Lower 18" of speedometer cable has gear lube on it - Is this normal?

[Robert W.]

I had some work to do on my tachometer cable so I checked the speedometer cable at the same time and I'm seeing gear lube on the lower 18". This is after ~150 miles of driving... Is this normal or do I need to replace the coupler/seal at the transmission?

[Joe L.]

Re: Lower 18" of speedometer cable has gear lube on it - Is this normal?

I had some work to do on my tachometer cable so I checked the speedometer cable at the same time and I'm seeing gear lube on the lower 18". This is after ~150 miles of driving... Is this normal or do I need to replace the coupler/seal at the transmission?

Robert------


I would recommend replacing the pinion seal in the fitting ("bullet") and the fitting external seal (o-ring). The pinion seal was GM #3869910 but it's discontinued. The o-ring was last available under GM #10054247 but it's also discontinued. Both are probably available in the aftermarket, though.

[Robert W.]

Re: Lower 18" of speedometer cable has gear lube on it - Is this normal?

Thanks Joe! I'm glad I caught it early then. I guess another order from LIC is in the near term plans. -Bob

[Joe L.]

Re: Lower 18" of speedometer cable has gear lube on it - Is this normal?

Thanks Joe! I'm glad I caught it early then. I guess another order from LIC is in the near term plans. -Bob

Bob------


One more thing I should have mentioned: I'd replace the speedometer driven gear or, at least, carefully inspect the area that contacts the seal lip. If this is at all worn, that will cause a leak, too. These gears do not really cost all that much.

[Richard G.]

Re: Lower 18" of speedometer cable has gear lube on it - Is this normal?

Joe is correct.
In almost 100% of the gears I have inspected they are worn at the lip seal.
The plastic doesn't stand up to the lip seal pressure. It almost looks like at factory grove as it intersects the radial groves that pull the oil inwards.
There used to be a seal that relocated the lip further out on the gear. This assured an unused portion of the gear would contact the seal.
It's likely available, I don't know where to get this seal anymore.
I would just go to the nearest transmission shop. They may or may not have the plastic gear.
But they will have the "O" ring and the factory seal. Left overs from and four wheel drive trucks that have the speedometer connection in the transfer-case. Ask them about the relocation seal. May have some around. Getting to be old school as all the speedometers are electronic connections now days.

[Joe L.]

Re: Lower 18" of speedometer cable has gear lube on it - Is this normal?

Joe is correct.
In almost 100% of the gears I have inspected they are worn at the lip seal.
The plastic doesn't stand up to the lip seal pressure. It almost looks like at factory grove as it intersects the radial groves that pull the oil inwards.
There used to be a seal that relocated the lip further out on the gear. This assured an unused portion of the gear would contact the seal.
It's likely available, I don't know where to get this seal anymore.
I would just go to the nearest transmission shop. They may or may not have the plastic gear.
But they will have the "O" ring and the factory seal. Left overs from and four wheel drive trucks that have the speedometer connection in the transfer-case. Ask them about the relocation seal. May have some around. Getting to be old school as all the speedometers are electronic connections now days.

Richard and Bob------


All of the nylon speedometer driven gears are still available from GM except for the 23 and 25 tooth gears. They are about 8 bucks, GM list.