2nd Gear Modifications

[Jerry]

Note on reassembly

I currently am putting my transmission back together after working on the "1st gear fix" (had done the "2nd gear fix" a couple years ago.)

First, putting in #3 and #2 shift forks. (I am working from beneath the bike. Also have the oil pump removed. On my XJ there is no kick-start mechanism, so this combination gives as much working room as possible.) This time I had a spare fork shaft from the used tranny I got on eBay. I put #2 fork in place, put the spare shaft in from the left side of the bike into #2 fork, and thus kept the fork in place. When I installed the gear cluster, with fork #3 placed in its groove, I was able to slightly (1/8 turn) rotate the shift drum counter-clockwise as viewed from the engin's left side, which moved fork #2 slightly left. Fork #3 dropped nicely into place and I was able to get the gear cluster installed in under 5 minutes. Remember to rotate the shift drum back. Much improvement (for me) from my first attempts!

I then pushed the shift fork shaft in from the right side of the engine into (through) both #3 and #2 forks then removed the spare shaft from the left side of the engine. Fork #1 is easier; there is a gap between two gears on the counter shaft; one leg of the shift fork fits nicely into that gap so you can install the gear without interference, then wiggle the for into place. Takes a couple minutes, but is easier than the other 2 forks.

Remember, the forks are numbered left-to-right, with #3 closest to the clutch.

I will put together some photos, but one last note: a useful tool to have is a "C-clip" pliers; unlike conventional snap rings with little "eyes" on them, c-clips have basically squared-of ends. the correct pliers helps remove / reinstall these clips without the chance of bending or damaging them. I hade a set for my 4x4 hubs and they worked great for those clips on the main gear shaft. Cost of the pliers is in the $10 - $15 range, I think. Very worh-while tool to have for working on the main gear shaft.

[prometheus578]

Nice eyes, Ken and TRBIG."

How I never saw this thread I'll never know.

[XSPastor]

Hey Prom,
So reports of your omnipresence have been exaggerated?

[webbcraft2150]

Referencing your first post. A garage that clean and neat is not acceptable among XS owners.!!!!! You have WAY too much open floor space. Please refer to classified ads on this site to load it up with 2-3 more bikes.

[webbcraft2150]

Originally posted by XSPastor
Hey Prom,
So reports of your omnipresence have been exaggerated?

************************************************** **
It will vary with his medication levels, planet alignment and the lunar table.

[Mashermoto]

Webb,

A more current picture might make you happier

Since that first picture the garage has a 1981 XS650 I bought off flea bay and drove to Colorado to get and a 1978 XS750 that I bought in a garage sale a month or so ago Then there was the 1978 XS650 street tracker that got stolen...so that opened up a little room

The 81 650 is waiting in the wings for me to give it some love. The 78 750 should be up and running again tomorrow. Had to replace petcocks with manual ones and replace the clutch rod seal. But the real mess is that I have two XS1100 engines completly torn down Parts everywhere

Oh yeah...I put a new carborator and fuel lines on a Mantis rotor tiller for moms Mothers Day present (Ain't I a sweet boy )

Anyway...by the end of the summer I hope to have control of my garage again...until then my anally retentive self will just stress out

[Mashermoto]

OK...the kids birthday parties are over so it's time to get back to work

I started out today to resume grinding on the transmission gears, but first re-read the modification post to refresh my memory. I noticed the post said to make a slight angle on the dogs. I guess I missed that slight part

So...I need someone to look these pictures over and let me know if the angle is too much



Here is a shot of the gear dogs I ground and the tool used. I basically held the grinding bit level and let the angle of the bit determine how deep to cut.



I know you can't see it well, but the slots were cut the same way. The dogs and the slots mesh nicely, but is it too much

Also, I noticed one post that had both sides beveled. Is that needed on all gears (1st, 4th, 2nd and 5th).

Signed,

Waiting patiently again

[XSPastor]

Mashermoto,
A few degrees angle is all that is needed but I don't see a problem as long as the angle of the slots and dogs match. Obviously, a really steep angle would make for some sharp fragile leading edges on the dogs and take away a lot of material, weakening the dogs. I have only heard of first and fifth being a problem with these bikes. I'll let others chime in on whether you should grind other gears, but for my money, do first and fifth, switch the washer to the other side of 2nd, slap it together and ride!

[TopCatGr58]

Hey MasherMoto,

And Pastor, it's the 2nd/5th gear combo that breaks down for most folks, but the 1st/4th combo also can go bad. Seems they have gone bad earlier in the later year models, whereas the 2nd gears seem to be the ones that go bad in the earlier year models...why that is I don't know. I just know that my 81 lost 1st gear 1st, and then 2nd a few months later. I have repaired 2 other 82XJ's that also had 1st that were badly worn, one so badly that anything above idle and it would sound like a machine gun!!

Masher, I'll tell you that after I did mine just a few degrees, that shifting OUT of gear from 1st to 2nd was a little more labored due to the better grip from the undercutting. SO...I would assume that you might experience a similar but even more extreme version of difficulty in shifting FROM 2nd to 3rd with those more severely angled cuts, you might be required to really let off of the throttle a bit more to be able to allow the gear to come loose. It might also put a bit more wear on the shift fork having to overcome such a STRONG merging of the gears with that much undercut!?!?

I would suggest reducing the angle of the cuts a bit so that you won't possibly experience the extra difficult shifting OUT of gear!
T.C.

[Mashermoto]

TC,

I have a few options.

I can dig into the gear a little further on the top side and reduce the angle, but the consequence is that I will have removed a lot of material.

The other option is to take the gears out of the parts engine and try again I would think this is the best route to go.

Other things I'm not sure about

Do I need to grind just one side, or both sides of the slots and dogs? I thought just one.

My first and fourth gears look real good. I'm inclined to leave them alone. Good idea or bad idea? This is an earlier model.

[DiverRay]

As I've been through it, I would say pull the gears, and do both sets. All you need is about 1 or 2 degrees of undercut. So just a light touch with the dremel, and you'll be good to go. Do put the washer on the other side of second, though!

[TopCatGr58]

These gears are overengineered, and so are quite sturdy and thick. I've removed over 1mm worth of thickness from the dogs for 1st gear due to severe rounding of the edge in order to get a square face/edge again!

But it's your choice to use the spare gears vs. cutting these a little straighter, you wouldn't be going any farther into the cut closest to the gear, and that's really where the stress will be and where a crack/failure would occur.....IF it were to occur, which most of us feel is very unlikely!

No, you don't need to cut both sides, just the portions that are for moving forward, not for decel!

I would still dress up the 1st/4th gears while you've got it open and easily accessible, it only take a little bit of rounding to get them to start skipping, and you'd kick yourself in the butt later for not doing them WHEN they start skipping!! Just remember, just a few degrees!!!
T.C.

[XSPastor]

And Pastor, it's the 2nd/5th gear combo that breaks down for most folks, but the 1st/4th combo also can go bad.

Sorry to be unclear. I assumed when I said 2nd that he knew that meant the second/fifth interface and when I said 1st he knew that would mean the first/fourth interface. Thanks for the clarification, TopCat!

[planedick]

Important

to make all of the dogs even after grinding. It's important to keep the load even on all the dogs and not all the load on just one. Try to keep it so all the dogs contact the surfaces evenly....

[Mashermoto]

Sorry for the late reply guys...lost cable service for a couple of days

OK...back to the gears

I've taken more than 1mm from the gear dogs so I'm going to play is safe and work the spare set

Just a few degrees this time and I'll work all of them as advised

I'll be back when I have the work finished and photos for final inspection