Lancia Motor Club

Model Technical and Interest => Aurelia => Topic started by: impaw on 16 April, 2020, 07:49:07 PM



Title: Flying steel balls!
Post by: impaw on 16 April, 2020, 07:49:07 PM
Another chapter in the story of me doing things I should not be doing.

I decided to open up the transmission of my 4th series B20.
Just to check how things looked.
Everything looked clean enough, my untrained eye did not detect any problems.
I then decided to switch gears a few times, and just move things around a little bit, when bam, flying steel balls ( and springs ) !

Are there any trick to getting these little buggers back in place?
Do I need a spare set of hands?




Title: Re: Flying steel balls!
Post by: chriswgawne on 16 April, 2020, 10:31:05 PM
I have never had your problem in quite the way you have. Did you move the selector from beyond the position used by gear lever connection?
I find the easiest way to get those balls and springs back together is with the makeshift assembly out of the transaxle..........but you might find a way with plastics or similar.
Chris


Title: Re: Flying steel balls!
Post by: impaw on 17 April, 2020, 07:01:47 AM
thank you for replying Chris!

I am really not sure, but I guess I must have moved something beyond its intended limits.
Steel balls over the place.
I had to order some new balls, so from the time the incident happened to I got the balls memory has become a little hazy concerning just what happened.
It first happened on the foremost gear ( the one with the masking tape surrounding it ) , then the gear in the picture

I think I will heed your advice and take the assembly ut of the transaxle.

In deep waters :D

Thank you!


Title: Re: Flying steel balls!
Post by: chriswgawne on 17 April, 2020, 08:46:39 AM
Its all perfectly straightforward Torstein but make sure you don't get the various washers and spacers mixed up. There is a good diagram in the Parts Book - I cant remember which TAV it is and I don't have that info with me in the UK. If you find you need any parts, I am sure I have them as I have various rebuilt transaxles and a couple in pieces and also some NOS parts.
Chris


Title: Re: Flying steel balls!
Post by: chriswgawne on 17 April, 2020, 08:55:55 AM
Here is TAV31 showing the internal arrangement of the gears in an early transaxle. There is a spate TAV showing the gearchange fork arrangement.
Chris


Title: Re: Flying steel balls!
Post by: impaw on 17 April, 2020, 09:05:39 AM
Thats very helpful and encouraging Chris!
So I take it the axle is coming out at the front of the transaxle.
This will be interesting :D


Title: Re: Flying steel balls!
Post by: impaw on 18 April, 2020, 04:46:32 PM
Encouraged by Chris, I think I will do more or less a complete tear down.
To learn more about transmissions in general and this one in particular.
Step by step  ;D

Seems to have been quite some heat at the front gear.
Normal?

The sleeve around the shaft had a dry and broken o-ring inside, in a groove.
I could not find this o-ring in the diagram, so perhaps Its a user modification🤔


Title: Re: Flying steel balls!
Post by: chriswgawne on 18 April, 2020, 08:45:05 PM
Oooh! That doesn't look right. What on earth has gone on there. I have never seen anything like that in an Aurelia transaxle.
Its a shame I cant send you a photo of that component in my stock. Further investigation needed Torstein I think.
Chris


Title: Re: Flying steel balls!
Post by: impaw on 18 April, 2020, 09:26:02 PM
Yes, there has been some serious friction here.
A blue/black colour on many of the components.
I have a theory of what has happened, but I need to investigate further.
Deep waters 😂


Title: Re: Flying steel balls!
Post by: DavidLaver on 19 April, 2020, 11:02:33 AM
From the first post "I decided to open up the transmission of my 4th series B20.
Just to check how things looked.  Everything looked clean enough, my untrained eye did not detect any problems
."

Having got this far I bet you're NOW pleased you did take that first step to open it up...


Title: Re: Flying steel balls!
Post by: chriswgawne on 19 April, 2020, 05:01:52 PM
What is your theory Torstein?
And how many replacement components will you need?
Chris


Title: Re: Flying steel balls!
Post by: impaw on 19 April, 2020, 07:44:17 PM
From the first post "I decided to open up the transmission of my 4th series B20.
Just to check how things looked.  Everything looked clean enough, my untrained eye did not detect any problems
."

Having got this far I bet you're NOW pleased you did take that first step to open it up...

David, indeed :D



Title: Re: Flying steel balls!
Post by: impaw on 19 April, 2020, 07:51:27 PM
What is your theory Torstein?
And how many replacement components will you need?
Chris

My theory is not a very strong one, and perhaps you can debunk it right away:)

Could it be that the end nut, #20 in the tavola you posted has been tightened too much?
I would think there is supposed to be some freeplay here?

As for parts is need, these are the ones that I am sure of at this stage:
#24. I am not sure what this spacer is supposed to babe made of, but it fell apart. Very brittle, I guess it has been destroyed by the heat and the friction.
The part that was badly heat damaged also has some damage on the gears.
I attach a photo.





Title: Re: Flying steel balls!
Post by: Niels Jonassen on 19 April, 2020, 07:53:30 PM
When I saw your first photos I thought that had just been a bit careless, but now I really feel with you. But at least now you have a chance do it right. Imagine what would have happened it you had taken the car out onto the road believing that you had a perfectly restored B20. Held og lykke med arbejdet. Forgive me this little inter Scandinavian lapse.


