67 Corvette Trailing Arm Bolts Through the Frame Spacing

[Thomas N.]

I've completed rebuilding my trailing arms, and have put them into the frame using the trailing arm bolt. If you look at the enclosed pictures, there is a quite a bit of spacing (about .450") between the castellated nut and the edge of the frame. Granted I do not have any washers or lockwashers installed, but with the standard thickness of a lockwasher .140" and I have some extra thick washers that are .120 and .175 respectively, it would take an extra thick washer on both sides of the frame to make up the spacing. The AIM doesn't spec out what the thickness of the washers should be so I'm a little puzzled. FYI, the width of the frame measures 3.375", and the bolt from under the bolt head to the beginning of the .110 diameter hole measures 4.075". The castellated nut width is .445" overall, and the back thickness from the notches to the back of the nut is .220". Does anyone have a picture of their washers they used, or the thickness of them? Thanks for any input you can provide.

[Joe L.]

Re: 67 Corvette Trailing Arm Bolts Through the Frame Spacing

I've completed rebuilding my trailing arms, and have put them into the frame using the trailing arm bolt. If you look at the enclosed pictures, there is a quite a bit of spacing (about .450") between the castellated nut and the edge of the frame. Granted I do not have any washers or lockwashers installed, but with the standard thickness of a lockwasher .140" and I have some extra thick washers that are .120 and .175 respectively, it would take an extra thick washer on both sides of the frame to make up the spacing. The AIM doesn't spec out what the thickness of the washers should be so I'm a little puzzled. FYI, the width of the frame measures 3.375", and the bolt from under the bolt head to the beginning of the .110 diameter hole measures 4.075". The castellated nut width is .445" overall, and the back thickness from the notches to the back of the nut is .220". Does anyone have a picture of their washers they used, or the thickness of them? Thanks for any input you can provide.

Thomas------


The GM #3693853 flat washers ( one on each side) are 0.090" thick. The GM #103328 lockwasher is 0.140" thick. However, I don't think these are going to make up the thickness you would need. Are you sure you have the right bolts? The correct bolts should be 4.56" in length (exclusive, of course, of the thickness of the head).

[Thomas N.]

Re: 67 Corvette Trailing Arm Bolts Through the Frame Spacing

Joe
My bolts measure 4.55" from under the head to the tip, so they check out with your numbers. Thanks for the response!
Does anyone have a width dimension for the frame from pad to pad where the trailing arm bolt fastens? I'm wondering if someone was overzealous in tightening up the trailing arm shims during an alignment.

[David H.]

Re: 67 Corvette Trailing Arm Bolts Through the Frame Spacing

Joe
My bolts measure 4.55" from under the head to the tip, so they check out with your numbers. Thanks for the response!
Does anyone have a width dimension for the frame from pad to pad where the trailing arm bolt fastens? I'm wondering if someone was overzealous in tightening up the trailing arm shims during an alignment.

Thomas,

Bolt length on my 1980 is about 4.5 inches. Frame width "pad-to-pad" is about 3.43 inches on both driver and passenger sides.

Hopefully someone will post 1967 values.

Any evidence of frame repairs?

Dave

[Larry M.]

Re: 67 Corvette Trailing Arm Bolts Through the Frame Spacing

Thomas:

How much room/space is there in the frame pocket for shims?? What is the overall length of the TA front bushing.....end to end??

I rebuilt my TA a few years ago, and have all the measurements. I will post later today regarding what I personally recorded for my above questions. This should help.

Larry

EDIT: New TA front bushing = 2.211 inches in length. This is approx 1/16 inch longer than the originals.

Total remaining space for shims = 3/4 inch.

2.211 + 0.750 = 2.961 inches inside frame dimension.

[Thomas N.]

[Joe L.]

Re: 67 Corvette Trailing Arm Bolts Through the Frame Spacing

Thomas,

Bolt length on my 1980 is about 4.5 inches. Frame width "pad-to-pad" is about 3.43 inches on both driver and passenger sides.

Hopefully someone will post 1967 values.

Any evidence of frame repairs?

Dave

Dave------


The 1980 frame dimension in question should be the same as 1967. At least, the same length bolt was used for both years (4.56").

[Thomas N.]

Re: 67 Corvette Trailing Arm Bolts Through the Frame Spacing

Thanks! Looks like my frame width is to spec, and the bolt is to spec. Nothing to worry about.

[Joe L.]

Re: 67 Corvette Trailing Arm Bolts Through the Frame Spacing

Thanks! Looks like my frame width is to spec, and the bolt is to spec. Nothing to worry about.

Thomas------


You will probably have to use extra flat washers to occupy the extra space. In fact, now that I think about it, I think that I had to do that, too.

[Leif A.]

Re: 67 Corvette Trailing Arm Bolts Through the Frame Spacing

Thomas,
Pictures of my left and right side trailing arms bolts. In your picture, I note that the nut is just barely past the hole where the cotter pin is inserted. Look at my pictures and you'll see that the bolt will have to go on a few more turns to make everything nice and tight. My bolt is the same length as yours. The washers are not overly thick. Hope these pics are of some help.

[Joe L.]

Re: 67 Corvette Trailing Arm Bolts Through the Frame Spacing

Thomas,
Pictures of my left and right side trailing arms bolts. In your picture, I note that the nut is just barely past the hole where the cotter pin is inserted. Look at my pictures and you'll see that the bolt will have to go on a few more turns to make everything nice and tight. My bolt is the same length as yours. The washers are not overly thick. Hope these pics are of some help.

Leif------


The flat washer appears thicker than the GM #3693853. In addition, the cotter pin is not installed per GM specifications. It should pass through one of the slots in the slotted nut as well as, of course, the hole in the bolt. To achieve this, a greater thickness of washers on one or both ends of the bolt would be necessary.

[Leif A.]

Re: 67 Corvette Trailing Arm Bolts Through the Frame Spacing

Thanks Joe...just what I needed. Went out to the garage, put the car on the Quick Jack, removed the rear wheels, removed the cotter pins, turned the cotter pins so that the head is now in the notch of the slotted nut. May not be per GM specs, but that nut isn't going anywhere. Thanks again.

[Thomas N.]

Re: 67 Corvette Trailing Arm Bolts Through the Frame Spacing

Leif:
I have exactly the same scenario as you are showing. I'm going to put a thick washer under the bolt head, and a thick, thin and lockwasher on the castellated nut side. Should take care of the gap and put the hole/castellated nut orientation to accommodate the cotter pin.

[Leif A.]

Re: 67 Corvette Trailing Arm Bolts Through the Frame Spacing

Picture it up when you're finished, Tom, and post for all to see.

[Joe L.]

Re: 67 Corvette Trailing Arm Bolts Through the Frame Spacing

Leif:
I have exactly the same scenario as you are showing. I'm going to put a thick washer under the bolt head, and a thick, thin and lockwasher on the castellated nut side. Should take care of the gap and put the hole/castellated nut orientation to accommodate the cotter pin.

Thomas------


That's exactly what I recommend. In fact, regardless of what the AIM indicates, the factory must have done something like this, too. There's no way they could have done it any other way.