Rockwell T221 Shift Linkage
 

Hi Everyone

I have been rebuilding the Rockwell t221 transfer case. I have it all back together now and all gears are turning smoothly as the should no discernable slop anywhere. Shift rails are in and move shift forks smoothly EXCEPT when I put in the poppet springs and balls and bolt down the lid with the interlock shaft. (What does the Interlock Shaft Do?? Now the shifter is very had to move in and out. I can pull the top rail out by hand barely but the lower shift rail only moves out if I wedge a 2x4 between the shift bar an case. I am wondering how hard it should be to shift this transfer case on the bench by hand. When I first took the case apart the shifters were frozen by old oil and rust so never tried getting it to shift so have no clue how hard these are to shift. I am going to set the engine and trans back in the frame and hook up the actual linkage to see how that works. If anyone has rebuilt one of these cases I would appreciate hearing from you with any info you can give me. There is very little on the internet about these old cases.

Re: Rockwell T221 Shift Linkage
 

If you can see the detents in the shift rails, where the balls seat, when the poppet springs and balls are removed, it's likely you did everything correct. Maybe add a drop of 90W into the holes after the inspection?

The lever adds a lot of leverage. I would finish assembling it in the truck and see how it functions just like you mentioned.

Re: Rockwell T221 Shift Linkage
 

No problem on the balls sitting in the detents on the shafts. I am going to drop the old motor and tranny in so when I mount the transfer case I can set up the shift lever part of the linkage and try it as it would be in the truck. Appreciate your thoughts

Re: Rockwell T221 Shift Linkage
 

I assume the interlock bar ensures no unwanted shift combination is possible, like 2WD Low. Yes these are difficult to shift and need the leverage of the shifter. The shifter is about a foot long above the pivot, and about 3" on the rod end, which gives substantial leverage. Possibly it is difficult to shift to ensure it stays in the intended position during off road conditions, which can bounce things around.

I had mine apart for inspection, cleaning and painting and it was indeed difficult to shift when reassembled. I used a dead blow hammer to assist my hand pressure on the lever.

Re: Rockwell T221 Shift Linkage
 

I set the 292 and transmission in truck and connected transfer case with shifter and all worked well. Took time to tighten up the slop in the linkage now on to the transmission.

Re: Rockwell T221 Shift Linkage
 

Well done! glad to know that the issue was resolved by connecting the shifter and shift linkage to the T221 shift arm.

I had the same concern when I took the top off my T221 and then reinstalled everything. It was incredibly hard to shift the rockwell by hand, I also thought I had done something wrong while reinstalling the top cover.

Nice to see you using a 292, I love those engines. Something about a 292 in an original k-series truck is so appealing to me.

I hope to find a 292 for my k10 soon, I would like to do the same thing

Re: Rockwell T221 Shift Linkage
 

Thanks for the response. I ended up setting the engine and transmission to be able to hook up the linkage and it shifted fine just very hard to shift by hand.

Re: Rockwell T221 Shift Linkage
 

I actually have two Rockwell transfer cases for my truck. When I took them apart, I noticed that the springs for the poppet balls in my original case were a good 1/2" shorter than the ones in the spare case that came from another 67. They were definitely cut down as you could see the grinding marks on them. As I reassembled both cases (I was using the spare one as a guide) I noticed that the replacement case was much harder to shift on the bench that my original one. I am guessing that the reason they were cut down at some point was to make shifting easier.


Clay