Speedometer drive seal replacement?

Dr.Jeff

Dr.Jeff

True Classic
Has anyone tried replacing the little "lip seal" (wiper seal) inside the top of the speedo drive unit?

The unit I'm referring to is on the transmission:
speedo drive.jpg

Mine has the metal version (upper one in the pic above).

And the seal I'm referring to is located inside the housing, where the drive's shaft goes into the speedo cable (red arrow), not the O-ring on the outside:
s-l500.jpg
IMG_6458-550x550h.jpg


I don't recall seeing the seal offered for sale , nor any talk about replacing it. But it is a regular type seal, so it does wear and leak lube into the cable sheath.
 
Not to hijack your post on the first response, but how did you get the assy out? My old cable end disintegrated in the trans & the new one won't go in. Trans in in the car.
 
Dr.Jeff said:
I don't recall seeing the seal offered for sale
Click to expand...
You mean this one?

X1/9 Speedo Drive Inner Top Seal : Eurosport (UK), FIAT X19 Bertone & Lancia Montecarlo Beta Scorpion spare parts

Eurosport (UK) X1/9 Speedo Drive Inner Top Seal - Oil seal to fit inside the top of the speedometer drive unit at the transmission casing. This stops gearbox oil leaking past the drive spindle and out of the speedo cable fitting. Note: Only suitable for drive units from 1977 that have a metal...
www.eurosport-uk.net
 
JKIDD said:
Not to hijack your post on the first response, but how did you get the assy out? My old cable end disintegrated in the trans & the new one won't go in. Trans in in the car.
Click to expand...
There's a bolt on the trans case just below where the drive assembly goes in. Remove that bolt and use something to pull the drive straight up and out. I use a pair of soft jaw pliers to grab it, but anything that won't damage the threads should be fine.
 
Ics19 said:
You mean this one?

X1/9 Speedo Drive Inner Top Seal : Eurosport (UK), FIAT X19 Bertone & Lancia Montecarlo Beta Scorpion spare parts

Eurosport (UK) X1/9 Speedo Drive Inner Top Seal - Oil seal to fit inside the top of the speedometer drive unit at the transmission casing. This stops gearbox oil leaking past the drive spindle and out of the speedo cable fitting. Note: Only suitable for drive units from 1977 that have a metal...
www.eurosport-uk.net
Click to expand...
Yes, that one.

Has anyone actually replaced it? I'm assuming it is simply a 'push-in' fit like any lip seal. But it is a bit down inside the drive housing and quite small, so it's difficult to tell exactly.
 
Dr.Jeff said:
Yes, that one.

Has anyone actually replaced it? I'm assuming it is simply a 'push-in' fit like any lip seal. But it is a bit down inside the drive housing and quite small, so it's difficult to tell exactly.
Click to expand...
With the unit out of the transmission its easy to push it out with a 1/4" extension. The new one can be driven in like any metal clad seal. Although given its size, "driven" is a relative term.

Ifs no easy task to remove the speedo drive from the case without dismantling the transmission. With the transmission still in the car its an even more daunting task.

Also critical to ensure the hole for the anchor bolt is lined up when re-installing it.
 
Hi All,
I have removed and fitted that little shaft seal, they just push out and push in. Be careful though your leak might not be the seal itself, it might be from a groove worn into the shaft where the seal rubs. I wish I could find a tiny speedy sleeve to fix this, but I don't think they make them that small.


I have removed the speedo drive a couple of times, it's not that bad a job.
I find it easiest to crack the nut that holds the speedo cable on, but don't remove it.
-Pull out the Allen head screw from the side.
-Use a screwdriver under the cable nut you just loosened but didn't remove to lift the drive unit a little and get it to move. This way you don't damage the thread but can still get a decent lifting force to move a stuck drive unit.
-Once the speedo drive is moving, undo the cable nut and move the cable out of the way.
-Gently grab the top of the speedo drive shaft with pointy nose pliers. One jaw inside, one jaw outside and pull up. The whole thing should come out.
-Try not to lift the speedo drive out by the body leaving the shaft/gear behind. I've that could end up making the gear fall into the case, never to be seen again.

