Gearchange / Shifter Repair Kit - TY125 & TY175

Full kit to solve those gear selection problems!

New Gearchange Repair Kit

Got a sloppy gearchange?

Missing gears and getting false neutrals all the time?

Worse when the engine is hot?

Then you have the standard TY125/TY175 gear selection problem!

This caused by excessive wear on several components behind the shifter cover, the one behind the gear lever with 4 screws in it.

Part of the problem is caused by the bush in the cover, even when this is brand new the bush is bigger than the shaft and, being phosphor bronze it wears out quite quickly. This causes the gearchange shaft to flop about which also causes excessive wear to the bush in the crankcase. All of this leads to wear on the upper lever, the one that attaches to the shift shaft that runs to the other side of the engine. This lever should look like the one shown below.

The slot has flat sides and round ends, the slot in the worn ones is normally oval. This in combination with the worn bushes can cause the roller to pop out of the slot completely giving very poor shift quality, or none at all!

Our repair kit consists of-

Replacement shifter cover - New

This is a new genuine Yamaha part that has been modified.

We have machined out the phosphor bronze bush and replaced with a CNC machined stainless steel bush that is the correct diameter and is extended all the way out to the gear lever spline. This offers a lot more lateral support to the gearchange shaft which, in turn compensates for the wear in the crankcase bush. Now when you push the gear lever with your foot it turns rather than twists.

Replacement cover o-ring - New

Shift lever 4 - New

This attaches to the shaft that runs through the engine at the top

Shift lever 4 circlip - New

4 stainless Allen screws - New

Fitting Instructions

1. Remove gear lever.
2. Remove flywheel cover.
3. Remove shifter cover (4 screws) watch for 2 locating pegs in crankcase/cover.
4. Remove circlip from top lever and remove lever 4 (the one with the slot).
5. Remove shift lever (the one the gear lever attaches to) should have 2 shims.
6. Remove burr from shift lever with a small file.
7. CLEAN EVERYTHING!!!
8. Check roller turns freely on shift shaft, if not replace they are on our website.
9. Put a BIG dollop of grease in the opening.
10. Refit shift shaft, make sure there is a shim on the inside and outside of shaft.
11. Fit roller to shift shaft after greasing.
12. Refit Shift lever 4, wide lip inwards, make sure there is a washer behind it.
13. Refit circlip.
14. Pack out the rest of the opening with grease, you can never use too much grease!
15. Fit new cover using the 2 existing locating pegs and 4 stainless Allen screws.
16. Refit flywheel cover and gear lever.

And that's it. We have had this kit on test for over a year with no problems and drastically improved gear selection. Replacing the shifter cover on its own will not do any good because the bush will wear out really quickly due to the burr on the shift shaft.

The kit takes a bit of bedding in, about 8 sections. We recommend that you use automatic transmission fluid (ATF) in the gearbox as this is much better for the clutch that synthetic or heavy oil.

The only other thing we recommend is to strip the mechanism annually and clean and regrease everything

Also fits twinshock DT175 models up to 1976 and all DT100 twinshock models.

Any questions please ask