A Common Problem

[4rd Xplora]

I've done several searches here for this "common" Explorer problem. Between 50 & 60, I've got a moderate vibration in the driveline somewhere. You can feel it in the steering wheel. I've done the u-joints and checked the trans mount (good, but still got a new one to install maybe tomorrow). Bought new tires today . Now, I think one of the new tires didn't get balanced (no weight on it) but here's the kicker, with the truck in park, raise the rpms to 2100 ( around 50-60 mph) and you can feel the vibration. Now my question is this is a 4.0 ohv engine with around 290K on it, could the harmonic balancer be bad? Does Ford even use a 2 piece balancer on this engine?

 

[Dono]

Wow...so its not driveline.
Interesting.
I know the harmonic balancers have rubber separarion on them. Not sure what to say.
Motor have a miss at certain rpm's? That's a possibility.

How many miles on the motor?

 

[4rd Xplora]

^ About 290K (odometer didn't work for about 3-4 years and is showing 244K now that it's fixed. It's a DD with about 40-45 miles a day put on it). Another weird deal is you can but the truck in neutral at speed and still feel the vibration. Going to pull the driveshaft and rotate it 180 degrees even though I marked the both yokes and the shaft when I put in the u-joints and install the trans mount tomorrow. Believe it or not, she still had the original u-joints in her with that many miles and they were still good.

 

[corkey]

my 96 did the same thing, it is definitely motor related,or transmission, not shafts or diffs for sure,,
i never did figure it out,, motor blew a head gasket at 375,000 kilometers, and i have not fixed it yet,,
i tried all the same things as you did so far,with no success,,
i did get it smoother, but the slight vibration was still there,, although when i went to 35's on 6 inches of lift, it didn't matter as much cause the aggressive tires vibrated a bit more than the engine did,,

 

[4rd Xplora]

Checked the balancer today and installed the trans mount, no difference. Just gonna drive the old girl till she decides to let me know exactly what's ailing her.

 

[4rd Xplora]

She Told Me!!!!!! Crawled back under her and double checked the trans mount install and found the two nuts that attach the mount to the cross member were finger tight only (my bad). A few turns with a rachet cured that AND I can't believe the difference. HUGE!!! AND so quiet! to all the people here and their posts that led me to the fix.

 

[Explorer's man]

I have the same problem on my 99' Explorer Eddie Bauer 5.0.
It happen when running and in parking when reach 2500-3000 RPM. It comes like from front underbody. Any ideas?