Hmm.. Howling/Rumble noise at 90mph w/ 4.10s?
 

Just wondering if someone knows what the issue is, but I have 4.10 OEM gears (installed recently from 3.23s) with a TruTrac and T/A Girdle, etc. No problems with the gears, tuned good, etc. I ran 10 heat cycles no faster than 40-45mph over a period of 2 weeks.

Opened up the throttle a bit and climbed to about 90mph and head a loud growl/howl/rumble coming from the rear end. It is nowhere near a whine, just a loud noise. Just curious what this could be? Doesn't feel right tho?

Any suggestions?

well...you just had the rear end messed with...and now you've got a new noise....I'd say it's your rear end. How good was your installer?

well, I kinda figured that part out. Just trying to think of exactly what the cause of the problem was (i.e. backlash off, bad trutrac unit, typical noise with a high gear ratio).

Installer was pretty reputable.

im going to say probably a bad bearing either a wheel or a carrior or maybe the pinion only cause my old truck had a bad wheel bearing and it maid a growling noise but it only did it on the highway

crewcab does not have a carrier bearing, atleast not to my knowledge? I guess it could be the pinion angle, I'll have to look into that. Good call, didn't even consider that!

is that the first time you've had the truck at that speed since you lowered it?

lol, oh no. I have had that truck alot faster than that before the gears and still dropped. :secret2:

It definetly has a 1-piece driveshaft.

well i figured you,ve had the truck faster then that since you lowered it but i just thought id ask lol

im thinking that its probably something inside the rearend because if it was the pinion angle the truck would vibrate not make a howling or growing noise it sounds like a bad bearing IMO

You might have had the truck faster before, but now you are spinning the driveshaft over 25% faster to reach the same MPH. That could definitely bring out noise that you didn't hear before.

Now, your pinion angle might be a bigger factor because of this increase in RPM of the driveshaft.

strap it down on a chassis dyno so you can get the same speed and still walk around to locate the noise, sounds like a well spent $75 rather than changing parts that might not need to be or the labor to do so...