Can't locate mild vibration!
#1
Can't locate mild vibration!
Alright guys I'm getting desperate, I cannot locate this shuddering/vibration I've had since I bought the vehicle, over a year ago.
Symptoms: it's felt in the seat / seat back, its the worse at around 25mph. Bad enough to shake the rear seats back and forth and giggle the steering wheel some. fades out as you speed up (is completely gone around 50pmh) and then comes back around 65-70. At highway speeds it's a dull pulsing sensation but I start to feel it in the pedals some. It's only felt in the steering wheel as a result of the whole vehicle vibrating, it doesn't originate from the front end.
What's been done: wheels balanced, by two reputable shops. Front steering bars replaced and aligned. Front CDL output bearing changed. Rear rotoflex and bushing changed. All u-joints checked and greased. Wheel bearings checked for play with wheels off the ground.
Do I need to start looking at the tranny? Are wheel bearings still a possibility even though I couldn't detect any play?
Symptoms: it's felt in the seat / seat back, its the worse at around 25mph. Bad enough to shake the rear seats back and forth and giggle the steering wheel some. fades out as you speed up (is completely gone around 50pmh) and then comes back around 65-70. At highway speeds it's a dull pulsing sensation but I start to feel it in the pedals some. It's only felt in the steering wheel as a result of the whole vehicle vibrating, it doesn't originate from the front end.
What's been done: wheels balanced, by two reputable shops. Front steering bars replaced and aligned. Front CDL output bearing changed. Rear rotoflex and bushing changed. All u-joints checked and greased. Wheel bearings checked for play with wheels off the ground.
Do I need to start looking at the tranny? Are wheel bearings still a possibility even though I couldn't detect any play?
#2
#4
How old are your tires? possibly misshapen or unevenly worn or the wheel balance is still incorrect. Jack up the truck onto axle stands and check the outer circumference of each tire with a dial gauge or an accurate pointer. Even if the circumference is 1.0 mm out of shape it will induce low frequency vibrations through all of the seats and steering. I suffer the same problems myself from misshapen tires. Try switching the front and rear tires/wheels around from front to back and vice versa. It won't get rid of the vibes but may isolate the problem from the front tires to the rear. I thought it was engine and gearbox mounts but having changed all 4 mounts the same problem persists. The final possible issue could be that one or both of the CV joints at the front are worn. Let us know what you find also.
#6
Definitely check your brake calipers, pads, and rotors. If these are binding you can chase "driveline vibes" forever. Just fixed this on the rear calipers of a BMW X5 last week.
Make sure the piston is moving freely. But what I've found mostly dealing with a stuck caliper is 1 or the other guide pins are not moving. So remove the guide pins clean them and then lube. Also check that the pads have enough meat on them, and they are moving evenly on the abutment clips in the caliper frame. Lube the pad abutment clips and guide pins with something like CRC Silaramic.
Make sure the piston is moving freely. But what I've found mostly dealing with a stuck caliper is 1 or the other guide pins are not moving. So remove the guide pins clean them and then lube. Also check that the pads have enough meat on them, and they are moving evenly on the abutment clips in the caliper frame. Lube the pad abutment clips and guide pins with something like CRC Silaramic.
#7
#8
Re: overheating the pad my answer is yes or no. I've seen both cases. If the caliper piston has no return or the guide pins are locked up then YES the pad can get cooked.
However for example that X5 had decent piston movement, but the right rear caliper top guide pin was not moving enough and the pad would get stuck inward at the top. I didn't take a pic, but the caliper frame looked off center top to bottom. There was also very little grease on the pad abutments. And in this case there was no pad "burn" smell. The rotor did have a definite groove worn in it.
IMHO, minimally it's a simple inspection/re-grease and it's worth having a look at. Good Luck!
However for example that X5 had decent piston movement, but the right rear caliper top guide pin was not moving enough and the pad would get stuck inward at the top. I didn't take a pic, but the caliper frame looked off center top to bottom. There was also very little grease on the pad abutments. And in this case there was no pad "burn" smell. The rotor did have a definite groove worn in it.
IMHO, minimally it's a simple inspection/re-grease and it's worth having a look at. Good Luck!
#9
Re: overheating the pad my answer is yes or no. I've seen both cases. If the caliper piston has no return or the guide pins are locked up then YES the pad can get cooked.
However for example that X5 had decent piston movement, but the right rear caliper top guide pin was not moving enough and the pad would get stuck inward at the top. I didn't take a pic, but the caliper frame looked off center top to bottom. There was also very little grease on the pad abutments. And in this case there was no pad "burn" smell. The rotor did have a definite groove worn in it.
IMHO, minimally it's a simple inspection/re-grease and it's worth having a look at. Good Luck!
However for example that X5 had decent piston movement, but the right rear caliper top guide pin was not moving enough and the pad would get stuck inward at the top. I didn't take a pic, but the caliper frame looked off center top to bottom. There was also very little grease on the pad abutments. And in this case there was no pad "burn" smell. The rotor did have a definite groove worn in it.
IMHO, minimally it's a simple inspection/re-grease and it's worth having a look at. Good Luck!
#10