1971 Steering Coupler

[Sheldon S.]

The lower steering coupler from my 71 BB Roadster with power steering has the splines completly around from where the bolt pulls the coupler tight on the steering worm gear. I purchased a new one which is a GM part and the correct Part number according to the GM parts book. But this one does not have the splines all the way around. Instead they end about 80% of the way around. It will not go on the steering box. Can someone explain what is the correct coupler and where do i find one or is there somewhere to get original ones rebuilt.
Thanks
Sheldon

[Joe L.]

Re: 1971 Steering Coupler

The lower steering coupler from my 71 BB Roadster with power steering has the splines completly around from where the bolt pulls the coupler tight on the steering worm gear. I purchased a new one which is a GM part and the correct Part number according to the GM parts book. But this one does not have the splines all the way around. Instead they end about 80% of the way around. It will not go on the steering box. Can someone explain what is the correct coupler and where do i find one or is there somewhere to get original ones rebuilt.
Thanks
Sheldon

Sheldon-----


The correct coupler for a 1971 is the one you have just bought if it has GM #7818568 on the box as I suspect it does.

Based upon your description it sounds to me like you have a 1963-69 style worm shaft instead of a 70-82. If so, I expect that the steering gear box has been previously replaced with the wrong one. I just don't see how a 63-69 style steering gear box could have been originally installed in a 1971. In fact, the change actually took place very late in the 1969 model year.

[Gary R.]

Re: 1971 Steering Coupler

Joe is correct, I suspect if you have the full fine spline input the box was swapped in the past. Your box should have an aluminum cover,flanged head lock bolts, and doble lip lower seal to be exact along with the coarse spline with D flat. The casting is the same and the ratio is also the same. If the box is in good shape you need a 67-69(manual) rag or if you want the correct box then you need to get a flat shaft box or new gears. Word of caution some of the rebuilt boxes out there are bad. I've had to repair many of them. If you get to that point let me know and I'll get you a link with more info on them.
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