bob850
Newbie
1993 Suburban C1500, 5.7L, 2WD, 3.73 G80 rear diff, auto tranny (4L60E), 135K miles.
There is a distinct whining noise between about 40 and 55 mph when load is on the drivetrain. If I take my foot off the accelerator and coast, the noise goes away. Again, it starts around 40 mph and goes away completely around 55 mph even when under load. It sounds like its coming from the front, but I can't really tell. The noise just sort of fills the whole cabin.
The transmission and rear diff fluid were both recently changed, and have been changed on a regular basis throughout the life of the vehicle. The most recent fluid changes had no effect on the sound. I think the noise has been present for a number of years, but seems to be a little more noticeable over the last year or so. The drivetrain has never been abused, but is getting up in miles.
I did some searching but can't find a good answer on the specific cause. Any advice from the experts on how to fix? I posted this on another forum a while back before I discovered this gmt400-specific forum (they suggested u-joints, which have never been replaced).
There is a distinct whining noise between about 40 and 55 mph when load is on the drivetrain. If I take my foot off the accelerator and coast, the noise goes away. Again, it starts around 40 mph and goes away completely around 55 mph even when under load. It sounds like its coming from the front, but I can't really tell. The noise just sort of fills the whole cabin.
The transmission and rear diff fluid were both recently changed, and have been changed on a regular basis throughout the life of the vehicle. The most recent fluid changes had no effect on the sound. I think the noise has been present for a number of years, but seems to be a little more noticeable over the last year or so. The drivetrain has never been abused, but is getting up in miles.
I did some searching but can't find a good answer on the specific cause. Any advice from the experts on how to fix? I posted this on another forum a while back before I discovered this gmt400-specific forum (they suggested u-joints, which have never been replaced).