Alfetta rear giubos

Started by festy, March 19, 2023, 04:53:44 PM

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festy

My '79 GTV has an early '76 style tailshaft, and I've been slowly collecting the parts needed to fit the correct type.
I thought I had everything I needed - larger clutch input shaft flange, three new giubos, new center support bearing and spherical bush, and the tailshaft itself.
While fitting the new rear giubo to the shaft I found that the old one that came fitted to the new (to me) shaft had a captive spherical bearing, but the new giubo has a 22mm diameter hole, expecting the spherical bearing to be attached to the back of the tailshaft.
And these two giubos have the same part number on them  ???

From what I can tell, in ~82 the tailshaft was revised a bit and instead of a 14mm pin on the rear, it had a 12mm pin with a 12 ID / 22 OD spherical bearing pressed on - which would make sense in the context of the redesigned rear giubo's center bore.

So it looks like I have the wrong rear giubo. I can't return it, I've had it for years while I collected the other parts.
The correct rear giubos are considerably more expensive, and a little hard to come by, so I was wondering if its possible to use the later style so started looking for options.
1) Use a 14mm spherical bearing - I can't find one in any catalog. Standard sizing is 12 or 15mm.
2) Stick the rear half of the tailshaft in a lathe and turn the pin down to 12mm - pretty sure my lathe is way too small for that :(
3) Fit a 14x22 needle roller bearing - bad things would happen if alignment wasn't perfect
4) Machine up a 22mm bronze ball, press onto the shaft and see how long it lasts
5) just assemble without any rear locating bearing #yolo  :o
6) Find somewhere that has stock of the correct giubo, hand over ~$350 and hope I'm sent the correct type

While researching all this, I came across this post where LukeC mentions that the later style giubos can be used for earlier cars so that sounds promising, but was wondering what's actually involved?

festy

#1
I should have known this would happen...
After a week of head scratching and staring blankly at my pile of parts, I gave up and asked the forum.
Then straight after posting I walked back out to the garage and came up with what I think is a pretty good solution.
I took a 12x22mm plain spherical bearing, and bored out its ID to 14mm. I added a 3D printed flexible seal to keep the grease in and the dirt out.

I think it should do the job just fine.

poohbah

Not that I have much experience with 3d printed parts - other than recently receiving 3-d printed side-skirt jacking point covers for my GTA - are you confident the 3D flexi seal will be robust enough to last? Seems a high-wear item.
Now:    2002 156 GTA
            1981 GTV
Before: 1999 156 V6 Q-auto
            2001 156 V6 (sadly cremated)

festy

#3
I'm confident enough to try it and see at least ;D
It shouldn't be too high-wear. The bearing doesn't spin, it only provides alignment.
The flexible filament (TPU) has a pretty high melting temperature, and holds up well to oil/grease and abrasion.

I've also printed a new grommet for the front to replace p/n 11600.15110.08 (NLA) that sits in the nose of the front giubo behind the alignment bush.
If they don't hold up, I'm no worse off than by not fitting them at all...

poohbah

Hopefully a neat and cheap solution.

Where did you get it printed?

My jacking point covers had to come from the Czech Republic, so shipping cost more than the actual items (which were very reasonably priced). They also need sanding (very rough finish), priming and painting before I can use them. They are currently just packed away as replacement parts in the event I lose or break the originals.
Now:    2002 156 GTA
            1981 GTV
Before: 1999 156 V6 Q-auto
            2001 156 V6 (sadly cremated)

festy

I printed them myself.
The flexible TPU filament is about twice the price of regular PLA, but even so they still cost less than a dollar each to print.

poohbah

#6
Cool - sounds like you could do a handy sideline in printed parts.  Especially all those crappy little plastic bits that are now impossible to find for Alfettas, like inner door latch surrounds.
Now:    2002 156 GTA
            1981 GTV
Before: 1999 156 V6 Q-auto
            2001 156 V6 (sadly cremated)

festy

Quote from: poohbah on March 21, 2023, 11:58:23 AM
...like inner door latch surrounds.
They were one of the first parts I tried to print, but the little hook tabs on the back kept snapping off as soon as I'd try to fit them :(
Maybe I got the dimensions wrong, or maybe they just need to be printed in a stronger type of plastic...
But some other hard to find bits like the little sliding headlight adjustment blocks were really easy to make, I've had them in for a few years now and my headlights are still pointing in the right direction :D

poohbah

You have just described exactly my passenger side door latch surround... Has one remaining hook stub.
Now:    2002 156 GTA
            1981 GTV
Before: 1999 156 V6 Q-auto
            2001 156 V6 (sadly cremated)

festy

#9
So far so good with the propshaft - the modified bearing and the TPU "rubbers" all seem to be doing their job well after half a dozen drives.

Quote from: poohbah on March 21, 2023, 01:47:35 PMYou have just described exactly my passenger side door latch surround... Has one remaining hook stub.
I had another go at printing one of these, and this time it turned out ok. I even managed to clip it onto a door handle and take it back off without breaking any of the hooks off  ;D
I'm now trying to print one in a harder/higher temp plastic, I'll find out in about 2 hours whether or not I've set everything up properly...


bazzbazz

#10
Could this be the beginning of a small cottage industry for you?  :)

I have said many a time that the only thing that will allow cars like 147 GTAs and their brethren to become future classics is 3D printing.

Think about all the plastic parts in them that are slowly going to disintegrate over time that are not financially suitable for aftermarket moulded injection production runs. 3D printing may just be their saviour in the future.
On The Spot Alfa
Mobile Alfa Romeo Diagnostic/Repair/Maintenance/Service
Brisbane/Gold Coast
0405721613
onthespotalfa@iinet.net.au

festy

#11
Quote from: bazzbazz on March 29, 2023, 03:16:40 PMCould this be the beginning of a small cottage industry for you?  :)
Haha yes, considering how many GTVs are still on the road... and two door handles each.... I'd only have to sell them for about $20k each to be able to retire  ;D

The stronger plastic print worked okay, I still need to tweak a few settings to improve its appearance a bit. Not bad for a first attempt with this type of filament though.
Lower right is the latest one.

poohbah

Great work Festy. Now I know who to ask next time my busted-stub surround falls out - again.

But $20k might be a bit above my limit...

Out of interest, I assume your purchase of a 3d printer was for work purposes? How much do they go for?

Just wondering if/when it might be cost effective to become my own parts supplier.
Now:    2002 156 GTA
            1981 GTV
Before: 1999 156 V6 Q-auto
            2001 156 V6 (sadly cremated)

festy

Quote from: poohbah on March 30, 2023, 08:06:22 PM
Out of interest, I assume your purchase of a 3d printer was for work purposes? How much do they go for?
Not for work, just hobby use - I do a lot of electronics prototyping, so use it for all sorts of things.
Mine is a Creality Ender-3, it cost about $300 a couple of years ago and I don't think the price has changed much since then.
There's quite a learning curve to 3D printing, but its not too difficult to master.

There's also plenty of places offering 3D printing services where you send them your design file and they'll print it for you, its not too expensive and you'll get a better quality part than an entry-level $300 printer will produce.   

I don't need those door handle inserts, so if you want them pm me your address and I'll send them your way.


bazzbazz

Quote from: festy on March 29, 2023, 04:35:25 PM
Haha yes, considering how many GTVs are still on the road... and two door handles each.... I'd only have to sell them for about $20k each to be able to retire  ;D

I didn't say it would be a profitable one . . . . . ;D
On The Spot Alfa
Mobile Alfa Romeo Diagnostic/Repair/Maintenance/Service
Brisbane/Gold Coast
0405721613
onthespotalfa@iinet.net.au