User Guide

5-22C

Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No. 3206007 -E

Transmission

Clamp the main shaft or counter shaft, respectively, into the vise (use protective jaws). Remove the gears and check the following

parts for wear and grooves:

● Bearings

● Pivot points of the main shaft and countershaft and pivot points of the idler gears

● Shift dogs of the gears

● Tooth faces of all gears

● Tooth profiles of the main shaft and countershaft as well as of the corresponding gears

● Check the profiles of all control gears for smooth operation

Thoroughly clean all parts, exchange damaged components. New axial securing elements should be mounted whenever repair work

is performed.

Assembling the main shaft (4-speed)

– Secure the main shaft with the toothed end facing downward in a vise (use protection

jaws).

– Prior to assembly, oil all components thoroughly.

– Mount the spacer bushing

1 and the 3

speed sliding gear 2 with the small gear

facing downward.

– Mount the spacer bushing

3 and the 2

speed fixed gear 4 with the collar facing

downward.

– Slip on the stop disc

5 (17.2x30x1 mm).

– Then, check all gear wheels for smooth movability.

NOTE: From Model 2001 onwards the spacer bushings

1 and 3 are made of steel (before

they were made of aluminium), the steel version can be used in Model 2000 gearboxes.