Shift Shaft Pin Alternative?

[->PrOjEcTGS<-]

Alright guys, I've got another question.

Currently I'm working on putting my 95 trans internals into an early '91 case because of this: Transmission Experts... Ever seen this happen?? (Carnage Pics)

I got everything in that thread fixed and I was putting it back together when I ran into a snag. The shift shaft nub that throws the shift rails is elongated and sets out further (towards the shift rails) on the 91 trans than the 2g shift shaft. This creates interference with the 2g shift rails and the 91 shift shaft. Also, if I use the 91 shift rails the hole for the 3-4 shift fork roll pin doesn't line up exactly.

I have thought of two possible solutions to this problem.

1. Egg out the roll pin hole on the shift fork so that the shift shaft can rotate enough to be in the proper position and use the 91 shift rails. I'm sure this is going to guarantee me a lot of slop in the 3-4 shift.

2. Pull out the 91 shift shaft and replace it with the 2g one. What this means is that I have to take out the solid "Impossible to get out" pin on the shift shaft somehow.

Attachment 99988

Here's my proposed solution to this. I'm thinking about drilling out the pin and tapping it to an M6x1.25 thread and threading in a long set screw with some blue loctite to totally replace the pin. Does anyone see any possible problems with this? Are set screws strong enough to take the abuse? This will also make serviceability a lot easier in the future.

Or what about drilling it out larger and throwing in a larger diameter roll pin from the hardware store?

I really don't want to buy a new shift shaft kit because for what I'm doing I'll have to buy both the 1g part and the 2g part to get everything I need to fix this.

So, what are your guy's thoughts on this?

[twicks69]

I usually use an air hammer with a point tip to get that one out. You can try drilling it out, but it won't be the easiest. There is no problem using a larger roll pin in its place as long as it doesn't bind up the movement of the shift shaft (use the same length roll pin).

DO NOT ELONGATE the roll pin hole for the 3/4 shift rail to accomodate the variation in the shift rail.

Are you using a 2G 3/4 shift rail/shift fork/3rd and 4th gearset and hub and slider? or just the 2G shift rail with a 1G 3/4 gearset with a 1G shift fork?

Can you fully describe which parts from which generation you are putting in which year case?

I will be able to give you a bit more information if you need it.

[turboglenn]

I've always ust used a steel drift and a dead blow hammer to getthat out. You just need to support the shaft with wooden blocks so you aren't beating the hell out of a bearing recess or bending a shaft etc...

[twicks69]

I agree with Glenn's statement.

[->PrOjEcTGS<-]

Pretty much everything 2g is going into my '90/early '91 case

Early '91 case
2g input shaft with 2g 3-4 gearset
2g intermediate shaft with 2g 1-2 gearset
2g front diff
2g front diff out put shaft
2g center diff
2g 5th gear set
2g shift forks
2g shift shaft
2g shift rails

Tried using 1g shift rails. (Does not work with 2g 3-4 shift fork)
Tried using 2g shift rails and 1g shift shaft. (does not work)

I went ahead and drilled out the pin and got the shaft out of the 1g and 2g case. I was trying to use the 1g shift shaft so that my cables would line up correctly. So I'm going to have to drill out the lever on top as well and swap them over. But, all I really need is the damn 2g nub that throws the rails and a 1g shift shaft. And it doesn't look like you can order it separately.

I'll post pictures here in a second.

[->PrOjEcTGS<-]

Here's a picture of the two shift shaft nubs. The one on the right is the 2g one and the one on the left is the 1g one.

Attachment 100020

I went ahead and tapped the hole with a 1/4-20 tap and threaded in a 1" set screw. Seems to work pretty good. I'm going to pull it back out and put some threadlocker on it to make sure it doesn't come out by itself in action.

Crappy picture but you get the idea. For some reason my camera has a problem focusing on stuff.
Attachment 100021

[twicks69]

That works! I wish it came like that from the factory as it would be substantially easier to service.

[->PrOjEcTGS<-]

So here's a complete list of parts inside this trans to make it work properly:
-1g Bell Housing
-1g center case
-1g bearing plate
-2g end case (2g 5th hub/slider has a larger diameter than 1g, the 2g end case provides clearance for it whereas the 1g end case does not. Probably could use the 1g 5th hub/slider & fork. I had brand new rings for the 2g parts)
-2g input and intermediate shafts, gears, hubs and sliders
-2g shift rails
-1g shift shaft w/2g shift nub
-2g shift forks
-2g front diff
-2g front output shaft
-1g reverse idler gear and shaft (2g's gear has a thicker step and the shaft is taller)
-2g 5th gear & Hub/Slider
-2g VCU and 23 spline output shaft

Words of advice:
For anyone who even thinks about swapping 2g internals into their 1g case or vice versa better have two complete transmissions ready for this swap because you'll need parts from both for everything to work out properly.