I have a '99 LX470 with 215K miles where I've converted the hydraulic ride system using a Strutmasters conversion kit. Did this conversion in the fall of 2014 (very improved ride). Most all my driving is highway with an occasional pulling my utility trailer or trailered drift boat.
This last year or so, I've been getting a "drone" vibration around 55 mph and up when the truck is under load (accelerating or up-hill). Goes away when I let off on the accelerator. Recently purchased new Michelin tires and the vibration still exists. I'm ruling out a tire imbalance or "out-of-round" because the vibrations are higher frequencies.
I've taken my rig to a couple of different Lexus dealers. Drove with a tech for 30 minutes one day demonstrating the vibration. One dealer wanted to R&R front axles, the other dealer, who's tech rode with me, thought it could be a worn pinion gear.
I've been doing research on this issue and have been reading about the relationship of drive shaft angles and/or transfer case output slope to pinion slope. I was thinking (dangerous, I know) since I've converted the suspension, maybe pinion slope might be my problem. Here's what I've measured - truck on the ground, TC (rear) output flange at 89.3 deg and pinion flange at 89.5. I'm thinking my pinion angle should be tilted down a bit more resulting in the (rear) pinion flange at approximately 87.3 degrees so the rear pinion can rotate up during "cruise throttle".
I've heard about guys removing a shaft, locking the transfer case and checking for vibrations. Can you safely test drive the vehicle (55 to 65 mph) with just one drive shaft?
Any comments or suggestions would be greatly appreciated..
This last year or so, I've been getting a "drone" vibration around 55 mph and up when the truck is under load (accelerating or up-hill). Goes away when I let off on the accelerator. Recently purchased new Michelin tires and the vibration still exists. I'm ruling out a tire imbalance or "out-of-round" because the vibrations are higher frequencies.
I've taken my rig to a couple of different Lexus dealers. Drove with a tech for 30 minutes one day demonstrating the vibration. One dealer wanted to R&R front axles, the other dealer, who's tech rode with me, thought it could be a worn pinion gear.
I've been doing research on this issue and have been reading about the relationship of drive shaft angles and/or transfer case output slope to pinion slope. I was thinking (dangerous, I know) since I've converted the suspension, maybe pinion slope might be my problem. Here's what I've measured - truck on the ground, TC (rear) output flange at 89.3 deg and pinion flange at 89.5. I'm thinking my pinion angle should be tilted down a bit more resulting in the (rear) pinion flange at approximately 87.3 degrees so the rear pinion can rotate up during "cruise throttle".
I've heard about guys removing a shaft, locking the transfer case and checking for vibrations. Can you safely test drive the vehicle (55 to 65 mph) with just one drive shaft?
Any comments or suggestions would be greatly appreciated..