This three part article covers my building of a RockLobster 6.5:1 transfer box. The article parts are:
The kit I am using (Trail Gear) contains gears and parts to replace/add to an SJ Transfer box. Within an SJ transfer box are effectively three gearsets/shafts as follows:
- Input shaft - The Trail Gear set contains a replacement shaft to which you add either the original bearings or new bearings as you prefer,
- Counter shaft - The Trail Gear set contains a replacement shaft and gearset to drop in,
- Output shaft - The Trail Gear set contains replacement gears for the original gears, you either re-use the original bearings or new bearings as you prefer.
In this stage, I use a press and a puller to install and remove the bearings/gears. The Trail Gear guide shows you how to do it with a hammer, some tubing and some steel plates i.e. no special tools. If you are concerned about this stage you could take the shafts, gears and bearings to a local engineer who would easily swap them around for you, it would take no time at all.
The Input Shaft is a straight forward process. The kit comes with a replacement shaft but without the bearings.
The picture on the left shows the complete original shaft. If you want to re-use the bearings then you can remove them using a puller or the Trail Gear "hammer" technique. The picture on the right shows the puller in use.
However, I believe in using new bearings so I did not bother with the original input shaft at all.
Instead I took the new Input shaft from the kit and pressed some new bearings on.
Input Shaft Front Bearing (Suzuki - 29981-80050) 62/28
Input Shaft Rear Bearing (Suzuki - 29982-80050) 63/22
Full bearing details HERE
Counter Shaft and Bearing
This is even easier to do as there is nothing to do at all. The new Counter Gear is complete and a new shaft is provided onto which the Gear will sit. Nothing needs doing to this until Part 3 - Re-assembly. However, here is a picture to show why I am pleased a new shaft is included, look at the surface damage on the original shaft.
The picture to the left shows the full original Output shaft.
Starting at the "front" end of the shaft, remove the circlip and the Clutch ring. This ring should pull off but may need a couple of taps to help it along.
With the clutch removed you can get a set of pullers onto the larger bearing. The Trail Gear instructions show the gear being hammered off by trapping it between two metal bars and hammering the shaft, in my opinion a proper puller is the best option.
With the bearing removed you can lift the gear out as well as the needle bearing and clutch selector sleeve.
Flip the shaft over and start on the "rear" end.
Using the puller, remove the bearing and bearing retainer in one go.
You are then left with the speedo gear and the Output Gear (Low). You can see I used a press. By laying the Output gear on the press base (with the shaft through a hole) I could then press the shaft through the Speedo and Output gears. If you are doing this then catch the shaft as it will drop away.
Grease the needle bearings and then place the new Output Gear (Low) in place along with the spacer.
Put the Speedo drive gear in place. You can either press on the gear at this time or add in the bearing and retainer and press the lot on together.
On the left, you can see me pressing on the bearing and the Speedo gear at the same time.
With the rear output elements in place, turn the shaft over and start re-assembling the front output elements.
Grease the needle bearings and put the CLUTCH SELECTOR SLEEVE back in place (do not forget it!)
Add in the bearing, note that this bearing should be fitted only one way around due to the retaining clip.
I then pressed everything on, the old Counter Gear set acted as a nice tool to press the bearing in with.
Finally add back in the front output clutch. This should push on but you might have to tap it into place.
This concludes the bearing assembly, I hope it helped. Pressing on the gears is straight forward and if you do not have a press you could well find a local engineer who will do it for you, if you have the gears stripped out and cleaned you could drop me a line and see if we can arrange for me to press them for you.
Next up is part 3, the re-assembly of the case.