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 Hints (Shifting)
Transmission Hints [message #263095] Wed, 01 October 2014 00:07 Go to previous message
George Beckman is currently offline  George Beckman   United States
Messages: 1085
Registered: October 2008
Location: Colfax, CA
Karma:
Senior Member
From time to time, there are questions here about transmission oddities. This is about my transmission not shifting into 3rd as it had a few days before.

During a the trip to Southern California the transmission began only shifting into 3rd at about 55 MPH (3.21 FD), when the governor forced the shift. I added a bit of fluid as I had lost about a bit full when putting in the transmission temperature sensor.

I also checked the vacuum tubing at the throttle body. I thought about checking the tubing at the modulator but it rained in the night,so we just drove home. The central valley is flat and it only had to shift up a few times. I thought the shift out of low was at a higher RPM than normal, as well.

Yesterday I jacked up the front and found that the curved hose to the modulator was badly cracked; almost separated at the modulator.

So, if you coach won't shift into 3rd, check the vacuum circuit. It can make you happy.


'74 Eleganza, SE, Howell + EBL
Best Wishes,
George
 
Read Message
Read Message
Read Message
Read Message
Read Message
Previous Topic: Olga's Odessey Portugal
Next Topic: Looking for GMC Motorhome, southwest Ohio
Goto Forum:
  


Current Time: Mon Oct 07 09:24:30 CDT 2024

Total time taken to generate the page: 0.00950 seconds