65 Alignment - 83 K-Member

[65GMCFirstride]

I am going to get my 65 GMC aligned today. It PO installed an 83 Chevy K-Member. I would assume it should be aligned to the specs of an 83 K-Member. Is that right?

[Clyde65]

No, I believe it should be aligned as the year model. the geometries were not changed that much going with a disc cross member

[64shortbox]

I would ask the shop you take it to for the alignment but I would think that you would want it aligned to the 83 specs. I would think that you would be able to get more caster out of the 83 K-Member. Radial tires - especially wide ones like a lot more caster than the skinny biased tires that came on our trucks new. I haven't seen anything on this site about more caster for radial tires but there's a lot of talk about it on some of the GM car sites.

[BMERDOC]

Originally Posted by 64shortbox

I would ask the shop you take it to for the alignment but I would think that you would want it aligned to the 83 specs. I would think that you would be able to get more caster out of the 83 K-Member. Radial tires - especially wide ones like a lot more caster than the skinny biased tires that came on our trucks new. I haven't seen anything on this site about more caster for radial tires but there's a lot of talk about it on some of the GM car sites.

Correct! 83 specs for those reasons. Most shops won't spend a bunch of time on a custom alignment so hopefully they will do as much as you request.
Here is my last alignment sheet. Notice that the camber spec is -.15 to .45. Ask that it be set negative, Preferably -.50 to -1.0 if you can. It will not wear tires and will handle a lot better. The caster spec is 2.0 to 3.0. You'd want to get as close to 3.0 as possible or even more. Factory performance cars can have 6,7 or even 8* positive caster. By increasing positive caster "return to center" (when you let go of the steering wheel doing a u turn and it spins back to center) is improved and high speed stability (highway and interstate and not just Bonneville ) is also improved. The toe setting can be set to stock spec but should be set at the average, refer to my spec sheet...08 to .15 the difference is .07, half of that is .35 so final toe setting should be .11 or .12. Ther rear thrust angle should be as close to zero as possible. Mine is .33 but I still have the stock bushings in the trailing arms. When they are replaced the angle should be a lot closer to zero. Thrust angle is important because it can cause the truck to "dog track" and the front toe is affected by it. Its kinda the backbone of a good alignment.
Im only using my sheet as an example but I'm sure '73-'87 isn't too far off.

[markeb01]

Here are the spec’s from my alignment. This is on a 1960 GMC with a 1975 front crossmember/suspension. Can’t help with interpreting the data, but it was aligned in March 1998 and continues to track straight. I’ve replaced front tires over the years and they always wear evenly. The guy that did the work was old school and spent several hours on it until he was happy with the result.

[BMERDOC]

Originally Posted by markeb01

Here are the spec’s from my alignment. This is on a 1960 GMC with a 1975 front crossmember/suspension. Can’t help with interpreting the data, but it was aligned in March 1998 and continues to track straight. I’ve replaced front tires over the years and they always wear evenly. The guy that did the work was old school and spent several hours on it until he was happy with the result.

Starting from the top: I would much rather see the camber's Specified Range be -0.3 to -0.8 and shoot for as close to -0.8 as possible. Caster doesn't have a Specified Range on this sheet so I'll stick with 2.00 to 3.00 with stock components if possible. If I was setting toe I would tried to hit .19 . At .11 your Thrust Angle is satifactory.

[markeb01]

Good to know, I'll retain this information for the next time it gets aligned. I was never quite sure how to read the information. Thanks for the input.

Originally Posted by BMERDOC

Starting from the top: I would much rather see the camber's Specified Range be -0.3 to -0.8 and shoot for as close to -0.8 as possible. Caster doesn't have a Specified Range on this sheet so I'll stick with 2.00 to 3.00 with stock components if possible. If I was setting toe I would tried to hit .19 . At .11 your Thrust Angle is satifactory.

[64shortbox]

BMERDOC,
Thank you for the break down of the specs and what all it means! I'm saving this link in my truck favorites so I can go back to it whan I get my 85 disc suspension under my 64 truck.
A Big
Thank You!!!!!

[BMERDOC]

Glad you guys can use this info. Not only do I have to align BMWs on a daily basis but I have to align track and autocross cars every once in a while so I've taken interest in what it means to do a performance alignment and not just make the numbers green.

BTW, 65GMCfirstride, how'd the alignment go?

