3 speed gears in 4 speed TC
Just put a transfer case together with the transition gear input gear part #36212-60030 $95.00 from Kurt.
Here's what I found .
Case dimension between the two thrust pads 3.513" ( 3/1978 transfer case
1963 3 speed transfer case gear set)
Idler gear width 3.150''
3 speed transfer case thrust washer 0.117" x 2
Idler gear plus thrust washers 3.150 +0.117 +0.117= 3.384"
Take this away from the case dimension 3.513 - 3.384= 0.129"
2 shim for behind the washers
Used 16 gage material 0.062 thickness to make two shims.
Cut the shims with 2.5" diameter hole saw for the outside and 1'' diameter hole saw for for the inside hole. Then filed a slot for the thrust washer tab. see picture.
0.062x 2 = 0.124" take this away from the the clearance above.
0.129- 0.124 = 0.005
FSM specifies allowable clearance range 0.0049 to 0.0187 so the clearance is within the lower end of the range.
Installing the idler gear is a little tricky Holding the shims and trust washer in place and installing the gear. Used two idler shafts to just support the shim washer set. Then installed the idler gear. Then pulled one of the idler shafts out and fully install the other one.
Using two shims ( one behind each thrust washer) put the idler gear exactly inline with the input gear when installed on the 4 speed trans.
You need to use all the gears from the 3 speed TC except the input gear. You need the transition gear. If do the welded idler gear then you are into a special, which would allow you to retain the wider 4 speed gears for high range which could give a quiet ride. Good idea from crushers.
Thanks jb