Oil leak rear main sealon 1996 f250...automatic trans,5.8l V8,4wd... how to fix?

There is a trans pump seal between the tourque converter and the pump. I would degrease the entire engine (including the trans)first and put some oil dye in the trans to see if the leak is actually comming from there. It's possible but unlikely.

This may be from excessive pressure in the sump from blow-by from the compression process . It is from a blocked PCV valve that is not equalising that pressure. I have also known oil leaks to happen because the rear main bearing cap is leaking oil past the join around the bolts (loose) or no sealing compound used in assembling the rear main bearing.. I would look at the PCV valve as it is the cheapest test first.. Check that the oil is not coming from the front gear box seal or torque converter seal.

Until the engine is sealed you will not know how much oil is burned. Price the parts. Difference too in whether its a 4x4 or easy access 2 wheel drive.

Check rear seal type to see if it can be changed by pulling trans and flywheel. If stick shift, probably good idea to replace clutch disc to verify not oil soaked. If automatic, oil is no consequence.

Kind of matters how much is wrong. With trans out, some rear engine seals can be replaced without removing oil pan. But if bearings are bad, on 2 wheel drive you may be able to squeeze off oil pan and check bottom of bearings.

You can do poor man's bearing job with plastic-gage. Rod bearings can probable be switched 100%. Main bearings lower cap can be serviced with upper 1/2 left in place. Not ideal, but can save from pulling motor.

Value depends on whether your Labor is free. You have a 14 Year ol truck. Depends on what you already replaced to maintain it or what else it will need. You could need rings after working on the bottom end even with a poor man's bearing job. Plastic Gage can tell you the size you need for each bearing. Then keep track and only buy individual sizes.

If you could find a wrecked truck with a good engine, places like carparts.com have a good multilist. Rule of thumb is different for each person. I would look hard at spending 1/2 of what truck is worth to fix it, knowing other things are wrong.

The pan gasket is cheap. Remove the pan install new gasket. A shop would charge around $100. Now the main seal, it will run you $800+ to fix. Difficult and time consuming.

is the a rear main seal leak? if yes then the trans must be removed, if no then the trans doesn't need to be removed.

Hi,

That engine will leak oil from

- cam cover gaskets (rear one drips on the exhaust)
- camshaft end seals
- distributor shaft o-ring (appears on top of transaxle housing)
- oil filter bracket to block o-ring seal (drips on front bank exhaust)
- crankshaft nose oil seal (have done with timing belt change)
- rear main seal (expensive, leave it be)

First of all, be certain that the leak is in fact from that seal. many leaks travel to that area.

To change the seal is fairly involved, you need to pull the trans and flywheel. There are some specialzed tools involved. Do you have manual or automatic? Manual requires clutch plate alignment on re assembly, by the way , if manual, be sure to change the release bearing and pilot bearing at minimum. Commonly it would make sense to change the clutch during this process....you're already all the way in there..

Could be quite costly. Especially the rear main seal on the engine. You have to take the trans out to even get to it. I would look for something else with less problems to buy.

could be the rear main seal on trans which you pull the driveshaft out then pull the seal out and pop the new one in of it could be the front seal or oil pan for trans.

There are only two paths for oil there. The rear main, and a oil galley plug a little higher up, about 2 o'clock.