Sloppy shift linkage at the transmission

[MikeB]

Any ideas on how to tighten up this gap between fingers and slots? Looks to me like both pieces are hardened, so it's not like they're worn out. I remember replacing them 30+ years ago with real GM parts, and they probably fit as loose then as they do now. But I just accepted it back then.

You can see the gap in the photos. This makes for a little too much slop up on the shift handle.

[AussieinNC]

Two options:

Clamp the U channel piece in a vice and slowly tighten to close up the gap. Leave about 1/32 " clearance.

or

Buy new set from a vendor like :

https://www.classicindustries.com/pr...E&gclsrc=aw.ds

[MikeB]

Originally Posted by AussieinNC

Two options:

Clamp the U channel piece in a vice and slowly tighten to close up the gap. Leave about 1/32 " clearance.

or

Buy new set from a vendor like :

https://www.classicindustries.com/pr...E&gclsrc=aw.ds

Thanks for the suggestion, but I already tried that. It doesn't bend at all. That's why I think it's hardened. Who knows if the aftermarket stuff is any better?

[TALLone71]

I was able to build mine up on the 71 with weld, using my mig, and then used my mini grinder to to carefully and slowly grind it back into shape, and hand finished it with a file, it works great now. I had considered buying the aftermarket replacement part, but just really wanted to save the original

[LockDoc]

-
I just welded mine up the other day. After putting a small pass of weld on the notches I opened it up with a file until I had a snug fit. There has to be a little play in it to make up for any misalignment in the linkage. It worked good after the "operation"....

LockDoc

[MikeB]

I've been thinking about the weld option. I'm not the best at building up an edge, but I could practice on some scrap.

I have an old Lokar shift rod kit, that doesn't work on my truck due to the large angle from the column lever to the trans shift shaft lever. But I have an idea I want to try: I have a rod end (heim joint) with a larger deflection angle, and will also try using a 5/16-24 coupling nut as a shift shaft extension. Can't find an 5/16NF nut locally, so will have to order one or make one from two standard nuts. Will post photos if it works.

[bry593]

Yes, that piece is hardened 1045ish steel.

Yes, you can weld it and grind for clearance. However, that piece is not worn (GM hardened). It is no more a problem now than when the truck was new. Most likely, bushings and such in the rest of the linkage are the issue.

[HO455]

I believe that GM designed the loose fit to prevent binding due to misalignment between the transmission selector and the frame attachment point. As you drive the transmission moves due to the rubber mounts which changes the alignment.

On my Burban there is a forward/aft misalignment of the transmission selector and the frame mount.

Just some thoughts to consider.

[LockDoc]

Originally Posted by bry593

Yes, that piece is hardened 1045ish steel.

Yes, you can weld it and grind for clearance. However, that piece is not worn (GM hardened). It is no more a problem now than when the truck was new. Most likely, bushings and such in the rest of the linkage are the issue.

I think you are wrong on your assumption that the cross arm is not worn. It looks to me like it is worn the same place that mine was. (where the arrow is pointing) Mine was worn down at that location at least 1/8th inch. And yes, it affected the shift pattern.

Originally Posted by HO455

I believe that GM designed the loose fit to prevent binding due to misalignment between the transmission selector and the frame attachment point. As you drive the transmission moves due to the rubber mounts which changes the alignment.

On my Burban there is a forward/aft misalignment of the transmission selector and the frame mount.

Just some thoughts to consider.

Yes, that is why there has to be some movement in it, but in my humble opinion it is still prudent to repair any excess wear in the assembly.

LockDoc

[MikeB]

Originally Posted by bry593

Yes, that piece is hardened 1045ish steel.

Yes, you can weld it and grind for clearance. However, that piece is not worn (GM hardened). It is no more a problem now than when the truck was new. Most likely, bushings and such in the rest of the linkage are the issue.

Yeah, I was pretty sure it was hardened. Like you said, the parts may have been like that when new. The clearance is well beyond what's needed, though.

There's a little bit of play between the shifter tube and shift bowl, but the linkage down by the trans is worse by far. Pretty easy to watch the movement from under the hood.

Played with the Lokar stuff today. Thought I had a plan, but it didn't work out. I'm gonna get half the slop out of the stock parts some way, somehow!

I appreciate all the comments.

[bry593]

Take that Lokar stuff and send it back. It's junk.

Weld up and grind the original to suit is a good option. I welded mine, but not to reduce slop. I had to section about 5/8" from the center to fit a 4L80E.

I know what you mean about it feeling a little sloppy. But that is how it came stock for the reasons mentioned (prevent binding or damage due to drivetrain twist).

I still would inspect the bushings. Don't forget the one up at the column.

[MikeB]

Trying to find the bushing that snaps into the column lever. It's GM#3975131. Mine's not real bad, but even with the steel insert, it wobbles around. So bry593 was right! On the Internet they cost as much as $40! Found one place that sells them for $10.50 shipped, but I can't get in touch with them to confirm stock. I've been looking at companies that sell all kinds of generic grommets, but can't find one that will work.

The Lokar kit is something I had laying around for 6-7 years. I think the only place it would work is on narrow-width 20-30s hot rod, where the trans is closer to the steering column (nearer to the drivers side). I have some aftermarket ball ends with more deflection angle, but the offset is still too much.

[Accelo]

try these guys.
https://4speedconversions-com.3dcart...3975131_1.html
It is $6.00


Looks like the grommet was also used in Used on many 1962 to at least 1982 cars and trucks from shifter levers to backdrive linkage. Measures .624 O.D. x .521 I.D. x .755 lip diameter.
This part number replaced part number 3833108 in April of 1970

https://4speedconversions-com.3dcart...3975131_1.html

[TALLone71]

mine was worn in exactly the same place as LockDoc describes on his, I remember back when I went to fix it, I crawled up under my 72, which has far less miles than my 71, to look at it for a comparison, and the 71 was clearly worn in the area where the notch is in the crossbar.after welding and filing it to the same size as the 72, it still has play, as it did from the factory for driveline movement, but now my shifter feels much better and the pointer is centered In each gear position. the previous owner had replaced the shifter bushings at one point, and they have some play, but felt pretty normal, and I would definitely replace them if they are sloppy too, as mentioned in previous post above

[MikeB]

FYI, I found a real GM #3975131 bushing for a reasonable price. So that should help some.

[Steeveedee]

Originally Posted by MikeB

FYI, I found a real GM #3975131 bushing for a reasonable price. So that should help some.

I expect mine is/are worn. I haven't looked; does the linkage take one or two? Also, where did you get it from? Thanks in advance.

[MikeB]

Originally Posted by Steeveedee

I expect mine is/are worn. I haven't looked; does the linkage take one or two? Also, where did you get it from? Thanks in advance.

There's just one where the control rod connects to the column lever. I got one from a board member, but I think his stock is low. I also found them in stock at Midnight Oil Muscle Car Parts, but I don't know if they are GM or aftermarket. https://momcp.com/?s=3975131

[Steeveedee]

Originally Posted by MikeB

There's just one where the control rod connects to the column lever. I got one from a board member, but I think his stock is low. I also found them in stock at Midnight Oil Muscle Car Parts, but I don't know if they are GM or aftermarket. https://momcp.com/?s=3975131

Thanks, I'll check it out!