nvrenuf
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You need to measure the current caster of the axle.
Castor shims
- Thread starter Ontheboulder
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Ontheboulder
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It has the correct arm for the lift installed, drag link angle is flat
Ontheboulder
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so with this picture I would be a negative castor with the shim in the front with the thick end forward? correct??
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The top ball joint should be farther toward the rear to give positive Caster!!!!!!! That is the top of the spindle should be leaning toward the rear of the rig.
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Depending on what is already built into the axle but typicly yes with the axle and shim under the spring thick forward is negative thick to the rear is posative.
This is posative
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Ignore that this image is for a Jeep it was the best image of this I could find.
The downside as you add positive castor or raise the vehicle the drive shaft angle changes (the pinion lowers). So, this diff with a decent lift to correct the drive shaft angle would need to have positive castor removed (more negative added) or the transfer case lowered. Finding the balance between the 2 is where it can be a pain. This can also get costly as correcting for a large lift could end up with having to have the ends cut off and re welded at a corrected angle that works better with the drive shaft/pinion angle.
The downside as you add positive castor or raise the vehicle the drive shaft angle changes (the pinion lowers). So, this diff with a decent lift to correct the drive shaft angle would need to have positive castor removed (more negative added) or the transfer case lowered. Finding the balance between the 2 is where it can be a pain. This can also get costly as correcting for a large lift could end up with having to have the ends cut off and re welded at a corrected angle that works better with the drive shaft/pinion angle.
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Grit dog
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Same with the 86. Had shims under the 4” springs for pinion angle that reduced caster. They were supposed to be I piece but came out like peanut brittle smacked with a hammer….lol. So slapped the zero rates in with no shims, made the pinion worse caster mo betta and it drives the same.
Straight and true but don’t be dozing off it ain’t got lane sense sensors!
I think the key to good handling and not worrying about the little twitches is keep running the old steering box with excessive play in it. It covers for all these “little adjustments” that need to be made! Hahahaha
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Still haven't heard what your toe is set at, @idahovette and @Ricko1966 make good points here toe can really impact how a vehicle handles.
Toe is probably the easiest and quickest alignment spec to measure and adjust at home, getting the steering wheel to center is probably the second easiest.
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Yeah, OP also has a thread asking about a track bar to help with steering wander. In that thread too, it was mentioned that it could be as simple as an improper toe setting.
Ontheboulder
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I haven't had a chance to measure it! My wife is not good on a tape measure and my buddy has been busy so I went ahead and got it scheduled for the shop on Wed.
Ontheboulder
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this whole issue is probably on me. I changed the front axle out to get matching gear ratios for the truck. I probably didn't pay attention to the location of the shims when I tore it apart!! This getting old **** ain't for sissy"s!!!
Grit dog
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Oh same dude… I didn’t notice.
Grit dog
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That was my point. I made everything a little worse theoretically for steering. Bout the same….
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On the IH Scouts, most of the housing c’s are welded with zero caster built in. A “cut and turn” is common on those vehicles.
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