"Chirping" Noise in the Drive Train
#1
08-14-2003, 06:57 AM
"Chirping" Noise in the Drive Train
On my last truck (a 1999 5.4 liter Regular Cab, short box, ORP 4x4) I had a problem with a chirp in the drive train that drove my dealer and I nuts. The noise was audible mostly when slowing down at lower speeds but actually turned out to be there (at the same speeds) when accelerating too. It sounded like a chirp or squeak and would speed up or slow down with vehicle speed. I concluded that it had to be in the drive shaft area because the noise seemed to match the frequency of my rear end gear. The truck had the 3.55 Limited Slip rear end and it seemed to chirp about 3 or 4 times for each rotation of the wheel.
My dealer agreed with my diagnosis and tried everything including greasing the slip yoke, removing surface rust from the yoke and finally replacing the entire drive shaft. (Yes, that was 3 separate trips.) Replacing it actually solved the problem – for 14,000 mikes, and then it was back.
I finally ended up pulling the drive shaft myself in a friend’s shop and we literally stumbled onto the root cause. When we picked the drive shaft up to put it on the workbench, the front yoke assembly pivoted to one side at the universal joint and chirped. We both looked at each other in disbelief. We then moved the front yoke back and forth and the darn thing made the exact same sound that was driving me nuts. We then isolated the noise as coming from the rubber seal at the center of the front joint as it moved very slightly back and forth with the motion of the joint. The cure? Take some grease and pump it in behind the rubber seal with a needle fitting on the grease gun. Presto – problem solved.
Well, I traded that truck in a little over a year ago after never having heard another chirp – until last week. That’s right, my new truck started making the exact same chirp at 26,000 miles. So, I crawled under the truck with my grease gun and lubed that bad boy up. Problem solved.
So, if any of you hear this kind of noise, you now know where to look. The seal is located in the front u-joint (there are two on the front of the drive shaft) and you can easily slip a needle fitting in from the front side of the seal with the drive shaft still in the truck. There’s really no need to remove the drive shaft.
My dealer agreed with my diagnosis and tried everything including greasing the slip yoke, removing surface rust from the yoke and finally replacing the entire drive shaft. (Yes, that was 3 separate trips.) Replacing it actually solved the problem – for 14,000 mikes, and then it was back.
I finally ended up pulling the drive shaft myself in a friend’s shop and we literally stumbled onto the root cause. When we picked the drive shaft up to put it on the workbench, the front yoke assembly pivoted to one side at the universal joint and chirped. We both looked at each other in disbelief. We then moved the front yoke back and forth and the darn thing made the exact same sound that was driving me nuts. We then isolated the noise as coming from the rubber seal at the center of the front joint as it moved very slightly back and forth with the motion of the joint. The cure? Take some grease and pump it in behind the rubber seal with a needle fitting on the grease gun. Presto – problem solved.
Well, I traded that truck in a little over a year ago after never having heard another chirp – until last week. That’s right, my new truck started making the exact same chirp at 26,000 miles. So, I crawled under the truck with my grease gun and lubed that bad boy up. Problem solved.
So, if any of you hear this kind of noise, you now know where to look. The seal is located in the front u-joint (there are two on the front of the drive shaft) and you can easily slip a needle fitting in from the front side of the seal with the drive shaft still in the truck. There’s really no need to remove the drive shaft.