to OD or not to OD?

stable

stable

0
Hello,

Hope everyone's warm and dry. Getting wet here in Wales :( About time to pack it in for the year I recon.

I'm just weighing up my options with regards to 5th (or 6th) gear. Trying to cost up the 2 paths. The 4 spd box on Charlie is on it's last legs.

There seems to be a few OD boxes about atm. I can't find a good thread on anyone fitting one on a non OD model. Lots of mentions but before I decide on which way to go could anyone give me a walk through of what's involved.

I have a local machine shop who I'm sure could shorten the prop. Other than that I assume some wiring?? is all that's needed?

Oh and which boxes with OD will be a straight swap from the rootes family?

thanks for any help,

Tom
 
Last edited:
Well worth it:)
Any non-Arrows box will go on without modification except the prop shortening (Arrows box is tilted over slightly and has longer bell housing and input shaft) the only thing to check is the splines on the input and out put shafts as the older ODs have coarse splines, not a problem as long as you have the matching prop and clutch plate. The other thing you'll need is a crossmember as the Commer one wont fit, I made one out of a piece of old bed stead. For the wiring you will need a 6RA relay and a switch, hopefully the gearbox will already be fitted with an inhibitor switch. Once you've got all the bits it's just the same as fitting an ordinary box.
I've got a wiring diagram somewhere, I'll dig it out and post it on here.
 
Sounds like a punt. So arrows is? sorry for my ignorance! I have a real black spot in my knowledge on Rootes family that I'm slowly filling.

Don't suppose you know of any pics of the 2x spline types, or know the number of teeth just so I can ask when hunting a box down? I'm assuming Charlie's clutch would be the 'finer' splines...

Although the 6 speeds looks long term like a good bet I think santa might only be able to stretch to a OD this xmas!


Thanks Panky.
 
Last edited:
Sorry Arrows is Hunter type cars, includes the Humber, Sunbeam and Singer types in the same range - late 60's and 70's. The engine in these is slanted over so when an Arrows range gearbox is fitted to an upright engine the gearbox is at a jaunty angle. Cant remember the number of splines but the difference is fairly obvious, I'll see if I can find any pics. Sometimes the gear boxes had a mixture of both just to confuse things even more:confused:
 
This is a fine splined shaft, the coarser one has very obviously much squarer splines.

 
And to show the difference between early and Arrows input shafts - Commer is on the left.

 
Yes OD every time! It will give you six speeds, if you count overdrive third, which I find very useful for those inclines which are just a bit too steep for 4th.

There's a bit about overdrive mounting and related stuff early in my "Jennings restoration" thread in readers rides, including reliable and safe lifting and lining up. I'm about to pull the box again to cure a silly little oil leak on the OD, so maybe we can swap notes.

If you are going to mount the box on an angle frame a la Panky style, you might want to add a simple reaction rod to stop the engine and box slopping back and forth under braking (and acceleration?). Once again it's shown in the same thread.
 
Try for fine spine if you get a choice... Coarser ones can be a real pain to find output shafts and clutch plates for if you need them or need to change...i know from experience :)
 
I fitted a coarse splined input shaft one to Bonnie and had no trouble getting a clutch plate (Martin M, who else) but I believe they are the same one used in the Bedford CA so other options available to find one if you need it. Luckily the box had a fine splined tail shaft so not had Jim's problems. I can only suggest that when you do find a box make sure you have a prop with a good gearbox end to match.
 
Yes thats key, don't buy a box with a coarse splines tail shaft without a prop. Doesn't matter if too long, easy to get chopped down - most important is that it has a good, smooth outer sheath (errm that the right word :)) as that seals all the oil into your gearbox against the rubber oil seal at the end of your gearbox. You may struggle to fix a rough one or buy a replacement.
 
Thanks guys, yes read your troubles with your warn... ahem, shaft. Sounded exhausting. Martin do you have any coarse yokes left?

Tom
 
Of course if you do find a prop with a ridge worn by the seal you could always(as you need to get it alterterd anyway) get the prop made slightly shorter than normal so it runs on a good bit of the shaft.
 
So let me get this straight - if your shafts got ridge wear - you've been lucky, if your shafts all rough and bumpy - no one touch it :oops:
 
You must log in or register to reply here.
Back
Top