242 Main Shaft Replacement Instructions

Confirm your transfer case is a 242 with identifying tag. Please also check that the speedometer housing appears to be correct for your application. The original housing may or may not have a port for insertion of a switch. If your old housing did not have this port you will not need it with the supplied housing and visa/ versa.

The basic process is a simple and partial dis-assembly of the transfer case and the re-assembly in a reverse order using a modified main-shaft. The transfer-case will be identical to its original configuration up to and including the rear out-put bearing. Any snap/s ring that was originally on the main-shaft and rearward of the rear out-put bearing will be discarded. 

Secure vehicle with wheel chocks or support securely on jack stands. Place transfer case in the neutral position. Remove rear drive shaft. Drain transfer case oil through drain plug and dispose of used oil properly.

You will have either the Early {E} or the {L} Late model out-put on the transfer case. The early model transfer case will use a yoke on the drive shaft that slides in past a seal, more or less like that on most automatic transmissions. The late model transfer case will have a rubber boot that clamps between the transfer case and the drive shaft. Where there is a difference in the procedure this will be referenced with the corresponding {E} or {L}.

{E} Remove the 3 bolts that securing the rear bearing and seal retainer/tail-cone. Tap this tail cone side to side with a rubber mallet to break the silicon seal. After the seal is broken the tail cone should pull straight away.

{L} Remove the rear out-put seal. This will expose the snap ring on the main shaft. You may find that there are two snap-rings separated by a small spacer. If this is the case, remove both snap rings and the spacer. These will be discarded. 

Mark the orientation of the Y shaped link to the speedometer driven gear spindle and the orientation of the speedometer driven gear spindle to the speedometer housing. A small punch mark or scribe will suffice. Then remove the speedometer driven gear and spindle.

Remove the four bolts securing the speedometer housing to the rear case half. Gently pry the speedometer housing away from the rear case half.

Remove all bolts securing the rear case half. These will be around the perimeter of the case. You may find one bolt which has an odd looking head. This is simply a 12 MM, 12 point bolt, use the corresponding socket with this bolt. 

Separate the case halves with a gentle prying, working around the perimeter of the case. It is important that you work it around the perimeter to break the silicon seal to prevent breaking the case half.

You should then be able to slide the rear case half away from the transfer case. The oil pump and pick-up tube will slide off the main-shaft simultaneously.

Remove the snap ring that retains the chain sprocket to the front out-put shaft.

You will now be able to simultaneously remove the rear out-put shaft, chain and front chain sprocket by pulling rearward on these.

On the main-shaft you have now removed from the transfer case, you will need to remove the parts which are on this main-shaft for installation to the modified main-shaft supplied with your kit. 

Start by removing the snap-ring on the inboard end of the main-shaft and the tabbed thrust washer which retain the intermediate sleeve onto the main-shaft. Note the orientation of this intermediate sleeve, thrust washers and other parts as they are removed as they will need to be installed onto the replacement shaft in exactly the same order. 

After removing the intermediate sleeve, the snap-ring which retains the planetary assembly to the main-shaft will be accessible. Remove this snap ring, then slide the planetary assembly off the main-shaft.

At this point you will probably drop the needle bearings out of the center of the planetary assembly. They will need to be re-stacked prior to installing the assembly onto the replacement main-shaft. This is easily done if you will wipe a medium film of grease through the bore of the planetary assembly. The “stickiness” of the grease will keep the bearings in place while re-stacking them and while sliding the assembly onto the replacement main-shaft. A little grease on your finger will make the needle bearings easier to place.

After the reassembly of the main-shaft components, wrap the chain around both sprockets and slide the main-shaft assembly back into place while simultaneously sliding the front chain sprocket onto the front out-put shaft.  Secure the Front chain sprocket to the front out-put of the transfer case with the snap ring. This is reverse of the dis-assembly procedure.

Clean all mating surfaces of the case halves and housings of all old silicon or RTV sealant and oil film. Before assembling these parts, wipe a thin film of  RTV sealant across the the finish machined mating surfaces. 

Install oil pump and the pick-up tube into the rear case half. Note that the oil pump tabs are external to the case half and the pick-up tube is internal. These two parts have a loose fitment and it’s easy for them to dislodge while installing the rear case half. So be careful.

Attach the rear case half to the front. This may require a little “jiggling” of the parts but they should more or less, snap together. A small rubber mallet would be ok to use, A steel hammer may be too much. Confirm that the oil pump pick up tube remains positioned in it’s proper place.

We recommend using a thread locking compound on all bolts and nuts.

Install the speedometer housing. 

On the early model transfer case you will then install the new bearing and seal retainer, slide the 3/4" long spacer over the main-shaft then slide on the rear out-put flange*. Secure this flange with the 7/16 diameter bolt supplied with the lock washer under the bolt head and the large flat washer next to the out-put flange. Suggested torque on this bolt is 45 FT/LBS in addition to using a thread locking compound.

On the late model transfer case you will then install speedometer housing, then slide on the rear out-put yoke*. Secure this yoke with the 7/16 diameter bolt supplied with the lock washer under the bolt head and the large flat washer next to the out-put flange. Suggested torque on this bolt is 45 FT/LBS in addition to using a thread locking compound.

* To help prevent leaks through the bore of the rear out-put flange or yoke, we suggest wiping a thin film of RTV through the bore before sliding this part on. The excess will ooze outward. Then attach the retaining bolt and washers.

Refill with lubricant and install drive shaft etc....