Title: Re: Flying steel balls!
Post by: impaw on 19 April, 2020, 08:03:43 PM
When I saw your first photos I thought that had just been a bit careless, but now I really feel with you. But at least now you have a chance do it right. Imagine what would have happened it you had taken the car out onto the road believing that you had a perfectly restored B20. Held og lykke med arbejdet. Forgive me this little inter Scandinavian lapse.

I was indeed careless! :D
I have never quite gotten into how transmissions works, so I was wiggling and moving things that clearly should not be moved :D

But as you and David say, something good came out of it: I discovered a quite severe problem.

Tusen takk Niels!



Title: Re: Flying steel balls!
Post by: frankxhv773t on 20 April, 2020, 10:08:40 AM
Could it be that the (apparently) alien "O" ring has prevented sufficient oil reaching this part or do things not work like that?


Title: Re: Flying steel balls!
Post by: chriswgawne on 20 April, 2020, 10:48:54 AM
I have been thinking about your problem overnight and I don't think its possible to over tighten the mainshaft  as you suggest Torstein,
The bearings have steps on the outside of their outer race which are used to locate them very firmly in their correct position in the outer case using long steel stepped pins and retaining fittings which fit snugly into the slots. And there are tab washers to hold the 'end' nuts or whatever in place. So the opportunity to either overtighten or self tighten with use is very limited.
It sounds to me as if someone has re-assembled your transaxle incorrectly. I suggest you visually inspect everything very carefully including the bearings and double check everything is there before ordering any spare parts just yet. Depending upon what you find, you can then make the correct decision as to what is the best solution,,,,,as in rebuild with new or missing  components , replacement etc etc comparing the attendant costs.
I am not trying to be pessimistic but as I am sure you realise, one doesn't want to have ongoing transaxle problems if only for the reason that its a bit of a pain to remove them from the car even with a vehicle lift. They are heavy,  awkward to handle and of course the brakes have to be removed each time you do a stripdown.
I will send you a pm.
Chris


Title: Re: Flying steel balls!
Post by: impaw on 20 April, 2020, 11:14:11 AM
Thank you for your advice Chris!

Yes, I agree, someone in the past has re-assembled this transaxe incorrectly somehow.
I am having a visit from a very technically gifted man ( my dad )  later, it will be interesting to see if he has any input.

The transaxle is going to be totally taken apart, that is now a must :)


Title: Re: Flying steel balls!
Post by: Brian Long on 22 April, 2020, 05:28:23 AM
The o-ring is a modification/replacement for a felt seal that stopped oil travelling between the inside surface of the sleeve and the shaft it sits on. If omitted, as was often the case, oil would find its way out onto the clutch surface. The o-ring sits between the face of the sleeve and the gear that it butts up against. Ideally the sleeve should have been machined to accomodate the o-ring
Furthermore, there is a another felt plug in the nose of the input shaft which is fed by the Archimedes screw/spiral inside the shaft. This arrangement was designed to allow a little lubrication of the spigot bearing which, in those days, was not sealed. With a modern sealed spigot bearing this feature is not required and the nose of the input shaft should be sealed with e.g. an aluminium plug.
Cheers
Brian


Title: Re: Flying steel balls!
Post by: impaw on 22 April, 2020, 05:58:37 AM
Thank you Brian!
Reading an old thread on the issue, I was thinking this was the case.
Great to have it confirmed.
There is a machined groove inside of the sleeve.

I have a sealed bearing, so I will seal the shaft, as suggested.

Thank again!


Title: Re: Flying steel balls!
Post by: GG on 22 April, 2020, 12:08:48 PM
The o-ring is a modification/replacement for a felt seal that stopped oil travelling between the inside surface of the sleeve and the shaft it sits on. If omitted, as was often the case, oil would find its way out onto the clutch surface. The o-ring sits between the face of the sleeve and the gear that it butts up against. Ideally the sleeve should have been machined to accomodate the o-ring
Furthermore, there is a another felt plug in the nose of the input shaft which is fed by the Archimedes screw/spiral inside the shaft. This arrangement was designed to allow a little lubrication of the spigot bearing which, in those days, was not sealed. With a modern sealed spigot bearing this feature is not required and the nose of the input shaft should be sealed with e.g. an aluminium plug.
Cheers
Brian

Thanks for this Brian, right on the mark. My car had oil on the clutch disk from the missing felt plug (had been replaced with silicone, but failed), and also along the outside of the shaft as noted above. We machined a 45 chamfer in the end of the sleeve, and snuck the thin O-ring in there.


Title: Re: Flying steel balls!
Post by: Dikappa on 22 April, 2020, 06:42:38 PM
I did the same, and machined a tiny oil seal in the aluminium nose piece that surrounds the sleeve.  Furthermore I tapped a tread into the shaft end and plugged it.  I then used a sealed bearing instead of the original open one where the shaft sits in the clutch.  There is a tread about it somewhere.


Title: Re: Flying steel balls!
Post by: impaw on 22 April, 2020, 09:06:08 PM
And heres another variation, with a groove machined inside the sleeve.