The Rear Caster tool everyone is talking about is usually not readily available at most shops. So does that mean that without the tool an alignment at a dealer or good Corvette Shop Is useless ?

 

Rear caster is easily adjustable with the

​​​​​ tool. I have the tool complete ready to ship. $85 shipped in the US

 

I understand all that but can anyone answer my original question ? question ??

 

It's not useless, can still help you with tire life if you've got uneven wear, but the rear caster can definitely affect predictable handling so I would definitely recommend finding a place that can adjust it. I would say they are not a "good Corvette shop" if they do alignments without a way to measure and set rear caster. Mine was positive on one side and negative on the other from the factory which can induce snap oversteer in corners without warning so, personally, I was glad I got mine taken care of. I found an indy shop that does alignments for weekend racers' cars and he had made his own tool to measure it and adjust. Had the alignment set in less than an hour for $100. I first tried my dealer who is normally excellent and they had the tool as well but they tried to charge me $350 to use it even though they couldn't get the toe aligned properly (tried to tell me I needed aftermarket toe-links even though I'm at stock ride height). The point of that story is that you don't have to go to a dealer to get a good alignment.

 

Thank you, very helpful.

 

This is the tool a dealer should have and a angle gauge.

 

Alignment Machines cannot measure rear caster so this is why you need these tools to adjust rear caster.

 

Our local dealer is very Corvette Friendly and has a good Corvette tech. But when we bought our car (at another dealer) and asked our local dealer for the rear caster to be checked/set as part of the first alignment, they informed me that they didn't have the rear caster tools yet. I asked how much they would charge me to buy the tools and use them on my car, they came back and said "we ordered the tools and will use them for everyone." Works for me...

BTW, our rear caster was ok but front & rear toe were out of spec after barely a thousand miles.

 

Sounds good so who is your local dealer ?

 

^^^
Martin Chevrolet; Crystal Lake, IL

 

I think the reason a lot of shops don't worry about rear caster is they never heard of it or if they are a GM shop GM service told them not to worry about it. From what I have seen most cars come from the factory with rear caster set in spec. The reason it is in spec is the GM spec is for plus or minus 0.8 degrees on each side with no cross-caster specification. With wheel alignment set within the stock specifications the vast majority of the time, it is going to fall in spec and that can mean one side will have a positive caster and the other will have a negative caster.

If you read the Jim Mero post about why they added adjustable rear caster to the C7 it was to correct the issue seen in the C5 and C6 when the rear camber was adjusted to increase negative camber and they got unwanted rear caster settings that could only be reduced back to 0.0 degrees by setting camber at smaller angles. If the caster isn't zero and isn't equal from side to side then you have a greater tendency toward snap oversteer when lifting off the throttle on corner entry or mid-corner on a road course.

When I first tried to get a track alignment none of the 5 Chevrolet dealers in my area had the complete toolset to measure rear caster. It took a year before I had a chance to actually check the rear caster after I purchased my own tools. That is when I found out my left side rear caster was something like +0.4 degrees while the passenger side rear caster was -0.5 degrees. I had participated in a year's worth of track events without noticing any negative issues.

Bill

 

I made a caster fixture with some stuff I had layin' around. Two pieces of strap steel, balsa in the middle, carbon-fiber tubes and epoxy the whole thing together. Got the angle meter online for about $20.

Tubes are wrapped with a little 3M blue tape as they were just slightly undersized.