Inspecting A 1975 Harley-Davidson - Four-Speed Inspection

3. Next, we checked out the swing of the clutch release lever, again feeling for roughness. The swing felt fine, but when we pulled upwards on the arm it came up and out of the side cover along with its mounting hardware and pivot shaft. That was a problem we needed to look into.

4. We then rolled the transmission over and checked the oil drain bolt. It appeared fine (it even had its sealing washer intact). The mounting pad for the fifth mount was worn down a little, indicating that the transmission was loose or not properly shimmed last time it was assembled in the chassis.

5. It was time to start addressing the problems. To tighten the sprocket nut, we put the transmission in two gears at a time to prevent the gear shafts from turning. To accomplish this we needed to remove the top, but first we had to dig the encrusted mung from the Allen screw recesses and from the dowel-pin holes.

6. Whoever was the last to assemble this transmission glued the top cover gasket onto the case and the top. We had to tap on the cover to remove the top-the easiest and safest way is to use a block of wood under the neutral switch area of the top.

7. The top came loose with a few love taps of the hammer, which were applied to the lower edge of the wood block. Notice how the gasket split: half on the ratchet top and the other half on the transmission case.

8. We checked the counter shaft endplay with a set of feeler gauges. The shop manual calls for .004 to .012 inches. Our endplay was .020 inch; we'd fix that with a thicker thrust washer when we reassemble the trans.

9. We now turned our attention to the gear set. We slowly turned the main shaft looking for missing or chipped gear teeth and we found none. Then we looked closer at the shift clutches. We checked out the shift dogs, especially the corners-when new they are sharp, when used (ours) are slightly rounded, but serviceable. If the corners are broken off, replace them. The same goes for the gears we can live with ours.

10. With the ratchet top removed, we could lock the trans into two gears and remove the sprocket nut. The sprocket nut has left-hand threads. To remove: turn the nut clockwise. JIMS Machine and H-D make a special deep socket to tighten and remove this nut. Ours was so loose we just pushed the lock tab back the rest of the way and the nut came off by hand.

11. With the sprocket removed, we were happy to see the L-key in place holding the seal sleeve to Fourth gear. This key is important to an oil-tight transmission. The seal sleeve and Fourth gear must turn together to maintain the transmission oil on the inside. If Fourth gear turns inside the sleeve, it is metal-to-metal contact. Metal-to-metal wears very quickly, letting the oil leak by and out onto your garage floor.

12. A small blade screwdriver was used to remove the thin oil seal pressed into the end of Fourth gear; finesse and patience worked wonders.

13. The same finesse and patience applied to removal of the main seal. The cork seal ring came easily once the seal was out of the way. Then we slid the sleeve off Fourth gear.

14. Down to the bearings, 44 rollers. We cleaned the seal cavity carefully using Q-tips and a spray of brake cleaner to wipe the area without disturbing the rollers.