1990 Tranny into 1993 GSX

[GSXplosions]

I recently installed a slightly used stage 2 shep trans from a 1990 car into my 1993 gsx. Everything went smooth for the most part, i got the transfer case with the new tranny to match the different splines.

I had read previously about the swap and i heard there were differences in the linkage and shifter assembly. However, i went ahead and did the swap before looking for or buying any linkage parts.

I got everything hooked up today and drove the car...wouldn't shift into 5th or reverse, and 1st and 2nd were stiff also. Not necessarily stiff going into the gear, but stiff going side to side in order to go forward or back into a gear.

Now that i'm at this point, i would like to know what i need to change. I have read some places on here that its the linkage, the shifter assembly, and some places that the adjustments on the shift cables will be enough to compensate for the differences.

To anyone who has done the swap, what did you change to make it work?

 

[ktime]

i did same swap had to change shifter linkage and the linkage mount on trans

 

[sciondan]

You need to swap the shift cable brackets and selector ARM. Then adjust your cables at the shifter inside the car.

 

[jmartinez1228]

You also need the shifter base. The 90 shifter base is different form the 91-94 base.
This may help a little. Shifter Differences, 90 and 91-94

 

[GSXplosions]

Problem Solved! Thank you guys for your help, but i answered my question today after work..

Where the shifter linkage bracket is, there is an upper and lower bracket. One has 4 holes, two for bolts to the tranny and two for bolts that hold the other bracket to it. That second bracket is the one that holds the linkage in place.

To begin with, i switched both the brackets from the newer transmission (93) to the older one.

I also changed the upper shift linkage on the transmission with the one from my 93. This is the one that is removable with just two bolts, and a lower plastic peice that holds it in place. There was a noticeable difference in size with this selector, and this is the piece that i think made the big difference.

I searched for the answer to this question and couldn't find it, but now it is solved! Here it is!

Swap the upper selector from the newer transmission to the '90 model, and both the upper and lower linkage bracket from the newer transmission as well. This solved the problem, just drove the car and it shifts fine everywhere!
*This is for putting a 1990 GSX transmission into a 1993 GSX

 

[buhay6]

Good to know I'm not the only person having this problem. I just got my car to start for the first time and went to move it around into the garage found I could only get it into 2..... I also need to check if the n/t shifter base is different then the awd 91-94 bases as I have a n/t base installed with a 93 tran and 90 shifter cable bracket. Hopefully a 90 shifter base will solve the problem.