First I'll run down a few points. I did not do the modulator pull off level check. Could not find a place to do it where I could get under it and
where an ATF spill would be acceptable. Also this dip stick and fill tube has worked successfully for 3 years. I would have to jack the coach to get
at the trans vent hose. I ran it inside the trans crossmember and cannot reach it without jacking. I will change this when I get home so if this
happens in the future I will have specific evidence that the fluid loss is coming from the vent.
Modulator vac line is dry.
So do I know what is going on inside the trans when the fluid loss occurs. No. However I have reviewed how I operatied the coach and how the
driving before the days of the loss compared to those two days. Also how my driving today differed from the two loss days.
First I have not driven our GMC up any long severe grades since we've had it. Lots of long gentle hills and steep but short pulls. So I have no
"mountain" driving experience in the GMC. I also prefer to use the cruise control.
So on the grades encountered on Friday and Saturday the CC would go to full wide open. Then as the speed dropped off the trans would downshift. Then
I would remember that I'm supposed to be on top of this and use "super". This really puts an undesireable load on the engine and trans. I suspect
the ATF got agitated enough to foam and try to escape.
Today, besides picking a flatter escape route from Alamogordo, I very actively managed trans gear selection, throttle management and kept the engine
vacuum a few inches higher than on those two days.
If I have no further problems on the way home I will tend to believe I understand what happened. But note, I have not talked to Manny about this yet.
I want to get a few more days in before I call him.
--
Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI
