The Stovebolt Site Forums The Shop Area Driveline Kingpins reaming tool 53 3600

Hi
Not sure who I need to ask … my mechanic says my 53 3600 needs kingpin’s replaced… but the parts I’m planning to order from Jim Carter parts require reaming … this requires a tool that is about 3/4” - 1” diameter … where can I find such a tool ? I would like to rent one if possible as I doubt I’ll ever have to use again. Are there shops that can do the reaming?
Is there parts available that don’t require reaming?
Any advice would be greatly appreciated thanks
Jeanie
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You're likely to pay well over $100 for a kingpin reamer. Link They have to use a pilot to keep the bushings aligned while reaming.
You might be better off taking your spindles to an automotive machine shop to have them do the work for you. A big truck shop would be more likely to have the tools to do what you need.

I took mine to my local engine machine shop, took the spindles, new bushings, new king pins. They had no issues honing them for a very nice snug slip fit, I can detect zero movement at my king pins.

I have a used once on my '52 GMC 152 (3/4 ton like your 3600) 0.921" reamer that I'll loan out for $100 deposit which will be happily returned when I receive it back + you pay postage both ways.

Reaming is good- - - - -honing is better. Check around for an oldtime automotive machine shop that has a Sunnen hone, and see if they would be willing to fit the kingpins to the spindles with the new bushings installed. Last resort- - - -send them to me and I'll do the fitting with my Sunnen machine.
Jerry

Sid at Dropped Axles told me this a long time ago. You don't want to replace parts without checking the axle for wear. Sometimes these old Stovebolts have lived a rough life on a farm on in a construction business, etc. Sometimes the owners skip maintenance. For example, if a king pin and spindle are badly worn there is a good chance the axle is also. Where I live, the big truck shops do this kind of repair work all the time, but they are very expensive. Look closely at the condition of the old king pin where it sits inside the axle. Take measurements (ID & OD) looking for roundness. Even though a king pin is hardened, it can still flex and wallow the axle.

My axle eyes were worn when I got my 3800 in '71. I didn't discover that till the first time I replaced the king pins.

I don't remember what tipped me off but I measured the ones I took out and they were 0.020" oversize. So that's what I ordered. Had 'em the next day (this was in about 1974). Later I ordered two sets. I also noted that the axle eyes had a couple of beads of weld running vertical. That tightens up the hole considerably. They are now "just" tight enough not to rattle even looser. I also don't let king pin bushings get loose and start to bang on the axle eyes. The axle can be bushed back to size but it's a hassle and expensive and I have one more king pin set left, so somebody in the next generation will have to do the axle eyes. I have a 1-inch adjustable reamer that goes just big enough to provide grease clearance. The 1-tons are just over an inch not the 0.921 of the 3/4-ton. I taped up the shank with electrical tape to mimic a king-pin reamer to keep the reamer square. Works fine.

Here's a .923" reamer for sale on Ebay:

www.ebay.com/itm/335501039235?

Jerry

When I got new king pins for my ‘55 to use later disc brake hubs/spindles, rather than making thin sleeves to make up the difference in diameters, I found a place in Detroit that makes bushings and had the correct ones made, $12.00 each. Can’t beat that! Local truck place had piloted reamer.

Ed

I don't think there is any difference between the '51 Chevy 3800 and the '51 GMC 250 front axle. The '51 GMC Maintenance Manual has both the 3/4 and 1 ton axles using the same 0.921" diameter kingpin. Chevrolet Master Parts Catalog 1929-1954 shows 3/4 and 1 ton using the same part.

What Bill said. There are only 2 kingpin sizes that need bushings reamed - 0.921" for 3/4 ton thru 1-1/2 ton conventional trucks, and 1.110" for 1-1/2 ton Forward Control (COE), School bus and all 2-ton trucks. This info is from my 1947-1951 Chevy Truck Shop Manual.

Jeanie, I had a original nos, GM part number BluePoint reamer that was specifically for our trucks. It reams .922 which is perfect for a .921 kingpin. It was new when I bought it and after using it to install new bushings on my 3600, I sold it to Stovebolt member, 5 Window 9434. Just checked and he's still active, you might reach out and see if something can be worked out.

RonR

Mine came with a tag reading J-3057, which in a Kent-Moore tool company part number.
It is listed in the GMC Maintenance Manual as "Steering Knuckle Bushing Reamer" for 15x and 25x (3/4 and 1 ton) models.

I think I might have a .922 reamer stashed away somewhere- - - -one I picked up in a horsetrade some time ago. I haven't used one in years, since I got my Sunnen hone machine which gives a much better fit than a reamer.
Jerry

Edit: Nope- - - -wrong size!
Jerry

I stand corrected. I just measured the new pins i have in stock and they are 0.941, which is 0.921+20. There is only one set in the shipping box so I must have installed the other one. There were two.