Pesky Right-Angled Drives

[AlanT]

I eventually got round to degreasing these and found a part that I had missed earlier.

 

There is a tiny hardened washer, for controlling the end-float of the pinion.

https://flic.kr/p/oAgmdC

 

Well there is in a Smiths anyway. Poor ol' Bastuck has to do without, of course.

You can just about see that without this the pinion eats into the casing and bush:

https://flic.kr/p/oiNGNb

 

I knew it had been doing this but didn't grasp why until I found the thrust-washer lurking in the Smiths.

 

Here you can see the longitudinal groove in the bevel bush of a Smiths. This is good for getting lubricant in there.

https://flic.kr/p/oiNARx

[AlanT]

I have now fixed all of these, by two different methods.

 

I really like the second way and I'll make a new topic to show this.

[AlanT]

The six drives I have fixed so far:

https://flic.kr/p/puu4wH

all LOOK very similar.

 

They are all a lot better than when they came and all work well.

They move sweetly , IN EITHER DIRECTION, when the gbox stub is turned.

 

As you can see I have secured them by cutting grooves for circlips rather than re-peening the body.

 

Two of them were originally made this way and I just copied the method for the others.

This makes them maintainable in the future and is actually a bit easier to get right.

 

If you are buying one of this sort of drive at an auto-jumble, there is a simple test to check the quality of the gears and bearings.

 

First eat a kebab. I get mine from Sainbury's. Use the stick to drive the gears from the "speedo" side.

The gear-ratio is against you when driven like this. So any friction will prevent you turning it.

 

Only "Smiths Originals" would pass this test at first. Now four of them do, having had a little attention.

 

Two of them never will, because the gears are too irregular to pass smoothly over each other.

This DOES NOT prevent them being usable, because when driven from the gbox end the gear-ratio works in your favour.

 

But I'd just rather pick one with smooth gears!

[RogerH]

...just to add to the angle drive thread. The other day I bought a new expensive (OE) angle drive (I know I'm silly).

When I come to fit it the square drive cable would not go into the pinion gear hole. The speedo cable fell in nicely.

Also there was some play in the square drive cable - this allowed the bevel gear to lock-up and feel very notchy.

 

The speedo cable was 0.115" across the flats. The AD was 0.122 to 0.125 across the flats.

Today I took it back and got another AD. I also tried both in a new pinion gear - they both fitted nicely.

The new sdquare cable on the end of the AD was 0.119/120"

There was play but it didn't lock-up or feel notchy.

 

I tried the new replacement in the original pinion and it fitted - on the snug side of nice.

 

Don't know the make but it had a Moss sticker on it.

 

It is now fitted and should work.

The new pinion will be returned.

 

Roger

[AlanT]

The holes in these, or the gbox, are NOT square. They are made by "squeezing" indents in four places.

 

It does not take much rounding of the corners on the cable to get a failure.

I am surprised there is not more trouble with this. Its a bit marginal really.

 

I cut dead square holes that are tight on 1/8 rod but have a little play on a 6mm:

https://flic.kr/p/pmCpNv

[AlanT]

So here I go again.

Fixing a batch of these pesky-drives, that came from Chris59, plus a few of mine acquired for restoring.

 

First off the big brass-nut that tends to get mashed up:

https://flic.kr/p/shobeW

 

but I can easily clean this up:

https://flic.kr/p/s35T8S

 

If you get one of these nuts stuck on then remember that there is not much metal in these things and if you get rough you may get this problem. This is not quite so easy to fix:

https://flic.kr/p/s3dUGD

 

Compare this repro with a genuine Smiths original and note the reinforcing ring left at the critical place:

https://flic.kr/p/s378eh

 

Note also that on an original the big-nut is retained with a spring-ring comapred with a push fit that gets a bit of a battering to lock it. This makes fixing the big -nut easier.

 

If selecting a repro you should look to see if they copied the reinforcing ring.

 

Fear not Chris, I have a body with no gears to go in it, This one had been cracked a long time and the Mazak exploded when I cleaned it.

Edited April 26, 2015 by AlanT

[AlanT]

Here I open one of the drives from Chris59:

https://flic.kr/p/sbdQ2Y

 

This process leaves behind a groove, into which I can fit a circlip, to close up again.

 

This drive came all still together and seemed to work just fine. But I decided to open it anyway.

The wire-stub looked too short and at a funny angle.

 

You can see the crimped ferrule has damaged the wire and left incipient failure.

https://flic.kr/p/sbdMXC

 

But the real problem is the the ferrule is loose in the gear and I can easily just feed it right through the gear.

It's really hard get a crimp against a wire to wind up accurate enough to push fit in a hole!

 

Chinese ones use a dab of MIG weld on the end. This is not guaranteed to succeed!

Edited May 4, 2015 by AlanT

[barkerwilliams]

Lubrication. Whilst a working drive is off the car is it recommended to lubricate (grease) the angled drive, or leave well alone?

 

Alan

Edited May 6, 2015 by barkerwilliams

[Chris59]

Thanks for keeping us informed Alan, what you do will help many people (including me !).

