My truck sounds like jet landing.

cdnuser · Post by **cdnuser** » Wed Dec 12, 2007 5:53 am

Today while I was driving on the highway during deceleration my truck sounded like a Jet coming in for landing. I would describe it as a loud whine that corresponded with speed. Earlier I had used 4wd to get out of my driveway and I was thinking it had not properly disengaged. The 2wd light was on but it felt like 4wd was still active but only felt active when the noise started halfway through my trip. I pushed the 4wd button and then pressed the 2wd again and the sound stopped.

This is the 2nd time it has happened and it happens while driving without warning. Could there be something wrong with the electronics that is activating the 4wd?

Post by **Walt** » Wed Dec 12, 2007 6:33 am

What you're describing sounds like the fan is staying on. I know in the summer, when I get up to speed, particularly higher rpms with the fan on, it sounds like a jet.

cdnuser · Post by **cdnuser** » Wed Dec 12, 2007 10:01 am

Walt wrote:What you're describing sounds like the fan is staying on. I know in the summer, when I get up to speed, particularly higher rpms with the fan on, it sounds like a jet.

No, I know that sound this is much worse. It is almost deafening louder than a 18 wheeler gearing down at highway speeds. All the people around me where freaked out by the sound.

Torskdoc · Post by **Torskdoc** » Sun Dec 16, 2007 2:59 pm

Had the EXACT Same thing happen about 8 weeks ago. Thread here....
http://www.s-10crewcab.com/phpBB2/viewt ... highlight=

1.) Take the cable off the vacuum actuator and make absolutely sure engagement and dis-engagement is smooth. Shoot PB Blaster (NOT WD-40) down the cable end and cycle the cable until smooth.

2.) Double check all vacuum line connections and push them together if not sure. Pull the 3 tube connector OFF the Vacuum switch on top of the Transfer case. Use Q-tips and Alcohol or Paint thinner and swab out the hose connections. Push connector back on the vacuum switch snugly.

The cable and connections are now part of my oil-change routine.

Also go and get the revised GM vacuum switch. Part # 89059420 http://www.s-10crewcab.com/phpBB2/viewt ... uum+switch

Larry

cdnuser · Post by **cdnuser** » Mon Dec 17, 2007 4:31 am

Torskdoc wrote:Had the EXACT Same thing happen about 8 weeks ago. Thread here....
http://www.s-10crewcab.com/phpBB2/viewt ... highlight=

1.) Take the cable off the vacuum actuator and make absolutely sure engagement and dis-engagement is smooth. Shoot PB Blaster (NOT WD-40) down the cable end and cycle the cable until smooth.

2.) Double check all vacuum line connections and push them together if not sure. Pull the 3 tube connector OFF the Vacuum switch on top of the Transfer case. Use Q-tips and Alcohol or Paint thinner and swab out the hose connections. Push connector back on the vacuum switch snugly.

The cable and connections are now part of my oil-change routine.

Also go and get the revised GM vacuum switch. Part # 89059420 http://www.s-10crewcab.com/phpBB2/viewt ... uum+switch

Larry

Thanks for the info

Torskdoc · Post by **Torskdoc** » Tue Dec 25, 2007 12:30 pm

Did ya fix the "WHINE" and what did ya do to fix it????

jeffc · Post by **jeffc** » Tue Jan 08, 2008 5:01 pm

My truck recently sounded like a jet landing and it ended up being a bad front wheel bearing (I've got 61,000 miles on the truck) I also found out that my front drive shaft was spinning all the time because the t-case vacuum switch was bad and it was stuck on, so I still had 4x4 but I couldn't switch off the front diff. I also took my truck in today for new ball joints, idler arm, and pitman arm. I knew what I was getting into when I decided to lift the truck but i'm really thinking about a sas. My truck will be paid off soon and reserved as a toy so I'll also thinking v8.