Installing 3 speed transfer gears into a 4 speed transfer case (1 Viewer)

[Cirbo]

Here is a good picture to show the difference between the two spacer sleeves. The one on the left is from the four speed idler gear, and the one on the right is from the 3 speed unit (you use this one).

 

[MD11Fr8Dog]

This is the fun part...

 

[Cirbo]

I actually came up with a solution for that one too. Remember I had the guts from two transfer cases. I fiddled with the finger method (exactly like the post above) and decided that wouldn't work before I went coo-koo. I ended up slipping an intermediate shaft into place from both front and back. I aided the shims and bronze washers placement by a little sticky grease as well.

 

[Cirbo]

Nice inside view from here too. It may be difficult to see, but I have two shims installed at this point. I reused the shim I removed from the 4 speed case and added one to the front as well. This gave me the necessary measurements to fit the idler gear back in place. Gabe and I built a second case which needed one of the thicker spacers achieve the proper spacing, so your results may vary.

 

[MD11Fr8Dog]

if you have two shafts, perfect! I actually had a little grease too!

 

[Cirbo]

Idler cluster installed. It takes a little fiddling with the feeler gauge, but the specs were .004 to .016.

 

[Cirbo]

At this point in time, I installed Georg's nose-cone saver studs.

 

[Cirbo]

The next problem was how deep to sink the bearing race on the rear side of the output shaft. The manual says to use a factory "special tool" for this application, but I didn't have one of those. (I'd be interested how others did this too) The manual also says to reuse the shim between this race and the rear retainer (speedo gear housing). I ended up installing the retainer, then the shim, and lastly seating the bearing race down into the case from the front side.

 

[Cirbo]

The next difficult process was the step where you were to install the low speed gear and bearing assembly onto the rear of the output shaft. I had to place the gear and bearing into the case and press the shaft/high speed gear into place.

 

[Cirbo]

Then I installed the nose cone and the Valley Hybrids saver. I skipped the step of installing the new bearing and shaft into the nose-cone. If that one causes you issues, you should not attempt this job.

 

[Cirbo]

Installed new seals in the 4wd shifter and attached it to the assembly.

 

[Cirbo]

Hi-Lo shifter was next, per the FSM.

 

[Cirbo]

After that was the lid and Georg's T-case saver. Don't forget the small O-ring inside the case that seals the Hi-Lo shifter. (this didn't come with my rebuild kit)

 

[Cirbo]

Output flange and a fresh stake-nut on one side and the parking brake backing plate on the other, then Bob's yer Uncle!

Hope the quick write-up and pictures helped. They always work for me.

Special thanks to Gabe (gabe4jlc) for the extra set of hands.

Follow-up thoughts: During preliminary discussions, some questioned whether or not it was worth the effort to increase the low range gearing in an older LC. I was in the unique position to have a worn and (somewhat) useless newer style case and a ready supply of older brittle cases to salvage gears and parts from. One MUD member asked "why go to all the effort to change from a 1.96:1 low range to a 2.31:1?" Another replied that doing the math showed it was like having your usual 4.10's on the highway, and 4.88's on the trail.

 

[1Fine40]

I performed this same exercise about 5 yrs. ago on my 78. The problem I had was the whine from the T-case was so loud that I could not hear myself think when driving....drove it for a year, then got an Orion.
Yeah, a ton of cash difference, but I can now actually listen to my stereo and make out the words!! I hope your gears are not as loud as mine were!!

Cheers!

 

[Cirbo]

Hmm... that's not a good return. Can anyone else comment on road tests for this configuration? It will be some time before I can do my own real-world test here.

 

[srgould41]

Send me your case and I'll test it for you

 

[Cirbo]

Is it ok to leave it where it is now, or do you want it removed before shipment?

 

[srgould41]

You better include the whole drive train. Just in case you know?

 

[3doghouse]

Many of these are built from worn components. Your awe inspiring to-spec build should not be any louder than any new solid case t-case.