crankshaft over the winter. When it got turned over, it probably got the twisted beer can effect and that was enough to pop the spring off toward the flywheel (wrong way). Fill the inner lip with NLG2 grease, leave the outside dry.
4) If you're doing the pan, by all means install the rear main seal by taking off the bearing cap like Poser suggests. I was very happy to see the bearing looked nearly perfect after 150,000 miles.
5) Find the 2F manual to find the torque values. That bearing cap is cranked TIGHT. I looked forever and could not download one. Finally noticed a guy has a link in his signature. Here it is:
Index of /Cruiser and M416 Manuals You need this. I spent a LOT of time trying to find proper torque values for everything I undid. Search didn't work, but browsing did.
6) That should take care of any possibility of oil getting in from seals. Now you need to prevent water and dirt (and oil) coming in from any other areas. I sealed the area on the top of the bellhousing above the crank with GOOP. I slathered it on about 1/8" thick. It will take a while to dry but will seal the area. Once I started the vehicle, it will stink some more (smells like 1-1-1 trichloroethane). It reduces a lot, to maybe 1/32" thick but forms a nice seal and can be peeled off if you need to remove that later. I hope it can take the heat.
7) If your seals on the bottom of the inspection cover are not well attached, you might peel them off and re-attach. Soaking in simple green (the most amazing detergent on earth) will remove some of the oil, but mine were oil soaked. I used GOOP to attach, but I think RTV might be better for those. GOOP is too thick to spread well and didn't like the oil still present. It will be fine though. By the way, simple green is by far the best laundry pre-soak there is. Spray your black greasy spots, rub it, and wash. Unbelievable stuff. I have the clear simple green aircraft variety. Nothing can touch it.
8) I'm attaching the rubber vent cover (opposite the clutch fork boot) and the clutch fork boot with GOOP as well. If they get oil soaked, they expand, probably not much you can do after that, but it might help. I won't have any oil now so I won't be doing this again anyway. If you haven't heard of it, it's marketed as "amazing GOOP" and is a thick, clear solvent based adhesive that you can spread around and it will adhere most stuff and remain flexible. It's not like a silicone caulk though.
9) Let the water out. Mine had the plastic plug in the bottom of the inspection cover. I left that in, but drilled (2) 1/8" holes on either side to let anything that still makes it past my defenses out.
10) Once the inspection cover is on and bolted, I plan to seal around the oil pan curve also. If there were any seals in this area, mine are gone. If not, this is probably how most of the water got in as there is a pretty large gap there, about 3/16", but the bottom of the inspection cover was very well sealed. The gap is so big, I'm going to use "great stuff", the spray-on foam that expands. I'll shoot it from a distance so only a little bit gets under the lip. The foam stuff should prevent water entry from the front. (It's usually used to seal air from getting in various cracks in homes). Temperature should not be an issue, it's polyurethane, so it should melt at 280°C. If it gets that hot, I have bigger problems.
11) I researched Hylomar which sounded like a great sealant, but decided not to use it on the oil pan. I guess the stuff is applied, and dries to the consistency of artificial fishing worms or gummy bears, but never sets much more than that. I read a story about a guy finding it on his oil pump screen and decided on RTV instead. But I hear Hylomar is definitely the best for a metal to metal gasket material.
12) The clutch disk didn't seem to have any issues, but did get some oil on it. I scrubbed it with simple green and it's as good as new (well, it was new anyway)
13) If you have the transmission and transfer case out, the root cause of the bad output shaft on the transmission is that the washer behind the stake nut can flex. So when you crank it to 110 ft lbs, it's fine, but if it flexes at all over time, maybe the staked nut is no longer as tight as it used to be. So now the splines on the transfer input gear can slap. The new design of the stake nut includes the thickness of the washer (you don't use one). Now the whole unit is very stiff and can't flex and cause this issue. I ordered my new design ones from SOR. This should work great on the transmission output shaft. On the transfer rear output shaft, where the parking brake is, it looks to me like the spline where the washer rests has some taper to it. And the washer is usually deflected there. So maybe this new design will only contact on the OD of the parking brake drum spline and may not be a good solution. It may have too little contact area, brinell out under stress and cause a similar issue. A compliant washer might be better here. I might re-use the old ones there (swapping front shaft to back so the stake area is fresh). Not sure if the new design is a benefit in this area. Update: New design won't fit where shafts connect. The nut size is so big you can't get a socket on it and fit inside the flanges. I think SOR thinks they will fit, I'll email them. Great solution for the transmission output shaft though. Update2: The new design WILL fit on the rear shaft / transfer output shaft, and you can get a (32mm I think) socket on it. It will not fit on the front output shaft. I had to re-shim my output shaft to take up some slack in the bearing while looking for a driveshaft vibration. It has no play now at all, yet still rotates with just a little preload, another post I should write on what I learned there. This can be done with the transfer in the vehicle. Luckily, we have a waterjet machine at work, it was easy to make a shim kit for this. I added 0.015" (0.4mm) to the 0.006" (0.15mm) original shim. Sounds like a lot, but this distance is also controlled by the new gaskets you will put in, so a small variation in gasket thickness could cause a preload issue, if not just ordinary bearing wear.
14) This pilot bearing didn't feel too bad, but I've had an issue sometimes with the transmission being driven by the pilot, mostly when wet like this. I replaced it with the style that has 2 rubber seals. If you have a slide hammer, mine has 3/8-24 threads. It just so happens that a 3/8-24 socket head cap screw fits just right inside the pilot bearing, making removal really easy. I wish I knew that last year.
15) Did I mention simple green? Holy Toledo, Batman. I spent as much time cleaning as wrenching. It's easy on your skin too. The stuff is incredible.
Hope that helps. Keep oil and water OUT, or at the very least, let it out. I had to do mine twice for other reasons anyway (transfer case) but the oil and water issues forced it before our next trip. You don't want this problem, trust me.
Check out this year's trip at
Upper Peninsula Overland: Upper Michigan Adventure Tourism. Get Out.
I now have an H41 for sale (no issues), an H42 with a bad output shaft spline (but otherwise fine), and a transfer case that has too much clearance between the high speed gear and the output shaft... Make offer.
Good thread, I hope I can prevent someone else from having the issues I did... Mike S.