When you go to fit the drive unit back in. Mark with nail polish where the hole in the side lines up with on the top of the thread. That way you can twist it around after putting it in and line up the Allen head screw. Makes fitting the screw easy.
 
Initially I wasn't sure what type of seal this was. It is buried into the housing enough that I couldn't get a good look at the whole thing. And mine wasn't leaking so I did not want to risk ruining it (by removal) if it turned out to be something unique...like some other seals are on these cars. But thanks to everyone's responses, I identified the seal and found it at my local hydraulic supplier. The size is 6mm ID, 12mm OD, and 5mm thick. A single lip ("SC") or double lip ("TC") seal will work, which are fairly generic (TC seems to be more available). The local shop here in Vegas said 6mm is small enough to not be regularly stocked (although my usual source in Calif keeps them), and 4mm thick is much more common than 5mm (either will work fine). Actually in some cases using a 4mm thick one may be a advantage; if the shaft has a groove worn in it where the lip normally rides (like @Dishy described in post #8), the shorter one will now ride 1mm lower on a clean section of the shaft. They are only about $1.50 each, although they said a couple years ago it would have been half that - prices definitely went up since the pandemic. Thanks for everyone's input. :)
 
Since the shaft protruding through that seal may well be pitted (mine is), an O-Ring between the cable and the drive seems like a better solution.
Midwest Bayless offers them here.
 
Russe11 said:
Since the shaft protruding through that seal may well be pitted (mine is), an O-Ring between the cable and the drive seems like a better solution.
Midwest Bayless offers them here.
Click to expand...
Unfortunately the O-ring you referenced from MWB will not really help if the factory seal is leaking. The fluid will still go up the cable and make a mess. Where you want to make a seal is on the shaft itself, not the cable fitting. The MWB O-ring seems to be more of a dust seal to prevent foreign material getting into the cable. Furthermore it will keep the speedo cable end from fully seating into the drive unit; not a horrible thing, unless you have issues there as well...I've seen where that caused the speedo needle to flutter. :(

As I noted, mine doesn't leak. I just want to replace the factory seal while I'm rebuilding everything...to go along with all of the other new seals and gaskets throughout the trans and engine (interestingly none of the trans seal/gasket kits include this seal). However on another X trans that I will be going through there is a minor leak (slight seepage) at the speedo drive seal. For that one I previously considered adding a O-ring on the shaft. However I realized it would not be effective. There is a considerable space between the factory seal and the nearest point of the cable/cable jacket. You would have to stack about a dozen O-rings to fill that gap and keep the bottom one against the original seal. o_O Otherwise the leaking fluid will still seep out. Plus I don't think a O-ring would be all that effective at stopping the leak anyway.

The only real solution to repairing a leaking drive unit seal is to replace it with a new seal. And to replace the drive shaft if it is too badly damaged....but you might get away with using the 4mm seal vs the factory 5mm one, to see if that avoids the damaged portion of the shaft. The initial reason for this thread was I had not noticed anyone selling a replacement seal (I'd missed the one from EuroSport that @Ics19 referenced). So I was trying to determine exactly what type of seal it is. Mission accomplished. ;)
 
JKIDD said:
Not to hijack your post on the first response, but how did you get the assy out? My old cable end disintegrated in the trans & the new one won't go in. Trans in in the car.
Click to expand...
I just had a thought for another possible approach to removing a stubborn speedo drive unit without tearing down the trans.

After I finished going through my current trans I wanted to paint the freshly cleaned outer surfaces to help keep them looking good. The speedo drive was already installed so I quickly covered it to keep the paint off it. I used a short piece of old 5/8" heater hose, with a fat bolt in the other end, and a couple of scrap hose clamps to hold things in place:
011 - Copy.JPG


The hose is clamped over the threaded section of the drive, which provides a secure attachment to it:
012 - Copy.JPG


If you made some sort of ring or hole on top of the bolt, then a slide hammer could be attached to tug the drive unit out:
011.JPG

Maybe weld a ring to it. Or instead of a bolt, clamp a piece of pipe in there with a hole drilled into the pipe. Even a piece of flat stock could be clamped to the hose with a hole in the end. You can also grip the hose with a pair of pliers and twist it back and forth, without damaging the threads.

