I Hate it When Someone Else Worked On It Before!

[Mike Stewart]

So, I have been wanting to take the 5 speed trans out for sometime to check out why I was having a false neutral shifting into 4th gear at high rpms. The previous owner told me that the trans was out before and had the updated shifter drum replaced to make the transmission shift better. Hmm I thought over the years since this was an 02 transmission which is suppost to have the updated drum already I thought that the shop must of shimmed the shifter drum wrong, so I pulled out the trans and checked it out on the bench. I noticed when I shifted it into 4th gear (yes while spinning the input shaft), the shifter drum would NOT keep the gear engauged, the shift drum would rotate backwards. Strange I thought to myself, hopefully shiming the shift drum would fix this problem.

 

I ordered the parts and two of each shim sizes, I went throught the different ways to shim up the shifter drum and I found that there was about 7 thou too much end play in the drum and I had to put the thickest shim at the rear of the shift drum to allow equal distance between 1st and 2nd gear (went from a .8mm to 1.2mm shim). Great I thought, put the puppy back together, tightened the input and output nuts, ran her through the gears And, it still will not engauge 4th gear, the shift drum rotates and engauges into 4th than rotates backwards and pulls out.

 

Oh no, my head was spinning, could it be a defective shift drum? I noticed when I take out the detent spring and put a small screwdriver into the detent sleeve, the transmission will shift fine. I looked at the detent spring and it looked like it had been cut. Thankfully I have another bike to check the detent spring against and would you believe the spring was cut by 1/4 inch.

 

Was this my problem all along or am I missing something else

[gstallons]

Uhhhhhhh, it's very likely. How hard would it be to swap places with the springs to see what happens?

[Chuck]

Was this my problem all along

Well, it certainly *could* be. You can see that the short one is either cut or broken on one end. From a production standpoint, a defective shift drum is more unlikely..

So. Have you tried the longer spring?

[gstallons]

Swapping springs will see if the problem follows the shorter spring....

[Mike Stewart]

One end of the shorter spring does look like it was cut

 

I did install the longer spring and everything shifts fine now on the bench Well, at least I now know the shifter drum is nicely shimmed

 

The true test is when it is back in the bike and it is road tested

 

Mike

 

Was this my problem all along

Well, it certainly *could* be. You can see that the short one is either cut or broken on one end. From a production standpoint, a defective shift drum is more unlikely..

So. Have you tried the longer spring?

[luhbo]

Before you put it back into the bike I think you should check the preselector as well. The retainer should work with the shorter spring also, as it does it with the other gears, at least as long as the preselector rotates the drum to the position where it belongs for the fourth. I'm not saying you should keep the wrong spring, just check also the rest of the box.

 

Hubert

[Chuck]

One end of the shorter spring does look like it was cut

 

I did install the longer spring and everything shifts fine now on the bench Well, at least I now know the shifter drum is nicely shimmed

 

The true test is when it is back in the bike and it is road tested

 

Mike

 

Was this my problem all along

Well, it certainly *could* be. You can see that the short one is either cut or broken on one end. From a production standpoint, a defective shift drum is more unlikely..

So. Have you tried the longer spring?

If it shifts fine on the bench, it'll shift even better when installed..

[Mike Stewart]

Hi Hubert,

 

Some history on the shifting problem I was having, the trans shifted well in all gears around town. The problem I had was when the bike was on the race track or even on the street at high rpms (redline), I would have a false neutral just about every time shifting into 4th gear. I have been told that 4th gear isn't the usual problem gear on the Guzzi 5 speed transmission.

 

When I took the transmission out, I did spend alot of time with it on the bench before I opened it up. To me, it seemed like the shift drum would not completly rotate enough to line up 100 percent with the detent hole. I tried adjusting the outside pawl adjustment, but it didn't make any difference. The drum would rotate into 4th gear but then would pull out when pressure was removed from the shifter arm. I was hoping that shimming the shift drum would fix the problem as the gap of the 3-4 shift sleeve was large on the 4th gear side.

 

So now the shift drum is correctly shimmed, the 3-4 shift sleeve is centered but the shift drum still does not line up with the detent hole 100 percent. That is when I looked closely at the detent spring and it looked like it had been cut. My thinking is that the detent plunger/spring aids the shifter drum to holding it into place. (under load the gear dogs are cut on a slight angle and will pull the gears together also).

 

So, with the correct spring, the transmission does finally shift correctly on the bench, but the real test is putting it back in the bike and taking it for a good run up to red line.

 

Thanks again for your input,

Mike

 

 

Before you put it back into the bike I think you should check the preselector as well. The retainer should work with the shorter spring also, as it does it with the other gears, at least as long as the preselector rotates the drum to the position where it belongs for the fourth. I'm not saying you should keep the wrong spring, just check also the rest of the box.

 

Hubert

[luhbo]

I thought maybe one of these pins (the fourth) shows wear or is bent even, something like that.

Also you can adjust the neutral position of group 32 so that it will give a bit more throw towards upshifting and vice versa (now I think preselector is the wrong term for it, don't know how it came to me)

Hubert