[AlanT]

Lots of the ones I have dismantled have virtually solid grease inside. I have to dig this out with a tooth-pick, it wont't dissolve.

 

There is a tiny screw, probably intended for lubrication, but you won't get much grease through that.

Light oil in there might help.

 

Really they want dismantle/clean. This is why I rebuild with circlips instead of peening.

 

If yours has circlips just take these out and the bits with tap out easily. There are no springs or other stuff to make it awkward.

Watch for a tiny thrust-washer on the pinion.

 

All the batch from Chris59 have good quality cut gears and will gradually find their way back together.

[barkerwilliams]

Alan,

 

Many thanks for this informative posting. I will be getting my hands on mine soon and it will be in for a strip clean and re-grease.

 

Alan

[AlanT]

In the bag-o-bits I got from Chris, were two "blue-perils".

 

If you look on ebay for these right now, you will see these on offer with the distinctive blue washer inside the big nut.

I'd really suggest you buy something else. These have lots of problems.

 

Firstly, realise that the lovely blue washer does not hold the big nut on, because its not peened in place and pulls off quite easily.

 

There is an internal clip to do this. Here you can see that this a just a piece or ROUND wire:

https://flic.kr/p/uefu72

 

(A real Smiths clip is on the left, flat wide spring steel, b*****rs to get off if you need to)

 

The round wire soon jams the big nut and then you are tempted to knock the body about to free it.

 

A common problem with all these drives is that the Mazak, that encapsulates the brass stem insert, is less than 1mm thick.

Half a mm, 20 thou in some cases.

 

Here is a Smiths with a fractured stem, you can see the knurling on the brass insert:

https://flic.kr/p/ue4uXg

https://flic.kr/p/uegT3V

https://flic.kr/p/udEDT5

 

Well both of the blue-perils I got from Chris had broken stems.

 

Here I am rectifying this:

https://flic.kr/p/tWuuaS

https://flic.kr/p/udPetW

 

To get this double interference-fit to work I must cut three parts to diameter, length and concentricity better than 0.5 thou.

It must press in without jamming and hold tight FIRST TIME of trying. I can't get it out and take a little off.

 

But after using my tiny lathe for 40 years I can cut to a few tenths just by feel.

 

At school the wavlength of light was in Angstroms. My ruler didn't have these and so I always assumed they were atomically small and of no importance to me.

 

But now light is in nano-metres. And so, just the other day, I came to realise that a TENTH is just about four times the wavelength of red light. I am still reeling from this. Some physics bod please tell me that I got this wrong!

Edited June 6, 2015 by AlanT

[TR NIALL]

Hi Alan,how many different Types of Angle Drive have you encountered so far and are any better than the Original ones.

[RobH]

Red light (say 700nM) is about 2.76 x 10^-5 inches wavelength or 0.0000276 inches so yes, one tenth of a thou is about four wavelengths. Your lathe skills are impressive Alan. The cross-slide leadscrew and the bed on my Drummond are so worn that to cut consistently to one thou is impressive to me !

 

Rob

[AlanT]

Thanks for that.

 

What actually amazes me most is that I have tenths dial indicators and

I can easily push the plunger so that the hand moves one quater of a division.

 

This means a human finger can position something to the wavelength of light.

For a soft, fleshy thing, best part of 70 years old, this is amazing!

 

The thing in my favour is that nobody ever used this lathe but me. So proper lube and no abuse.

 

It's mainly technique and order off work that you need. You can forget using a 3-jaw chuck for example.

 

This wonderful thing did most of the work-holding on the drives:

https://flic.kr/p/hE2h74

 

These are almost unknown in the UK, I imported this one from the USA, where they are quite common.

The collets are made by bonding rubber to steel.

 

And you must finish a drilled hole with a tiny boring bar.

But these cut taper because they flex, so you must cut from alternate ends.

Stuff like that!

Edited June 6, 2015 by AlanT

[RobH]

Thats very nice. Looks like a cross between a Jacobs chuck and an ER collet. Does the rubber interleave give a wider range of adjustment than available from a spring collet? You are certainly right about the boring bar, and it takes several passes of cut for all the flex to be released I find, even with a fairly robust one.

[AlanT]

Jacobs Rubberflex collet system.

Nine collets to go from 1/8in up to 2in. Grip like crazy. Release easily, unlike ER25 which are a pain.

 

If you have a worn leadscrew use a dial-indicator on the cross-slide.

This is called a "dashboard gauge" in the USA.

[AlanT]

This is a genuine original Smiths drive with my repair for a broken wire:

https://flic.kr/p/usvvMj

 

I just sent one like this to a famous forumite, here is a second one looking for a home.

[Guest ntc]

Alan

It works spot on so chaps do not miss out on this

[AlanT]

One thing stands out doing up these drives.

 

The Smiths original is superior in every way to any repro I've seen.

 

1. better gears

2. better fit on the cable

3, better bearings

4. better casting

5. better machining

6. easier to open and close up again

 

Some don't even have hardened gears. I've machined a few to get a fit.

