after over a month, i findally solved one of my vibration issues and wanted to share my experience since this is a common topic. i've spent hours reading and re-reading vibration threads and there are very few with follow-up on whether or not the issue was solved. looking back, i should've started where i ended up, but this is what happened.
to give some background, i have a 96 with 209k miles and recently mounted a set of used (~7500 miles on 'em when i got em) BFG 315 MT's. i swapped the OME yellow bushings with slee blues to bring the caster in spec and it definitely improved the handling. shortly after i had them mounted, i noticed a speed-specific vibration around 65mph. it felt like i was driving on a washboard road. more of a "shake" than a vibration.
at first i suspected the tires, so i had them balanced several times, and ultimately went to dynabeads with no change. then i checked the driveshafts removing one, then the other (using the CDL) with no change in the shaking (i replaced the u-joints while i had 'em off but they seemed to be o.k. despite having over 200k on 'em). i pulled the plug and replaced the fluid on the diffs and the transfer case and the fluid was clean/clear. same with the transmission. i then removed and inspected and repacked all 4 sets of bearings and they were in great shape. at that point, i suspected it was either the tires or a dry/worn spindle bushing. i should've suspected that all along, i guess.
bcs i got the tires used, i was really suspicious that they might be the cause, so i replaced them with new BFG 295 AT's with no change in the vibration/shaking. so i finally decided to replace the spindle bushings and voila, the rumble-strip vibration is GONE!! after reading all the posts, the speed-specific shaking always got a lot of dry spindle responses, but i didn't read one that had a follow-up post to say that the new bushings fixed the shaking except for a post from alia.
anyway, that was one of my experiences with vibration. i now have developed another vibration (more like a "hum") in the front drive shaft (it goes away when i pull the shaft) that i seem to notice most when i'm going abt 50mph. i didn't notice it until i pulled the shaft and replaced the u-joints. (i made sure i had it 90deg out of phase.) i'm gonna pull it again and send it to have it balanced. i'm trying to decide if pulling the napa u-joints i have in there now and replacing them with OEM will make a difference.
to give some background, i have a 96 with 209k miles and recently mounted a set of used (~7500 miles on 'em when i got em) BFG 315 MT's. i swapped the OME yellow bushings with slee blues to bring the caster in spec and it definitely improved the handling. shortly after i had them mounted, i noticed a speed-specific vibration around 65mph. it felt like i was driving on a washboard road. more of a "shake" than a vibration.
at first i suspected the tires, so i had them balanced several times, and ultimately went to dynabeads with no change. then i checked the driveshafts removing one, then the other (using the CDL) with no change in the shaking (i replaced the u-joints while i had 'em off but they seemed to be o.k. despite having over 200k on 'em). i pulled the plug and replaced the fluid on the diffs and the transfer case and the fluid was clean/clear. same with the transmission. i then removed and inspected and repacked all 4 sets of bearings and they were in great shape. at that point, i suspected it was either the tires or a dry/worn spindle bushing. i should've suspected that all along, i guess.
bcs i got the tires used, i was really suspicious that they might be the cause, so i replaced them with new BFG 295 AT's with no change in the vibration/shaking. so i finally decided to replace the spindle bushings and voila, the rumble-strip vibration is GONE!! after reading all the posts, the speed-specific shaking always got a lot of dry spindle responses, but i didn't read one that had a follow-up post to say that the new bushings fixed the shaking except for a post from alia.
anyway, that was one of my experiences with vibration. i now have developed another vibration (more like a "hum") in the front drive shaft (it goes away when i pull the shaft) that i seem to notice most when i'm going abt 50mph. i didn't notice it until i pulled the shaft and replaced the u-joints. (i made sure i had it 90deg out of phase.) i'm gonna pull it again and send it to have it balanced. i'm trying to decide if pulling the napa u-joints i have in there now and replacing them with OEM will make a difference.
