Carrier gearbox problem - any advice?

[Tom Millward]

Hello all. I’ve developed a problem with my Carrier gearbox and I’m hoping it’s something that someone here has seen and fixed before...

It was changing gear without any problems at all. But I have developed a problem whereby I can no longer get it into 1st or second gear using the gear lever.

If I manually pull the lever on top of the shifter plate across to align with the 1st and 2nd gear gates it moves freely in the neutral gate, but when moving it over to align with 1st and 2nd gears, it initiatially resists and then clunks over into position. From here it will engage 1st and 2nd without any issues. But as soon as it shifts over to 3rd, it will not go back into 1st or 2nd without manually pulling the selector lever over again.

I've taken the shifter plate off the top of the gearbox and all looks ok inside the gearbox. There’s nothing obviously amiss.

Does anyone have any thoughts, as I am baffled at the moment?

[Michael R.]

. . . would you know if you bent the connecting part number CTL 4950? There is a test to determine if the connector is bent. I will look it up for you.

Does your carrier have the gear shifter guide stiffener bracket installed? The part number is CTL 13451, it was introduced at serial #3655.

Considering what David and Lynn have suggested, there are a number of locations to inspect fasteners. I anticipate you would remove the transmission top as a complete assembly with the connector arm CTL 4950, rather than disassembling the connector.

[David Herbert]

So am I right that the gear lever will move freely all the way from one side to the other across the N part of the gate but will not easily move into 1 or 2 even though it lines up with the 1 or 2 slots. However if 'persuaded' to go into 1 or 2 it will then freely go into the other as long as you don't move the lever sideways as you go through N ?

If so I suggest you look for something loose in the linkage or a mounting relating to the linkage or possibly a bush with a lot of clearance in it. It seems that the gearlever is not able to move the gear selector mechanism sideways enough to line up with the 1&2 position of the actual gear selector in the top of the gearbox. This could just be wear that got to a point where something obstructs you or something has come loose so movement is lost.

David

[Lynn Eades]

I;d say the bolts in the tube under the engine are loose. There are two up front, near the division plate, and two at the rear in front of the bearing.
Movement is happening there at one end or both, and your gear lever gate is stopping you travelling side ways enough.
If it has been loose for a while, wear will occur as David has said. Select first or second and tighten the bolts.
There is a reason why the Australians did away with the gate..............

[David Herbert]

If you get someone to hold the gear lever in the middle of the N position and someone else tries to move the top of the selector on top of the gearbox from side to side, it should become clear if there is any movement within the linkage. Hopefully it will only be a matter of tightening bolts....

David

[Michael R.]

Portions of the speed change assembly from the 1944 FUC03 publication.

[Tom Millward]

Thanks for all the input guys. I’ve had a look at all the linkages, there is indeed a nut missing from the back half of the gear selector rod. The front joint looks to be adjustable, as it is secured together with a clamp rather than a bolt. I guess the bolts at both ends, as per the drawings, were a later modification to the Mk2 design? Mine is a 42 Mk1*.

However, my main issue seems to be that then gear selector lever on the top of the gearbox doesn’t freely move across the neutral gate. When it comes into line with the 1st/2nd gate it seems to stop short and needs a further push to get into line, as if it is moving across a detente pin. The force required is more than can be done with the gear lever at the drivers position.

Can anyone elaborate what the stiffener modification is to the gear shifter guide bracket?