Thrust bearing failure

General engine tech -- Drag Racing to Circle Track

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MoPar_Kid
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Thrust bearing failure

Post by MoPar_Kid » Tue Oct 17, 2017 8:50 pm

Lost a thrust bearing on a sb Chrysler with a 3spd 727.

Still uncertain as to what killed it.. I suspect it was a transmission issue. Trans is high mileage with transgo shift kit and stock converter. I've read on the subject, seams the two primary causes are ballooning TC, too high of line pressure (blockage) or splines on TC binding/hanging on input shaft. And of course not correctly seating bearing or insufficient clearance from flex plate to converter.

I doubt my tc was actually ballooning. My guess is line pressure or splines. I've looked at the input shaft, the splines are a bit sharp, but no high spots or obvious ridges etc.

Anyone else have this happen? I've since modified the new thrust bearing with an added oil hole on the thrust face with ab additional corresponding oil galley from the main feed, as well as chamfering the upper bearing shell to add additional feed via the parting line of the bearing halves.

Anyone thats familiar with 727's I'd greatly appreciate some advice

peejay
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Re: Thrust bearing failure

Post by peejay » Tue Oct 17, 2017 9:28 pm

EVERY thrust failure I have seen was because of a trans problem. They don't kill themselves.

Make sure there are no kinks in any of the cooler lines and that the cooler itself isn't plugged.

Geoff2
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Re: Thrust bearing failure

Post by Geoff2 » Wed Oct 18, 2017 5:04 am

Is the flexplate aftermarket?

tenxal
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Re: Thrust bearing failure

Post by tenxal » Wed Oct 18, 2017 6:16 am

Absolutely have the hub on the convertor checked.

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