C2 Trailing arm shims � slotted or not

[Daniel D.]

If I do use non-slotted shims, can I accurately set/determine the toe with a tape measure or string as I shim the trailing arms? Or is this not feasible? Any tips or suggestions would be appreciated.

When I disassembled the car, I documented the strut rod camber bolt positions, so I can get that in the ballpark. But the toe was off, so I cannot just replicate the old shim arrangement.

[Edward J.]

[Harry S.]

[Richard M.]

Perfect. This took about 15 minutes with no cursing or bloody fingers.

Tanked it up with gas and went for a hands-free ride up Rte 1 with no probs.

Rich

[Joe L.]

I had my trailing arms rebuilt, and am getting ready to put the car back together. I would like to use original type non-slotted shims if feasible. My first question … is it worth the hassle (or even possible) to use non-slotted shims, or should I just go with slotted shims and let the alignment shop figure it out? My frame has not been drilled for the cotter pin/slotted shims, and I’d prefer not to drill holes if I don’t have to. The car is a driver, but I try to do things mostly “correct”.

If I do use non-slotted shims, can I accurately set/determine the toe with a tape measure or string as I shim the trailing arms? Or is this not feasible? Any tips or suggestions would be appreciated.

When I disassembled the car, I documented the strut rod camber bolt positions, so I can get that in the ballpark. But the toe was off, so I cannot just replicate the old shim arrangement.

Here’s how I’m thinking that I should proceed:
The shop manual indicates that toe should be 0-1/16” at each wheel for a total range of 0-1/8”. (Please confirm that this means the difference in the distance between the fronts of the wheels compared to the distance between the rears of the wheels is 0-1/8”.) It appears that the inboard sides are to be shimmed first to get proper toe setting, and then the outboard gap is filled in with shims.

I was thinking that I would attempt to set the shims before connecting the leaf spring and half-shafts so that the trailing arms won’t be unwieldy. The car is on jack stands, so I could space/block the tires up to the proper ride height.

Finally, the shims that I’ve seen available, are either slotted at one end and have a hole at the other end, or have holes at both ends. I believe the “correct” shim has a hole only at one end? Which vendor carries the correct ones? Thanks in advance.

Daniel------

I absolutely do not recommend the use of the original style, 1964-69 "two hole" shims. Use the slotted shims. It is not necessary to drill any holes in the frame for the cotter pins used to retain the slotted shims. If the shims are tucked down into the frame pocket and the bolt is torqued as required, the shims will not fall out. Actually, I don't see how the slotted shims can be detected when they are installed in the car. But, even if they can be, I still recommend using them. Personally, I prefer the stainless steel variety.

[Joe R.]

Daniel------

I absolutely do not recommend the use of the original style, 1964-69 "two hole" shims. Use the slotted shims. It is not necessary to drill any holes in the frame for the cotter pins used to retain the slotted shims. If the shims are tucked down into the frame pocket and the bolt is torqued as required, the shims will not fall out. Actually, I don't see how the slotted shims can be detected when they are installed in the car. But, even if they can be, I still recommend using them. Personally, I prefer the stainless steel variety.

I totally agree with Joe L. on this one. It is just insane to to use the slotted shims just to take them out and replace them with original stock shims. Just a total waste of time.

JR

[Daniel D.]

[Steve G.]

Late in the game, but no, the toe-in is not simply the difference between distances centre of tires at front to centre of tires at rear. You can have the differences correct and both wheels pointing left or right. The reference is toe-in per wheel to the centre-line of the vehicle, 1/16" toed to the centre line on each wheel. Be careful how you determine the centre line if using plumb lines and pencil marks. Centre line should be identified using defined suspension mounting points, not arbitrary points on cross members or parts of the frame that appear to be the centre.

If I were doing the string and tape measure method I would find the centre between the rear wheels by dropping a plumb line from the rotor surface with camber at 0 (spring disconnected for ease), same point each side.

For the front, drop the plumb line from the centre of the lower ball joint stud on each side.

Mark the centre of those two lines and snap a chalk line on the floor front to rear through those two centres past the most rearward edge of the rear tires.

For highest accuracy, make one mark at roughly the front centre of the tire and drop your plumb line down. Rather than try to accurately mark the same spot on the rear of the tire, rotate the front mark to the rear to make your measurements. All measurements to the centre line.

While I advocate the use of highly accurate electronic measuring systems used in alignment shops, this will get you very close, if not spot on.
Steve g