Replacing rear main seal without dropping crank? (NAA)

[verticaltrx]

Well my Jubilee is up to using 1qt per hour when bush hogging, etc, so it's time I do something about the excessive oil use. It's leaking profusely out the rear main seal and a little out of the pan. My plan was originally to just pull the engine, do a complete top to bottom rebuild and be done with it, but winter has turned to spring and I need the tractor before hay season (so I need to get it going quick). I also did a compression test on it and it was between 112-120psi on all cylinders, so I would guess that the engine is in decent shape, oil pressure is almost 40psi hot, no knocking etc.

With that being said, I ordered a full gasket kit from my local tractor parts dealer (probably Tisco brand) and I'm going to get started as soon as it comes in. My plan is to just drop the pan, rear main cap, and pull the old seal out, slide a new seal in around the crank, put in the new packing along the main cap, new pan gasket and be done with it. This sounds great in theory, and I know it CAN be done, but I know it wont be that easy.

Any advice on this operation would be great. I have virtually all of the service literature made on this tractor (I&T manual, Ford shop manual, owners manual, parts book, other ford books, etc) but first hand experience/knowledge is what I look to first. I don't know if the kit will have the old rope type seal or a new neoprene one, pros/cons of each? Any tips tricks to replacing a rear main seal without dropping the crank? Just bit the bullet, split the tractor and do it on the engine stand?

Thanks in advance.
 

[Hobo,NC]

Pull the engine,,, flip it over,,, remove the crank and have it turned,,, buy good a name brand gasket set,,, only way I will do one if it does not have excessive crank case pressure... if it has blow by then I go for the kill...
 

[verticaltrx]

Thanks for the replies. For some reason this one is the only reply that showed up in my thread, the others were just in the ford section with Re:(my title) as the topic.

Anyways, good info and input. I am afraid that once I pull the oil pan and rear main cap I will be pulling the engine to do a complete rebuild. I have noticed that the crank has more fore/aft thrust movement than I would like to see, when you push the clutch in you can see the front crank pulley move forward slightly.

A little off topic, but if I do decide to do a complete rebuild should I just get the engine bored slightly over and go with an overbore piston (which despite the fact that it has sleeves, is what the service manual recommends), or go ahead and get a kit with new sleeves and pistons? Every kit I have seen has sleeves, but CNH sells overbore pistons.
 

[john_Bud]

I don't have much ability to change rear rope seals in place. I would first check compression and blowby on each cylinder, then determine if it just needs new seal or a rebuild.

It could probably get by with new bearings, rings seals, gaskets and a valve job. The valve guides are press in and cheap.
 

[verticaltrx]

I dropped the oil pan and main bearing caps on the tractor last week and found that the engine had recently been rebuilt. The bearings were .030 under and looked almost new. When I pulled the rear main cap off I found a new style rubber seal that not only had they lined the edges up with the bearing cap (bad), but they installed it backwards (really bad!) Needless to say its easy to see why it was pumping oil out.

I got my Tisco gasket kit which came with a rope seal, so I decided to go to New Holland and get a two-piece neoprene seal. Got it installed no problem, mains all torqued back to spec etc, but now I can't get the wedge seals between the main cap and block to seal. I tried the set from Tisco first, soaked them in oil for a few min, pushed them in and left them for a couple hours, they didn't swell. Went to New Holland and got a set (which looked identical to the ones from Tisco, green in color), soaked them in oil really well, pushed them in, and 24hrs later they still have not swollen into place. Anyone have any suggestions on where to get a set of wedge seals that will actually swell? Look for some of the original rawhide ones? Any suggestions would be great.
 

[john_Bud]

That's weird. I actually had to install mine dry as they swelled so fast they only got 1/2 way down then stopped.

I've read guys clean and dry all the parts and use a coat of RTV.