Rear Main

[Moye]

my rear main seal is leaking badly. just pulled it to press in a new one. noticed the housing has liquid gasket all around it. didn't think that would be needed when i reassemble it, but the prior person used it. should i put liquid gasket on it when i put it back together?
also, there pilot bushing is worn smooth and flush with the main bearing. can't get it out. OK to fire it up with the torch to get it out?

 

[resqur]

I just replaced mine...I made a gasket from sheet material...as for the bushing, I cut it out with a chisel. Its only bras and deformed and come out easy. I decided not to chance putting a tourch to the housing.

 

[doghead]

[media]http://www.youtube.com/watch?v=WSGD9UuI5-I[/media]

 

[clinto]

Re: doghead

This is cleaner and easier. This is what I use. Have had it for 10+ years, works on everything from Deuces to mopars.

Snap-On part # A78, $158

 

[plym49]

Grease, or peanut butter from your lunch.

 

[gimpyrobb]

Re: doghead

This is cleaner and easier. This is what I use. Have had it for 10+ years, works on everything from Deuces to mopars.

Snap-On part # A78, $158

$0.30 of grease, or $158. Hmmmm

 

[moriboy]

The grease trick is fantastic, I've done it many times and never had to invest in a puller for that purpose.

 

[Moye]

New Rear Main Seal STILL Leaking!

i just replaced my rear main seal and it's still leaking! not just a little oil, but a lot. followed the TM exactly, made sure the 3 weep holes were clear on the bottom of the housing, put in a new seal and gasket. crankshaft was firm, so main bearing seems OK. also i replaced both main shaft bearings on the gearbox, all tight there now, no wiggle at all. what could possibly be the problem????

 

[WillWagner]

Too much oil in the engine?

 

[doghead]

Is your oil contaminated with diesel fuel? Smell it.

Was your crank hub smooth or did it have a groove? You can renew the surface with a speedie sleeve.

Was your new seal, new or NOS?

 

[gimpyrobb]

What does the oil smell like? It could be gear oil from an over-full transmission.

 

[Moye]

oil level is fine. not too much in there. very dirty and definitely needs changing. the crank hub was very smooth w no groove. i polished it up well before putting on the seal. seal was NOS but seemed fine. it wasn't as tight on the hub as i expected, slipped on without a mallet, just by hand. but seemed snug. maybe it's not tight enough?
i had an issue about 2 months back where the turbo oil drain hose dissintegrated. as i replaced it, some pieces of hose fell in the oil pan. a few hours later, the oil pressure dropped while driving it, then came back to normal levels. any way some how pieces could be junking up oil flow behind the crank and forcing oil out the seal? i made sure the seal housing weep holes were clean when i reinstalled the seal. if junk is behind the seal, can i take off the oil pan and get behind it and clean it out?
is the seal the only place where oil could be entering the flywheel housing? the housing mounting bolts to the block weew all tight and clean.
thnx!

 

[Moye]

its definitely engine oil. i just rebuilt the gearbox, new bearings and seals and proper clean gear oil level. this is dirty engine oil leaking out the flywheel housing drain. about 1/4 cup everytime i stop.

 

[gimpyrobb]

If you have not smelled it, you'll never know. Gear oil in the bell can pickup clutch dust and look dirty. Its either the trans or the rear main seal. After you drive the truck, pull the plug on the trans and see where the level is. The oil pump has a screen on it that I hope would block the rubber. Have you looked in the LDS trouble shooting manual? It has a schematic for the oil flow. I figured the oil would go to the filters first, then through the motor.

 

[Moye]

will do. have the NOS rear main seals been problematic? how tight should the seal fit the crank hub? my NOS seal slipped on by hand w/o using a mallet as the TM said. think it's not tight enough? do you know of an aftermarket better seal if i need to go that route?

also, my clutch disk is new. i cleaned it and the pressure plate n flywheel well w brake cleaner. still had dark oil stains on the disk. think i need a new disk?
thnx.

 

[hemichallenger]

When this happens to me I pull the trans out. Remove the pressure plate and flywheel and spray it good with brake clean. Put the flywheel back in and run it about 10 minuts and remove the flywheel again and find out what is leaking. Are you sure the seal you put in does not need a speedy sleave that would go on the crank.

 

[Moye]

this is the first i've heard of a speedy sleeve. sounds like i may need one. thnx!

 

[gringeltaube]

.....my NOS seal slipped on by hand w/o using a mallet as the TM said. think it's not tight enough? ...................

Q: .... just went in with finger pressure and you installed it with no sealant...?
I don't recall any of my main seals to ever fit that loose. In your case the smallest deformation will cause it to leak! Maybe not as much as you described, but still...

Also to keep in mind: the seal carrier is aluminum, which expands more than the seal's (steel)case, when heated. Also hot oil is very thin and does creep out of anything not tight or well sealed.

G.

 

[Moye]

what should i do next? use a speedi sleeve? use sealant (what type?)? do both? get a new seal? not looking forward pulling tranny and all out again. need to make sure i got it right this time. will def run w the flywheel only to check for leaks before putting back again next time! thnx.

 

[gringeltaube]

After next trip, spray everything as clean and dry as possible and do another short run. Then pull the transmission and try to follow the oil traces. If its running down the bellhousing, behind the flywheel then the next step is doing what Ted suggested. With that black oil over clean surfaces it should be easy to tell where its coming out.

I do not think a speedy is needed here, if the crank is OK. (Just in case, crank diameter is exactly 5.00") Closely inspect the seal's lip: should be a sharp edge; sometimes two in wave form, facing inward. Then try it on (oiled) and check for adequate interference.

A good sealant for metal to metal surfaces is #515 or #518 from Loctite. Otherwise use their (blue, grey, red...) RTV silicone.
Also, when re-installing that carrier w/oil seal, put some RTV on both sides of that gasket....

G.