Recommendation for Best Way to Lengthen Hi/Lo 4wd Shift Linkage Rod (1 Viewer)

[Green Bean]

I will be converting a 3-speed to a 4-speed, keeping the vacuum actuated 3-speed transfer case and under dash shift mechanism for hi/lo. It is my understanding that because the 4-speed is approximately 4-6" longer, I will need to extend the hi/lo shift linkage rod. I measured the diameter as being approximately 10mm. I'm looking for ideas or suggestions for the best way to splice in an extension. It looks like I can buy some steel tubing 0.625" OD x 0.12" Wall x 0.39" ID Carbon Steel Round Tube A513-Type 5 DOM. So one idea is to cut the linkage rod in the middle and mig weld the tubing to get the required added length. But the splice would not have solid rod inside the tube. I'd sure appreciate ideas.
Thanks.

 

[PIP]

You could just make a new longer linkage the length you need. You could cut the 10mm rod where it's straight, thread the ends left and right, make a rod with left and right threaded holes in it and put it all together with some jamb nuts.

You can just butt weld any kind of mild steel rod to make up the length. 10mm 1018 is available in the USA, just not common like 3/8" or 1/2".

 

[ntsqd]

Going larger on the OD when lengthening it isn't a bad idea, if there is the room to do so. When the rod is being pulled the cross section is really all that matters, and a 10mm rod should be drastic overkill. When the rod is being pushed then it's OD and to a lessor degree the wall thickness become more important than the actual cross section. I would overlap the tube and the rod as much as possible.

 

[cruisermatt]

I will be converting a 3-speed to a 4-speed, keeping the vacuum actuated 3-speed transfer case and under dash shift mechanism for hi/lo. It is my understanding that because the 4-speed is approximately 4-6" longer, I will need to extend the hi/lo shift linkage rod. I measured the diameter as being approximately 10mm. I'm looking for ideas or suggestions for the best way to splice in an extension. It looks like I can buy some steel tubing 0.625" OD x 0.12" Wall x 0.39" ID Carbon Steel Round Tube A513-Type 5 DOM. So one idea is to cut the linkage rod in the middle and mig weld the tubing to get the required added length. But the splice would not have solid rod inside the tube. I'd sure appreciate ideas.
Thanks.

Mark, I did exactly this on my 71. The tubing is just fine, there is very little force on that rod. I can send you measurement or post it here on how long it needs to be