[matt_ramsey]

I'm hoping to try and fix my speedo leak this weekend on my th350. I tried to do it once before I had the transmission rebuilt, and somehow ended up dropping the gear inside the tailhousing. What exactly did I do wrong, and what should I look out for this time to avoid doing it again? I suspect that the mechanic who rebuilt the tranny didn't even put the o-ring on... is this the only thing that seals it?

[M&M CUSTOM]

If I remember right when I changed out my speedometer gears, there is only the O-ring. But it's been almost a year and a half now since I did mine.

[Riverman]

Yes, it is only an O ring. The key is to make sure that the speedo is squarely
into the housing and tight along with a good O ring. Make sure your threads are nice and clean make sure the cable is snug and not moving side to side.

[matt_ramsey]

sweet, thanks. i'm still not sure about dropping the gear inside though... is that just some nearly-impossible stunt i managed to pull or what? doesn't seem like anyone else on the board has managed to achieve exactly that level of screwing stuff up.

[Ricky Rocket]

Matt, There is only an o-ring on the outside of the speedometer gear housing to seal it to the case. There is another seal inside the housing to seal between the housing and the plastic speedo gear, it is a small lip seal held in with a small wire clip. This is removed from the outside end of the housing with a screwdriver or pick tool (a lot easier to do with the housing and gear removed and separated). When you have the housing out, you should see how much play there is between the gear and housing. The housing is made of aluminum and the gear is plastic so they both wear out. If it is too loose, it will leak!

I don't think you will have a problem with dropping the gear inside the extension housing as long as you are aware of it now, it is usually not a problem. Just watch the gear inside the housing when you are installing and make sure it doesn't work its way in.

Good luck,
Rick

[Crosley]

If the speed-O bullet / insert is aluminum , it will be worn out.

there are steel replacement bullets available.

Often the plastic gear has a groove worn into it from the seal. A deep groove? replace the gear too

[matt_ramsey]

update:
fixed it.
had to wedge a little piece of metal in between the bullet and the thing that holds it on to keep it held in place with pressure on the o-ring. without it, the bullet had about 1/4" of slop and could slide in and out. I don't know if it is the wrong bullet or what, but the rebuilder covered it up by gooping permatex around it.

[matt_ramsey]

another update on the same topic, it is over a month since I fixed the leak, and out of the blue it started leaking again. I have ordered a new bullet and nylon gear and once I get it sealed up again, i'll post. hopefully no one else out there is having as much trouble as i am sealing their tranny up but if so, check out my posts... I will have changed about every part of the thing by the time i'm done!

[Deuce]

Originally Posted by matt_ramsey

doesn't seem like anyone else on the board has managed to achieve exactly that level of screwing stuff up.

Rest assured that most all of the guys/girls who have been working on their stuff for a few years HAS made some of the same mistakes. THEY just do not post their mistakes......or they happened WAY BEFORE the computer became common place in the households of America....