Oil pan gasket and new rear main seal- tips?

[Basod]

Changed all my fluids diffs, TC, Transmission and engine.
Started it up still on jack stands to see if I could get into 4h and with it idling a steady drip from the RMS- it’s been leaking slightly and getting worse over past few test drives.

Picked up a new pan gasket and rear seal this afternoon with some 15w-40 as what I’ve read here 10-30 isn’t really recommended. Still don’t think heavier oil is going to fix this one.

Anyone whose done it before is it better to have axle on jack stands or on frame for extra clearance?
Also torque specs(fsm is on my work puter)
10 ft-lb on the oil pan
80 ft-lb on the rear main block
At a loss on the lower rail bolt torque- not sure these models have it like later AMC 258 i6 / 4.2l .

 

[lowcountry]

I'll just address one of your issues for now. If you have an oil leak, going to a heavier weight oil will not stop the leak...

 

[Basod]

I'll just address one of your issues for now. If you have an oil leak, going to a heavier weight oil will not stop the leak...

Understood that’s why I’m doing the seal tomorrow. The engine will be 35yo on 7/17/19 if my decoding is correct: 407C17.
4 is 1984, 07 July, C 258ci, 17th day

 

[Lumpy Grits]

How do you know it's the rear main seal and not drip down from the back of the valve cover?
You need to remove an engine mount to drop the oil pan.
Hope you have a torque wrench, and a tool called a 'sneaky-pete' is handy for the seal install.
https://www.amazon.com/Lisle-27000-Sneaky-Pete-Tool/dp/B0002SRCJW

Also-Check to be sure your PCV valve is clean and functioning correctly.

FWIW-I run Castrol 20W-50 with a blue bottle of STP, year round.
I lose maybe a 1/4 cup of oil in 2500-3K miles from main seal drips.
Just ain't worth the hassle-yet.


LG

 

[Scout1067]

I am curious to hear how this job went as I am looking at possibly doing a main seal replacement in a month or so if my leak is not the Valve Cover.

 

[Basod]

It’s definitely not coming from rear of valve cover and I ruled out the pcv and breather. I have a drip every 4secs at idle it slows to 1-2 a minute when off.

Anyways the fsm temporary support seemed a little hokey supporting the engine on the fenders. I used my homemade steering wheel puller and added another 7/16” hole now it’s all rigged up to a chainfall on my garage beam.

Ideally I’d have used a 7/16-14 eye nut but none to be found locally.
Will update with progress tomorrow- heat index was 104 today

 

[elwood blues]

I did my oil pan gasket and rear main seal last year. I can tell you that rear main is tricky to get out. I ended up using a small drift punch in a socket, with two extensions on it and gently tapping it around until I could get a set of needle nose pliers on it to pull it out. It's tricky, and you have to be very careful to not knick anything with the drift punch.

Also, when installing the new rear main, make sure you follow the directions, there is a right and a wrong way to install it.

Did you get the one piece oil pan gasket? It's definitely worth the extra $$$, it's easier to install, and it's almost leak proof. You only need to rtv the corners and by the water pump. Definitely recommend it.

On the recommendation of SOWHAT, who lives like 5 minutes away from me, I also installed a Melling high volume oil pump while I was in there. I ordered one from Summit, what it didn't tell me was that it came without the pickup tube installed, and if you don't have the correct tool to install a oil pump pick-up tube into the pump, it's basically impossible to do on your own. SOWHAT hooked me up though and took it to work with him and got mine together the same as his.

I have great oil pressure now all the time.

 

[Basod]

All back together started around 7 and finished at 2 with a few dips in the pool and water breaks. Mostly cleaning old cork gasket and oil pan crud.

The motor mount came out easy, I did loosen the driver side to get the engine up a bit. It fought me going back together. An extra hand would have been nice kind of had to rock the engine and try to get bolts started.

RMS came out relatively easy I used a finish nail punch that is radiused from a past prying experience. Getting new one started back in is little challenging but it slid right in snugly.
Bearing had some scoring that’ll wait for another time.
Cap torques down in 40-60-80 increments.

Not a bad job. Time for test drive and leak check.