Hey guys! I’m needing a little help diagnosing a problem. Our church has a 99Intrrnstional 3800 with the 7.3L and an Allison AT545. Recently is started making a whining noise only at highway speeds and high RPMs. If I’m going down the highway and it does it, I can shift it into neutral and it goes away. So it only does it in gear. If I feather it then it doesn’t happen until I’m in 4th gear at around 45 mph or above. Sitting still I can’t make it recreate the sound. I’ve put belt conditioner on the belt and penetrating oil on pulleys and it still does it. I know the transmission is going out wilhich I suspect is where it coming from. Anybody have any insight? I would greatly appreciate it!
just a shot in the dark , but you may want to check the driveshaft center support bearing for wear if it has one and make sure the driveshaft is phased properly they can cause a whirring type noise if removed for tow or something and reinstalled incorrectly .
just a shot in the dark , but you may want to check the driveshaft center support bearing for wear if it has one and make sure the driveshaft is phased properly they can cause a whirring type noise if removed for tow or something and reinstalled incorrectly .
Didn’t think of that, worth a shot though. Thanks!