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Old 08-01-2004, 08:34 AM
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1st and 2nd gear Dremmel Fix Pt2


Tranny Fix 1st and 2nd Gears Dremmel Technique, Part 2


Now that it's on its back, you can proceed to removing the tranny pan. On the XJ, you'll want to remove the sidestand switch assembly, and the oil sensor, just 2 bolts and it slides out...has an o-ring fitting/seal, just lay the oil sensor and sidestand switch aside/tie them up out of the way, whatever!!

I also removed the oil pump, there are some metal collars around the bolts, don't drop them into the engine or loose them, and note how the gear meshes with the gear on the clutch side, that's the shift fork shaft and gear that meshes with the gears on the inside of the clutch basket. Next, remove the C-ring for the shift pawl and remove it.

Now, remove the C-ring that was beneath the shift pawl for the shift fork shaft. Note the torx bolts on the bearing/oil cover of the counter shaft on this side.

You will need a good quality Torx bit (T-30).

The one on the wrench is good...the splines are all the way to the tip, not rounded/crowned like the loose bit below!!!! These screws are locktited in. They will turn with a standard wrench, but a perfect grip/fitting bit is a must!! I sprayed carb cleaner into the recesses of the heads of the screws/bolts before putting the bit into it to further reduce the possibly of slippage due to oil. I also sprayed liquid wrench into the holes behind it from inside the tranny case...not sure if it really helped, didn't hurt.!! On a previous machine, while using the aforementioned "BAD" bit, I stripped one badly, was able to take a 1/4" drill bit and just drill the head out down to the shaft...then once I got the bearing cover off, I was able to grab the remaining piece of the screw/bolt with lockjaws and remove it, and replace with a new bolt/screw. Just an FYI! This shows the Counter Shaft Bearing removed!

Next, slide the shift fork shaft out slightly just enough to clear the most distant fork, that's engaging gear #5, and let the shift fork slide down away from 5th gear against the shift drum.

Also note the position of the shift drum and the slots the shift forks slide/fit into. Next, slide 5th gear out the side of the engine.


Next, you can pull the shift fork shaft the rest of the way out, allowing the other 2 shift forks to slide down into the engine. Also note the slot/notch that is cut out of the shift fork shaft near the gear.

The shaft has a notch very close to the gear as well, to allow it to only line up and slide back in all the way in only 1 position. This keeps the recessed notch towards the first countershaft gear called the "middle drive" gear, but it's the one closest to the side of the tranny case, then the actual 1st gear sprocket...and it rides on a collar bearing..be careful when pulling these two off after you remove the entire assembly from the tranny, they will just slide off the countershaft. Now you can slide the remaining countershaft gear assembly a bit towards the open bearing hole, allowing it to separate from the shift forks and away from the bearing, and to be pulled upwards and out of the engine.. .sometimes a slight rotation of the rear wheel will allow the gears to turn a bit to facilitate the movement of the other gears below the countershaft assembly. The middle gear sprocket and the actual 1st gear sprocket just slide onto the countershaft...1st gear rides on a collar bearing..be careful when pulling these two off after you remove the entire assembly from the tranny, don't forget the spacer washer.
Once you get the counter shaft assembly removed, and you slide off the other two loose gears(the middle drive and 1st gear), then you need a C-clip remover again to remove the large C-clip keeping the 4th gear which has the dogs that mesh with the 1st gear sprocket off. It's best/easier just to leave the other two sprockets/gears on the shaft. Now, even if you are doing this to repair 2nd gear, I highly recommend a close inspection of the 1st gear dogs and slots, and going ahead and giving them the dremmel fix as well...since you're already in there, and they "ARE" going to fail eventually!!!
Here are the numbers of the Dremmel stones I used. 8193 is the large stone for both working on the dogs of second gear.

(which are actually on the 5th gear sprocket), and also for the dogs of 1st gear(on 4th gear sprocket) provided they aren't worn as much as the ones in this picture.

For this particular repair of these dogs I actually used a cut off disc instead, and made cuts along the red lines shown in pic#24, removing 1 to 1.5mm of the dog. I used a caliper to measure the width of the dog, and then used that for the other 2 dogs, and tried to keep them very close to the same size, to better ensure that all 3 would make contact with the 1st gear slots when put back together. I also cut them at a slight angle to make them better fit with the slots and to help them stay together when engaged....see the following 2 diagrams for a better view and explanation of how to grind them. Again, just a very slight angle of a few degrees is all that is required.



For the slots of 1st gear,


I used Dremmel #455 which are actually chain saw sharpening stones, they are kinda long, but they will wear down, round off kinda quickly after only working on a couple of slots. So then I used a cut off wheel to cut of the rounded ends of these stones to get a nice flat cylinder shaped section again to save a little $ being able to reuse the remaining grinding stone that was still on the shaft of the bit! The 1st gear slots are the hardest to grind, since they are closed and don't go all the way thru the gear. The large diagram shows and talks about how much of the slot/shelf you need to grind, but using this small bit, you can get very close to the corners, and it's best to grind as wide an area as you can on this shelf, again following the diagram to attain that slight angle in the shelf. It's a little difficult to grind a perfectly flat shelf with a round bit, so turning the dremmel tool so that it's not exactly perpendicular to the gear....like swinging the motor end of the dremmel towards the center of the gear can help to allow you to slide it back and forth across the shelf as you grind, to help keep the shelf edge flat, otherwise, as you put pressure towards the gear, and downwards against the shelf, you can inadvertently grind a round spot into the shelf!! This gear is the only one that I held the gear in one hand, and the Dremmel in the other hand to better view the slots and control the angle and amount of pressure applied to the shelf during grinding.
The final Dremmel stone is #932, which is used to grind the slots of 2nd gear.

All of these pictures show the Dremmel tool grinding the gears, but except for 1st gear slots, the 4th gear/1st gear dogs and the 5th gear/2nd gear dogs and the 2nd gear slots were all clamped into a table vise for stabilizing while grinding, so you could have both hands to control the dremmel!!!! The stone for the 2nd gear slots is slightly larger than the actual slot when you first go to grind it, but just barely, and with a sturdy grip and the Dremmel at high speed, you can grind right into the middle of the slot first, then move it towards the contact end, again NOTE the slight angle of the Dremmel motor to create the undercut angle in the slot once you make contact. I also used an in/out movement of the tool/bit to spread the grinding affect over the entire length of the stone, which helps keep the stone the same size over it's total length, for more even grinds on subsequent slots, there are 6!!!!! ALWAYS wear protective eyewear during grinding!!! Again, please refer to the large diagram on the special techniques for grinding the different dogs and slots. After grinding 2nd gear slots, you'll want to spray/dip off the gear assembly to remove any grinding dust/metal shavings that will have been created. Then recoat it or dip it in engine oil before reassembling. HOWEVER, the threaded end of the shaft that gets the countershaft bolt screwed in it should be kept clean of oil, to ensure a good torquing and so it won't work loose!!

On to Part 3>