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How do I replace Rear main seal
https://www.slantsix.org/forum/viewtopic.php?t=48570		 Page 1 of 1
Author:  65Dodge100 [ Wed Apr 18, 2012 9:51 am ]
Post subject:  How do I replace Rear main seal
I did a search. I can't find much but so far it doesn't look good.

I definitely do not want to pull the engine. Just don't have the time or energy and I HATE trying to get an engine mated back up with the transmission. It just never works for me.

Is it even feasible to replace the rear main seal with the engine still in the truck? It could just be the pan leaking but my clutch is acting "grabby" so I'm pretty sure it's the rear main.

Also, this engine never leaked anything. It sat for a long time, 10 years or so. Is there a chance the seal just dried up and will expand now that I'm driving it and start sealing again? I'm sure it's the original rope seal. Nothing has ever been done to the engine - has about 70k miles on it.

It is a truck too so I have a little more room than a lot of you guys do...

Thanks,
Danny
Author:  CNC-Dude [ Wed Apr 18, 2012 10:26 am ]
Post subject: 
Rope seals are hard enough to remove when the engine is on an engine stand and the crank is removed. I don't envy that job. Hope its just the pan gasket for you instead.
Author:  Joshie225 [ Wed Apr 18, 2012 11:23 am ]
Post subject: 
Yes, you do want to pull the engine. Replacing the pan while under the vehicle is miserable. Replacing a rope rear main seal is near impossible with the crank in the block. If the seal dried out and stuck to the crank then it's likely been shredded and there is no hope for it to seal again.
Author:  65Dodge100 [ Wed Apr 18, 2012 8:07 pm ]
Post subject: 
Well I wrote a reply and it lost it somehow. Just as well it was mostly whining. Thanks for the advice guys but I can't use it. The engine is not coming out of this truck at this time.

I'm not able and I don't have the equipment. I would have to change it while it was swinging on an engine hoist. Is that easier? I have an engine stand but I don't think it will hold this thing even if I were able to pull the engine. My health just won't let me.

Are you saying the crank has to come out to change a seal? That's over my head. I'm not an engine builder.

I know it's been tried. I know it's been done. Is there any advice on how to do it without screwing something up? I've done it before when everyone said it was impossible - on a car that it was impossible to remove the pan.

And I did not remove the pan.

But I DID put a rear main seal in it. Also tore a rotator cuff that took a couple of years to heal but I put a seal in it. Very good mechanics still scratch their head trying to figure out how I did it.

Engine not coming out. Need more input. #5 is alive.

Thanks guys,
Danny
Author:  WagonsRcool [ Fri Apr 20, 2012 11:33 am ]
Post subject: 
The slant 6 has an "old school" split type rear main seal. It is captive, sitting in a machined groove- the top half in the block, the bottom half in an aluminum retainer. Older ones might have been "rope-type" (woven graphite packing), but all replacements (& most old ones) I've seen were a 2-piece rubber lip seal.

To replace it you have to remove the oil pan & the seal retainer. The rubber lip seal is "fairly" easy to drive out from the block, but the rope type can petrify, requiring you to at least loosen the main bearing caps & sag the crank down (can't do that with the trans & possibly timing cover in place). Since it's very difficult to R&R the oil pan in the vehicle (without ending up with more oil leaks) anyway, the suggestion to pull the eng out is a good one. When putting the new seal in, make sure the lip points to the front of the eng, & use RTV silicone to seal the retainer instead of the cardboard strips that come in the kit.

Last thought, if your clutch is getting grabby due to oil contamination, you could have gear lube seeping past the input shaft seal on the trans.
Author:  65Dodge100 [ Mon Apr 23, 2012 4:29 am ]
Post subject: 
Thanks WagonsRcool, and thanks everyone for the input. It just seems to be looking more and more bad. I was thinking of "sagging" the crank but forgot about the transmission being in the way. I don't know which I'd rather pull - engine or transmission. Jeez I hate pulling engines! Not real crazy about transmissions. Project creep is going to force me to put a new clutch in while I'm in there. Throw-out bearing is starting to make a vibrating sound.

I know some do it a lot and it works - they know what they are doing. I've just never had any luck at all pulling and putting engines. It always seems to end up a nightmare.

I could still pull the pan and the rear cap and see what I can do but from the way everyone talks I'd be lucky to get the pan back on and sealed. I am meticulous and patient though. I think I can do it. It's about to get too hot to work here soon anyway. I guess it will leak for a while until I figure out what to do.

Thanks,
Danny
Author:  hantayo13 [ Mon Apr 23, 2012 2:45 pm ]
Post subject: 
this is a truck???? you can loosen engine mounts ,jack/pull front of engine up and remove oil pan...aint easy but can be done
Author:  65Dodge100 [ Tue Apr 24, 2012 4:55 am ]
Post subject: 
Quote:
this is a truck???? you can loosen engine mounts ,jack/pull front of engine up and remove oil pan...aint easy but can be done
Thats what I'm hoping/thinking too. I have a few projects all going at the same time on the truck at the moment but if I get to it I'm going to try that first.

Thanks,
Danny
Author:  65Dodge100 [ Sun May 06, 2012 5:39 pm ]
Post subject:  False Alarm
I really appreciate all the advice and from people I really respect.

I think I screwed up though. I felt behind the valve cover and got an oily finger. I had replaced it with a rubber gasket and everyone said not to over tighten it... I tightened the rear two and the next two toward center. Now it's not leaving a piddle everywhere it's parked.

I'm still watching it but I think the rear main is okay. Some things do work in a good way. I haven't seen that in a while.

Thanks all. I'm still getting ready to pull the engine in case I'm wrong. I just can't right now. I know you are right. I come here for advice and I got it from some of the best. I just can't do it right now.

Thanks,
Danny
Author:  ValiantBoyWonder [ Mon May 07, 2012 1:02 am ]
Post subject: 
how did you find out it needs to be replaced (diagnosed?)...
Author:  65Dodge100 [ Mon May 07, 2012 8:33 am ]
Post subject: 
Quote:
how did you find out it needs to be replaced (diagnosed?)...
I was just going by where the puddle of oil it was leaving was - right at the junction of the transmission and engine. I had just replaced the valve cover gasket and didn't even think about it - assumed it was the rear main.

Danny
Author:  ValiantBoyWonder [ Mon May 07, 2012 9:36 am ]
Post subject: 
keep us updated here on how it all works out..
Author:  Doc [ Mon May 07, 2012 9:37 am ]
Post subject: 
Have you re-tightened the oil pan bolts?
Does the engine have spark plug tubes with new seals?
Make sure the oil pressure sending uint is not leaking, when under pressure.
DD
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