Oil leak near rear crank seal, but not rear crank seal

[jeremy93ls]

I've had a slow leak for years at the engine/transmission area and hoped it was just an oil pan gasket. After replacing the gasket with a rubber Fel-Pro, it continued to leak near the same place.

I pulled the transmission (quite fun by myself) and clutch/flywheel only to find that the rear crank seal was not the source. After cleaning it all and letting it sit overnight, I had a small amount of oil above the pan/gasket, but not a drop from the seal. It looks to have been replaced when the previous owner had the clutch done years ago. After wiping it clean again, I carefully tightened the 3 oil pan bolts just a bit and saw oil ooze out from these two areas:

Would replacing the two 'side seals' solve this problem? Should I bother replacing that main seal while its accessible? Bummer I pulled the transmission only to find this out, but it did give me a chance to clean 40 years of gunk off it. I can adjust the parking brake assembly, too.

Edited June 17, 2018 by jeremy93ls

[Zed Head]

If the engine is not running most of the oil is below that seal area.  It's in the pan.  When the engine runs that's when that area will leak.

[Diseazd]

Replace the rear seal. I just had the same problem. I pulled the flywheel and the seal looked leak free, but in the time it takes to pull the tranny the oil (very clean and invisible after sitting) it can look like it’s not the culprit. When you install a new seal, push it in a little farther or a little less, so it doesn’t set in the groove left by the old seal. I thought mine was a waste of time, but my leak is gone. BTW.....I carefully drilled two small two small holes on opposite sides of the seal and power drilled in two long wood screws which I used to pry the old seal (actually only 1000 miles) out. Just take your time so you don’t mar any metal. Side seals are hardly ever the problem unless no sealant was used. Z Doc told me he didn’t even use sealant on side seals and said he still never had them leak....the stick seals do the job by themselves pretty much. I have since bought a Lisle seal remover tool for the next escapade. BTW, liberally grease the seal lips and crank journal before installing. Good luck.....nice to not have a leak anymore.

Edited June 17, 2018 by Diseazd

[jeremy93ls]

It's been a few weeks since it was running and oil has very slowly, but consistently dripped. Maybe that extra quarter-turn on the rear pan bolts took care of it. I'll have a look tomorrow after wiping it clean this afternoon.

Is the oil wicking up between those two areas I'm pointing to in the pictures?

I'll replace the seal for good measure.

[Dave WM]

I resolved a leak, it was obvious from the side seal. You could  see it in the attached pic. I used the after market kind and applied sealant as the FSM directed. This was after replacing the pan gasket and the rear main and still having a leak that looks like the pan gasket back at the rear of the pan. bone dry since replacing the side seal.

 

Edited June 17, 2018 by Dave WM

[jeremy93ls]

I've got a Fel-Pro seal kit and clutch alignment tool on the way from Rock Auto. Oil still builds up at the same place I'm pointing to above, so I'll replace the side seals, too. It's got to be coming from there. Dave, what sealant did you use?

I always like a new tool, but think I'll try the wood screw trick first. It sure looks like a good curved pick would yank it out of there.

[siteunseen]

Sorry I'm late to the thread but those felpro "nail side seals" suck. I have the Nissan part number if you want it.

One of the best tips I've gotten (hundreds in all) was from @Diseazd. He told me how to get the rear cap about 3/4s down then put the sides in, push them down then torque it. Works great.

I use the black RTV for oil and fuel. Good luck with your task.

[jeremy93ls]

I'd be happy to have that Nissan part number. I don't want to do this again anytime soon. Our basement has that transmission fluid aroma my wife is not so fond of.

[siteunseen]

Goog these numbers, their receipts are lacking. I think  its the  12289-W0400

and here sthe rear main  12279-2B500

M phones takin  dump right now for some reason

 Sorry.  Wil follow up with my laptop in the morning. I

[siteunseen]

Google these numbers, their receipts are lacking. I think  its the  12289-W0400

[jeremy93ls]

Mah man. Thank you sir.

[Dave WM]

don't let the sealant setup apply sparingly where the FSM shows it and reassemble immediately.

The FSM does not mention this (IIRC) but the how to rebuild you Nissan book does. The book notes that you don't want the sealant to impede the bottoming out of the bearing journal at all.