Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing King pin options

I suspect that line boring would merely increase the clearance particularly where the tubes are misaligned.

I suspect that a decent adjustable 1 inch reamer with a sufficiently long pilot as recommended for over half a century is best, then second because of cost, line boring the assembly with new bushes.

Hard chrome has extended the life of the kingpin/bush assembly considerably. Combine that with protective gaitors over the bottom bush/spring area and one has gained an acceptable service life.

First measure the new pins. Mine were only a couple of tenths (of a thou) difference in diameter to each other so nothing to worry about. Then add .003” and that’s the bearing I/D. Don’t take .003” as gospel. It’s just the clearance that I have chosen to go with. It’s not that precision but still feels ‘very nice’. As DavidC pointed out everything distorts when the loads come on so it’s an attempt to negate binding. The bearing O/D’s are clearance in the tubes so they should float in the adhesive when I come to bond them in. This should overcome the stub axle housing distortion rather than having to remove extra metal with the reamer to achieve the desired fit. This isn’t a new technique, just my preference.

I thought the bushes should be a press fit into the tubes. Or do they all vary?

I make My KP's out of 1" X 22' hydraulic rod. The second batch were "Hardened" under the very thin chrome. It took a special saw to cut the 22' rod into 15" lengths. I am hoping the hardened pins give the thin chrome covering a better base and wear a bit better. I have no idea if the Factory or MULFAB use this hardened rod. All 3 of My Morgans are still using the non-hardened KP's of the first batch I made. The +8 Bitsa has about 45,000 miles with Vesconite bushes. I can see a bit of wear. No wear on the Vesconite bushes that I can determine. At 50,000 miles I will measure the bushes with an inside micrometer and turn the KP's 180 degrees. So maybe 100,000 miles on this system. But at 87 going on 88 I doubt I will be driving much longer so I will never attain the 100,000 mile goal.

I believe all the available standard bushes are a press fit