I faced an unpleasant issue with my bike a few days ago. I got one of the gears worn out and had to fix the gearbox on my custom Dnipro MT. The necessity to repair the gearbox made me decide to create a post dedicated to this topic. So, if you ever face a problem with your gearbox, hope this article will be of great help to you.
If you are a fan of heavy motorcycles produced in ex-soviet countries, you probably know that the gearboxes from Dnepr MT motorcycles are the best ones for those bikes because of their reliability, durability and comfort.
Those gearboxes are interchangeable, that’s why lots of Ural and K-750 owners install Dnepr gearboxes on their bikes. As I mentioned in the article about the difference between Dnipro MT and Ural motorcycles, I can’t name even a single advantage of a Ural gearbox over a Dnepr one, so I will simply create a list of why a Dnepr gearbox is much better than a Ural gearbox:
So, if you are a Ural owner, you are strongly advised to buy and install a Dnepr MT gearbox on it to make your bike more reliable and comfortable.
Before we can move on to fixing problems with your gearbox, I would like to explain you in a plain language how it works. I’m sure most of you know this part of the bike well enough to skip this section of the article.
When you push the gear shift, the movement is transmitted to a special plate, which is called a coulisse in my country, but in English it is probably called a shift quadrant or something similar.
When this plate rotates, it moves the forks, which are connected to shift sleeves. We call them synchronizers because they synchronize the movement of 2 gears situated next to each other. Gears have special teeth and a shift sleeve connects the teeth of the gears it is installed between. This allows to connect and disconnect gears and thus change the number of rotations that is transmitted from the engine to the rear wheel (and to the sidecar wheel in 2WD models).
Now, when you know some general info about this part of your bike, let’s move on to the details on how to identify and fix different problems that may occur with your gearbox.
Problem #1: when in some certain gear, the bike twitches.
That’s the exact problem I faced this time. Most often this problem occurs when the forks wear out and place shift sleeves in a slightly different position than they should be placed. And when the shift sleeves are placed incorrectly, they start ruining the teeth on gears. When you experience the “twitching” of your bike, it’s a 100% sign of the gear teeth being ruined. If nothing is done and you continue using the gear you have this problem with, it will result in the problem #2.
Solution: if the forks are in poor condition, they should be replaced. If they are slightly worn out, you can save the situation by adding main shaft adjustment shims. These shims help adjust the position of the gears and thus their teeth. Please note that the chances are that the teeth on a problem gear have already been ruined pretty hard. If that’s the case, you will need to replace this gear.
Problem #2: when some gear is turned on, the bike behaves as in neutral and only produces strange noise.
This is what happens, when all the teeth on a certain gear are ruined. The reason for this is described in the problem #1 section.
Solution: you will definitely need to replace the problem gear. Additionally, you might need to replace the forks or add main shaft adjustment shims.
Hint: whenever I deal with a gearbox, I use a special highly technological tool of my own development :). I call it a wire-helper. You can make one for yourself too. When the gearbox is reassembled, I use this tool to check whether the shift sleeves are adjusted properly. Here is how it works: I turn the 1st gear and check the space between the main part of the gear and the shift sleeve. If this gap is too big, this will result in the problem #1 pretty soon. If the gap is too small, you will probably have the problem #1 with the 2nd gear.
If the gap is just right, I turn the next gear and repeat the procedure.
Problem #3: when some gear is turned on it jumps out.
This often happens when the plate (shift quadrant) that moves the forks gets worn out or the rear part of the fork gets worn out.
Solution: you will have to replace the shift quadrant and/or the forks.
Problem #4: something prevents from shifting to higher gears (from 1st to 2nd, from 2nd to 3rd, from 3rd to 4th)
I had this problem last year. When I was trying to shift to a higher gear, something was preventing me from pushing the gear shift high enough to do this. That’s why I was able to turn the next gear only by pushing the gear shift several times in a row. As it turned out, the problem was with the plate that is connected to the gear shift. It got worn out and started to move from one side to another and this side movement caused the gear shift jam when trying to shift to a higher gear.
Solution: there is a nut that fixes this plate and prevents it from moving from side to side. All you have to do to fix this issue is to tighten the nut. There will be no need to completely disassemble the gearbox.
Personally I bought a used gearbox for $15 and took the parts from it. We have lots of Dnepr parts for sale here in Ukraine, but I think such parts might be quite rare in other countries. If you have friends or relatives in Ukraine, you can ask them to buy the needed used parts here and send them to you. If you don’t have anyone to ask for such a favor, contact me, I’ll try to help you out.
Another great source of spare parts for Dnipro gearboxes is a guy from Kyiv. He produces brand new gears, forks and other parts on some Kyiv plant. And the best part is that he also offers the needed parts to install the 5th gear (the 5th gear will be turned on via the foot gear shift, just like other gears). The parts this guy sells are of excellent quality and all his customers leave only positive testimonials. I also bought a set of gears and other parts and made my gearbox have the 5th gear and I’m damn happy with what I got. He also sells new gearboxes for those who are lazy enough or simply don’t have time to install new gears themselves. If you want to get brand new spare parts for your gearbox or a completely new gearbox, let me know and I’ll connect you to this guy.
As you can see, it’s not that hard to fix the problems you might have with your Dnepr gearbox. I did my best to describe everything related to fixing a Dnipro MT gearbox, but if something is missing or you have some problem you can’t solve, please let me know the details in the comment section below and I’ll update the article with the info you are looking for.