Reamers are used to have a final fit on the kingpin bushings after the bushings are pressed in. Pressing in the bushings swedges the bushing, so the bore is smaller than necessary for a good fit. reaming leaves 1 to 2 thousandth clearance for the kingpin to fit. When I had to put new kingpins in a 111, the wear ended up being almost all on the kingpin and not on the bushing. when I slipped the new kingpin into the bushings, it was a snug fit, so I did not replace the bushings.
If anyone has manually replaced the sleeves for OM 616/617 engines, they are a bear to push in without a press. You can actually see the cylinder bore getting smaller. This is why the new sleeves are bored AFTER being installed in the block. Same principle with kingpins and bushings. With current machine tools and machining practices, I believe bushings and the kingpins and the bore where the bushings are pushed COULD be made accurately enough so that no reaming is required, however in the 50s and 60s, the machining was not accurate enough, so the tolerances were usually + - ,001 for fine work and + - .005 for most work. When you add up the total possible variation for all 4 surfaces, it could result in either an interference fit, and wheels no turny, or way to loose for accurate steering, thus the reaming step to assure perfect fit and alignment of both bushings. OOPs! it looks like Tom already addressed this. Oh well, another $.02 At 10:17 AM 10/14/2007, you wrote: >I believe the reamers are to get the correct clearance if the parts do >not fit correctly out of the box. > >I seem to remember that you had to use spacers on the bottom nut too, >but I don't know that for sure, I don't have that manual here anymore >-- returned it to the owner. > >New kingpins can be a fiddly thing to install, but if you do it right >and keep them greased (every 3000 miles without fail), they pretty much >last forever. > >Peter > > >_______________________________________ >http://www.okiebenz.com >For new parts see official list sponsor: http://www.buymbparts.com/ >For used parts email [EMAIL PROTECTED] > >To Unsubscribe or change delivery options go to: >http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com Loren Faeth _______________________________________ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
