Track Marshall 56 Gearbox Issue

[andycknight]

Hi, I am having trouble with an old Track Marshall 56 Dozer

The problem is selecting first and reverse gears
(Note second and third work fine)
But when trying to move the stick towards you (from the middle neutral position) it is like something is mechanically preventing this. So it is impossible to reach the "left-right gate" to select first or reverse.

Anyway assuming something is either rusted or jammed, I am attempting to remove the top off the gearbox.

I have undone the bolts down each side, plus two at the front and two at the back hidden under the seat, but the top of the gearbox will not move despite reasonable persuasion.

Has anyone taken one of these apart before?
Are there any other hidden bolts?
Does the "lump" in front (that holds the steering/brake levers) need to be removed beforehand?

Any guidance would be appreciated as I fear giving it a harder whack with a big rubber mallet will crack the casting!

Regards

Andy.

 

[nick...]

I owned a TM 56 blade a few years ago and from what I remember there is a lock on each gear to stop it jumping out of gear.don’t know if this could be an issue with yours
nick…

 

[andycknight]

Hi Nick - Thank you for the reply
Yes you are correct, the lock is due to a spring that holds it in gear. It could very well be the spring assembly that has frozen solid (I.e. if the spring can not compress that would stop you from reaching the forwards/reverse gate)
But either way I still need to remove the top casting off the gearbox.
My fear is a bolt (or two) are still holding it on somewhere, so I don't want to wack it too hard.

Regards

Andy.

 

[2wheels]

is the top casting mounted on dowels?

 

[andycknight]

Hi 2wheels,

Thank you for your reply

Not as far as I am aware, it just looks like a load of bolts around the perimeter. But you raise a good point. This weekend I'll have a go at passing a rope through the speed change and oil filler holes and see if I can jack it upwards.

Regards

Andy.

 

[andycknight]

Hi All,

I had another go at the weekend... Spent ages trying to remove the top off the Gearbox, but no joy. Whatever is holding it down has beaten me!

Anyway - When moving the Change Speed Lever leaver forward, I noticed that the bolt (highlighted in Red) moves out of the rear of the gear box on its shaft. Flooding it with lots of WD40 (and then oil) seems to have fixed the issue. I can now get all 4 gears and both springs are working correctly.

There was quite a bit of dirt back there. I guess over time it had removed every last trace of lubrication, thus preventing the "bolt" from going inwards to enable first and reverse gears... So this looks like a routine lubrication point from now on!

Anyway just wanted to say thank you for the replies I recieved... and if anyone else has a simular issue, this area is well worth a look.

Regards

Andy.