[chevyrestoguy]

BMERDOC-
Your explanation of alignment settings is right on. Oftentimes, some alignment shops don't put enough caster in the alignment. I like a lot of caster because it makes the vehicle go down the road so much better. If it's done right, you can one-finger it when you're cruising down the freeway. Too little camber is scary to me because you're constantly trying to bring the truck back to center. It'll wear you out mentally and physically.

[bo-w]

Originally Posted by BMERDOC

Glad you guys can use this info. Not only do I have to align BMWs on a daily basis but I have to align track and autocross cars every once in a while so I've taken interest in what it means to do a performance alignment and not just make the numbers green.

BTW, 65GMCfirstride, how'd the alignment go?

good stuff BMERDOC good to see other techs out there who don't just git er' in the green and call it good ! its sad because understanding alignment angles is really simple and many "techs" just get em close and call it a day. i dislike color screens on alignment machines as well as color printouts of alignments just my 2 cents

[BMERDOC]

Any word on how things went?

[blackedoutharley]

Originally Posted by bo-w

good stuff BMERDOC good to see other techs out there who don't just git er' in the green and call it good ! its sad because understanding alignment angles is really simple and many "techs" just get em close and call it a day. i dislike color screens on alignment machines as well as color printouts of alignments just my 2 cents

The key word here is "tech" with the emphasis in parenthesis...

[steverino66]

Great thread - you guys rock.
I'll save this for when mine exits the garage for alignment ('83 x-member on a '66)

[BMERDOC]

I hate to take this guys thread but he isn't coming back. I still have things to talk about. I will start an alignment thread within the next week using my 67 as an example. I plan to lower it and add a crossmember swap on it too, so I will add to that thread after the progress. Seems a pure discussion on alignments is rare in these parts.
Short rules fellas: Negative camber, Positive caster, Stock toe is ok for a DD, Try to keep the Thrust Angle under .10 (or -.10) . Dont go over -2.00 camber and dial in as much caster as you can without going super silly on shims or homemade spacers (unsafe).

[TR65]

Just one note on toe. For best tire wear set the toe to as close to zero within the specs. as possible.

If your tires are wearing on the inside shoulders you have too much toe out. If they are wearing on the outside shoulder you have too much toe in.

TR

[bo-w]

biggest key on alignment its useless to align a vehicle with worn out parts !! if need be i can go through some things and possibly post general info on angles and possibly some handy picks , may take a little time to get them to post here (info is on my work computer)

[blackedoutharley]

As far as toe in it should be set between 1/16" - 3/16" in regardless of what tire you're running (within reason). I can't speak to a crossmember swap because I haven't dealt with one (and frankly haven't figured out why anybody would go through the hassle aside from getting rid of torsion bars) but the specs are pretty close to those for a '63-'66.

I tend to run about .25* negative camber on both sides and caster at about 2.5* positive with the the passenger side about .5* more than the drivers side to compensate for road crown.

My '65 has 31X10.50R15's on it with these specs for years and tire wear is more than acceptable (got 62K out of a set of Bridgestones) and it drives very good. I am sure I will have to play with it a bit once I rebuild the front end and add power steering though.

[BMERDOC]

Originally Posted by TR65

For best tire wear set the toe to as close to zero within the specs. as possible. TR

Originally Posted by blackedoutharley

the passenger side about .5* more than the drivers side to compensate for road crown.

Im not picking on you guys and I don't want to start anything in what is an otherwise good natured thread but I have my reservations about both of these points. I will address these segments when I post my own thread about alignments. Both are good points that bear discussion.

[markeb01]

Originally Posted by BMERDOC

I will address these segments when I post my own thread about alignments. Both are good points that bear discussion.

When you do post that thread, please link it to this one as I would really appreciate having that information and may not find it if posted elsewhere. Thanks again for your contributions.

[BMERDOC]

10-4 markeb01. I will keep you in mind!

[Mechanic77]

Subscribed just for the link to come

BMERDOC, are you going to get into performance alignment specs too?

[BMERDOC]

2WD C10 Modern/Performance Alignments

Here it is. I wrote it quickly so I hope I didn't leave anything out!

[markeb01]

Originally Posted by BMERDOC

2WD C10 Modern/Performance Alignments

Here it is. I wrote it quickly so I hope I didn't leave anything out!

Thank you!