ghetdjc320 Posted February 19, 2021 Share Posted February 19, 2021 Just wanted to get some input regarding the numbers were shooting for in alignment. Caster 5-7* Camber 1-2* negative Toe .000-.125 inward Are these figures about right? Currently i have a lot of wear on the outer half of the tread of my passenger tire and have attributed this to the 1* of positive caster I’m seeing at the knuckle to unit bearing surface. This was checked with the axle adjusted dead level with the jack and the passenger wheel off so there was no weight on the inner C. Link to comment Share on other sites More sharing options...
BeatCJ Posted February 19, 2021 Share Posted February 19, 2021 Measuring the unit bearing surface is camber. Caster is leaning back. I bet you know that and it's just miss entered. And I believe camber is supposed to be measured with weight on the axle. I don't know how you could do that in your driveway, though. Probably indexes somewhere else. Also, as a rule of thumb, the larger your tires, the larger the toe needs to be. Your measuring datum is farther from the center of the axle, and greater weight and drag create more force, pulling the number down under power. Link to comment Share on other sites More sharing options...
ghetdjc320 Posted February 19, 2021 Author Share Posted February 19, 2021 8 hours ago, BeatCJ said: Measuring the unit bearing surface is camber. Caster is leaning back. I bet you know that and it's just miss entered. And I believe camber is supposed to be measured with weight on the axle. I don't know how you could do that in your driveway, though. Probably indexes somewhere else. Also, as a rule of thumb, the larger your tires, the larger the toe needs to be. Your measuring datum is farther from the center of the axle, and greater weight and drag create more force, pulling the number down under power. Yep those are the measurements I took. Camber off the knuckle unit bearing surface, caster off of the top of the inner c. Are the actual figure I’m shooting for looking right though? At this point I need a 2* offset upper ball joint to get my camber back to between .5-1* negative camber. Going to also reinforce the C’s. I didn’t realize how much flex there was there. If camber is tested with full weight on the axle then perhaps I can lift that corner by the knuckle or some good point that would simulate that weight. Link to comment Share on other sites More sharing options...
AZJeff Posted February 19, 2021 Share Posted February 19, 2021 14 minutes ago, ghetdjc320 said: Yep those are the measurements I took. Camber off the knuckle unit bearing surface, caster off of the top of the inner c. Are the actual figure I’m shooting for looking right though? At this point I need a 2* offset upper ball joint to get my camber back to between .5-1* negative camber. Going to also reinforce the C’s. I didn’t realize how much flex there was there. If camber is tested with full weight on the axle then perhaps I can lift that corner by the knuckle or some good point that would simulate that weight. I made a “precision” spacer from a piece of PVC pipe that slide over the top of the upper ball joint and rested on the flange of the joint where it seats against the upper surface of the inner C. Then I set my angle level on the top of the tube. I figured that was as close as I was going to get to measuring the kingpin angle for caster without a real alignment rack. I wouldn’t trust measuring the camber with a level on the axle tubes. The face of the unit bearing hub flange is probably a much more accurate spot. Link to comment Share on other sites More sharing options...
BeatCJ Posted February 19, 2021 Share Posted February 19, 2021 I don't know for sure, but I'm seeing -0.25 as the spec. I have the TSM for my CJ, but not the XJ/MJ. Link to comment Share on other sites More sharing options...
ghetdjc320 Posted February 19, 2021 Author Share Posted February 19, 2021 18 minutes ago, AZJeff said: I wouldn’t trust measuring the camber with a level on the axle tubes. The face of the unit bearing hub flange is probably a much more accurate spot. Yeah agreed. I just used the level on the tube to make sure my axle itself was level before taking the measurements. The camber was taken from the machined face of the knuckle where the unit bearing bolts in and the caster was taken from both the ball joint and the inner C just behind the ball joint. Both give the same reading and are in good spec. It’s primarily the camber angle that has me concerned. I’m getting a lot of premature tire wear on the outer half of the passenger tire and I would venture to guess that the positive camber isn’t helping. Granted, that figure may change with the weight on the ground so I’ll have to try that. It drives and tracks excellent but I’m tracking down some accelerated tire wear and a light clanking noise when the truck shifts weight around corners. New tires will be in order once this is fixed Link to comment Share on other sites More sharing options...
BeatCJ Posted February 19, 2021 Share Posted February 19, 2021 (edited) Pretty broad range Edited February 20, 2021 by BeatCJ spelling! Link to comment Share on other sites More sharing options...
ghetdjc320 Posted February 20, 2021 Author Share Posted February 20, 2021 1 hour ago, BeatCJ said: Pretty board range Awesome thanks for those specs Link to comment Share on other sites More sharing options...
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