Smiths are glass hard, smooth as a BB and would need grinding to alter them.

 

The second thing is that, even the Smiths, are weak on the stem, where the big nut goes

and will break here if knocked about or levered.

 

I can't make standard parts that fit any drive. Each one is different and must be made to fit.

But I do make a batch of parts for Smiths so I can fix these more easily.

[TR NIALL]

One thing stands out doing up these drives.

 

The Smiths original is superior in every way to any repro I've seen.

 

1. better gears

2. better fit on the cable

3, better bearings

4. better casting

5. better machining

6. easier to open and close up again

 

Some don't even have hardened gears. I've machined a few to get a fit.

Smiths are glass hard, smooth as a BB and would need grinding to alter them.

 

The second thing is that, even the Smiths, are weak on the stem, where the big nut goes

and will break here if knocked about or levered.

 

I can't make standard parts that fit any drive. Each one is different and must be made to fit.

But I do make a batch of parts for Smiths so I can fix these more easily.

And an Excellent Job you do to Alan,the 4 you done for Me are all Perfect and Operating as should be,Thanks.

[AlanT]

Thanks for that, Niall.

 

I am hoping that a solid-stub rather than a wire will stand up over a long period.

 

I use "key-steel" for these, this is tougher than ordinary mild-steel.

https://flic.kr/p/p58rxw

 

The "waist" is where I fit rubber to retain the stub.

This leaves a little compliance to allow tolerance and also brings some "damping" to arrest vibration.

 

The trick is to get the stub to run absolutely concentric with the gear.

This means the hole in this part must be exactly in the middle:

https://flic.kr/p/pmCpNv

 

I do this by turning the part on a tiny square mandrel and then bring the OD to size.

 

This is the part that I can't make efficiently as a one off.

So I use up a 300mm length of brass making these and cut most of them to fit Smiths.

I leave some big to use of repros with oversize holes.

 

The rest of it is pretty simple but this liitle bit is awkward.

 

Just look at the superb finish on this Smiths gear:

https://flic.kr/p/pjAjsN

 

This has most probably run many thousands of miles, enough to wear out the wire-stub, but shows no wear.

These are as hard as a cutting-tool.

 

NOT like this:

https://flic.kr/p/p75aiv

Edited June 17, 2015 by AlanT

[AlanT]

There have been a few questions on here about the fit of the cable to the speedo, into the angle-drive.

 

I made this little tool to check drives:

https://flic.kr/p/uVtDAu

 

The wire is just taken from a broken drive and sticks out of the plastic by 1in.

 

In a genuine Smiths dive it just fails to bottom in the pinion:

https://flic.kr/p/uVC1uM

 

But often it will stick out of a repro:

https://flic.kr/p/vzT4ed

 

Any more gap than this could cause trouble by forcing the cable into the speedo-head.

 

Here I have withdrawn the tool to the point that it just stops engaging the pinion:

https://flic.kr/p/vzSLDC

 

So now we know that you must have between 1/2in and 1in of cable sticking out for the drive to grab hold on.

 

I use this tool to drive the pinion round. Any wear in the bearings, wrong end-float, poor finish on the gears will cause the drive to jam when back-driven like this.

 

Even serviceable ones tend to stick a bit when you do this, so you get a good idea of the state of the drive.

[AlanT]

A fellow forumite sent me two failed drives. One was another Bastuck.

These are not as good as the original and the first one got well again after a bit of work.

 

This one is better. A bit better.

The main difference is that whereas the first used a 10mm bronze bush to fit a 3/8in shaft this one has a casting for the stem:

https://flic.kr/p/wXwMKx

 

This is probably pretty good because it may be more resistant to the `'cracked-stem" problem

I fixed on a couple that had been attacked by the French.

 

However the bevel was jammed in the stem and I had to hammer it out.

You can see something nasty stuck to the inner wall.

This is probably left over from the casting process.

 

I chipped it out and recovered a bit. Some kind of clear resin full of metallic dust:

https://flic.kr/p/wEV31E

 

The bevel has gradually worn its way down the bore until it met this obstacle.

You can see the wear ring on the lip of the bore:

https://flic.kr/p/wVdgns

 

Having said all that, the pinion fit on this one is OK. The gears are OK.

So this will make a servicable unit with only a little work.

 

The other drive is a genuine Smiths with the trivial fault that the wire is rotating in the bevel.

This will get fixed with a 3mm solid stub.

Edited August 5, 2015 by AlanT

[AlanT]

I've just finished a third batch of restored angle-drives.

 

These came to me from good homes, three well-known forumites who turned out their junk boxes!

Thanks chaps and if you read this and would like one back then you get first refusal.

 

These are original Smiths and each time I do a batch I learn a few new tricks:

 

 

 

In addition there are a couple of others that are good, but repro. One actually has real Smiths gears in it because the original body had been run loose:

 

[

 

 

PM me if you would like one of these.

Edited January 10, 2016 by AlanT