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Camaro Research Group Discussion => Maintenance => Topic started by: sixt9x33rs on August 16, 2009, 02:22:52 AM

Title: M-21 lube leaking out of the speedo cable
Post by: sixt9x33rs on August 16, 2009, 02:22:52 AM
After running my car for about 20 miles in City traffic I have gear lube leaking off the speedo cable just before the cable attaches to the speedometer underneath the cluster. Any idea what would cause this? I am using Royal Purple synthetic lube. I checked the level and it is not over filled.

Thanks
Title: Re: M-21 lube leaking out of the speedo cable
Post by: Stingr69 on August 16, 2009, 10:25:54 AM
I tried royal purple and it was slightly more noisy and leaked for me as well. We could argue the reasons but bottom line is I would go back to GL-4 dino 90Wt and look at replacing the O-ring on the speedo gear holder.  Leave the speedo cable attached, loosten the tiny screw that holds the retainer and swing the retainer out of the way, then use the speedo cable to pull the whole thing out so you can get the O-ring replaced.

Definately go back to the GL-4 90Wt gear oil. Synthetic is not good for the brass in your transmission. 90Wt will be quieter, it will leak less, and the brass synchro rings will be much happier.

-Mark.
Title: Re: M-21 lube leaking out of the speedo cable
Post by: sixt9x33rs on August 16, 2009, 01:09:01 PM
Thanks for the input.
Title: Re: M-21 lube leaking out of the speedo cable
Post by: JohnZ on August 16, 2009, 04:49:02 PM
There should also be a pressed-in rubber seal in the end of the speedo "bullet" where the cable ferrule screws on to keep gear lube from "climbing" the flex shaft.
Title: Re: M-21 lube leaking out of the speedo cable
Post by: sixt9x33rs on August 16, 2009, 09:33:51 PM
Thanks John I will check that.
Title: Re: M-21 lube leaking out of the speedo cable
Post by: sixt9x33rs on August 16, 2009, 10:25:46 PM
There should also be a pressed-in rubber seal in the end of the speedo "bullet" where the cable ferrule screws on to keep gear lube from "climbing" the flex shaft.
John do I have to unscrew the cable from the bullet to get to the rubber seal?

Are these parts I can buy at NAPA?

Thanks again
Title: Re: M-21 lube leaking out of the speedo cable
Post by: JohnZ on August 17, 2009, 04:27:37 PM
There should also be a pressed-in rubber seal in the end of the speedo "bullet" where the cable ferrule screws on to keep gear lube from "climbing" the flex shaft.
John do I have to unscrew the cable from the bullet to get to the rubber seal?

Are these parts I can buy at NAPA?

Thanks again

Yes - unscrew the cable ferrule from the "bullet" and you should see the black rubber seal. Don't know offhand if NAPA carries the seal separately or not. The "bullet" is called a "fitting", and is P/N 3869912 (includes the seal), in group 4.338. The seal itself is P/N 3869910.
Title: Re: M-21 lube leaking out of the speedo cable
Post by: sixt9x33rs on August 18, 2009, 10:47:59 PM
There should also be a pressed-in rubber seal in the end of the speedo "bullet" where the cable ferrule screws on to keep gear lube from "climbing" the flex shaft.
John do I have to unscrew the cable from the bullet to get to the rubber seal?

Thank you very much.

Are these parts I can buy at NAPA?

Thanks again

Yes - unscrew the cable ferrule from the "bullet" and you should see the black rubber seal. Don't know offhand if NAPA carries the seal separately or not. The "bullet" is called a "fitting", and is P/N 3869912 (includes the seal), in group 4.338. The seal itself is P/N 3869910.
Title: Re: M-21 lube leaking out of the speedo cable
Post by: JohnZ on August 19, 2009, 02:13:32 PM
Photo below shows the end of the fitting where the speedo cable ferrule screws on; if you look closely at the end of the plastic speedo gear, you can see the black rubber seal.
Title: Re: M-21 lube leaking out of the speedo cable
Post by: jl8dale on August 19, 2009, 02:23:31 PM
Awesome pic John.

I have the same problem in one of my Pace Cars with oil under my dash around the speedometer and wasn't sure why it was happening.

Thanks for your insight on this.
Title: Re: M-21 lube leaking out of the speedo cable
Post by: click on August 19, 2009, 03:18:35 PM
A few more pics of speedo leaking issue. Mine is off TH350 but same problem, leaked down onto my foot while driving on a 2500 mile trip to a car show in Seattle. Chev.dealer replaced the bullet and all the seals and O-rings, dry ever since. :)

(http://www.carsbyjim.com/storage/Tranny/speedoGearSeal1.JPG)
(http://www.carsbyjim.com/storage/Tranny/speedoGearCarrier1.JPG)
Title: Re: M-21 lube leaking out of the speedo cable
Post by: 68Zproject on August 22, 2009, 08:05:52 AM
A picture is worth a thousand words.  I didn't know about that one in the end of the bullet.
Title: Re: M-21 lube leaking out of the speedo cable
Post by: sixt9x33rs on August 22, 2009, 07:00:49 PM
Thanks for the pictures guys. That really helps explain the situation. Now I just need to find the time to fix it.

