more rear main seal questions

[thistle3585]

I can't tap the rear main seal out. Can I loosen the rest of the bearing caps and let the shaft drop a bit to take the tension off? Also, I noticed that the rear bearing has some wear marks in it. Is it possible to replace the upper and lower bearing without dropping the entire crankshaft? Also, I assume I may as well change the oil cover seal while I'm in there? Unfortunately, I am doing all this with the motor still in.

 

[PaRenegade]

Yes, and you'd be best to do that because the caps need to be tightened up in a rotating sequence. The rms will be tight till it starts to move. Use a small drift punch and only hit it with one hammer swing at a time, repositioning the punch after each swing. You don't want to mar or nick anything else due to the punch bouncing.

Personally I would not replace just one set of bearings. I'd replace them all due to wear on parts that are measured in hairs. And if one is worn chances are good there may be more worn also.

By "oil cover seal" I assume you mean the oil pan gasket? Yes definately replace that with a good Fel-Pro gasket. I use the 4 piece set and some rtv sealer. Snug the bolts down, then torque in sequence after a couple hours when the sealer has cured.

 

[thistle3585]

Thanks. I tried getting it out with a drift and I will try loosening all the caps. What is the sequence to retighten them? I could not find that in Hayne's. Also, I guess I am using the wrong term but am referencing to also replacing the front main seal? I believe it is on the timing cover.

 

[PaRenegade]

The sequence is like the head bolt seq. A circular pattern getting smaller, working from the outside towards the center. Done in 3 stages. If the torque reqmnt. is say 80 ft.lbs., then do it like 40 the first time thru, then 60, then 80 for the final pattern.

The timing cover seal is a bit more involved, at least on a AMC 258 i6 / 4.2l inline 6cyl. But I can't comment on a AMC 304 . But it's one of those situations that will keep pulling you further and further into the repair. Does the thought "well, I've got it torn down this far" or "while it's apart I might as well replace....." ring any bells? You have to make the call based on your time and money for parts. Other parts have to come off to replace that seal and you may find more to fix, like a timing chain and sprockets, water pump, harmonic balancer, etc. I'm not familiar with your engine though.

 

[thistle3585]

Yeah, I hear what you're saying and I've decided to get the rear seal replaced then it goes back together.

Well, I went back out and decided to take one more crack at it before loosening the rest of the caps and it popped loose. Thanks to all.