I have an '88 f150 4x4. It is a 351W and C6 automatic. I don't know exactly how many miles the truck has because I had a period of no speedometer working, then changed instrument panel. It is approximately 150,000 miles.

Rear main leaks about 1 qt of oil every 2 weeks. It doesn't seem to burn oil at all.

I have been running 10W40 conventional Motorcraft oil and a Motorcraft filter. Been using this combo since buying the truck about 3 1/2 years ago. Change the oil every 3000 miles or so.

I have been discussing synthetic oils with my brother-in-law who runs a quick lube place. He said he would switch.

Opinions? Recomendations? Change oil change intervals?

Any opinions welcome.

 

if you leak that much oil, i wouldnt worry about goin to a more expensive oil, those 351s must be hard on the rear mains, the wife had an 87 years ago and it did the same thing

 

Unless you want to throw money at repairing the rear main, which means dropping the transmission and all that good stuff, try going to a heavier oil, say 20w50 and throwing in a quart of Bar's Leaks Rear Main Seal Repair. Worth a try. The Bar's Leaks Radiator repair totally stopped the leak I had in my radiator, and has slowed the oil leak in my rear main--'95 F150 302 V8 with 96k. Good Luck.

 

Yeah, there's no way I'm going to pay what it would take to fix the rear main. $4 a month in oil will last until the motor needs to be rebuilt.

I will try the bars leak.

 

tstjohn,

I used Lucas Power steering stop leak in my Volvo. The P/S used about a pint of fluid a week. About 2 quarts of the Lucas product dropped the usage to less than a pint a year! I wish I tried it eight years earlier.

I've never used their Oil Stabilizers. They are supposed to stop or slow leaks. But I am very happy with their P/S product.

http://www.lucasoil.com/products/dis...tid=2&loc=show
http://www.lucasoil.com/products/dis...tid=2&loc=show

I was following a truck loaded to the gunwales on the 57 freeway in rush hour in 1996. A 4x8 slide out off the back of the bed and boom! As I hit it, it ripped the body piece off from below the bumper and hit the steering rack. I only had the car a week! My brand new Volvo 850!

-Lance