Dana-18 Transfer case

Note: I am NOT going to duplicate the excellent work already done on the web regarding transfer case rebuilding. Rick Stivers rebuilding guide is where you should go.

This is just to document what I did, which mostly was spilling smelly gear oil all over my shop and clothes and creating a general mess.

With a helper, I lifted the engine and transmission assembly up on the bench. Note I had already scraped and scrubbed a TON of crap off the set. I have never worked on a more gunked up filthy mess in my life than this thing!

The parking brake shoes.

The three main pieces of the completely broken down case. Here you see the main case, and front and rear cap. This is my first time doing a transfer case, and I found it quite easy, by following the manual, and Ricks guide, which I printed out.

Painting the transmission and transfercase with Synthetic enamel chassis black.

Here are all the components painted and ready for assembly.

Here are the contents of the transfer case rebuilt kit you will get from any of the major willys suppliers. Bearings are as follows (cup - 2 rqd.: Timkin 14276, cone - 2 rqd.: Timkin 14131, Front shaft ball bearing - 1 rqd.: SKF 6206) The kit comes with the intermediate shaft and bearings. Warning: The shaft in my kit was soft. I.E. I could nick it with a file. Subsequent research turned up that this is common with these OEM kits. Novak Adapters make a hard shaft for this and the T-90 transmission. I bought one from them.

This photo shows the Novak shaft with it's O-seals at the left, next and OEM shaft and then the original shaft to the right.

The three castings of the D-18 ready for assembly.

My bearing installers for the front output shaft bearing. A large deep well socket will install the bearing on the shaft. The very large 3/4" drive socket was used to seat the bearing into the front cap.

Socket in use to install the bearing.

Shims and front cap. Note: Buy a shim kit before you start rebuilding. If you replace the bearings you will need it. Also note that the manual says there should be .004 to .008 endplay in the mainshaft bearings. Novak's website says that .002 to .006 is better. I set mine to .002-.003

Measuring endfloat with a dial indicator. I will say here that you cannot do this by feel. If you can feel it you probably have too much endplay. You must carefully pry the gear with a screwdriver to measure all the play. Rick's guide covers this quite well. Just be careful that you have the bearing cups seated well when you are dry fitting it. I spent a long time on this step.

Need to tourque the cap bolts to 30 ft-lbs but don't have a crows foot? Use your torque wrench like so. Just be sure to hold the head of the wrench and turn it just like you have a bolt under the drive tang. This is dead accurate, even though it looks weird.

A 1-7/8" socket makes a perfect seal driver for both output shafts.

My fixture to hold the yoke while you torque the nut to 120 ft-lbs. It's a chunk of angle iron with two holes drilled for 5/16 bolts to grab the 2 holes on one side of the yoke ear. Allows clearance for the socket to reach the nut.

The finished T90/D18 assembly. Note I left the levers and shift tower off. I think this will make installing the tub easier when the time comes, we'll see.