How much caster change per shim movement?

5spdCab

G-Body Guru
Thread starter
Dec 29, 2019
930
93
Tukwila, Wa.
I took my Caballero in for an alignment a few weeks ago. When I got it back, it was evenly shimmed at all four corners. Three 1/8 shims all the way around. At frwy speed, I have to be 100% involved in controlling the car, no relaxing and enjoying the ride.
I do not know what the current settings are, this was a freeby redo of my alignment, but it is probably one degree or less, considering how super easy it is.
My question, how many degrees of caster change will I get by moving one 1/8 shim from front to back? Should I split the shims, move 1/16 or 1/32 instead?
I thank you all for your help and advice.
 

pontiacgp

blank
Mar 31, 2006
29,396
113
Kitchener, Ontario
if you move the shims you'll need to do the toe again. I have my own set up and tell the shop what I want and they always give me a sheet when done to show me what the settings are. It sounds like you do not have enough caster so I would go back to the shop who did the alignment and have them ajust it. Even with stock set up there is enough caster to let the wheels follow the direction of the car so you don't need to constantly correct it.
 

fleming442

Captain Tenneal
Supporting Member
Dec 26, 2013
13,009
113
Yep, they screwed ya. Good luck finding someone that can align a car with shims anymore. If it's not an eccentric with gradients, they don't have a clue. Your best best is buying a Longacre or Fastrax, then do it yourself. Maybe have them set the toe once done...
You can pull all the shims from the front and stack up the back bolt until you run out of threads, then adjust from there to get it even.
 

5spdCab

G-Body Guru
Thread starter
Dec 29, 2019
930
93
Tukwila, Wa.
if you move the shims you'll need to do the toe again. I have my own set up and tell the shop what I want and they always give me a sheet when done to show me what the settings are. It sounds like you do not have enough caster so I would go back to the shop who did the alignment and have them ajust it. Even with stock set up there is enough caster to let the wheels follow the direction of the car so you don't need to constantly correct it.
Thank you for the quick reply, but I think that I am done with that shop. They have left me a bit disappointed before, but I gave them another chance. Thanks also for reminding me of the toe change. The car is on ramps now and I have been able to loosen the driver side, but I can't get a wrench or socket on the wheel well side to tighten, so I plan on getting it on jack stands and popping the ball joint so I can get inside to tighten the bolts this coming weekend. Then I will do the other side to match, and start looking for a better shop to use for the future when needed.
 

pontiacgp

blank
Mar 31, 2006
29,396
113
Kitchener, Ontario
the bolts are splined so you shouldn't have to hold the head of the bolt. I have removed the bolts in the past and used a cold chisel to make new splines and installed the bolts with loctite to stop them from moving. I also have used a socket on the bolt with a breaker bar to hold it.
 

5spdCab

G-Body Guru
Thread starter
Dec 29, 2019
930
93
Tukwila, Wa.
Yep, they screwed ya. Good luck finding someone that can align a car with shims anymore. If it's not an eccentric with gradients, they don't have a clue. Your best best is buying a Longacre or Fastrax, then do it yourself. Maybe have them set the toe once done...
You can pull all the shims from the front and stack up the back bolt until you run out of threads, then adjust from there to get it even.
I have heard of a system by/called Quick Trick, which is a DIY caster/camber adjustment system. The pics look like it is easy to use. I might just go on line to find/order one of those.
 

fleming442

Captain Tenneal
Supporting Member
Dec 26, 2013
13,009
113
I have heard of a system by/called Quick Trick, which is a DIY caster/camber adjustment system. The pics look like it is easy to use. I might just go on line to find/order one of those.
You can get them with toe plates, too. The measuring devices are super scientific Stanley tape measures.
 

superbon54

G-Body Guru
Apr 15, 2014
637
93
Wisco
I have heard of a system by/called Quick Trick, which is a DIY caster/camber adjustment system. The pics look like it is easy to use. I might just go on line to find/order one of those.
I have a quick trick system with the tire plates. It takes a try or two to get the hang of it, but I can now knock out an alignment in 30-45 minutes. Love it.
 

5spdCab

G-Body Guru
Thread starter
Dec 29, 2019
930
93
Tukwila, Wa.
I have a quick trick system with the tire plates. It takes a try or two to get the hang of it, but I can now knock out an alignment in 30-45 minutes. Love it.
Didn't remember if I had heard of those here on GBF, or if it was the elcaminocentral.com site that I heard it from, but they sure look like a good way to go.
 

Similar threads

G-Body Performance Upgrades

GBodyForum is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of Amazon.com, Inc. or its affiliates.

Please support GBodyForum Sponsors

Classic Truck ConsolesDixie Restoration DepotMike's MontesP-S-TSouthside Machine PerformanceUMI Performance

ContactAdmin@GBodyForum.comfor info on becoming a sponsor