NEED HELP. 727 SPEEDO AREA LEAKING

[ACUDANUT]

 Can the speedometer gear get so worn out, it won't seal. ?  I have am stuck and need professional advice on how to seal this Transmission.
PLEASE HELP ME.

[John_Kunkel]

If it's leaking from around the adapter housing, the seal is a common O ring 1.75" OD by .100" thick. If it's the inner seal the leak will be from the speedo cable. Both seals are available. Pinion shaft wear rarely causes a leak.

https://www.ebay.com/itm/TF8-727-TF6-904-Transmission-SPEEDO-HOUSING-LEAK-STOP-SEAL-KIT-Speedometer-A727/300695995128

[Swampwing2]

Could it possibly be leaking from the nearby neutral reverse switch? The brand new one in mine had a metal ring behind the O-ring that prevented it from sealing. It would leak like crazy from there and just run along the pan to make it look like other things were leaking. I ended up using the original switch as the new one just would not seal.

[ACUDANUT]

Nope, it's the speedo area. I had it on a lift today..

[bee1971]

I could never get those small inner black seals to work , drove me nuts as it was the only drip on the tranny after fixing everything else

My tranny shop actually gave me one , pretty sure it was a GM seal , had a garter spring on it

Perfect the last few summers

[ACUDANUT]

If it's leaking from around the adapter housing, the seal is a common O ring 1.75" OD by .100" thick. If it's the inner seal the leak will be from the speedo cable. Both seals are available. Pinion shaft wear rarely causes a leak.

https://www.ebay.com/itm/TF8-727-TF6-904-Transmission-SPEEDO-HOUSING-LEAK-STOP-SEAL-KIT-Speedometer-A727/300695995128

Thanks John !!

[ACUDANUT]

If it's leaking from around the adapter housing, the seal is a common O ring 1.75" OD by .100" thick. If it's the inner seal the leak will be from the speedo cable. Both seals are available. Pinion shaft wear rarely causes a leak.

https://www.ebay.com/itm/TF8-727-TF6-904-Transmission-SPEEDO-HOUSING-LEAK-STOP-SEAL-KIT-Speedometer-A727/300695995128

Bought the Kit (2 piece). Still leaks pretty good. 1 drop every second when running.  The big orange "O" ring does not seal...I am going MAD.

[Alaskan_TA]

Is the housing 'clocked' right for your pinion gear size?

If it is not clocked right, the housing can be crooked & not letting the o-ring & housing seat into the transmission case correctly.

[John_Kunkel]

Did the adapter go into the tail real easy like the O ring wasn't the correct size? IOW, the installed O ring should require a noticeable push when installing the adapter.

[ACUDANUT]

it went in fine. I felt it grab better and thought I would have a better seal. NOPE.

[c00nhunterjoe]

If you didnt have to give it a noticable push and get a "pop" when it seated, its not the right o ring. If so, i assume there are no burrs or damage on the adapter and trans?

[RD]

did you put the big o-ring on dry or did you put some assemblee goo (http://www.lubegard.com/~/C-185/Dr.+Tranny+Assemblee+Goo) or vaseline on it before install?

[ACUDANUT]

did you put the big o-ring on dry or did you put some assemblee goo (http://www.lubegard.com/~/C-185/Dr.+Tranny+Assemblee+Goo) or vaseline on it before install?

It was lubed of course. But thanks.

[BLK 68 R/T]

It's not leaking from the access plate for the tail shaft housing snapring is it? It's close to the speedo area on the bottom and not really visible with the crossmember installed.

[ACUDANUT]

It's not leaking from the access plate for the tail shaft housing snapring is it? It's close to the speedo area on the bottom and not really visible with the crossmember installed.

NOPE. It's from where I described.

[John_Kunkel]

You need to remove the adapter again, clean the area and inspect real close for anomalies like a crack or burr. If worse comes to worst, goop the O ring with RTV.

[ACUDANUT]

 I am throwing in the towel here.   I need someone local to fix it.

[Nacho-RT74]

some crack on tranny case or speedo gear housing ?

[ACUDANUT]

 Nope, non of that.  I wonder if Stuart knows someone. 

[charger Downunder]

The  number on the adapter cover must correspond to the number of teeth on the gear. This must be lined up at the 6 o clock position. In other words your teeth number must be at the bottom of the housing when installing.

[ACUDANUT]

The  number on the adapter cover must correspond to the number of teeth on the gear. This must be lined up at the 6 o clock position. In other words your teeth number must be at the bottom of the housing when installing.

Going into this again. Wish me luck.

[ACUDANUT]

The  number on the adapter cover must correspond to the number of teeth on the gear. This must be lined up at the 6 o clock position. In other words your teeth number must be at the bottom of the housing when installing.

Can you or someone please show me picture of what you are talking about PLEASE.
Also, does the small black bushing/seal snap in with the C ring ? I never found a groove in there to see where it resides.

[John_Kunkel]

The pic below shows the orientation of the adapter in relation to the small bump on the tailhousing. The seal is installed with the lips facing in and a wire ring holds it in place.

[ACUDANUT]

John, What do you say about this "The  number on the adapter cover must correspond to the number of teeth on the gear. This must be lined up at the 6 o clock position. In other words your teeth number must be at the bottom of the housing when installing"

Do I have to count the teeth ?  I just want it to stop leaking, I don't care about the correct speed it shows.

[Kern Dog]

The numbers on the housing correspond to the tooth count of the pinion gear. The gear will have the number molded into the plastic of it. The "range of numbers" that has the numbers including your speedo pinion needs to be at the 6:00 position. The housing has an offset built into it so as it is clockedaround, the speedo gear aligns  with the grooves in the transmission output shaft.