Fortunately mine haven't been difficult to remove so I have not tried this. But it is simple and cheap to try.
 
Dr.Jeff said:
I just had a thought for another possible approach to removing a stubborn speedo drive unit without tearing down the trans.

After I finished going through my current trans I wanted to paint the freshly cleaned outer surfaces to help keep them looking good. The speedo drive was already installed so I quickly covered it to keep the paint off it. I used a short piece of old 5/8" heater hose, with a fat bolt in the other end, and a couple of scrap hose clamps to hold things in place:
View attachment 72835

The hose is clamped over the threaded section of the drive, which provides a secure attachment to it:
View attachment 72836

If you made some sort of ring or hole on top of the bolt, then a slide hammer could be attached to tug the drive unit out:
View attachment 72837
Maybe weld a ring to it. Or instead of a bolt, clamp a piece of pipe in there with a hole drilled into the pipe. Even a piece of flat stock could be clamped to the hose with a hole in the end. You can also grip the hose with a pair of pliers and twist it back and forth, without damaging the threads.

Fortunately mine haven't been difficult to remove so I have not tried this. But it is simple and cheap to try.
Click to expand...
Somebody mentioned to make sure the gear didn't fall into the trans. Is this normally a concern?
 
JKIDD said:
Somebody mentioned to make sure the gear didn't fall into the trans. Is this normally a concern?
Click to expand...
I don't think that could happen. But I'll defer that question to @Steve Hoelscher. I can say unless the lip seal at the top is extremely worn out, it holds the gear and shaft quite firmly in the housing so it won't just fall out. But if I recall correctly the gear will hit the other drive gear and not go any further inside.

JKIDD, did you manage to get yours out?
 
Dr.Jeff said:
I don't think that could happen. But I'll defer that question to @Steve Hoelscher. I can say unless the lip seal at the top is extremely worn out, it holds the gear and shaft quite firmly in the housing so it won't just fall out. But if I recall correctly the gear will hit the other drive gear and not go any further inside.

JKIDD, did you manage to get yours out?
Click to expand...
Heading on Vaca Fri, so nothing I'm willing to tackle right now. With the FFO coming, I don't want to end up disabling the car before the event. My original cable rotted off in the speedo drive. I trimmed the new cable to fit, but the speedo is jumping at lower speeds. I didn't dare cut any more before I got all the old cable out of the drive & have the cable end up too short. It seems to be jumping more when I took it out for the first drive of the season last week. I may try greasing up the internal cable & see if it helps.
 
JKIDD said:
Heading on Vaca Fri, so nothing I'm willing to tackle right now. With the FFO coming, I don't want to end up disabling the car before the event. My original cable rotted off in the speedo drive. I trimmed the new cable to fit, but the speedo is jumping at lower speeds. I didn't dare cut any more before I got all the old cable out of the drive & have the cable end up too short. It seems to be jumping more when I took it out for the first drive of the season last week. I may try greasing up the internal cable & see if it helps.
Click to expand...
If the tip of the old cable is broken off inside the shaft it might be difficult to get out, even with the drive assembly removed from the trans. It goes inside the narrow shaft (red arrow) and is pretty deep in there. Especially if it is rusted in place....which is likely why it broke off.
012 - Copy.JPG


You may have to get a replacement part. But either way the unit has to be removed from the trans, so give a try to removing the broken bit first.
Enjoy your trips.
 
Dr.Jeff said:
If the tip of the old cable is broken off inside the shaft it might be difficult to get out, even with the drive assembly removed from the trans. It goes inside the narrow shaft (red arrow) and is pretty deep in there. Especially if it is rusted in place....which is likely why it broke off.
View attachment 72838

You may have to get a replacement part. But either way the unit has to be removed from the trans, so give a try to removing the broken bit first.
Enjoy your trips.
Click to expand...
I bought the 1 piece cable when mine broke. I never liked the way it fit. Looking at things today I noticed it was rubbing & chaffed. Ordering the 2 piece unit as after reading some posts on it & may be too tight causing sharper bends. I have 2 transmissions in storage in unknown condition. They were in damp conditions for a while. I may practice on these first. Does anyone know how deep the hole is for the cable (red arrow). It may help to determine if I can use it as is.
 
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