Gearbox & Transmission Brake

This forum is for the Fordson New Major, including the Super Major and the Power Major.
Post Reply
Laurie
True Blue
Posts: 56
Joined: Mon Aug 10, 2009 10:08 pm
Location: Buckinghamshire U.K

Gearbox & Transmission Brake

Post by Laurie »

Hello . This is my first post on what is am sure will be a most helpful site. Although I do not own a Fordson directly my local villagehall and recreation ground committee ,of which I have been a member since 1982, does. I bought the tractor on their behalf back in 1984. Tractor No 1415835 with an engine casting code of A18A and a gearbox code of A24A. (Jan 1957) have not been able to locate the rear axle code as yet. Since purchased she has been very lightly used and garaged. Apart from a new dynamo and servicing the tractor is as we got her. She starts on the button and runs well and apart from the brakes which need abit of attention the tractor was fine. However recently she was driven by an inexperinced user who either left the transmission brake on or for some reason it stuck on. I was called in after the gearbox jammed with the tractor in the middle of the field.
I removed the clutch pivot plate from the side of the gearbox and could see the damage.The rotating plates had welded themselves to the stationary ones and the pressure had been enough to shear off the two pins that locate the stationary plates. These had then revolved and become enmeshed with one of the gears. With a bit of keyhole surgery I was able to remove the remains of the transmission brake and recover the pins from the botton of the gearbox. This freed up the gearbox.I removed the reverse idler gear and was able to drive the tractor back to its garage.
From what I can see there is no other major damage to the gearbox
I realise that I will have to split the tractor and remove the gearbox to sort things out but my immediate questions are :
Are the two pins just an interference fit in the casing and will it be possible to drill out the bits that are left in the casing without stripping the gearbox down completely, and is is possible and safe to split the tractor using a fixed jack and a trolley jack in the absence of a proper splitting rail

Sorry for the the long post but any help /guidance would be welcome.

Emiel
True Blue
Posts: 729
Joined: Wed Apr 16, 2008 3:22 pm
Location: Netherlands

Post by Emiel »

Hello Laurie,

Welcome to the board.

Sorry to hear about the damage on your tractor, but I think it can be repaired.

Splitting the tractor can be done, with your tools, on level and hard ground. Secure the front pivotting point before unbolting the clutch housing and block up the front end good and drive the back end away.

Finding new or used parts should be quite easy in the U.K.
Getting the old parts out I'm not quite sure about, but Brian or Mike can tell you something about that I think.

Good luck and best regards

Emiel
Best regards

Emiel

N 1937, E27N 1948, 8N 1949, E27N 1950, E1A Diesel 1953, E1ADKN PP 1956, Dexta 1959, NH Clayson M103 1964

Brian
Grumpy
Grumpy
Posts: 5216
Joined: Wed Apr 16, 2008 2:07 pm
Location: Norfolk, England.

Post by Brian »

Transmission hand brake failure can be easy or serious, you will not really know until you get the gearbox out. From the sound of your damage it does not look good. The two pins are pushed into the gearbox housing but, in the worst case, the seizure of the handbrake can split the housing.

First job is to drain the oil from gearbox and rear axle. Remove the PTO shaft then unbolt and drop the PTO gear housing from under the gearbox. This is very heavy and has to be wiggled out, it does not come straight down.

Then split the tractor at the clutch housing. Remove the clutch thrust bearing and cross shaft.

Go in through the selector plate and remove the main gear selector lever, the one that fits into the selectors, then look right into the top of the box and remove the Hi/Lo selector. Usually wired up, just undo the bolt and it will slide along the shaft as you draw the box out of the front. Do not forget to put it back when you reassemble.

Now undo the ring of bolts in the clutch housing and with a wriggle and a tug off the dowels, or use two drawing bolts in the threaded holes provided, the gearbox will come out. It is heavy and awkward.

You may be as well to get a complete box from a breaker if your housing is broken. I do not know how easy the handbrake rods will be to get. I suppose they could be fabricated out of the correct steel.

When you put her back together, remove the handbrake ratchet and grind off the first three teeth. This may prevent the problem occurring.
Fordson Tractor Pages, now officially linked to: Fordson Tractor Club of Australia, Ford and Fordson Association and Blue Force.
Brian

Laurie
True Blue
Posts: 56
Joined: Mon Aug 10, 2009 10:08 pm
Location: Buckinghamshire U.K

Gearbox & Transmission Brake

Post by Laurie »

Emiel and Brian thanks for your prompt and helpful responses.
Reading through previous posts had alerted me to the possibility of a crack in the gearbox casing so last friday I collected a gearbox and exterior casing from a breaker (£45) on the basis that it was in working order with special reference to the transmission brake components.
I will have a go at dismantaling this gearbox before I start on the tractor. If the original gearbox is Ok then I should be able to rebuild the transmission brake but if the original casing is split then I can rebuild/overhaul the replacement or get it done for me if I find that it is beyond me.
I hope that the original is OK because I know that it was working fine before apart from the usual problem of oil moving to the rear axle from the PTO or output shaft seals.
Brian thanks for the tip about the parking brake ratchet. From what I have read and heard the parking brake is an accident waiting to happen.
Regards

Laurie

Post Reply