Which sealer to use

[Chuck W.]

Still chasing oil leaks on my F134 engine, and have a question: The two 3" rubber dowels that seal the rear main cap, is Permatex #2 still the recommended sealer to coat them with?
Thanks!

[Rus Curtis]

From what I've read and practice, those packings get no sealer.  According to what I remember, if you coat them with sealer, you'll never get them out again - and it may be very difficult to insert new ones. 

I can't find a reference to coating the packings in the Service Manual (SM), p D-77, nor can I find a reference in Eric Lawson's rebuild guide:

https://cj3b.info/Engine/Rebuild7.html

The manual does mention applying gasket cement to the cap but I've never added any to the sides (where the packings do their work) only on the top where the oil pan gasket sits.

From the SM, the packings will expand (if you don't trim them) and seal between the block and cap but will be easy to remove if necessary.

I have had problems with the main seal not sealing.  I got lucky the first time I installed the seal and offset it about a 1/4" from the cap seam so that it has a solid rear seal at the cap seam.  That worked well.  This time, I really struggled to get the seal (different type) into the groove and may have added a dab of sealant to the edges of the rear seal halves when installing the cap.  I don't remember now.

I would suspect either the main seal or one of the oil pan bolt holes first.  Is it a fast or slow drip?

[Chuck W.]

Actually, the leak was at the front of the pan, so i pulled the pan down to change the gasket. While I was scraping the old gasket off the block, I noticed that the rubber dowels were not sticking out the 1/4" like they should, in fact, they were actually about 1/4" IN the hole. I got the old ones out and have a couple of new ones to go back in, but found conflicting information on whether to seal or not and with what. Considering the trouble I had getting the old ones out, I think no sealer is a good idea! Thanks, Rus!

[Rus Curtis]

Chuck,
Not knowing what you're having to put up with, those packings - even if old - should have popped up a little when you removed the pan.  Makes me wonder if perhaps a previous owner (PO) did cut them and seal them.  I had to order 3 sets from Walck's (years back) just to get two that would fit.  Hopefully, your replacements slide in.  Lawson suggested water to help.  I've had luck with alchohol making rubber slippery when necessary.

Up front, I did just like Lawson did and smear some sealant across that junction with the timing cover. 

Good luck!

[Chuck W.]

I have a set of new ones, actually, they have been in my spare parts box for who knows how long, but they are still pliable and flexible, and the slide into the holes easily and have the correct 1/4" protrusion. I may need to use a little grease to hold them in, since I am working overhead!
I don't think anyone has ever been into this engine, the old pan gasket was so brittle, it fell off in pieces, and the rubber dowels broke into chunks as I pulled them out. The connecting rod nuts still have the pal nuts on them! I think the 57K miles showing is correct!

[Chuck W.]

I cleaned all the sludge from the oil pan, cleaned the pickup screen,  new pan gasket, new rubber dowels (just a little grease to hold them in), a little silicon as the timing cover joints, installed and torqued the bolts to 14 ft lbs. Filled with Rotella T4, new 51010 filter. No leaks so far!