timelapse
New member
I'm currently chasing an annoying vibration that happens under light acceleration right at 40mph. At one point I felt it around 30mph, but not since I have really started to trouble shoot it. 40mph-ish seems to be the sweet spot.
If I let off the gas when the vibration begins, it immediately goes away.
I have also confirmed that I can replicate it getting up to speed @ 40mph even if I have the transmission in a fixed gear like 4th. So, it's not happening during a gear shift.
If I accelerate with a heavier foot to get up to speed, I can't replicate it. Only seems to happen on stretches of stop and go with stop lights or the occasional traffic on the highway.
I'm hoping this is a tire issue, but initial steps to solve this have started to blur the line.
Some more info: 2014 Trail Premium KDSS w/ 150k. 285/70 C-rated KO2. Toytec 3/2 lift with SPC UCAs. Tires were new in Nov 2019 @ 106k, so I have 44k on them. My prior E-rated KO2 set lasted 80k.
I have been to Discount Tire twice in the last few weeks since this issue started occurring. Both times they did a full re-balance. The 2nd time they didn't rotate again. I do have some subtle cupping on all tires (I have rotated every 10k). The issue didn't change at all. It could very well be due to the cupping, but I haven't committed to a new set of KO2's just yet. That might be next on my list.
I also had Toyota grease and check the torque on my propeller shaft today during an oil change. I had them do a ATF fluid replace based on some other users experiencing a similar issue. Issue is still present and didn't change at all.
I also recently changed the rear diff fluid and did my spark plugs since this issue started. I still need to drain and fill my front diff when I get a chance (it's been 50k since the last fluid swap).
If it's not the tires, what's the most efficient and cost effective approach to continue troubleshooting this?
I would hate to find out it's the torque convertor or something expensive. Maybe a bearing? Not sure how I could easily narrow that down though.
Thanks in advance.
If I let off the gas when the vibration begins, it immediately goes away.
I have also confirmed that I can replicate it getting up to speed @ 40mph even if I have the transmission in a fixed gear like 4th. So, it's not happening during a gear shift.
If I accelerate with a heavier foot to get up to speed, I can't replicate it. Only seems to happen on stretches of stop and go with stop lights or the occasional traffic on the highway.
I'm hoping this is a tire issue, but initial steps to solve this have started to blur the line.
Some more info: 2014 Trail Premium KDSS w/ 150k. 285/70 C-rated KO2. Toytec 3/2 lift with SPC UCAs. Tires were new in Nov 2019 @ 106k, so I have 44k on them. My prior E-rated KO2 set lasted 80k.
I have been to Discount Tire twice in the last few weeks since this issue started occurring. Both times they did a full re-balance. The 2nd time they didn't rotate again. I do have some subtle cupping on all tires (I have rotated every 10k). The issue didn't change at all. It could very well be due to the cupping, but I haven't committed to a new set of KO2's just yet. That might be next on my list.
I also had Toyota grease and check the torque on my propeller shaft today during an oil change. I had them do a ATF fluid replace based on some other users experiencing a similar issue. Issue is still present and didn't change at all.
I also recently changed the rear diff fluid and did my spark plugs since this issue started. I still need to drain and fill my front diff when I get a chance (it's been 50k since the last fluid swap).
If it's not the tires, what's the most efficient and cost effective approach to continue troubleshooting this?
I would hate to find out it's the torque convertor or something expensive. Maybe a bearing? Not sure how I could easily narrow that down though.
Thanks in advance.
Last edited: