Nope. Ash is that black color you see in your old motor oil when you're changing it. Varnish is what's left of oil after the volatiles evaporate out of it. They're both normal conditions, which is why we change our oil as often as we do -- the oil itself without that stuff would go a long, long time, as it does in the differential. But because it catches ash and the volatiles get cooked out, we get that stuff and have to remove it before it does harm.

 

no no, no no no, no no no.... no

rear main on 5.2/5.9 is a two piece seal thats in a groove inside the rear most main cap and its inside the oil pan. its not external to the motor and cannot be changed from the outside by dropping the trans.

to replace it, remove starter, oil pan, oil pump, loosen the mains, remove the rear main cap. replace seal and reassemble. not too hard.

to answer your original question - the leak will be very slow, and if you don't mind a small and continuous drip of oil, just keep it full and drive on forever.

 

Hey dhvaughan, how long did it take you to replace the rear main seal? I gotta do this here pretty quick.

 

Oops, my mistake. Thanks for setting me straight, and my apologies to all for futzing that one up.

 

i did it as part of a several day plenum and timing chain project, so its hard to remember. with my snail slow pace, and fighting with the starter for a long time, and having to take the starter and plate cover off a second time... probably 3-4 hours. i'm real slow.


i used this DIY guide.
i did NOT have to remove the Y-pipe, jack up the truck, jack up the engine, or any of that nonsense. the oil pan came off easily with a inch to spare.
reinstalling the oil pan is a 2 man job to guide it into place.
squirrels had a good tip to tie the gasket to the pan in the 4 corners with a piece of string.

edit - do seal the face of the flange with the rtv on the outside and either the anaerobic sealer (service manual) or a super thin layer of rtv (shade tree) on the face. or else it will leak across the face.

http://www.pavementsucks.com/tech-article-31.html

 

Thanks for that link. I have to change it out, I can't stand a leaky vehicle. I hear you on the slow part, I'm the same way. I think the job out over and over, triple check everything as I go. Hate to do the same job twice.

 

my starter was a mother ****** to remove. must have been torqued to 175 pounds or more. the engine mount is in the way and you have to use extensions to get past it. 3/8" drive extensions of that length flexed and wouldn't turn. 1/2" drive extensions combined with a 2 foot pull bar finally broke it loose. be sure and disconnect battery when handling starter or you start welding things.

 

+1 on the battery disconnect deal, I learned that the easy way. I watched my dad some how make a connection with his metal wrist watch and he had to peel his watch off because it was so burned into his wrist, he still has the scar.

 

I can totaly see from the picture how to get at the bottom half, but how would someone replace the top half? Special tools? I don't exactly have the smallest fingers for getting in there

 

The top is removed by using a small punch to push the seal through and around. Once you punch it through the opposite end will protrude and you should be able to use pliers to pull it out. Oil up the new seal before installing it. Be careful not to cut the seal on the sharp edges when you install it. Use some sealant in the corners when installing the bearing cap.