wheel locking up

[Joohn]

Hi all, I have a Fordson Dexta when the LH drive wheel is rotated backwards by Hand it stops in the same place each time and can't be moved more by hand? I marked the tyre with chalk and revolving it forwards is no problem but when you turn it backwards it lock's up in the same spot!

When I drive it the same happens going backwards the wheel stops and skids, if I engage the diff lock that will force it to turn but with a lot of resistance. Diff oil is good I have had both drums off looking for the fault?

Any ideas?
Joohn UK

 

[Fawteen]

Broken tooth (teeth?) in the rear end?

 

[Joohn]

Broken tooth (teeth?) in the rear end?

I was going to take off the LH side of the diff I did the RH side to free up the diff lock and it was not hard to do, yes it could be a broken tooth but why it hasn't dropped out of the way? Thank you for the input I think you may be right, John

 

[Brown David]

Brakes out of whack would be my guess but you say you've had the drums off so likely you would have seen any problems there and made the proper corrections.

Sure sounds like brakes binding up though.

 

[Tx Jim]

My guess is differential pinion gear shaft has slipped out of housing. One would need to remove rockshaft cover for a visual inspection to confirm my suspicions.

 

[DanielW]

I'm with Brown/David on this one: I've seen exactly the same thing happen a few times when either the brake shoes have a lot of slop in their adjustment or (more commonly) when a spring is broken/rusted on one of the shoes and leaves it free-hanging in there and not retracting to its home position. When rotated backwards, an edge of the shoes catches on the eccentric I.D. of the drum (they're always worn slightly eccentric - there's always one slightly high spot they'll catch on), and the loose shoe catches and causes it to bind up.

Hearing how yours can power through if the diff lock is engaged makes me think it's almost certainly something brake-related like this. Which is a good-news story if that's the case, as that's a fairly simple brake mechanism to work on.

Pull the drum off that side, have a look, and try rolling it backwards with the drum off. I'd bet dollars to buttons it'll roll just fine.

 

[rustred]

Hi all, I have a Fordson Dexta when the LH drive wheel is rotated backwards by Hand it stops in the same place each time and can't be moved more by hand? I marked the tyre with chalk and revolving it forwards is no problem but when you turn it backwards it lock's up in the same spot!

When I drive it the same happens going backwards the wheel stops and skids, if I engage the diff lock that will force it to turn but with a lot of resistance. Diff oil is good I have had both drums off looking for the fault?

Any ideas?
Joohn UK

Brakes do not lock up in reverse due to the design. Are the primary and secondary shows on correctly ?

 

[J.Wondergem]

Brakes do not lock up in reverse due to the design. Are the primary and secondary shows on correctly ?

Shoes.

 

[DanielW]

To add to my previous point about the brakes: Once again, I've seen this a few times: My Massey 555 had exactly this problem when I bought it (PO thought there was some internal damage, which is why I got it so cheap), my Uncle's F250 developed exactly this problem (one rear wheel skidding in reverse), and by grandfather's piddly little 2N had a very similar problem (in that case it wasn't a broken spring, just a lot of slop. And in that case it bound going fwd but was fine in reverse. But pretty much the same cause). All resultant of very worn brakes/broken internal components.

It could happen in fwd or reverse, depending on which spring is broken or how it's worn. See this picture below for an idea of how it could happen. Imagine what would happen if the spring at 'A' and the retainers were rusty/broken (pretty common on old drums that haven't seen regular/proper service): The lower shoe drops at 'B', and the edge of that shoe (depending on how it's worn) is a 'sharp edge' catch point where shown. When rolling forward (see direction arrows sketched) there's no way for it to catch. But when running backwards, it's a catch point. If there's any eccentricity or high spot in the drum (there almost always is), it'll catch there and be 'self energizing' - binding harder as you force it. All dependent on the shoe geometry and how they're worn.

I may be wrong, but it's definitely a symptom I've seen before, and I'd certainly be starting with pulling the drum off and seeing how it rolls with it removed before I dug into it any deeper.

 

[Janicholson]

If the chalk mark stayed in the same place after "powering through it", I suspect a bull gear tooth is missing. backing the tractor down a modest grade cold check if the i
tooth is missing by the binding up not happening. The forces on the gear would be the same as forward driving. The brakes, if at fault would still bind. Jim

 

[Joohn]

Thank's for a fantastic reply to this, 4 weeks ago I took off both sides and removed everything to remove and free up the adjustment post's they were solid the shoes and springs are new by the last owner.

I will do the job in the new year due to commitment's, the idea to see if it locks up with the drum off would tell me if the diff parts are locking up! I will check if the shoes are the right size also?

I will keep you informed when I do it, when I brought the Dexta there were no brakes really they were backed off too far this prompted the total strip down I did to free the adjuster posts, I was not happy with the adjustment the posts when rotated did not adjust as was shown in the book after it kept dragging so I backed them off about 5 clicks, there is something wrong in there!, I watched many videos on fitting the shoes and am sure the springs are correct but never checked to see if the shoes were correct

Thank you boy.s and girls for your help!!!

joohn.