tracking bar

[mater63]

I have a stock 63 c-10 (not lowered) with a 72 rear end that's 3/4 inch out of alignment (checked on alignment rack) Would an adjustable tracking bar move it enough to fix this? How do i correct the pinion angle to be straight with the drive shaft ? Do i cut the mounts loose & reweld them to the angle i need ?

[oldtrux]

hey mater,i do believe an adjustable trac bar will help in aligning th rear end.cpp sells pinion angle shims in 1 2 3 4 degrees.page 44 if you have their catalog.hope this helps dan

[bubba327]

There was a great thread a little while back on making your own adjustable track bar http://67-72chevytrucks.com/vboard/s...d.php?t=430738

[Captainfab]

If both rear ends are original trailing arm rear ends, you shouldn't need to worry about the pinion angle. If you are unsure of where it should be, I would suggest reading up on setting the proper pinion angle first. Basically you want your pinion angle to be parallel to your trans output shaft.

[blackedoutharley]

When you say the rear end is out of alignment which measurement are you referring to?

If it is thrust angle an adjustable panhard bar will not cure this. Thrust angle is the relation to the rear end being square in the chassis front to rear.... one side being further forward of the other.

If it is offset to one side too much I don't know if an adjustable bar has enough adjustment to overcome this. My thought would be to look at the trailing arm bushings and make sure they or an arm isn't bad and causing the rearend to move over to one side. Or didn't the '63 use a different panhard bar than the truck your rearend came from? Maybe that is the issue.

[lakeroadster]

Originally Posted by blackedoutharley

.... Or didn't the '63 use a different panhard bar than the truck your rearend came from? Maybe that is the issue.

As I understand it 60-62 had the x-frame. 63-67 had the ladder style frame.

[blackedoutharley]

True but the panhard bars are different lengths which could cause issues.

[lakeroadster]

Originally Posted by lakeroadster

As I understand it 60-62 had the x-frame. 63-67 had the ladder style frame.

Originally Posted by blackedoutharley

True but the panhard bars are different lengths which could cause issues.

I guess I wasn't clear. I thought '63 through '72 used the same track bar? But the LMC catalog shows a standard, non adjustable bar, P/N 34-1240 that fits 1965, 1966 and 1967? That seems strange?

Ok lets do this, and start with what we do know:

• A 1965 track bar length is 24" (I measured mine).
• Mater63, What is the length of the track bar you are using, c/l to c/l?
• Can somebody with a stock '63 measure there track bar length and post it up here?

[64fleetside]

the OE track bars are diff, 63 thru some time in 65 are the same & sometime in 65 thru 66 are the same-I found this out putting a 66 rear into a 64. Its not much IIRC, but enough to make the rear sit off to one side.

[Tx Firefighter]

Originally Posted by 64fleetside

the OE track bars are diff, 63 thru some time in 65 are the same & sometime in 65 thru 66 are the same-I found this out putting a 66 rear into a 64. Its not much IIRC, but enough to make the rear sit off to one side.

Yes. On the 63 I built last year, I learned this to be true. I had to adjust the aftermarket ECE track bar as short as possible to barely get it centered. I later modified the mount to get it better located.

[blackedoutharley]

'63 arm should be 27" long.

[mater63]

my rear end is off to one side & its not square with the frame (dog legged going down the road) i put all new poly bushings in is a 72 axle housing the same length?

[mater63]

i asked about the pinion angle because about 45 MPH the whole truck starts vibrating so bad i cant see out the mirrors any suggestions

[mater63]

my tracking bar is 24 in. center to center i think i used the tracking bar out of the 72 the 72 rear end was a coil spring with trailing arms can anyone tell me how to adjust the thrust angle trailing arms are good & new bushings

[lil hoodlum]

Originally Posted by mater63

is a 72 axle housing the same length?

No the 1971 and 1972 axle housings are longer. It believe it to be 2 inches (total) longer than the earlier housing.

begining in 1971, the wheels came in a five lug pattern. The axles are just a little bit longer than the pre 1971 axles.

Good luck!

Keith

[Captainfab]

The late '70-'87 truck rear ends are 1-1/2" wider than the '63 to early '70 rear ends. Which is 3/4" on each side. The '63 & '64 panhard bars are the same length (longer) as they attached to the differential in a bracket welded onto the passenger side axle tube. The '65-'72 parhard bars are the same length (shorter) and they attached to a stud bolted into the center section of the differential housing.

[blackedoutharley]

This is the simplest way of explaining thrust angle that I know of:



If this is what you're trying to fix the very first thing I would do is get the rear of the truck ground and make sure that the rearend is mounted on the saddles correctly and basically go over the install again just to make sure everything is good and nothing is binding causing the rear end to sit off center.

If everything is good some small amount of thrust angle can be taken care of during the alignment by a competent technician that is schooled in the art of alignments.
Stay away from the big box or chain stores.

[blackedoutharley]

Mater63 has pm'd me a question in further response to this thread asking about the vibration he is experiencing. I replied back asking if the u-joints were indexed properly and of course he replies back, for further clarification of this, when my brain has, for some reason, decided it is unable to articulate my thoughts to words.... LOL

Does anybody have pictures or a diagram of a properly indexed driveline or perhaps able to explain it for him.... I know what it looks like and I know how to do it but I just can't seem to find the words to explain it (I am not fond of this aging crap!)

[lakeroadster]

Originally Posted by blackedoutharley

Does anybody have pictures or a diagram of a properly indexed driveline or perhaps able to explain it for him....

Here Ya Go....

[kieth]

1. first thing we are talking about is the drive line being "In Phase" This means the u joints are lined up the same on each end of the drive shaft.

2. The next thing we are talking about is "Angularity" a driveline should not exceed about 15 degrees of angle before you start to have some really wild issues show up. (air ride trucks have this condition when the leveling valve is not properly adjusted, it can feels like the transmission is going to fall out of the truck.

Here is what I would do.

1. drive line in phase: look at it , the u joints should be lined up the same front and rear. If not in phase drop the drive line and get it in phase....cheap and easy. If it is in phase move on to step 2.

2. remove the panhard rod, check the alignment of the rear end and its relationship to the front end of the vehicle. (if this is bad correct it with new bushings etc....) if it is good with out the track bar than you need a adjustable track bar or the proper one.

3. For the really bad shimmy, have a driveline shop check the angularity of the drive line when it is at the height you normally drive at. If it is way out of whack ( more that 15 degrees) then you will have to change the relationship of the rear axle by changing the angle of the rear end or where it is pinned on the central crossmember.

[blackedoutharley]

Originally Posted by kieth

1. first thing we are talking about is the drive line being "In Phase" This means the u joints are lined up the same on each end of the drive shaft.

This! This is what my brain was trying to get out!

[mater63]

THANKS for all the replies now i know what to check for