3/4T knuckle bearings

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PareosWC
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3/4T knuckle bearings

Post by PareosWC »

Gents- I am rebuilding both knuckles on the WC52. Upon removing the top and bottom halves and inspecting the bearings, the top brass bearing 'looks' good? Is it truly an 'upgrade' to replace the brass bearing with another Timken roller assembly?

I typically like the Dodge designer's intent and try not to veer from it, but smooth roller bearings are hard to beat!
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Gordon_M
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Re: 3/4T knuckle bearings

Post by Gordon_M »

Early trucks had roller bearings top and bottom, later had bearings on top and bushes on the bottom. I suspect the lower bearings were prone to complete failure when badly overloaded and stressed, stranding the truck, whereas the bushes would fail more gradually.

I've never heard of anyone who went to twin bearings having any problems, but then I've never had issues with bearing / bush either. If yours look OK just grease them and put them back, but do a by-the-book adjustment for wear.
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PareosWC
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Re: 3/4T knuckle bearings

Post by PareosWC »

Thanks, Gordon. I went into the archives and gathered some earlier intel as well. The bearing race looks new on the brass bearing, but the Timken race will need replacing. Must have been a lot of stress to degrade that Timken bearing. All kinds of metal shrapnel at the bottom of the knuckle :shock:
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Gordon_M
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Re: 3/4T knuckle bearings

Post by Gordon_M »

It seems to be a failure mode sort of thing. When the Timken bearing goes the truck is effectively offline, whereas the bush just wears and slops but keeps going.

To be fair the Timken bearing size is set by the hub design and load rating, so it would need a complete redesign to rework it. It is more a question of inadequate design than poor manufacturing by Timken. Keeping the tapered Timken bearing at the top means you can still shim the whole thing to eliminate end play, which is quite neat - something you couldn't have done if you had gone to bushes top and bottom.
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Re: 3/4T knuckle bearings

Post by PareosWC »

I find it interesting that in a NOS knuckle rebuild kit, you get felt, grease retainer, paper and metal bearing shims, and cork gasket. However, you do not receive a metal spring felt retainer? How is this part not with a kit?
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Gordon_M
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Re: 3/4T knuckle bearings

Post by Gordon_M »

I can only guess they assessed the spring as indestructible - not needing to be replaced under any circumstances, but that does seem a little odd.
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Kaegi
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Re: 3/4T knuckle bearings

Post by Kaegi »

the bushing goes on top. all the weight is on the bottom roller bearing. the top bushing just keeps everything aligned right and prevents any lateral movement. very durable set up. in many of the civilian closed knuckle the bushings and bearings are half the size and wore out frequently. these last a long time considering the life these trucks have led for decades being used as a tool.