Caster Help

[cycledog]

Time to fine tune. The caster on passenger side is 10 deg the driver is 6.5. I got on the National T Bucket alliance site and according to info there caster should be 5deg or as low as 2-3.

Question what is the best route to accomplish this. Disconnect at the axle and adjust or disconnect at the frame and adjust. According to the NTBA site only the top clevis should be used to adjust.

Please any help, comments or instructions will be greatly appreciated.

 

[grouchy]

I'd use the threaded ends to adjust it.

 

[hotrod preacher]

just curious, but how does it drive now? if it drives good then i wouldn't bother it....but if you must adjust-grouchy is right, only one end of your rods have adjustment, according to those pics, and i'd start by taking the 10 degree side back to the 6 degree mark-evening it out-then if it drives good leave it alone, front end adjustments aren't rocket science but you do need to be cautious as far as the "test drives" are concerned....do a little adjusting and then drive it out- that's the only way i'd know to do it w/o an alignment machine....
btw- improper toe in makes one drive bad too, so be sure to check that as well... let us know how it works out!

 

[Gastrick]

I would disconnect at the axle and adjust. If your wheelbase is the same on both sides and everything is square, I would use both upper and lower to adjust, that's what they are there for. (ie half turn out on the top, half turn in on the bottom). I use 6 degrees as a general rule. I'm not a pro but that's how I do it. I've never had an issue.

 

[bob w]

It looks like your four bar ends have an angle built into them. As a result you are stuck making a full turn when adjusting. I don't know how the caster can be that different from side to side on a tube axle unless the kingpin bosses are not installed the same in both ends of the axle. It seems to me that no matter what caster you set one side to, the other side will be be 3 1/2 degrees different. If the cap on the top of the kingpins is irregular or if there is any reason why you might be getting a bad reading, you need to find out if there is a difference in the axle from side to side, not in the 4 bar adhjustment.
I'd pull the kingpins out and remove the spindles and recheck the caster on each side by placing the angle finder directly on the kingpin boss. If the axle is manufactured correctly, the reading should be the same.

 

[fuzz]

I have found that 6 to 8 degrees works best on the street. The reason the NTBA suggests adjusting the top bar is because the lower bar is used to establish the wheelbase. Check wheel base and disconnect one top bar and correct wheelbase by adjusting the lower bar if necessary. I'm a bit concerned about the difference in caster of your tube axle because the axle shoud have been built with the king pin bosses in alignment so they would be the same. Tube axles are more ridgid than an I beam axle and it will be hard to twist to make any corrections. I would disconnect the top bar on the 10 degree side and check caster to see if it has moved [untwisted]closer to the 6.5 side. If it didn't move then I would leave it like it is, 10 and 6.5.

 

[midwestResto]

4 degrees isnt much but can be noticed while turning as far as under and over steer. I would definetly check your king pins since it could develop into a long term problem.