Carrier gearbox problem - any advice?

[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?

[rob love]

The stiffener can be seen in the illustration Michael R. shows above as part number CTL13451. It helps support CTL 13250 from stressing and breaking the mounting ears off the top plate of the transmission.



Re the bolts, that is all I have ever seen, whether late or early Cdn carrriers. There should be two bolts at each end. They are shown in the photo as TL156.



I have had to make adjustments before to the linkage, although it is not designed to be adjusted. I made my adjustment by heating and bending the cast arm with the ball on it that comes up form the shifter rod. But in your case, I think I would determine if the indexing of the 3 part shifter rod is correct and all 4 bolts are in place.

[Michael R.]

More reference images . . . guide and stiffener
The original shifter forks (i.e.BB 7230) were replaced in production and service with strengthened C11T-series forks. The replacement fork reduced slipping out of gear and hard shifting.

[Lynn Eades]

Tom, you need to remove the lid (as per Michael R's picture and put it in a vice. Maybe you can hold it by the two cast horns. Movement of the gear change mech. toward or away from the housing (lid) should be relatively easy across the three selector fork slots while all are in the neutral position. If this is not the case, I would pull the gear lever from the housing to establish why. It has to be at the lever.
under the nut is a washer and spring. Remove them and the lever and check the small pin that engages the slot in the lever. It is fitted from the inside.

On the gear change clamp: it will be a post service mod. The early ones had an adjustable left and right threaded bolt like the ones in your linkage adjustment, only bigger. They were a dumb idea and by the time of the building of the U.C. I think they had moved on to the fixed arrangement as Rob and others have mentioned

[Ron Pier]

Reading with interest! Sorry to but in though. I've realized that my MK2* is missing the stiffener 13451. Has anyone got one surplus or an accurate drawing please. Ron

[Tom Millward]

Hello Ron,

I'll be stripping my Engine & gearbox out over winter to restore the inside of the hull. You're welcome to borrow my stiffening plate as a pattern. The Carrier is only up at Larkhill, so not to far from you. That or I can post it.

[Tom Millward]

Originally Posted by Lynn Eades

Tom, you need to remove the lid (as per Michael R's picture and put it in a vice. Maybe you can hold it by the two cast horns. Movement of the gear change mech. toward or away from the housing (lid) should be relatively easy across the three selector fork slots while all are in the neutral position. If this is not the case, I would pull the gear lever from the housing to establish why. It has to be at the lever.
under the nut is a washer and spring. Remove them and the lever and check the small pin that engages the slot in the lever. It is fitted from the inside.

On the gear change clamp: it will be a post service mod. The early ones had an adjustable left and right threaded bolt like the ones in your linkage adjustment, only bigger. They were a dumb idea and by the time of the building of the U.C. I think they had moved on to the fixed arrangement as Rob and others have mentioned

Thanks Lynn,

I will take the top off the gearbox on Friday and see if I can ascertain the issue. The little pin sounds like it could be the guilty culprit!