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No worries.

I did do the first few to use gaskets. I measured the thickness of the gaskets I was going to use and fitted shims between the cap and case to that thickness, less 0.001", bore away, job done.

Few years ago 'took my 333 box to the dippers for cleaning.
He took out the main casing but, forgot about the diff housing which nearly disappeared overnight.
I brought up the subject of mix 'n' matching on this forum and in a roundabout way Rich and Vegard told me I was a git and threatened to come down to my house and set fire to my trousers if I tried it.

It worked after some careful machining but to be fair it was only down to luck AND you must re-torque the fixings after you have run up the unit to full temp on the dyno...not so easy if you haven't got a dyno. Still leaked so had to gob a load of silicon around the joints - not ideal.

I suppose in the end if you are not lucky enough to get a match it will be down to the quality of the machining. Spider & I have discussed this and you probably do need a simple Jig to hold the box. Once you have that it is probably only 2 hours, if that, of work. Anybody who set themselves up could surely rattle them out even tig welding to build up the housing and re-machining.
As compared to the original 1960s modern machine tools have come on in accuracy especially in measuring.

Like I said earlier, and I realise that bike casings are a single plane mix and match, but bikers have been re-jigging mis matched casings since pontius was a pilot. Blimey...... how would you ever see an oil tight Brit bike if we didn't. Every one on my Commando is a mix and match pick 'n mix!

Spider wrote:

agricola wrote:Oh I forgot to add: I personally would not remove the dowels as they really accurately locate the two pieces together hence most flywheels are dowelled and bellhousings.

Funny you mention this - that's today's job - correcting one of these.

Well, this turning in to a bit more than just correcting the dowels and housing alignment and bought forward another back ground project to the forefront. I know this is not the first time it's been done;-





The housing to gearbox - as fitted up on the dowels - was so far out, it had distorted the machined needle roller bearing bores to the point where the bearings were falling out, there are never brilliant, but this one by far was the worst I've come across - as best as I could measure, 0.92 mm out. The Outrigger bearing was also worn out - and after only 12 000 km. I could have TIGed out the gearbox and housing, then rebored, but in the end, a Tapered Roller Conversion of the Idler was most definitely the way forward. Of course, I did e-align the housing and re-bored the dowels. No more Idler Gear chatter out of this one now or ever again.

I'll now be re-doing all my cars.

A down side of this was that I had to go to custom bearings, but even so, I think it'll be streets ahead of the stock set up.

Well done looks good, very impressive.
I have tried a sound 4 synchro diff housing from a cracked main-case. unusually? the crack went from the diff bearing surface on the case towards the pinion, not damaging or effecting the remote. I have tried the diff housing on the 3 synchro casing I have, and although I havent had time to mic it the alignment is very good. Because its a spare for a rally S for safety sake I will surface the diff housing and bore it as discussed and shown by Spyder. I first need to make a Jig to hold it on the mill. If you read this post the moral of this is accurate machining with something that is difficult to hold or place accurately on a mill table. In other words you have to have a trustworthy machine shop and check there work. One other thought cast iron improves with age aluminium alloys do the opposite and we are dealing with 40plus year old casings!

Interesting thread....Have always been lucky with any I have used.

However, kind a struck me as strange...what has happened to all of the diff housings...we seem to have lots of casings but few diff housings!!!!

I know we broke these back in the day when used for hard rallying....hitting rocks etc. pushing the toe of the housing up against the sub-frame and...bingo...broken housing...doesn't explain why we see so many casings without diff housings.

Great stuff as usual Chris!
nice Tapered Roller Conversion for helical idler!

Cheers
luis

360gts wrote:doesn't explain why we see so many casings without diff housings.

people dropping engines normally and breaking the back part of the rectangle casting

I also see a lot of rod change ones where the diff housings are scrap because the little rubber bush has been twisted and broken the case, normally due to people dragging the engine by the gearlever/rods or trying to smack the bush out with a chisel

360gts wrote:Interesting thread....Have always been lucky with any I have used.

However, kind a struck me as strange...what has happened to all of the diff housings...we seem to have lots of casings but few diff housings!!!!

<snip>.

Think in reality the apparent shortage of rear end casings on 22G1128 & 22G846 casting remote boxes is because most of those on the market are from ADO16's these days. These employ a sandwich plate and side bolts of course to attach the remote arm, not the four bolts through the bottom used on Mini's. I know you can always get lucky but consequently regardless of gear condition the going rate when the bidding stops on a well known auction site for a complete Mini type seems to currently be about £150, and ADO16's sub £100, with a variation if it comes with a CR gear set.
Many moons ago I did run a Mini with a sandwich plate type and it worked fine but seem to recall it was a bit of fiddle getting the side bolts in and out as the exhaust got in the way...

Cheers for the comments guys. Fingers crossed, but I can't see why the TR Bearing Conversion won't work.

360gts wrote:Interesting thread....Have always been lucky with any I have used.

However, kind a struck me as strange...what has happened to all of the diff housings...we seem to have lots of casings but few diff housings!!!!

I know we broke these back in the day when used for hard rallying....hitting rocks etc. pushing the toe of the housing up against the sub-frame and...bingo...broken housing...doesn't explain why we see so many casings without diff housings.

I did have a 'glut' of caps for Rod Shift boxes. On the Big Wheel Mokes, they have a habit of breaking teeth of the FD Gears and in doing so, usually crack the centre web of the casing. Many years ago, before I had them welded, I used to keep the caps and throw the casings. I think I have one cap left!

YMJ wrote:Few years ago 'took my 333 box to the dippers for cleaning.
He took out the main casing but, forgot about the diff housing which nearly disappeared overnight.
I brought up the subject of mix 'n' matching on this forum and in a roundabout way Rich and Vegard told me I was a git and threatened to come down to my house and set fire to my trousers if I tried it.

It worked after some careful machining but to be fair it was only down to luck AND you must re-torque the fixings after you have run up the unit to full temp on the dyno...not so easy if you haven't got a dyno. Still leaked so had to gob a load of silicon around the joints - not ideal.

I’ve got a couple of rod diff housings to spare if someone has got their matching up and running...

Vegard, sent you a message.

I know you cant really adjust the clearance between the drive and diff pinion but does anybody know what it should actually be?

agricola wrote:I know you cant really adjust the clearance between the drive and diff pinion but does anybody know what it should actually be?

The Centre to Centre distance should be 4.000 to 4.003" but seldom are. I've measured tom up to 4.017"

spider I take it they are never under say 3.997 to 4.003?
the reason I ask is if you do have to machining opperation to fit a diff housing if you had a box with greater than 4.003 doesnt it give you the option to machine the gearbox as well as or the diff housing and set a more accurate diff to pinion clearance? I am assuming the diff and pinions dont vary?

agricola wrote:spider I take it they are never under say 3.997 to 4.003?
the reason I ask is if you do have to machining opperation to fit a diff housing if you had a box with greater than 4.003 doesnt it give you the option to machine the gearbox as well as or the diff housing and set a more accurate diff to pinion clearance? I am assuming the diff and pinions dont vary?

Off hand, the 'tightest' I've come across was 4.004". I've certainly never had one at 4.000" (or less)..

Yes you can (and I do now as 'routine') re-bore the tunnels to get them to where they should be. Likewise, this give a little bit to 'play with' if re-capping a box.

The Gears themselves seem quite accurate, I don't think I've found more than 0.001" variance on the CWs and less than that on the Pinions.

As always, it's best to measure what you are intending to run with.

Might explain why some boxs seem noisier- if the gap is larger.

Spider , where to you get the diff centre size of 4.000" - 4.003' from ?