I would be very hesitant to introduce any foreign substance. If you haven't already, peek at the valve body and think about the possibility for mayhem if something gets in there.

I take it you have looked on the euro ebays and there is nothing there? It just blows my mind that it can be so hard to get parts like this over there. When I was heavily into Triumphs I used to look forward to going to autojumbles and specialists like Rimmer and Moss when I was on business in the UK in the 90s.

X2
You are asking for trouble Army !!
Keep the snake oil out !!!!!!!
Look up the tensile strength of high tensile steel, that maybe close to what your parts are & compare it with the strength of the loctite stuff.
I would guess the loctite wont be 1/10 the strength of your splines.
It just wont work.
The first time you go off & on the throttle it will be all unstuck & the bits of loctite floating.


I lean towards you finding another trans & playing with it.
Your rough operation sounds like more of a vac or valve problem.
Its years since I have seen a 4 speed auto in pieces, maybe some one can comment on if this particular spline is meant to be an interference (press) fit or if it is a slide fit. I have an old 3 speed MB trans in pieces, it is not the same, none of the splines are as bad as yours.
My impression is that the car has been used for towing something heavy like a caravan in hilly conditions. Probably did not have fluid changes. That loads the trans up to the max with minimum lube.

Have you ever contacted the original owners?

I've not got in touch with the original Swiss owners - I'll look into it but I expect they've passed on.

There is no evidence of a tow bar ever been fitted. I've stripped and repainted most of the underside when I did the rear subframe.

Yeah I've cleaned out and reassembled the valve body - that's ready to go back in now.

As for parts - automatic gearboxes just aren't that popular. They do exist but everyone is scared to take them to bits so you can only buy complete second hand ones in "only low miles hardly used" condition... I just don't believe the sellers.

Thanks for everyone's input. I guess the snake oil is out. (Poor snakes they try so hard to please us)

Solution 4 and 5 are shelved for the time being. So no foreign material allowed...

I'll carry on with solution 2 => CNC machinists.

Can anyone help with material specification for this part?

http://en.wikipedia.org/wiki/Tool_steel

http://en.wikipedia.org/wiki/Category:Steels

They are probably made from an alloy that is then flame hardened.
I had a spline replaced on an axle a few years ago. The alloy they used to build up the axle was a much tougher material. it had to then have the spline electro eroded out of the built up metal before polishing the surface with a diamond grinder. It cost several $k . The alternate was a $12k axle.
A second hand dead trans from a location that is flat is probably your best & cheapest option.
I still think that spline would last many miles depending on how you drive the car.
Is that part of the trans the same as a later trans?

Yeah I live in a very flat land. Most people want about 300 euros plus for one that they say works. I'm always wary of these sorts of situations - lots of people call it a gray area - I think it is more likely people are trying to make as much cash from junk as possible... so far I've had my fingers burnt buying second hand parts here. Dishonesty reigns.

The 722.3 transmission is very different from the 722.1 it doesn't have the front planet set up at all.

If I were to be buying a second hand transmission I'd probably be buying a second hand 722.3 and modifying my car to get it to fit. But that project seems a bit much when I might get a few more years out of the transmission I've got.

The way I see it is that if I were to put it back together as it is (solution 5) I take the risk of an exponential wear on those splines that will result in violent failure. If I stick some glue in there (solution 4) I might delay this failure. I agree that it is a big might.

If I try to buy second hand transmissions - strip them down and perhaps get lucky I might spend as much money as getting the part made. Judged on my luck with second hand parts so far I think I'll be spending more that way.

I'm going to finish off my CAD drawing of the bit and see what the CNC chaps have to say about it.

In the mean time I'm taking barry123400's suggestion of finding some one who has done this before.

I agree that talking to some one who has had this problem previously is a smart move.
I am surprised that a CNC chap would want to make a new part. The should just remove the old spline, build up the part & cut a new spline.

It is surprising that you dont have a line of parts out of the middle east.
There are plenty of second hand late model 123 parts from there (Lebanon) that find their way over here.
Typically a good low km late model auto out of a W123 300D Turbo can be found for around $A600 with a 6 months replacement warranty.

What were the clutch packs like in yours?

My apologies about suggesting another transmission. Your location is obviously different. As you quoted it sounds like things are even a little worse where you live.

The transmissions are not a dime a dozen over here in north america either. Yet I suspect at least here with a little effort a guy can get his hands on one very cheap.

This ethic thing on used parts is simular over here. There are just too many people that find lying and other negative character flaws to be rewarding. So it is buyer beware in spades. Compound this with sellers just not having enough knowledge or experience to qualify things properly and you have bad situations.

I still feel the majority are fairly honest but the percentage of crooks is such you have to be very careful. I for example would never buy a motor on the ground.

The exception to that and about the only one might be from just a few members on our site. I know that if I sell something and say it is good it is good with no exceptions. If I tell you it is junk it is junk.

I have no wish to defraud any person or cause them to waste their time. Unfortunatly some people have such low abilities the bad dealing methods seem about the only way they can make their way through life.

I have to sleep at nights.

You make some very true statements Barry. Its the same world over.
One thing I like about this site is the way members are not scared to speak up (me included) & challenge any one who tries to be less than ethical in their dealings.
Ignorance is one thing, dishonesty is another.

The CNC blokes don't even know I'm going to turn up yet - I'm just working on the drawing. I reckon it would be quite difficult to repair the old part these days.

Firstly it is a casting that has been machine finished. Some of the casting edges look like there have been voids or air bubbles trapped during the casting process... that doesn't give me a warm wet feeling for starters... but then looking at the amount of metal around the splined shaft area - well I guess a new piece could be let in, but hmmmm, well, I don't know. May be 30 years ago when people were better skilled? I've just got a gut feeling a new bit machined from a blank might be less hassle in the long run. But when I speak to the CNC geezers I might be persuaded otherwise.

As for the clutch packs - it is almost a shame to replace them. The only reason I have is that they were actually quite cheap and I'd got that far into it. If I remember correctly when assembled the new clutch packs were about 0.1mm thicker...

The rest of the transmission (excluding the brake bands and these pesky splines) looks like it has just been round the block once or twice.

A little bit of progress
 

I've got this far with my CAD drawing. It is enough to show the CNC blokes what I need - I'm emailing this picture along with photographs to people to get some price indications.

http://www.peachparts.com/shopforum/...1&d=1307201479

As you can see it isn't quite there yet - but I'm not going to go any further just yet. It might not be needed.

I eagerly await the price feedback !!!
If I showed that to my local tool maker, he would hand me a mortgage application!! ;)

Yes I'm expecting a price quote between 500 and 1000 euros from the classic centre... I usually drastically underestimate these prices though. Even knowing what I know I expect I'll be shocked. I will be interested to see what the local CNC boys quote.

it will be an interesting one. If they make it out of a alloy steel & then heat treat it to try & get it hard enough, chances are it will deform badly. Making it out of a piece of hard (tough) material would be best except that it would need to be electro eroded as the machining could not be done even with a diamond cutter. This is the reason why I think the best repair would be to remove the spline, replace the metal with a super tough alloy & electro erode a new spline in. We have several of this type of repairs here, be it on much larger splines & they work well, thousands of hard hours without a failure of the repaired shafts & a hub.
My old 300D parts car probably has a good spline in it but the chance of me removing the trans over the next few months is very low!! I will one day just to see what 800k miles looks like in a trans.