The Fordson Tractor Pages Forum

Hi all
I have a problem with the transmission brake on a SM. I do not have room to fit all the stationary plates onto the reverse idler gear.Even with the adjusting nut fully tightend the plates can still drop off the end of the shaft.
All the plates are flat.The centre part of the reverse idler has started to wear the casing.
The shaft has the correct amount of protrusion (30.5mm)

url=https://flic.kr/p/nJeE2M][/url]DSC_0435 by markhdm4, on Flickr

Should the gear be in to parts or should the centre be fixed in somehow ?
Why is there a grove around the end of the inner part ?

url=https://flic.kr/p/nJkMDj][/url]DSC_0437 by markhdm4, on Flickr

Thanks
Mark

Hi Mark

Don't know if this will be helpful, but here are some photos of my SM handbrake with the old busted plates, and the new ones.

Hi Atkiman
Thanks for the reply.
Here is a better picture of the issue I have.

url=https://flic.kr/p/nsZo1x][/url]IMG_0204 by markhdm4, on Flickr

As you can see the end plate drops of the shaft. I think the gear should be in one piece not two as in the previous picture. Can someone confirm this ?
Does anyone have an idler gear to hand and can give me a measurement as marked in the next picture

Thanks
Mark

url=https://flic.kr/p/nKtRJz][/url]IMG_0203 by markhdm4, on Flickr

Hi Mark
If it ain't broke, don't fix it! On that basis I have never taken the transmission brake apart, as I have never encountered a broken one. I write this just to let you know my experience in this matter.
Having said the above, the drawings leave us in no doubt (see link below). The gear is a one-piece item; a larger diameter cog that steps down to a smaller diameter cog. The smaller diameter cog engages with the brake discs that interleave with the wear plates. Pull the handbrake lever and the brake discs and wear plates are squeezed together, and friction provides the braking effect. The larger diameter cog transfers the braking effect to the transmission.
You need to find a new idler gear. More knowledgeable members than I will be able to advise on which Majors would be a suitable donor. I have a NP Super and I know the gearing for this model was changed from earlier models.
Great photos, by the way. Very informative.
Best
Adrian

http://partstore.agriculture.newholland ... 51ar235546

the 2 gears are not one piece but shouldn't just come apart. im sure there is a circlip in this groove.

Whats your reason for stripping it out?
Have you installed new plates?

They are a fine art. It took me a while to set mine up, if the plates are only 0.5mm too thick, they wont fit.

Hi
Thanks again for the very helpful posts.
I pulled the gearbox out to fix a bad oil leak from the front gasket, I suspected there may be something wrong with the trans brake as the handbrake ratchet had been removed.
I think you are both correct the gear was manufactured as two parts and then somehow fixed together. The groove in the centre part is not there for no reason and must have had a clip of some sort in it but what does it lock into there is no corresponding groove on the outer part. If I could get the measurement as in the previous picture I could reattach (ie Weld)the two parts together. If done slowly so as not to get to much heat in the gear I think it should be ok.
Any thoughts ?

Mark

Hi Mark
I defer to Jim - he's done the job, I haven't.
On closer inspection of your photo I see that the smaller cog transfers the braking effect to the larger cog by engaging with teeth on the internal circumference of the larger cog. So I was completely wrong!
Sorry I haven't been able to help. I'm going to duck out of this conversation and watch and learn!
Best
Adrian

Hi Mark

On my second photo, it shows the gears without the brake plates. There is a washer/shim that looks like it fits in the groove to stop the small gear sliding too far into the bigger gear. I think that is the part that is missing from your assembly.

The reverse idler gear and the splines for the handbrake are one unit and should not be in two parts. The parts book shows no circlip or retainer in the groove just the complete assembly. It may be possible to fit a circlip in the groove if you cannot get a replacement.

Thank you everybody for your help
I will look for a new gear and post a picture when I get one.
Mark

Hello Mark,
I was just doing a search for a reverse idler gear on line & came across your recent problem. I'm trying to put new brake plates in after taking them out many years ago. My problem is that there is to much space between the plates that can't be taken out by adjusting the nut, due to the retaining plate running out of square bolt to slide on. I measured the hub boss distance & this is correct. Having removed the gear mine is also in two parts & presumed there may have been something to keep the gear at bay part way along the inner slines to give me correct plate clearance. I Have read somewhere that the early Majors (mines 1954) had a different way of keeping the gears together to the later ones. When i find the info' i'll let you know.
I'm not sure if they're interchangable.

Regards, Philip

Hello again,
Further to what it wrote the other day i have found some info' on the net from a manual dated October 1963. In basic terms it states that from serial number 08C 960337 the assembly of the reverse idler gear & hub ( the inner splined part) has changed. In the previous assembly the gear was a press fit on the hub. On the later one (form the serial above onwards) the gear was positively retained on the hub by a circlip.
The individual parts aren't interchangable but the whole assemblies are. Hope this helps.

Hi Phylishe S
It sounds like you have exactly the same problem as I had.I have welded the two parts together,keeping the gear cool.
The next problem was running out of square section on the shaft just as you have to obtain the correct adjustment.
I have overcome this by fitting a spacer against the sholder on the other end of the shaft.I will let you know if this works ok.
Mark