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Transfer Case rebuild issues

Posted: Fri Apr 19, 2024 7:59 pm
by CapnDan
I am rebuilding the transfer case in my 54 M38A1. Has anyone had this problem:

I have installed a new bushing in the rear output shaft that the front output gear shaft fits in. I got it driven in with a piloted bushing driver. The inside diameter of the newly installed bushing checked .626 diameter without having to ream it. This is acceptable based on the .626-.627 called out in the repair limits of TM 9-8015-2 chapter 18 paragraph 271d. My new front shaft pilot end measures about .6235. After putting it all back together in the case I am having difficulty rotating the front shaft independently of the rear shaft.
This is with the front output shaft clutch gear in the two wheel drive position. I cannot get turn the front independent of the rear just gripping the shafts by hand. If i put the yokes on the shafts then I can turn them but it is pretty tight. I am using 90 weight gear oil for assembly lube. Is that a normal condition? Will it stop sticking after I fill the transfer case with gear oil?

Posted: Sat Apr 20, 2024 3:51 pm
by wesk
Have you reviewed the Rick Stiver's Dana D-18 transfer rebuild pages or the Novak's D-18 rebuild page?

https://www.cj3apage.com/index/Tech_Tip ... ebuild.htm

Note: Rick also has loaded U Tube with this guide data:
https://www.youtube.com/watch?v=3-2TgW2hE_w Pt-1
https://www.youtube.com/watch?v=O5-M7ep1ag8 Pt-2
https://www.youtube.com/watch?v=l8isUHHgdus Pt-3

https://www.novak-adapt.com/knowledge/t ... s/model-18

Posted: Sun Apr 21, 2024 4:21 pm
by CapnDan
Yes I have been using Rick's rebuild guide instructions and you tube videos. I did not have the end play set correctly. I added shims to get the required end play of .004-.008. The front shaft does rotate easier relative to the rear shaft with correct end play, but it's still tight. Just read Novak's instructions and double checked shimming and the end play. I have about .005 end play. I had to add a lot more shim with the new Timken bearing cups and cones. It had .073 shim stack in it when I disassembled. I am now at about .125 shim.

Posted: Sun Apr 21, 2024 5:01 pm
by 4x4M38
I was wondering if it was end play, but waited to see if you got there.