Title: Re: M-21 lube leaking out of the speedo cable
Post by: sixt9x33rs on August 24, 2009, 06:29:42 PM
There should also be a pressed-in rubber seal in the end of the speedo "bullet" where the cable ferrule screws on to keep gear lube from "climbing" the flex shaft.
John do I have to unscrew the cable from the bullet to get to the rubber seal?

Are these parts I can buy at NAPA?

Thanks again

Yes - unscrew the cable ferrule from the "bullet" and you should see the black rubber seal. Don't know offhand if NAPA carries the seal separately or not. The "bullet" is called a "fitting", and is P/N 3869912 (includes the seal), in group 4.338. The seal itself is P/N 3869910.
John thanks for the part numbers. NAPA had just the seal. I will intall it and see how it works
Title: Re: M-21 lube leaking out of the speedo cable
Post by: sixt9x33rs on August 25, 2009, 12:25:00 AM
John do you have another part number for the seal? What I got today at NAPA was for an automatic transmission and they did not have the part number for the bullet.

Thanks!
Title: Re: M-21 lube leaking out of the speedo cable
Post by: JohnZ on August 25, 2009, 03:53:34 PM
John do you have another part number for the seal? What I got today at NAPA was for an automatic transmission and they did not have the part number for the bullet.

Thanks!

The GM part numbers for the fitting w/seal and for the seal by itself are as I posted above. Paragon has the fitting w/seal (their #7188K) and the seal by itself (their #10481). Pre-1966 fittings (bullets) aren't machined to accept the seal.
Title: Re: M-21 lube leaking out of the speedo cable
Post by: sixt9x33rs on August 26, 2009, 10:34:24 AM
John,

I was able to buy a new bullet for $5 from a local transmission shop. I put it in last night. I will take the car for a nice long drive and see what happens.

Thanks!
Title: Re: M-21 lube leaking out of the speedo cable
Post by: sixt9x33rs on December 22, 2009, 11:57:31 PM
This is a follow up to the earlier post:

As I mentioned I have replaced the speedometer cable bullet and things seem to be fixed, but now I am getting the same issue as before. Oil walking up the cable dripping out on my foot at the point the cable connects to the speedometer.

Any ideas of what may be happening?

Thanks,
Title: Re: M-21 lube leaking out of the speedo cable
Post by: JohnZ on December 23, 2009, 03:05:11 PM
This is a follow up to the earlier post:

As I mentioned I have replaced the speedometer cable bullet and things seem to be fixed, but now I am getting the same issue as before. Oil walking up the cable dripping out on my foot at the point the cable connects to the speedometer.

Any ideas of what may be happening?

Thanks,

Does the new "bullet" you got at the transmission shop have the black rubber seal in it around the end of the plastic gear, or is it the old style without the internal seal? If it has the seal, you shouldn't see any leakage up the cable.
Title: Re: M-21 lube leaking out of the speedo cable
Post by: sixt9x33rs on December 23, 2009, 03:32:36 PM
John it has the seal, and it worked for awhile. I bought a second bullet as a backup so I guess I will put that one in and see what happens. I guess there is not another culprit?

Thanks,

Lawrence

This is a follow up to the earlier post:

As I mentioned I have replaced the speedometer cable bullet and things seem to be fixed, but now I am getting the same issue as before. Oil walking up the cable dripping out on my foot at the point the cable connects to the speedometer.

Any ideas of what may be happening?

Thanks,

Does the new "bullet" you got at the transmission shop have the black rubber seal in it around the end of the plastic gear, or is it the old style without the internal seal? If it has the seal, you shouldn't see any leakage up the cable.
Title: Re: M-21 lube leaking out of the speedo cable
Post by: JohnZ on December 24, 2009, 04:36:30 PM
John it has the seal, and it worked for awhile. I bought a second bullet as a backup so I guess I will put that one in and see what happens. I guess there is not another culprit?

A bad seal (or no seal) is the only reason I can think of for trans lube to climb the flex shaft.
Title: Re: M-21 lube leaking out of the speedo cable
Post by: mark x22 on December 24, 2009, 05:18:55 PM
Could the cable be damaged cutting the new seal ?
Title: Re: M-21 lube leaking out of the speedo cable
Post by: sixt9x33rs on December 25, 2009, 01:43:28 AM
John it has the seal, and it worked for awhile. I bought a second bullet as a backup so I guess I will put that one in and see what happens. I guess there is not another culprit?

A bad seal (or no seal) is the only reason I can think of for trans lube to climb the flex shaft.

ok I am going to put the spare bullet in there and see what happens.
Title: Re: M-21 lube leaking out of the speedo cable
Post by: L78 steve on February 10, 2010, 05:17:23 PM
Check the plastic gear also where the seal contacts for damage.