Speedo gear fell in differential....Was : Speedo gear came along cable

[Modano]

Hi
in order to try to remove my dashboard, I first, as instructed here , removed the speedometer.
Long story short, I found it very long to unscrew, and at some point, I took something to lever, and the whole package came along
(I was a bit angry and disappointed so when I saw the dashboard wouldn't come, I stopped everything)

I'll first try to unscrew, but I think it's a bit seized and there are even some impacts.

If I cannot unscrew the cable, I should be able to put it back, but my question is : how shall I put the gear back ? can i insert it and lightly hit the whole assembly, or does it need a gentle rotation while inserting it ? I don't want to ruin the gear which seems in pretty good shape btw.

What's your opinion ?

Thanks a lot

[SanRemo78]

I haven't read the instructions on here but when I removed my instrument cluster I unscrewed the 6 knurled knob screws at the front of the panel and then pushed the outer cable, inside the engine bay, towards the inside of the car. This created enough space that I could get my hand behind the gauges to unscrew the cable from the back of the speedometer.

This was on a right hand drive car so I can understand why you might need to remove it from the gearbox on a left hand drive car - there's not enough slack to use? But if I had to undo it I'd just have unscrewed the knurled nut on top of the gearbox to pull the cable free. The driven gear assembly doesn't need to come out? When you removed it did you put the retaining screw back in place so you didn't lose it and is it stopping the driven gear housing going back into place? If it's not then I'd suggest trying taking the nylon part out first and putting that back in, with a little more wiggle room it'll drop back into place more easily and then you can put the metal upper part back in and secure with the locking screw before re attaching the cable itself.

Guy

[Modano]

Hi !
Thanks for the reply.
Yes the idea was to push the cable towards the dashboard, pull the dashboard a little bit, repeat.
I guess this ease the process and refitting.

Regarding the cable and gear. I’m somewhat confused because I’m not sure how it is supposed to be removed normally. (Unscrew the bolt ? Unscrew the smaller 10 Allen on the cable?)

Anyway, in my case, the bolt is so tightly fit (rust and damage)  to the housing cage that I don’t think I’ll be able to separate them anymore. Btw Ia this housing the same as many other fiat and lancia ?

But you seem to mention there is a screw that tightens the cage inside the diff box ? That would make sens since I don’t see how it’s not supposed to rotate inside the diff housing.

And regarding your last idea. As I can’t take apart the cable from the gear housing  , im afraid that if I remove the nylon insert , i won’t be able to make sure the speedometer inner cable would securely fit.

[Nigel]

From the description, it appears that the locking screw is either missing or broken.
That's perhaps why the whole thing came out. Also, the knurled nut
may be cross-threaded on the speedo drive making it even more difficult.

Modano, I suggest you unscrew the cable from the speedo-drive, clean the threads, then check
if you have the locking screw. It's likely missing.
The speedo-drive should have a hole to locate the locking screw [not seen in your photos]
Refit the speedo-drive by rotating it as you insert it,making note of where the locking hole is.
Do not hit anything, it should all fit in easily.
 

[Modano]

Thanks !!
So there is a locking screw. Makes sense now. There is a hole on the housing, yes.
Tomorrow I’ll have a look but my guess is that the screw was not in place and I only kept rotating the whole housing hence the torsion on the cable.
I guess when everything is fine, rotating the knurled nut does not rotate the cable itself (as I see in pictures that the nut is “ loose “ from the cable )

Nigel, problem is that I won’t be able to unscrew the nut, unless I tighten with tools that may scratch the housing (maybe this won’t matter ) . And I’m pretty sure the locking screw is missing and the whole thing was held by itself …

[Modano]

The screw is pretty big http://www.fiatplus.com/SPEEDO-DRIVE-RETAINING-SCREW.html

[SanRemo78]

The locating screw must be missing from the diff housing or the assembly wouldn't have popped out.

Try finding a piece of tubing with a similar internal diameter to the gearbox part and drill a hole in the side that you can put a pin into to stop the gearbox part rotating. Clamp the tube in a vice and you ought to be able to get enough leverage to remove the cable/knurled nut from the housing. It'll go back together easier that way. And best to sort out the locating pin too, I think that the rotational forces on the nylon gear from the driving gear on the diff will want to push the gear upwards and that will end in premature failure as the contact area between the gears reduces.

You'll have to dismantle the parts at some point if/when the cable fails anyway. Might as well sort it properly now.

Guy

[Modano]

Good idea ..you’re probably right regarding the housing rotating inside ..
Look : This is the “screw”
For me it’s a standard nut that was put there to prevent leakage.
There is no trace of cut or breakage and it definitely doesn’t look that the original part .
So my guess is that this is an old problem which was taken care by forcing the housing in the diff and no screw. Will buy the screw anyway.

I put my magnetic “finger” in the diff, nothing inside. No trace on the housing so my attempts didn’t break anything … I just think this is a “tap” only.

