Technical Time for new axles, but....

[babbo_umbro]

Definitely replace the steel flanges as their internal splines are a (deliberate?) weakness. I'd also replace the aluminium/rubber flexible couplings unless you're absolutely 100% sure they're in good condition - which, as has been noted - can be hard to judge. Note that there should also be a circlip round the extreme outer end of the driveshafts - you haven't mentioned one.

 

[The Whitakers]

Nick just a thought, Are you running a standard box or a synchromesh box?...…..It would be worth measuring that you have the shorter 500 length drive shafts and not the slightly longer 126 drive shafts if you're on a synchro box....

 

[Bleeding Knuckles]

I also noticed the clutch shaft moves in and out maybe a quarter inch or so. Is that normal?

Hi Nick, I would check the connecting sleeve and pin for any wear if you have a lot of movement. Check at the inboard end of the Input Shaft, the connecting sleeve has a circlip holding a small pin in place that secures it all to the counter shaft on splines. If you get a copy of the Haynes manual from this web site look on page 56 fig 6.6 it shows the counter shaft components. If you have a problem with movement on the counter shaft you will have to strip the gearbox to investigate
Ian.

 

[fiat500]

the clutch shaft moves in and out maybe a quarter inch or so. Is that normal? T

...just check that on a couple of good gearboxes in my "collection". As I vaguely remebered, what you describe appears to be "normal".

 

[fiat500]

,I have been advised by a (real!) expert that you do NOT have to replace the crushable spacer (between the bearings) if the bearings sound OK, BUT, you do have to do the big stub-axle nut up to the correct torque.

I have always been slightly bemused by the fact that Fiat only use 1/2 the threaded hole in the couplings for the bolts that secure the metalastic to the sliding flange

I disagree with your "expert" whilst not denying he, she (or whichever gender identity they have ) the status of expert.

There is no torque specification for the hub-nut because the measurement you look for is the rotational torque of the hub itself. If you need to replace the rubber-coupling and wish to keep the original bearings, I guess you might get away with using the existing "crush"-sleeve because there may have been some wear in the bearing since it was fitted. So the sleeve could be crushed a tiny bit more when tightening the nut. This means is would continue to serve its purpose of keeping tension on the bearings. But whatever the case, you are unwise to simply tighten the big nut without carefully checking that you have the correct rotational measurement at the hub.

In my experience, even when well lubricated when fitted, the four M8 setscrews which secure the drive-flange to the coupling can be a right sod to remove when they have been in place for a while. So I wouldn't wish to potentially make the job harder by fitting ones which are overlength. I think they are a size which is repeated in other applications on the 500 and on other Fiats, so I guess that in addition to this the designers were trying to rationalise the parts stores.

 

[the hobbler]

Peter, I was poor in my choice of words---you are quite correct in that it is not the nut which has a torque setting. but the nut which is tightened until the rotational torque of the bearings is achieved, which is what I meant. I do assure you that my source regarding the re-useability of the 'crush' spacer really does know what he is talking about.
Maybe I have been lucky, but I have never (touch wood!) had any problem removing the coupling bolts, even my extra long ones. However, I do agree with you in that the choice of size may have had a 'rationalising' factor in it.

 

[Nick Striker]

I have springs on order, but I am unclear how they go in? I see you grease them well but what holds them in place, or do they fit over the splines?

 

[the hobbler]

The (small) springs fit into the detent in the coupling end of the drive shaft and act against the end of the stub-axle. This way the axle is held away from the stub-axle. Be careful, there are 2 different sizes (diameter-wise) of spring. I have 25mm axles, but they take the 'thinner' springs, whereas I expected them to need the bigger springs. You pop them into place just before you slide the drive-shaft coupling up to meet the 'metalastic' coupling. It is a very simple design, but it works.

 

[Nick Striker]

Just to let you know I got the springs fitted, replaced the boots, and clutch and throttle cable while the engine was out, put everything back together and voila! no more sound. What a great group - thanks from Colorado!