Three 4 Speed Linkage Questions

**Joe G.** · February 16, 2009, 01:04 AM

Re: Three 4 Speed Linkage Questions

Well the photos didn't upload. I will try it again due to size.

Attached Files

**Joe L.** · February 16, 2009, 02:59 PM

Re: Three 4 Speed Linkage Questions

Originally posted by Joe Greer (37305)

Hello everyone,

I am working on hooking back up all of my shift linkages. I am see some conflicting info from the photos of when I took my 4 speed assembly apart and what the AIM drawings are depicting. I was wondering if anyone knows the answers to these:

1. My 3-4 lever (front) on the side of the transmission sticks straight up and angles out toward the side of the car when mounted. The drawings I see show this lever angling inboard. Is this correct?

My 1-2 lever angles inboard.

2. The washer that goes on the 3-4 lever the AIM shows it on the backside (center of the car) when installed. When I took mine apart this washer was between the linkage and the lever. Is this correct?

My 1-2 lever had the wavy washer inbetween the linkage fork and the lever.

I don't believe my reverse linkage had a washer.

3. The shaft that runs through the 4 speed housing, which the long mounting bolt passes through and holds the shift levers seems to have a little bit of end play, or a gap, when mounted up between the outer housing and the head of the bolt. Is there supposed to be a spacer there? I don't show any evidence of one when it was disassembled.

Photos attached for clarification of these items.

Thanks for any help.
Joe

Joe-----

The 3-4 lever washer should be on the inside of the lever (i.e. between the clip and the lever and not between the swivel and the lever). It's very possible, though, that it was installed incorrectly at the factory or by some later servicer. There should be a similar and similarly installed washer on the reverse lever.

The spring washer on the 1-2 clevis should be as you have it installed. I don't recall if it was on the inner or outer side of the lever but I think it could be installed either way.

The shifter shaft (the part that the bolt inserts into) does have a little bit of "play" as I recall. However, it's also a part that's subject to wear. So, it's hard to say which is the case here. There should be a "c" clip which retains it but no other spacer on 68-81.

By the way, your shifter bolt and washer are the correct parts as originally installed. You might want to check this bolt CAREFULLY for cracks or damage as it's a common problem.

**Joe G.** · February 16, 2009, 04:05 PM

Re: Three 4 Speed Linkage Questions

Thanks Joe. I am missing the "C clip." I see where it is supposed to go in the recess of the shaft.

I will configure the washer as you suggest and the AIM shows. I previous servicer had changed it over to short throw and the washer wear marks are evident on the outside of the lever. See photo. Which leads me to wonder about my first question of whether this arm was reversed (if it is possible).

Any idea on the orientation of the front shift lever on the transmission with regard to angling in or out?

Joe

Attached Files

DSCF0020.jpg (108.4 KB, 83 views)

**Joe L.** · February 16, 2009, 05:17 PM

Re: Three 4 Speed Linkage Questions

Originally posted by Joe Greer (37305)

Thanks Joe. I am missing the "C clip." I see where it is supposed to go in the recess of the shaft.

I will configure the washer as you suggest and the AIM shows. I previous servicer had changed it over to short throw and the washer wear marks are evident on the outside of the lever. See photo. Which leads me to wonder about my first question of whether this arm was reversed (if it is possible).

Any idea on the orientation of the front shift lever on the transmission with regard to angling in or out?

Joe

Joe----

I think the front lever is positioned correctly as you have it.

The shifter shaft retainer, GM #3841725, is GM-discontinued and I don't know of a source for a replacement. However, I think that a proper sized "C" clip available in a hardware store will function fine.

**Joe G.** · February 17, 2009, 12:26 AM

The answer to the mystery

I think I have solved the mystery. I reversed that front lever (like it is in the AIM) and found the wear pattern matched up with the bolt that goes into the side cover. I was also missing two washers, one for each 1-2 & 3-4 lever at the side cover lever bolt location.

I found that a 5/8" E clip solved the problem at the through bolt location.

Thanks for the help Joe.

Joe

Attached Files

**Joe L.** · February 17, 2009, 01:24 AM

Re: The answer to the mystery

Originally posted by Joe Greer (37305)

I think I have solved the mystery. I reversed that front lever (like it is in the AIM) and found the wear pattern matched up with the bolt that goes into the side cover. I was also missing two washers, one for each 1-2 & 3-4 lever at the side cover lever bolt location.

I found that a 5/8" E clip solved the problem at the through bolt location.

