DEPLOY THE BUTT-HOOK! (Why make the climb any harder than it has to be?) 

The rear main is such a miserable seal to get to (gotta pull the transmission or engine to get to it) you really have to get it right on the first try. What I would probably do in the case of a groove is unbolt the seal retainer and take it off the back of the block, get the seal out, try to identify if it's an original or aftermarket seal and then get the opposite seal (OEM if aftermarket, or aftermarket if OEM) trying to move the position of the sealing lips away from the groove. If it looks like that isn't going to work (due to seal position or multiple grooves) then you're into the speedi sleeve. I would also get the speedi sleeve install tool. They used to not come with the install tool, you had to buy it separately. Not sure if that's the case still, but if an install tool doesn't come with the sleeve, buy one. It is CRITICAL that the speedi-sleeve goes down perfectly square or it's not going to work. They are so thin that it's really easy to booger them up trying to tap them down without that install tool. If the engine is still in the truck I would fire the truck back up without the transmission in there and let it build oil pressure and make sure the seal is holding before I put the transmission back in. if the engine is out of the truck, frankly, I would pull the crank and take it to a reputable machine shop and have them fix the groove (weld the groove and machine the sealing surface back to spec.) That would be the best solution, but way more expensive than the speedi-sleeve.

@@WheeliePete Excellent response, I knew that you would have some real solutions. Thank you for writing such a fully comprehensive solution. Jim.

@@WheeliePete I installed a Redi-sleeve from Timkin, now I'm looking for the lipseal install tool, it looks lick a feeler gauge with a handle, I'm trying to get the rear main seal onto the crank without messing up the seal lip. Any suggestions would be great, Jim H.

The rear main seal is installed in the seal retainer, right? That I would do the bench with a seal driver to make certain it is square in the bore of the retainer. (Grease the sealing lips before you drive it into the bore of the seal retainer. With the lips of the seal greased (I would add a bit more after driving it into the seal retainer, carefully work the seal retainer with the seal in it, onto the back of the block (making sure you've got a good gasket surface/interface for the seal retainer to the block.) The main seal lips will flex as you go down over the sealing surface of the crank. The grease on the lips of the seal will help it slide onto the crank and protect them at initial start-up.

@@WheeliePete Thank you, it's all back together now. Jim.