68 4 Speed Shifter Schematic

[Charles F.]

Need help...mechanic has the shifter apart but doesn't have access to a schematic of it. I am in New York, the car is in Massashusetts; my A.I.M. is also in Massachusetts.

Can anyone scan the schematic of the 68 shifter assembly and e-mail to me: cfaillace@rcn.com.

Many thanks.

Chuck

[William C.]

Re: 68 4 Speed Shifter Schematic

Chuck are you looking for how to assemble the parts of the shifter together, or assemble the shifter and linkage into the car?

[Charles F.]

Re: 68 4 Speed Shifter Schematic

The shifter has a lot of side-to-side motion in it such that it is "locking" between gears. The mechanic is not a Corvette specialist. He is not sure how the shifter is shimmed (which would get rid of the slop). He wants to see how the shifter is put together to figure out if anything is missing or if any additional shims are needed.

Thanks.

Chuck

[William C.]

Re: 68 4 Speed Shifter Schematic

Attaches is 64-67 exploded view, almost identical. Look for a broken weld at the tab where the sides of the box meet and are spot welded together. If excess clearance is a problem the "box" can be compressed in a press to tighten the parts inside.

[Charles F.]

Re: 68 4 Speed Shifter Schematic

Excellent...thanks so much...exactly what I was looking for. Thanks also for the advise regarding the box; suspect that is the problem as there is a shim in the shifter.

Chuck

[William C.]

Re: 68 4 Speed Shifter Schematic

Be careful, the one "shim" shown is actually a part of the reverse lockout system. It's a pretty simple piece, just take a good look at it and the problem should be obvious, and don't forget the linkage rods must be tight with anti-rattle springs installed where the rods meet the shifter.

[Charles F.]

Re: 68 4 Speed Shifter Schematic

I'm not seeing the anti-rattle springs shown on the schematic ?

Chuck

[Joe L.]

Re: 68 4 Speed Shifter Schematic

I'm not seeing the anti-rattle springs shown on the schematic ?

Chuck

Charles-----


The shifter rods are secured to the shifter levers by special retainers. These retainers act like both a cotter pin and a tensioning spring. In the latter function, they act like an anti-rattle spring, preventing lateral movement between the shifter rods and the shifter levers.

One other thing I will add when inspecting a used shifter assembly. Carefully examine the "blade" at the base of the shifter lever (handle). This blade is critical to the proper operation of the shifter. If it's worn, the only practical way to repair it is to replace the shifter lever (handle). Unfortunately, while once available from GM, I don't think these are currently available from reproduction suppliers. Even if they were, considering the cost of the shifter lever (handle) was always the "lion's share" of the cost of the shifter assembly, it really doesn't make sense to replace the shifter lever (handle).

[John H.]

Re: 68 4 Speed Shifter Schematic

Here's what the "special retainer" looks like - commonly called a "pretzel clip".

[Joe L.]

Re: 68 4 Speed Shifter Schematic

Here's what the "special retainer" looks like - commonly called a "pretzel clip".

John-----


Yes, originally known as GM #3749084, the retainer is currently known as GM #15553615. What's the difference? The 3749084 is SAE size; the 15553615 is metric. However, they're so close they're virtually indiscernable.

[William C.]

Re: 68 4 Speed Shifter Schematic

The ones from a HURST kit work well also. Don't ask...

[Charles F.]

Re: 68 4 Speed Shifter Schematic

Thanks to all. With your assistance, the mechanic has determined (as Joe suspected) that the shifter blade is worn. I have looked around and Joe is correct that the shifter handle is not available as a stand-alone part. However, Eckler's has a "1968-81 4-Speed Shifter" [Part # 45919] described as a "reproduction of original" for $225. The photo shows a stock looking shifter handle and there is no mention of the reverse lock-out being non-functional (as they do say with the Hurst shifter they also sell).

My question: I think this should solve the problem; any thoughts that it wouldn't ? Do you think it would pass judging ?

Thanks

Chuck

[Joe L.]

Re: 68 4 Speed Shifter Schematic

Thanks to all. With your assistance, the mechanic has determined (as Joe suspected) that the shifter blade is worn. I have looked around and Joe is correct that the shifter handle is not available as a stand-alone part. However, Eckler's has a "1968-81 4-Speed Shifter" [Part # 45919] described as a "reproduction of original" for $225. The photo shows a stock looking shifter handle and there is no mention of the reverse lock-out being non-functional (as they do say with the Hurst shifter they also sell).

My question: I think this should solve the problem; any thoughts that it wouldn't ? Do you think it would pass judging ?

Thanks

Chuck

Chuck-----


The reproduction shifter assemblies I've seen are identical to the originals. I suspect that they're manufactured by the same company that made them for GM in the first place.

[Jean C.]

Re: 68 4 Speed Shifter Schematic

Joe, if one had the proper dimensions of an original "blade" on the shifter handle, could a worn blade be built up and reshaped to original dimensions and config?
Best regards,
Charlie

[Joe L.]

Re: 68 4 Speed Shifter Schematic

Joe, if one had the proper dimensions of an original "blade" on the shifter handle, could a worn blade be built up and reshaped to original dimensions and config?
Best regards,
Charlie

Charlie------


I've considered that idea myself. While I think that it could be done, I think it would be very difficult to get it right. I expect it would involve a lot of trial-and-error. If there were no other alternatives, it would be worth the effort. However, with the cost and availability of new shifters which I can't tell from the originals, I don't think it's worth the effort.