Thanks for the help Joe.

Joe

Joe-----

Yes, I see what you mean now. In your original photo I was looking only at the rod and not the lever. The rod looked like it was correctly oriented, so I could not understand what problem you were referring to. However, I now see it involved the orientation of the lever. As I look at it now, focusing on the lever, the orientation of the lever in your first photo is incorrect. The 3-4 lever should be installed and oriented just like the 1-2 lever. In your latest photo you have the levers correct. I'm ashamed of myself as I don't know how I could have missed the incorrect lever orientation in your first photo; it stands out like a sore thumb.

I'm not so sure about the c-clip you've used. The end tangs of the clip need to be beyond the major diameter of the shaft. Otherwise, the clip can fall off. I can't tell from looking at it if the tangs are beyond the major diameter of the shaft. They don't look like they are, though.

**James H.** · February 17, 2009, 07:00 PM

Re: Three 4 Speed Linkage Questions

After reviewing all the great information shared on this thread pertaining to 4 speeds, I have 2 questions.

#1)looking at the photos, the linkage is hooked up differently on 2 tranys, 1 in the upper hole and 1 in the lower hole, what benifit does that serve ?

#2) I have a 68 427x400 M21 all original "for sale BTW" that 3rd gear will stay in as longe as power is applied but once I back off it kicks out of gear. I havent had the car long but have noticed that the shifter has created a dent in the metal surrounding the shifter from previous owners slamming 3rd gear. Any ideas what I need to do ?

Thanks, BTW 3rd year member but 1st time on the discussion board,
Jim Hummel

**Joe G.** · February 17, 2009, 08:17 PM

Re: Three 4 Speed Linkage Questions

Hi Jim,
Welcome to the tech discussion board. There is alot of info here and a lot of great people willing to help out. You will find that using the search function can be frustrating at times but it usually produces an answer to a problem you may have.

To answer your first question on the linkages going into the different bolt locations on the arm. The upper hole gives you the original long throw shifter position; ie: how far you have to move the shift ball from first to second with your hand. The middle position converts you over to short throw. Mine was converted to short throw by a previous owner. I am converting it back to long throw. You are seeing the before and after photos. It is a matter of personal preference if you are not having your car judged.

Thoughts that come to mind for the second question vary. If you are talking about the center console inside being dented from hitting 3rd, it could be that the center console is not positioned properly inside. There are locating tabs on the interior pieces that sometimes get busted or are reassembled incorrectly. If you measure the clearance between the stick and the console say between the 1st and 2nd gear position or 3rd and 4th, is there a significant difference? You may be able to move the console forward. Another thought is that, the 3-4 linkage rod could be setup wrong. There is a specific procedure for adjusting them. Another option would be convert to short throw and you will see the stick not travel as far forward (or rearward). The linkage rods underneath may need adjusting if you do this. I readjusted mine (had to lenghten them).

As far as it popping out of gear, it sounds like an internal issue beyond my knowledge. If you search for this problem, you will find other threads.

Hope this helps.

Joe

**Joe L.** · February 17, 2009, 10:49 PM

Re: Three 4 Speed Linkage Questions

Originally posted by James Hummel (47065)

After reviewing all the great information shared on this thread pertaining to 4 speeds, I have 2 questions.

#1)looking at the photos, the linkage is hooked up differently on 2 tranys, 1 in the upper hole and 1 in the lower hole, what benifit does that serve ?

#2) I have a 68 427x400 M21 all original "for sale BTW" that 3rd gear will stay in as longe as power is applied but once I back off it kicks out of gear. I havent had the car long but have noticed that the shifter has created a dent in the metal surrounding the shifter from previous owners slamming 3rd gear. Any ideas what I need to do ?

Thanks, BTW 3rd year member but 1st time on the discussion board,
Jim Hummel

Jim-----

1) Already answered by Joe;

2) The problem you describe with the shifter hitting the console plate in 3rd gear is VERY common, even for cars that have not been shifted hard for a period of their life. Usually, they've had this condition since "birth". The only way to correct this is by a somewhat tedious process of trial-and-error shimming of the crossmember-mounted shifter bracket at its attachment points to the crossmmember.

The popping out of gear is most likely a problem with the brass synchro rings, the synchro teeth on the gears, or the synchro hubs or sliders. Most likely, though, it's the brass synchro rings. They are the major "wear point" in the synchro system.

Three 4 Speed Linkage Questions

Three 4 Speed Linkage Questions

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