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I am helping a friend restore a 1933 box. We have a choice of two gearboxes. The better looking one has a drive flange for a fabric coupling, the other for a Hardy Splicer U.J. We have a sound Hardy Splicer prop shaft. Is it possible to swap the end covers and flanges of the gearboxes, or are the final drive shafts in the gearbox different?
Any advice greatfully accepted!  Cliff.
The splines on the output shaft of the gearbox are suitable for the spider for a fabric coupling or for the circular flange for a Hardy-Spicer, so they are interchangeable without disturbing the end of the gearbox. A Hardy-Spicer usually fowls the handbrake, but I know that mods are made by some on the handbrake mounting to overcome this. I have not done it myself so cannot give the details.
What an amazing result, a reply in two minuites! Many thanks Robert. All I have got to do now is undo the retaining nut!
hi Cliff

Dunno your experience but some idea of state can be assessed. The input splines should be unworn. General wear of selectors may be an indicator of genral state. The synchro cones should bnot be loose and ideally retain some of the fine sipes .You may be able to espy the 1st gear on cluster and if seriously pitted (not that it prevents use). The fabric uj box might have no synchro on 2nd, although some prefer these as more reliable. Cluster and mainshaft gear end float can be determined. Beware selecting gears with the interlock removed as synchro springs might explode.
Thanks for your advice Bob. I checked the items you mentioned and am glad to say we seem to have a nice sound box.
The reason I raised the queary in the first place is that the end covers of the gearboxes are quite different. The one on the box that I intend to use is nowhere near as tapered beond the speedo take off as the other, in fact it is almost parallel, and is machined to take an oil seal. As it was going to be quite a job to remove the spider from one, and the flange from the other, I thought I would just check that despite the external difference the internals would be the same. With the exception of the oil seal they are.
Hi Cliff
I am not sufficently familiar with details to comment. In my experience a modern seal at front was very worthwhile but seems most avoid trouble by not filling boxes as high as handbook advises.
Hi, if you just need to remove the coupling, take off the top cover & move the selectors to put gearbox into forward & reverse. Don’t forget to put them back before replacing the top. 
Hope this helps.
I changed to a Hardy-Spicer on my '34 Tourer.

It took several goes to get the handbrake to clear, involving (as far as I can remember) a spacing washer or two - to angle it away a bit - and some minor bending to bring it back up the hole in the cover.

I think it took about 5 attempts - a little bit this way, a little bit that, another thin washer ....

The final clearances are tiny, but enough.

After which, the speedo stopped working.

The speedo drive gear is just held in place by being pinched by the output flange/spider, and a little corrosion on the splines meant that the flange hadn't quite drawn home.

Another tweak of the nut sorted it.
   I like your tip, jonblob33, But in this case it would have given the gears considerable grief. On one box not only had the nut probably never been off, but was rusted on to the shaft. The method I use to save having to make any special tools is to fit two D shackles to the flange, and run a large pry bar through them. If you don't have a proper hardware shop D shackles come under chain fittings on Ebay.

[font=Tahoma, Verdana, Arial, sans-serif][attachment=12969]  [font=Tahoma, Verdana, Arial, sans-serif][attachment=12971][/font][/font]

[font=Tahoma, Verdana, Arial, sans-serif][font=Tahoma, Verdana, Arial, sans-serif]But for one nut there was also a need to heat the nut, add an extension to the tee bar, and help it on its way with the help of a big hammer! [/font][/font]

[font=Tahoma, Verdana, Arial, sans-serif][font=Tahoma, Verdana, Arial, sans-serif]Cliff.  [/font][/font]