Here's the lay out.

Lifted truck 6" with new 35" M/T's from stock with 32" M/T's.

After install and a week of driving, no odd noises but the front end was flighty, so I had them add more positive caster to get a more in the road feel. I went from +1.8 Left and +2.2 Right to +3.8 Left and +4.1 Right. every thing I read recommended +4.0 to +5.0 on a lifted truck.

I now have a wa-wa-wa sound above 60MPH. It is not RPM based, I checked. It gets faster as I increase speed.

It's more pronounced under throttle vs coasting. I can't tell where it is coming from, one minute it sounds like my LF, next it sounds like it's from the rear end somewhere.

It dissipates for a second when going over a dip/bump on the highway, but I can't tell if it's on the down flex or up flex because it happens so quickly.

Too much pinion angle?

No excessive vibrations beyond what an M/T feels like.

All my weights are still attached to wheels.

Tire pressures same as when first installed (3 weeks ago).

I found one post with similar complaint but the find was never posted and I haven't received a return PM from the thread author.

 

I had a wah wah wah sound like that one time in my car....it turned out to be Totallyrad sticking his head out the window pretending to be an Indian brave.......

 

I had the same sort of thing with my truck. I think it was a bad tire, maybe a flatspot on it, but I don't know. I have Toyo MT 35's, and when I would rotate the tires, the vibration would be felt on whatever front side that particular tire was put on. Whenever it was rotated to the rear, I wouldn't feel anything. These tires are on there last legs, and will be replaced next month (along with a free spin hub set), but overall, loved the Toyos, and will get them again. Like I said, I think I had one bad tire, and balancing them didn't seem to fix it, unless that tire was put on the rear end.

 

Thanks, Chris. When we added more caster the tires were only a week old but we decided to swap the front two to see if it would help with the pulling to the right. Think I'll try moving it back first.

Lary, shouldn't your comment be in the "Modifications you regretted" thread? I've heard nothing but bad things when any one installs a Totallyrad in their truck.

 

I was gonna say tires too. Rotating them off the front ought to help troubleshoot. But if you rotated the axle a little bit with the alignment it makes to think it's a bearing or ujoint on the front diff.


Is the Totallyrad a free mod? Is there a write up? Does it help with mpg? Or is it one of those kinda mods that the cops are always on the lookout for? Because I don't need that.

 

There is a typo on the free but burdensome mod called a TotallyBad.
There is a B where the R is...please correct.

I think I saw that modification strapped to the roof of a semi the other day.

wa wa wa

 

That sounds like a corrupt tuner file

 

Update:

Had it looked over at Les Schwab, each member of the crew (5) test drove it and inspected everything. Lead tech feels it's not a tire noise, thinks it's too scraping-like, but has also never heard this sound before on any vehicle.

All U-joints cold as can be after a 20 mile drive at 65mph.

Does not sound like a drive train vibration and caster is within factory spec.

Hubs good, no drag whatsoever which also cancels out sticky calipers.

No excessive play in any components.

Moved offending tire to rear, will test drive after work to see if sound dissipates or follows the tire.

 

Definitely tire related noise. Hear the same thing on a lot of the more aggressive tires, and even on the less aggressive ones, when they start to wear.

Check your shocks and springs in the lift kit, could be causing an oscillation that you don't feel, but you hear the resulting road noise from the tires.

 

Went back by Les Schwab after I closed the shop early on Saturday.

Sound remains.

Tuesday or Thursday we are going to pull the front drive shaft and test drive.

Also on a weekday he has access to Schwab and Tuff Country Techlines.

 

That would be my next move too. That may have been just too much caster for the working angle of that front u-joint.

 

So if that is that issue (too much pinion angle) does anyone make tranny/transfer case drop blocks? The driveability at initial caster 2.1 and 1.8 IIRC was borderline deathwobble scary, extremely flighty and on top of the road rather than in the road feeling.

I did notice with the new caster 4.1 and 3.8 that it felt like there was some resistance from a stop but coasting it's not noticeable.

One other thought is my axle is much more centered with more caster and maybe it should be off-center a bit? I know my 88' 2500 suburban the wheels were offset a bit before I lifted her.

Late 90's didn't Dodge have a shim to make the front wheels appear evenly spaced under the truck to appease people that noticed from the factory that the front axle was shifted over a bit?

I'm rambling...Blame Sierra Nevada.

 

No, the spacer behind one front wheel was used to correct steering geometry in an attempt to correct the erratic braking on those trucks. They had big issues with the truck diving to one side or the other when braking, and that spacer was one part of the repair.

 

Thanks TF.

I dropped her off this morning.

 

They backed her down to 3.5 and 3.2 sound remained.

They backed her down to 2.8 and 2.5 sound is gone.

Funny that factory spec is 4.0-5.0. I know geometry changes when lifted, but that's a pretty big swing.