Topic: 69 Transverse Exhaust Rear Frame L Brackets and Carriage Bolts

[Bob Zink]

The flange nuts that secure the L bracket to the frame seem to bottom out so you cannot overtighten them.  I thought I had a defective flange nut, but all 4 nuts are the same way.  I currently have to use 2 washers on the flange nut side to allow me to tighten the nuts to the carriage bolts securely.  I either have carriage bolts that are too long (I bought the AMK 69 transverse hanger bolt kit F-1454) or my L bracket is not thick enough, which is possible since it is the NPD version.  Is it possible my early car used 1968 carriage bolts for the L bracket and maybe they were a slight bit shorter than the 69 carriage bolts?  Am I doing something wrong here? 

[Bob Gaines]

The flange nuts that secure the L bracket to the frame seem to bottom out so you cannot overtighten them.  I thought I had a defective flange nut, but all 4 nuts are the same way.  I currently have to use 2 washers on the flange nut side to allow me to tighten the nuts to the carriage bolts securely.  I either have carriage bolts that are too long (I bought the AMK 69 transverse hanger bolt kit F-1454) or my L bracket is not thick enough, which is possible since it is the NPD version.  Is it possible my early car used 1968 carriage bolts for the L bracket and maybe they were a slight bit shorter than the 69 carriage bolts?  Am I doing something wrong here?

There should be threads showing on the other side of the nuts.It looks like maybe the wrong carriage bolts. 

[7Lscjracer]

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[Bob Zink]

I think I figured out the problem.  The flange nuts are locking, which is why there is resistance when the bolt reaches the last set of threads on the nut.  The amount of torque needed to get past the locking thread is a bit more than I would expect.