GMCforum
For enthusiast of the Classic GMC Motorhome built from 1973 to 1978. A web-based mirror of the GMCnet mailing list.

Home » Public Forums » GMCnet » Transmission (Shifting Problems)
Transmission [message #136199] Wed, 27 July 2011 01:05 Go to previous message
George Beckman is currently offline  George Beckman   United States
Messages: 1085
Registered: October 2008
Location: Colfax, CA
Karma:
Senior Member
We are about 500 miles from home. The transmission is not shifting as normal. It is not shifting into low at stop signs and sometimes lags when it should shift up. If I put the shifter in low it always starts in low. When I shift to second, the transmission shifts instantly 90% of the time. Shifting into 3rd is a little more iffy and it sometimes takes a minute to decide to do that. If, on a hill, and I shift to second it shifts instantly. One time at about 30 it shifted into second without me moving the shifter. Otherwise, once in 3rd gear, it runs great.
I understand that this could be anything from a modulator to needing a new transmission. Oil is beautiful. It is not getting hot, nor has it been hot. It is not slipping.

Modulator seem like a logical place to start, although I notice that extreme vacuum did not help shifting. It is not adjustable.

The governor also seems to be a likely suspect. I have headers, can I get the governor off without removing the headers? Speedometer and cruise work fine.

What do you think?


'74 Eleganza, SE, Howell + EBL
Best Wishes,
George
 
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Previous Topic: Trim or substitute?
Next Topic: Smashed passenger side window
Goto Forum:
  


Current Time: Thu Oct 03 18:20:18 CDT 2024

Total time taken to generate the page: 0.01712 seconds