Gearbox - Can’t engage reverse!

[geoffreyworthington]

I’ve just bought a Series 1, with a Series 2 gearbox. Reverse was working fine – until I got her home after a long journey. Now the gearlever will only push left against the spring, but won’t budge up into reverse (or down for that matter) at all. There’s no grinding, just the ability to move the lever laterally against the spring. It won’t then move up or down a single millimetre.

Any clues on what’s wrong and how to fix? I’m still waiting for the manuals to come through, so I don’t even yet know what the various parts are even called! Thanks!

[JDNSW]

There are several possibilities. I would remove the floor and transmission tunnel to investigate. The gear lever and selector shafts are out in the open. It is possible that dirt/rust etc can stop the selector shaft moving, and it this is the case, a squirt of WD40 should work. Note that friction on the ball can also contribute. Second possibility is that the adjustment screw (or mounting screws) on the spring loaded hinged flap that keeps you out of the reverse gate has come loose and this is preventing it from getting into the gate. Another possibility is that there is something foreign preventing the selector shaft moving, or preventing the gear lever from getting fully into the gate - and trying to move two selectors at once won't work!

If there are no problems there, the most likely problem is the reverse selector stop has come loose - I think you will need a manual for this. Worst case is the bush in the reverse gear has come loose, meaning a box dismantle, but one of the above seems more likely.

John

[Blknight.aus]

most likely

1. Something is fouling in front of the selector "cup" outside the box
2. the selector rod is stuck on some galling
3. the interlock or detent "ball" has siezed up against the groove it sits in in the selector rod.

pull the floor + tunned cover and get in there with the MK I's even if you have to take the top off of the box to inspect the rods selectors interlocks and detents its only about 30 minutes worth of work once the floor is up.

a smear of molly on the balls springs and rods will prevent it from happening again if that was the cause in the first place.

[fc110]

Now the gearlever will only push left against the spring, but won’t budge up into reverse (or down for that matter) at all. There’s no grinding, just the ability to move the lever laterally against the spring. It won’t then move up or down a single millimetre.

One I've had before was extremely worn ball on the gear lever end, you could move the lever across the gate while one of the other shafts had not returned completely to the neutral position & the interlock plugers did their job of not allowing two gears to be selected. The shafts stick from rust & sometimes incorrect GB top cover (covers are machined while bolted to the GB case & are NOT interchangable).

The bush moving in the gear as mentioned would be my next choice.

[geoffreyworthington]

Thanks again for all your comments.

I took the top off. Now I understand exactly what you’ve been describing.

The reverse selector shaft will now run freely backwards and forwards with all the ball bearings and springs removed. They don’t cost much to replace, so I’ve ordered all new detent springs, ball-bearings, grommets, etc, and gear lever end o-ring. I’ll then just clean up all the parts, reassemble with a little Lithium grease around the ball-bearings and springs, and threadlock the threads.