The Ford Barn

29As · 01-01-2017, 01:59 PM

Hello,
I picked up a few Bendix Springs in a box of "Model A" parts and noticed a couple variations. Mainly, some of them turn in an opposite direction. In the attached photo, the spring on the left appears to be a Model A spring, while the one on the right is "opposite" in terms of the direction the ends are turned, and the direction the spring turns. Also, the one on the right has a very slightly smaller inside diameter. Can anyone shed some light on this mystery. Thank you.

Kurt in NJ · 01-01-2017, 02:30 PM

A lot of different cars used similar bendix, some turned the other direction---model T is one---and a lot of different companys made relacements, both cheaper, and "improved' that have detail differences

DaWizard · 01-01-2017, 04:51 PM

Quote:

Originally Posted by forever4

This is what you can achieve when you use a low quality Model T wound spring on a Model A.

Materials and direction of helix matter!

Normally the spring is in tension and trying to wind tight radially inward on a Model A during loading.

If you use a Model T spring, the spring is in compression and is trying to expand radially outward on load.

If the spring material is not so great, it can also buckle and reverse on itself on the shaft and start to unwind and do a 180 and rewind in the opposite direction.

This will continue until you reach a point where now the spring has enough 'spring' in the proper direction, and the shock loads are lowered enough that additional unwinding stops.

It takes a special kind of luck to achieve this!

Well, I wish I could say I was "special" but this came on the car and all I did was abuse it. True, I do feel lucky that it didn't implode all over the inside of the clutch/flywheel housing and turn the flywheel gear into mush.

Tom Wesenberg · 01-01-2017, 09:10 PM

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The spring on the left is the correct one for the Model A. At least in appearance it is. The Model A had two different size bolts used to secure the ends, so that one thing to watch for. Also some of the earlier springs used a shim under each end, while later Bendix springs had the end coil come in to a slightly smaller diameter, so the shim was no longer used.

This information is found in the SERVICE BULLETINS, which is one of the "must have" books for all Model A owners.

01-01-2017, 02:30 PM	#2
Kurt in NJ Senior Member Join Date: May 2010 Location: on the Littlefield Posts: 6,159	Re: Bendix Spring Question A lot of different cars used similar bendix, some turned the other direction---model T is one---and a lot of different companys made relacements, both cheaper, and "improved' that have detail differences

01-01-2017, 09:10 PM	#4
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: Bendix Spring Question Sponsored Links (Register now to hide all advertisements) The spring on the left is the correct one for the Model A. At least in appearance it is. The Model A had two different size bolts used to secure the ends, so that one thing to watch for. Also some of the earlier springs used a shim under each end, while later Bendix springs had the end coil come in to a slightly smaller diameter, so the shim was no longer used. This information is found in the SERVICE BULLETINS, which is one of the "must have" books for all Model A owners.