Gearbox selector top pivot bolt removed and now can't get forward gears.

[Spook Hill Man]

[img]Can anybody help me with advice or diagrams for a 4speed gearbox model DT 21 02 3?
In error I removed the top pivot bolt for relay selector (that's what Bentley call it) which hold the gear selector shaft in place and now I cant get any forward gears.
I'm not sure where the bolt is suppose to fit into the shaft. The sparse information that i have found on the internet and in Bentley etc doesn't really show the arrangement.

Has anyone made the same mistake and found a remedy?

Or do i need to open up the gear box to resolve?

Pictures attached[Can anybody help me with advice or diagrams for a 4speed gearbox model DT 21 02 3?
In error I removed the top pivot bolt (that's what Bentley call it) which hold the gear selector shaft in place and now I cant get any forward gears.
I'm not sure where the bolt is suppose to fit into the shaft. The information that I have found on the internet and in Bentley etc doesn't really show how the pivot nut fits into the selector arrangement.

Has anyone made the same mistake and found a remedy?

Or do i need to open up the gear box to resolve?

Thanks in advance for any guidance.

[Aidan]

The bolt holds the relay lever which operates 1st and 2nd gear so that it can't move sideways and remains engaged with the 1st 2nd selector fork - without it when you move the selector shaft in and out the cage on the shaft may displace the relay lever, though it can't move too much as the reverse switch cover limits the amount the relay lever can move towards the side of the case, I don't think it can actually disengage with 1st 2nd fork, more likely the cage is pulling the relay lever so that if you try and engage a gear it can't because the whole system is disigned to prevent 2 gears being engaged at the same time, but that is effectively what is trying to happen.
If the selector shaft is in neutral and can move in and out of the box against the spring then you may be able to fix it by removing the reverse switch housing and pushing the selector shaft out of the box (may need a tap for the last 1/2 ") then you can reach in and reposition the relay lever so the slot aligns with the end of the bolt and screw the bolt back in and then refit the selector shaft. It could be awkward to do if the relay lever has shifted or if it is in either 1st or 2nd gear, in that case you'll need to remove the end case and manipulate the selector forks to ensure you are in neutral to get the shaft out
Good luck

[Spook Hill Man]

Thank you Aiden for your very detailed (and rapid) response.
The gearbox is in neutral so I'm going to have a go at removing the selector shaft.
I'll let you know how I get on.

John

[Spook Hill Man]

Quick update:
Couldn't get the selector shaft out.
Now trying to remove the end case. I've though t i was doing quite well, but it seems to be stuck on the selector rod and wont come off.

[Aidan]

There's nothing really that can stop end case coming off, the selector fork for reverse gear has a nylon bush that slides in the end case but there is no lip or the like to impede it coming out of its hole and the hole is vented so it can't be held hydraulically , you just need a little wiggle

be aware the thrust washer for reverse idler may stick to case and then fall out

[Spook Hill Man]

Okay. I seem be at a brick wall.
In summary:
1) Selector shaft wont tap out. Something is preventing it coming out the whole way.
2) I removed the end case.
3) I've tried to remove the drive end case but this will only move about 10mm as it seems to be stuck on the selector rod.
4) I cant get to the selector rod from the bottom ( differential ) casing.
5) I've got an endoscope and I'm trying to work out what's preventing the shaft from being removed fully.
6) I'm not giving up.

Do you have any drawings or photos that I could use for reference?

John

[Aidan]

It's all in the Bentley manual.
Where are you ?

[Spook Hill Man]

I'm in Surrey.
I have found some better drawings of the mechanism and have formed a new plan. I'll post how I get on.

John

[Spook Hill Man]

Final Update.
Firstly, thanks for your help and comments Aiden.

I've found the problem. The gear selector plate has bent (probably when I wound the bolt back in first time) and is snagging the selector shaft preventing it from coming out. i tried a couple of things to desnag the plate but to no avail.

Now I've spent much too much time trying to solve this, so I have got a second hand gearbox off eBay to be carrying on with. So should be back on the road by the weekend.