You got a little more work to do, pull that bell housing adapter plate off and then you will have a seal retainer, pull the 8 ? bolts out and there is a seal on the back of that,it makes replacing the main seal a lot easier. if you Text me ill send you some pics of when i did mine , and i got my seal kit at napa and it had both seals in it ! Oh and from your picture it looks like you just drilled a little into your old seal, the metal part so you should be fine !
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Jeff

 

Hey sorry to introod, but I believe my rear main is leaking also...just wondering how hard they are to replace and how much it costs?? Thanks

 

The seal cost about 35 bucks for both, and its a day job for sure, drop your tranny, drop your bell housing adapter plate, pull seal, replace, repeat . alot of other little stuff, but that the down and dirty you will want a trany jack

 

service manual says to install a new "rectangular ring seal for cam bore", while replacing retainer, has anyone had to do this? does this seal come with the retainer?

Yep, if you pull the seal retainer off to change the seal you need the new gasket. You could use silicone gasket makes but I don't trust in that loacation.

The gasket is avialble separately.

 

Pull bell housing, remove seal retainer, 6 bolts. 8mm bolt heads. You may or may not damage the oil pan gasket, I always try to slide a feeler gauge in between the retainer and gasket to try and separate the two. I would replace the retainer, cummins is cheap and they don't include alignment dowels so you have to make sure the retainer is center, it is crucial that it is centered or your rear main will not seal. You can use wooden dowels or take 4 measurements from around the crank. I always use gray rtv and goop it up real well to get everything sealed beck up. If you do tear the oil pan gasket, you can buy a new gasket and cut out the rear section of the gasket and rtv it in. Says to do that in the cummins manual.

 

If you purchase the "premium" rear main seal kit from autozone it comes with the retainer gasket,the real main seal, the starter sleeve, and the alignment tool. All for about $30 if I were you I would buy one of these and never have to worry about it New Improved No Leak Rear Main Seal for Cummins 4BT 5 9 6BT 6 7 Diesel Dodge | eBay <<<He also sells an alignment tool but it's cheaper to just buy the autozone kit, toss the rear main seal and use the gasket and alignment tool. Watch his video in the listing for more info on the install, EXTREMELY helpful

 

Thanks guys, I ended up just getting a new retainer from cummins and throwing it in, haha im a real dummy,
FYI the rectangular ring seal it says to replace in the manual goes into the bellhousing adapter and seals it to the end of the camshaft, i got a new one but I really don't think it was necessary to replace it.