1971 Deduction for mismatching front lower control arm shafts

[Jerod M.]

Would there be a deduction for a 1971 with one i-beam and one flat style front lower control arm shaft?

[Paul O.]

Re: 1971 Deduction for mismatching front lower control arm shafts

Jerod

For the points that are available for the control arm shafts I would expect a notation no deduction if that is the only issue for that judged area.

Just to add on most 70 to 72 that I have judged the majority are the solid shafts not the I beam type. That is why I stated a notation no deduct.


Paul 18046

[Dick W.]

Re: 1971 Deduction for mismatching front lower control arm shafts

For the life of me I cannot remember when they changed over to the round shaft. I do know during that period of time, it was not unusual to see one of each on a car.

[Joe L.]

Re: 1971 Deduction for mismatching front lower control arm shafts

Would there be a deduction for a 1971 with one i-beam and one flat style front lower control arm shaft?

Jerod-----


I feel pretty confident that what you have there are the original shafts. A side-to-side difference in the configuration of the shafts is quite common on many C2 and C3 cars. So, making them the same could make a car non-original.

I would hope that judges would recognize that fact.

[Joe L.]

Re: 1971 Deduction for mismatching front lower control arm shafts

For the life of me I cannot remember when they changed over to the round shaft. I do know during that period of time, it was not unusual to see one of each on a car.

Dick------

The 63-82 Corvette front control arm shafts are the same as 1958-64 full size passenger car. Although the part number and, as far as I know, the forging number, never changed from 1958 to 1982, there are THREE different configurations of the shaft.

The first configuration used a completely round shaft. I don't think this configuration was ever used on Corvettes, though. I think its use was limited to the late 50's-early 60's passenger cars. I think that, functionally, it could be used on Corvettes but I don't think it ever actually was so used.

I THINK the "flattened round" shaft configuration came next. These were definitely used on Corvettes I believe beginning with the 1963 model year. My 1969 has this configuration shaft on both sides.

The I-beam configuration came last or, perhaps, coincidentally with the "flattened round". I believe these are seen on some original C2 cars as well as some C3's.

All three of the above carry the same forging number-----GM #3738505. This leads me to believe that the original GM specifications for the part either allowed various configurations for the shaft section or the specifications were changed at various times. However, the fact that the "flattened round" and the "I-beam" style rods were used simultaneously would seem to indicate that at least those two style were simultaneously allowed on the specifications for the part.

As far as I know, the shafts available in SERVICE for about the last 20 years before their discontinuation about 6 years ago were of all the "I-beam" style.

[Edward J.]

Re: 1971 Deduction for mismatching front lower control arm shafts

Jerod-----


I feel pretty confident that what you have there are the original shafts. A side-to-side difference in the configuration of the shafts is quite common on many C2 and C3 cars. So, making them the same could make a car non-original.

I would hope that judges would recognize that fact.

Joe, I believe you are correct as my 63 has 2 different style shafts. when I took my front suspension apart the lower shaft were different and appeared that the suspension was never apart.