[Modano]

Real time progress here 
Could separate (see pictures)
Now to avoid any mistake. I need to pull the wire right ? As per Google pictures the nylon gear is one piece. The cable has a flat side correct ?
It seems a bit seized so I prefer to ask.
Thanks !

[Nigel]

Yes, that squared-ended cable should just pull out. It may be tight.

If you're able to, you could take a bolt of the correct
thread and length and file down the end to fit the hole in
the speedo-drive. Careful measuring is the idea here.
Alternatively, Mark at BetaBoyz could probably help.[but he's vacationing around this time]

It looks like it's time to buy a new complete speedo cable.

[SanRemo78]

It's possible the metal part is threaded? If that's the case then i wouldn't expect to see a thread in differential casing. If you can get a bolt onto the metal part then check and see if the same bolt will just pass though the casing from the outside. If it does then it's just a case of alignmnent when you reassemble.

The cable should have 4 flat sides and shloul pull out easily enough. If there's evidence of the end fraying it's time to replace it. If it seizes in the outer cable then you can round off the square hole in the nylon drive. And replace inner and outer cable so you know lengths are correct.

Guy

[Modano]

Here they are
Thanks a lot for your help.
The screw seems to be “findable”
Not sure the Speedo cable is to be replaced but it is definitely dirty inside (muddy).
I’m also pretty sure it somewhat disconnected the dashboard end at some point.

At least I can put the housing and gear back now !

[Modano]

Hi Nigel
The metal housing is not threaded.
Have a look at the link above , the original screw has an extra unthreaded length as far as I see

The end seems  fine .
Both nut and housing threads are clean and easy to operate

[Modano]

Ok so I’m now having a bad day.
The housing was difficult to fit. And once I removed it a little bit too far.. the nylon went into the diff unit.
I think it went sideways I cannot even see it. And it has no metal part so nothing to attract
… I’ll try a little more but I guess it will require full diff removal
I’m so ashamed

What would you do ?
Try again with proper tools ?
Try to shred the nylon by "driving" , and purge oil and set a new nylon gear
Dismantle everything ?

[Nigel]

It's not supposed to do that. The bottom end of the plastic drive should locate in a hole in
the inside of the diff casing. 

Hmm, now I don't know what i'd do.
I'd try fishing it with wire perhaps.
The oil drain is nearby, would it fish through there?

Sorry for your predicament.

[Modano]

Hi Nigel.
The origin of this problem is that the housing doesn’t fit pretty well.
I lubed it , I sandpapered it to remove the impacts of the tools used to remove the cable.
I tried the housing alone and i wasn’t able to make it go down to the bottom.
I cleaned it once more and put the gear along, it inserted fine but as before got stuck . Then I wanted to check my hole alignment before trying to push a bit , but when I removed the housing the gear went sideways, and after a couple of attempts disappeared.

I’ve noticed in a picture what you say. But with casing out the gear goes sideways with very limited balance. I made things worse I guess.

I think it’s atill on the upper part.

[SanRemo78]

You could try getting a piece of thin walled plastic tubing and tape it to the end of vacuum cleaner and put it into the gearbox through the drive mounting hole? It's a long shot but it might work.
Guy

[Modano]

Thanks for your advices
My first actions would be :
- Try my camera with a small mirror to see whether the gear is on the top or fell
- Tilt the car on one side (towards the hole, and towards the drain plug)
- Drain the oil and inspect through this more comfortable place

These are non destructive and rather safe ways to try first.
I think that if it goes on the bottom (even if this requires moving the wheels) it should be at reach. Putting the camera inside the drain hole is possible, too, as the angle is much better.

[Modano]

I tried many things, the closest one being able to use a thin camera to see through the dipstick and insert a properly sized hose attached to a vacuum cleaner, while the diff is without oil.
Visibility is not the issue. The problem is that the gear is pretty long, and it is in a place rather difficult to reach. And if I can reach it the vacuum power (being pretty ok , a big miele vacuum cleaner) it not enough to move it to a more reachable place. I can imagine pulling it through this system but here I have to move and raise it.
Seems a very long shot

All others attempts (through draining hole, with a wire) were far worse.

I'm heading towards a diff carter removal I'm afraid.
My only hope is that there is a way to only remove this cover that does not require big operations (ie gearbox removal etc)

Has anyone already done this ? I was thinking of removing only two bolts on each cover plate, but then I don't know if removing the frame to diff cover would disbalance something that would prevent fitting the cover back
I'll post pics.

[SanRemo78]

I never removed a diff cover back in the days of Beta ownership... But if memory is right there will be a number of bolts holding the the casing to the bell housing/gearbox that will need to be undone plus the rear upper and lower bolts on the driveshaft flanges as well as two mounting the gearbox to the subframe? You may have to remove these two first and then raise and support the gearbox with an axle stand. Will there be enough room to access all the bolts? Not sure. Hope you manage to get it out and get everything back together successfully. Can you pre assembly the dropped parts and the steel housing onto the rear casing before you bolt it back into place?
Good luck...