Dear Fiat Forum

Hope you can help. I've recently had an issues with gearbox oil leaking from the rear boots. Following advice from some of the members I got the spanners out and started to replace the rear seals. However, during the process I noticed that the drive shafts (gearbox end) were badly worn. The attached pictures are taken from the rear of the vehicle looking forward. The left hand side is pitted but the right hand side is totally knackered. It doesn't take a brain surgeon to realise these need replacing. However, I've got a couple of questions:

1. What will have caused them to get so bad? I've only had the car for 1 year and don't have much history on her and don't know if they have ever been changed.
2. Could this have caused any other damage to the diff or gearbox?
3. Am I right in assuming this will be a full engine out and gear box off to change them?
Finally, I am pretty good with the spanners but I've never tackled a job quite as big as this before. I this something your average DIY mechanic can tackle?

Any advice would be very much appreciated.

Idleboy08

I'm just in the middle of exactly this job (doing it VERY slowly over the winter)
to answer your q's
1. looks like heavy wear, could just be old shafts, or more likely years of dirt and grit getting caught under the boots and wearing the shafts. These shaft are a weakpoint it seems, outboard on the drive splines and to a lesser extent inboard on the boot seal
2. unlikely, unless all the oil has leaked out/ dirt and water has got in.
3. Yes, gearbox has to be split/ diff out to change the driveshafts. There is a photo guide on here iirc. very doable by a home mechanic, just go steady and methodically regarding the diff bearing carrier positions (to maintain bearing preload).
I got a kit of shafts etc from VDL for 100 euro and am in the process of splitting the box at the moment, pretty straightforward so far, go for it


1. What will have caused them to get so bad? I've only had the car for 1 year and don't have much history on her and don't know if they have ever been changed.
2. Could this have caused any other damage to the diff or gearbox?
3. Am I right in assuming this will be a full engine out and gear box off to change them?
Finally, I am pretty good with the spanners but I've never tackled a job quite as big as this before. I this something your average DIY mechanic can tackle?

Any advice would be very much appreciated.

Idleboy08[/QUOTE]

Hi Cambio

Thanks for taking the time to respond to my post. The information you have provided is very useful and has reassured me this is a job I could tackle. I think I might have managed to find the photo guide, which I've had a quick look through and at first glance it looks pretty straight-forward.

I know I'm asking a lot of questions but how difficult was it to remove the engine and are there any guilds on how to do that too? Roughly how long did it take?

Idleboy08

Personally, I always take the engine and gearbox out as separate units. Always start by disconnecting the battery! I have built myself a little wheeled trolley that JUST sits under the engine sump, with a deck wide enough and long enough that I have plenty of 'wiggle space'. With this in place the rear cross-member can be removed. With the throttle and choke cables disconnected, the fuel pipe disconnected as well as all electrical connections, it is basically a matter of undoing all the engine/gearbox/starter bolt/nuts and then wiggling the engine out on the trolley (hence the wheels).
The gearbox is very simple--undo the drive-shaft couplings as well as the clutch cable, the gear-change connector and the speedo cable. I would recommend a trolley-jack is put under the gearbox before you undo the gearbox cross-mount. With all the bits undone, it is a simple matter of letting the jack down a bit and pulling the gearbox out.
I expect other Forum members to come up with little extra tips, but basically the above is how to remove and refit engine and gearbox.

No Probs
engine removal pretty straightforward, I made a small box on castors to pop the engine on, based on a photo very kindly supplied by the hobbler aka Tom.
There is a PDF document somewhere, or its detailed in the Haynes manual pretty comprehensively. Not a big job anyway, as the engine hangs off the crossmemeber and gearbox, so support the engine then undo the rear mount and crossmember and then access gearbox bolts. Took about an hour tops with tea and pee breaks and being in no particular hurry.


<edit>
^ he beat me to it! Thanks again for your help Tom and yes, disconnect battery and fuel line at the tank end first!


<2nd edit>
just looked at your profile - we both have 500R models, mines a '75 flavour with the 594 engine and I hark from Horsforth, just down the road from Idle. Small world

I am sure that you will be fine with the gearbox rebuild and good luck with that. I found this very interesting as I have worked on quite a few of these gearboxes and never seen anything like that until the one I just finished last week. It came to me in bits and the dif bearings and boots were missing but both drive shafts were worn like that. There is no way that the lip seal would cause such wear so it is a bit of a mystery.

Oh wow - That is unbelievable! It really is a small world. If I run in to any problems I might be knocking on your door for some advice and support.

Hi Hobbler

Thanks for taking the time to get back to me. Taking the engine and gear box out sounds a lot more straight-forward than I originally thought. I'm confident this is a job I can tackle. I actually really looking forward to it and can't wait to get started. Onwards and upwards!

Hi Toshi

Thats exactly what I was thinking and hence the original question. I'll be interested to see what everything looks like inside when I crack it open. I actually drove the car last weekend and didn't have any problems with gear selection, including reverse, so I'm not expecting it to be in bits. Like you say, it's a bit of a mystery!

I have migrated south these days but occasionally return for proper beer and fish and chips!
Post any problems on the forum and help is never far away