Chipped Block

[MJlife]

Hello all. I am currently stripping my 4.0 from 89 Mj to do a rebuild. Everything is looking good so far. Then I went to remove the rear main seal on the block side. I’m sure I’ll get some backlash on this but I’m already beating myself up for it. I was not beating it with a hammer and the previous owner put a plentiful amount of RTV on it. Then a piece came with it. It chipped on the inside and not sure what it will effect. So my question is whether it will be fine or should I seek another block. Thanks in advance. 

[Warren Mohler]

run it I always put a dab of form a gasket there anyway

[MJlife]

Great thanks so much it’s going to the shop this week to get hot tank!! 

[Dzimm]

I'm pretty doubtful that will seal up completely but you never know.  At this point I'd put quite a bit of rtv or some kind of sealer on it and hope.  If you are lucky it will only drip like all Jeeps do.

[Eagle]

I think it'll be fine.

 

[DirtyComanche]

Given how cheap a block is I'd get another one.  Yeah, it probably will seal, but I had a truck that I fought with the rear main seal on and hated every minute of it.  Personally I think it will be okay, but the two piece rear main seal is a weakness to begin with.

 

 

I got $4.51 for the last block I got rid of.  It was a NVH block too. 

[75sv1]

Do you have the other piece?  If so, I'd probably soft soldier it back in place. That is after it was cleaned. If a bunch of $$ is going into this, then I might search for another block.

[MJlife]

Thanks again for all the replies. When I drop it at the shop I’ll ask what they could do with the chip wasn’t really sure about soldering until 75 brought that to light. I’m not spending crazy amounts of money on the rebuild but would prefer to only do it this once for a long while. Plus the rest appears to be in great shape. The magnaflux will bring light to that though. I’ll post results as they come along. 

[Minuit]

My 91 has a similar chip, but on the other side of the seal. I reluctantly put it back together expecting oil to pour out of the back of the engine. It's totally fine and has been for years. I can park my truck on a concrete floor for a week and not see any oil on the ground.

 

Make sure you use Mopar anaerobic sealant between the seal halves and my guess is it'll be OK. Make sure there aren't any loose pieces of block left where the chip broke off.

 

Also, get a new drain plug for your oil pan. That is an overlooked possible leak. It contains a crush washer with limited life.

[derf]

8 minutes ago, Minuit said:

I can park my truck on a concrete floor for a week and not see any oil on the ground.

Are you sure there's any oil in it? 

[Minuit]

1 hour ago, derf said:

Are you sure there's any oil in it? 

We'll, I drove it 70 miles this morning and no pistons escaped, so I reckon there's gotta be something in there

[DirtyComanche]

7 hours ago, 75sv1 said:

Do you have the other piece?  If so, I'd probably soft soldier it back in place. That is after it was cleaned. If a bunch of $$ is going into this, then I might search for another block.

 

Or braze...  Pretty easy to do.  I didn't really think about that, but I'd 100% do that before "just sending it."

[Liketosmash]

I had nearly the same issue on the block I just rebuilt.  My mechanic friend who helped me with the rebuild has rebuilt many much higher performance engines was not too concerned with it based on how the seal functions.  I have about 100 miles on the engine but so far no issues.

[MJlife]

That’s good to hear. I’m still trying to get it to the shop. Busy week thanks again for all the replies. 

[MJlife]

Update..... Brought it to the machine shop and they have no concerns. Should seal no problem. Guess I’ll really only know for sure till it’s running again but he was very experienced and I’m trusting his judgement.