1964 Odometer Rebuild/Speedo Gear Fitting Seal

[James W.]

I will be sending my speedo and odometer to get them rebuilt soon. The odometer quit working, probably due to the transmission gear lube being pulled up the speedo cable casing into the odometer mechanism. From what I can see, the only thing that is allowing this to happen is the o-ring seal that fits on the speedo gear fiiting in the transmission is bad and is allowing the gear lube to get into the speed cable casing. Is it in fact the o-ring seal or something else that is allowing the gear lube to get into the cable casing? I don't want to have to pull this apart again for another rebuild next year or have the gear lube drip on my leg and floor mat when driving. Any help in answering this question would be appreciated. Also, who is a reputable speedo/odometer rebuilder?

Best Regards,

James West
Omaha, NE.
NCRS #18379
1964 Corvette Convertible #9258

[William C.]

Re: 1964 Odometer Rebuild/Speedo Gear Fitting Seal

Look more closely, there is an actual seal that is pressed into the outboard end of the unit that holds the speedo gear. The "O" ring seal only keeps the lube from escaping the trans case to the outside.

[James W.]

Re: 1964 Odometer Rebuild/Speedo Gear Fitting Seal

Bill,

Is this seal avaialble from GM or a parts vendor? For instance, Corvette Central only lists the o-ring seal as do others like ZIP and Paragon.

Thanks,

James West

[William C.]

Re: 1964 Odometer Rebuild/Speedo Gear Fitting Seal

I'd take the whole unit down to your local seal distributor and have him find a match, easier and cheaper, he might pull the old one for you too if you get lucky

[Joe L.]

Re: 1964 Odometer Rebuild/Speedo Gear Fitting Seal

James-----

The only seal involved in the entire assembly is, as Bill described, the o-ring on the outer circumference of the speedometer adapter. I do not understand how, even if this seal was bad, that transmission lubricant could enter the speedometer cable casing. There is NO seal on the inner portion of the adapter nor does there need to be. Not enough lubricant could ever pass through this area to ever be a problem anywhere. The transmission case is, in no way, pressurized.

My suspicion is that your lubrication problem is due to some previous owner's ill-advised or inept attempt at lubricating the cable. Since accessing the cable at the speedometer end is somewhat difficult, some folks resort to using a special tool to force grease into the cable at the transmission end. I don't recommend this procedure for EXACTLY the reason that you are currently experiencing.

Anyway, the adapter o-ring seal is currently GM #10054241. Many dealers will stock this item. If you wish to replace the adapter assembly, this part is GM #345215. The latter part includes a new seal. However, I must add that I don't think that any of this will affect transmission lube entering the speedo cable casing.

[John C.]

Re: 1964 Odometer Rebuild/Speedo Gear Fitting Seal

I know this isn't a Corvette but I did have a similar problem with an '89 Suzuki Swift GTi. The o-ring on the speedo cable fitting to the transmission failed allowing the spiral wound cable inside the cable sleeve to act like Archimedes' screw pump. I kept smelling trans fluid in the car for about a week. One day I got in and the stuff was dripping on my shoes! I removed the instrument housing and the speedo cable had pumped trans lube into the back of my instrument panel. It ran down and collected in an area just below it until it overflowed onto my shoes. What a mess caused by a $2 part!

Oh yeah, it wasn't caused by anything the previous owner had done since I had purchased the car new. The dealer replaced the o-ring...twice. Second time was a charm.