Where did it go?(was: Trip Report)

[patrick flowers]

I read Jim's excellent trip report yesterday and the paragraph below
made me wonder. We often hear that a transmission "went". But what
"goes"? I'm really not trying to be funny here. It seems like we often
treat the transmission as a mysterious black box that we insert power in
one end and get power out the other with little concept of what really
happens inside. If my engine quits, I don't immediately assume I need a
new engine. So what is it that usually breaks on a transmission and do
you really need to overhaul the entire transmission when it happens.
Apologies to any transmission mechanics out there, but I wonder if we've
not been sold a "bill of goods" on transmissions that we wouldn't accept
with any other part of the machinery on our coaches.

Just curious,
Patrick

>
> Finally reached SC yesterday afternoon about 2 PM. Came down a long 6% grade
> and thought engine braking was a little lax. Then at the bottom I hit the gas
> and the engine went but the coach didn't. The tranny was completely gone
> with no warning, no noise, no nothing. I had reverse but not forward. Checked
> fluid and it was less than half a pint low, checked linkage and it was OK.
- --
Patrick Flowers
Mailtoatrick

The GMC Motorhome Page
http://www.gmcmotorhome.com

 

[travism]

> The tranny didn't actually "go anywhere" but its function of making the
motor
> home move in a forward direction "went" somewhere. The coach would not
move.
> I suspect the front band is worn out. I will remove the tranny Monday,
> disassemble it, and if the damage isn't too great, I will put in a heavy
> duty rebuild kit. In the meantime, the ole tranny is still out there
hooked
> up to whatever it hooks up to.
>
> Jim Greer

Not likely that a band wore out that suddenly, and they don't use bands for
forward motion. My bet is either a piston ring ruptured or, perhaps, a sprag
clutch let go. But it is likely entirely worth fixing.

Travis