2005 Ram 1500: Brake shimmy/pulsing

[AZRedhawk44]

My Ram has about 80K miles on it.

I've had the most wretched luck with the Goodyear Wranglers on it.  Rocks piercing the meat of the tread, things like that.  I've had to replace the tires individually at non-matching intervals.

As of this morning I had 1 original tire with 80K on it, 1 tire with about 55K on it, 1 tire with about 15K on it that used to be the spare and 1 tire with 15K that was new a year ago.  The spare under the bed has about 40K miles on it.

Today, I swapped out the two oldest tires for some Cooper Zeon LTZ's.  Much more aggressive tread that will probably cost me a little MPG, but save me $$ from flats off-road.  The next two best tires got re-balanced.

I had a bad shimmy/pulse coming from my truck whenever hitting the brakes.

This gets better, but never fully disappears, if:
1.  I pull the fuse for the ABS pump;
2.  it is lessened after balancing the tires and adding two new tires.

The front brakes were replaced around 50K miles, and the front suspension was replaced about 2 months ago.

I was abusive to my suspension when moving across town (overloaded the trailer and bed on the first trip) and I believe my rear shocks are damn-near worthless right now.  Looking at the rear brakes, I have very little life left on them.

I plan on:
1.  Having the rear shocks replaced tomorrow;
2.  Having the rear rotors turned and the rear pads replaced.

Can anybody else suggest what might cause an ABS-equipped truck to pulse or shimmy heavily when braking, even if ABS is disabled by pulling the fuse?

[Ex-MA Hole]

Bent rotor?

[Nick1911]

Warped rotor.

[Bob F.]

Yeah, my guess would be warped rotor. They're not worth a crap anymore. Like most everything else.

[Declaration Day]

Yep ^^^

I am 99% certain you have a warped rotor.  Just have to find which one it is.  That's often caused by improperly-lubed caliper bushings.  If you're taking it to a reputable shop, they'll clean and lube them when they replace the pads.

Too bad you don't live in SE Michigan, I'd do the job for 1/3 to 1/2 what the shop's going to charge you.

[RoadKingLarry]

Mine is a '97 but I've had issues with warped rotors if the bubba with the zap wrench gets a little carried away. Might also consider new front shocks.

[Gewehr98]

Insert obligatory Dodge truck driver put-down here. 

[RocketMan]

Insert obligatory Dodge truck driver put-down here. 

Aw, shucks man, we never get any respect.   [RocketMan kicks rocks and walks off]

[Hawkmoon]

Warped rotor.

^^^ What he said.

Unfortunately, the "technicians" who work in most shops either don't know or simply don't care that not properly torquing the lug nuts causes the rotors to warp. Although they make "torque sticks" for use with air impact guns, they don't work well, and most shops don't bother with them anyway. This is why I never let a shop put a tire/wheel on my vehicles. I take the wheels to the shop in the back of a pickup, have the new tires mounted and balanced, then I bring them home and I put them on the vehicle -- with a proper torque wrench.

[never_retreat]

Try removing the radiator cap and replacing the truck underneath it with a ford.

[Gewehr98]

Oh so funny.