View Full Version : 351W Rear Main Seal Question

Michele Welch
05-31-2003, 03:26 PM
"We have a 79 Ski Nautique with Ford 351W, Reverse Rotation (RH) engine. Just rebuilt the engine, had to have the crank turned 20 over and now can't get the thing to quit leaking oil, badly I will add, from the rear mail seal. We did purchase the correct seal for the reverse rotation engine, but are still having a problem.

Any ideas??

Michele Welch
[email protected] ("")"

06-02-2003, 08:47 PM
" Michele, if the crank was machined, it's now .020 under (not over), meaning it's that much thinner. Even if your seal was installed correctly, this may be part of the problem. Sometimes replacement oil pumps put out more pressure than standard, or the pressure relief valve malfunctions (which is very rare). A little more oil pressure in combination with a little looser seal can result in a leak.

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Bill Rodgers
06-09-2003, 12:08 AM
"Michele, Post your question at the following site and place "George Help" in the Subject. You will be pleased with the replies. I have a 351W and I think my seal was a two piece. No problems with my rebuild.

http://www.boatered.com/forum/ ("")"

04-25-2004, 09:49 PM
" I have a 351 ford engine in a 89 SUPRA. I am in the process of getting it ready for the summer season. I changed the oil and filter today and when running the boat with my garden hose being used for cooling, the prop started turning while the shift was in neutral. Is this common on these boats or is there something wrong with the rigging of the throttle cable? The prop turned over very slowly but my thoughts are if the boat is in neutral, then the prop should not turn. Please enlighten me.. Thanks "