Strange hum around 55 mph

[shadowfax101]

I noticed this when i was coming back from the shop with my AAL's installed. It does not do it until 55. Would have the front shocks disconected cause this? I am also having a hard time telling where the sound is coming from. I was wondering if any of you out there with AAL's have ever noticed this?

[J4GRAND]

Sounds like it could be a driveline angle issue. When I put the HD front springs on my truck, I got about 2 inches of lift and got a hum in my front driveline. Had to align the front pinion and driveshaft. No hum since then.

[Cecil14]

Driveline could be the culprit. Also check to make sure it's not if 4wd. Some t-cases aren't suppose to by used after 55-60mph. I don't think shocks would do that...not sure.

Do you have a cv front driveshaft? If not you might look into one.

Good luck,
Anthony

[shadowfax101]

how hard is it to align the front pinion and driveshaft. I am sure I will not be able to do that my self. How much should I expect to pay a repair shop. Thanks

[ibnfe]

All you really do to align the pinion and driveshaft is add some angled shims between the spring and perch. You do this by pulling the u-bolts, sticking the shims in, and putting the u-bolts back on or replacing w/ new. The trick is to get the right angle on the shims. I would venture to guess that if you only have AAL's, you shouldn't need more than 2 degrees or so.