Cars We Remember: Fixing a Leaky 1957 Ford Thunderbird

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1957 Ford Thunderbird Bestride
Jim Gardner and his grandson, Tristin, enjoy a ride in Jim’s absolutely beautiful 1957 Ford Thunderbird. Gardner needs advice on what to do with a constant rear main seal oil leak coming from his 292 V8. A respected machine shop owner has some sound advice for Jim in this week’s column. (Jim Gardner Family photo).
Q: Hello Greg. I enjoy your articles very much and I see them in the Easton Express in Easton, Pennsylvania.
I own a 1957 Ford Thunderbird with a 292 V8. The rear main seal leaks oil, and the former owner said he had the seal replaced two times. He told me to live with the leak because the Ford 292 Y blocks always had this issue.
Do you know of any fool proof solution to this issue and what would be the expense to the fix?  Thanks for the info. The engine was rebuilt about 10,000 miles ago and runs great.

A: Jim, sadly, you’re friend is correct that the 292 V-8 has been cursed with this rear seal problem. I also have a 292 Y-block V8 in my ’59 Edsel Ranger, and until now, the rear seal is holding its own.
Since my engine has never been rebuilt, that ol’ 292 still has the original Ford-Edsel-Mercury “rope type main seal” that, not surprisingly, contains asbestos. The new 292 main seals that are used in re-builds today I don’t believe contain asbestos, which may be why this “curse” hits the 292 more so than other V8 engines. IE: When the original 292 seal leaks or the engine is re-built, use of a “new” rear main seal just doesn’t get the job done, as proven by it being replaced twice already since the re-build.
Although you could pour a can of a name brand “rear main sealer” into your crankcase (with hopes of a miracle), the reality of the situation is that even if these products do offer a temporary fix,  both you and I know these “sealers” won’t cure bad leakers for any length of time.
Thus, to assist in answering your questions, I contacted Harry Nikulich of Harry’s Machine, in Sayre, Pa. Harry is a well-known and respected machine shop owner and former drag racer. Harry recommends a complete engine removal that will allow a machine shop to get to the problem area, check the crankshaft, rear main seal cap and mic everything for roundness before installing a brand new rear main seal. Surprisingly, Harry said he would charge in the neighborhood of about $125 to make sure everything is machined to perfection, including the crank, rear main and cap. Nikulich said he charges $40 to $50 for crank polishing, and to mic, turn and true up the areas of the rear main seal might run another $75 or so.
Remember, this is the labor charge only. If you can’t pull the engine with some friends, you’ll be looking at a bill over $1,000 if you have a garage/machine shop do the entire job.
In ending, and even though your 292 was rebuilt 10,000 miles ago, I would not just replace another rear main seal by jacking up the engine and removing the oil pan to get at the rear main. Your previous owner has already done this twice, which means it will start to leak again.
If you can’t live with the leak, Harry and I highly recommend a complete recheck in a disassembled state, which means the crankshaft is out of the engine. You’ be glad you had the crank polished and turned (if necessary) to perfection and have that cursed rear seal area machined to absolute roundness. Good luck, let me know what happens and thanks for your letter!
(Greg Zyla writes weekly for GateHouse Media, More Content Now and He welcomes reader questions at 116 Main St., Towanda, Pa.18848 or email at
Greg Zyla

Greg Zyla