While tearing down my 10:1 street engine I noticed that the front side of the crankshaft seal retainer looked like something had been rubbing on it. Such wear would have to occur when the crank was pushed toward the rear of the engine, not when it is pushed forward when you push in the clutch. So I checked the crankshaft end play to see if it was excessive. It measures .010" on the dial indicator or .003" over the maximum spec of .007" in the shop manual. This would not be enough to let the flange on the front edge of the sealing surface contact the retainer. So I suspect the wear I observed happened sometime in the past, like maybe the time I installed the #3 main cap and thrust bearing on the #2 journal. I drove it about 12,000 miles like that and never had a problem! I was lucky that #2 and #3 caps were machined almost the same, not always the case.

Anyway my question is, is there any way to decrease end play? The thrust bearing does not appear to be worn and measures 1.25" wide, the same as a new one. The thrust surface on the crank measures 1.26" and appears to be smooth on both sides. An extra thick thrust bearing would be nice but I have never heard of such a thing. I have heard of welding up the thrust surface and regrinding it but that seems a little extreme. Does anyone know of another way to decrease end play? What do you think would happen if you have a little too much?

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If you didn't drive it there, it's not a street car.

Some bearing companies used to offer thrust brgs. in some of their bearing sets in an oversize(thicker) to compensate for wear, and the crankgrinder would just bump the thrust faces to clean and straighten them up at the time the crank was reground. The only other method to compensate for this, is as you mentioned, welding the thrust faces, but sometimes this also requires the journals to be reground as well, as the crank sometimes cannot be straightened back into spec without doing this. However, .010 of thrust isn't overly excessive to the point of being alarmed. I've seen some strange things happen when a timing chain gets real sloppy, do you think this might be something to consider, because you surely have more than .010 of clearance between the seal retainer and the crankshaft movement forward or backward.

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There's no such thing as too much cam....only not enough engine!

Thanks for the ideas CNC Dude. I didn't think about the effect on the timing chain. I am using the Aussie Kangaroo chain and I was very pleased how little slack had developed in it, but too much end play could tend to stretch the chain. I'll ask the guy who grinds my crankshafts if there are any bearings like that available for a Slant 6, crank is .010 under.

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If you didn't drive it there, it's not a street car.

My 2 cents is to not worry. I think when I measured my '64 Dart crank endplay it was 0.009-0.010" and I've had no issues.

Lou

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Home of Slant6-powered fun machines since 1988

End play in my motor has been .014" for years.

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Official Cookie and Mater Tormentor.

Looked up the specs for the V8s........

Thrust is .002 to .007", same as S6.

Plus there's an additional spec of .010" maximum....

So you're fine.


BTW, the specs for my toyota 22RE are .0008-.0087"; .012" max

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes