GMT800 2500 - Wide tires & broken pitman arm

[Mr. Merk]

Recently picked up a 2005 Silverado LT Crew Cab Duramax. 175k miles. Appears to have a torsion key lift and some blocks. 285/75R16 TerraGrapplers. Looks ok but would benefit from some Deavers or at least a set of Bilsteins.

I was planning on hitting some trails in the Ozark National Forest this weekend, but the pitman arm apparently sheared off yesterday while my wife was backing out of a parking spot.

Apparently the original arms (if thats what it was) are prone to failure, especially with wide tires. I've also read that wide tires will cause bead failure of the OEM 16" aluminum wheels.

I'm going to have my local GMC dealer (where I used to be Service Mgr) install the updated pitman (19153392) and idler (19168473) arms, and I've been kicking around the idea of running "pizza cutter" 255/85r16. That's the widest tire that specs a 6.5" wheel and stands at 33.1" iirc.

Any advice from those of you rocking a GMT800 or 900?

 

[Buliwyf]

Those tires look fine to me.

Are there any aftermarket arms? Pitman arms are garbage on all American trucks right now. Likely made at the same vendor. Major source of death wobble. Being that it's an old fashioned hunk of cast iron, this happening consistently across all three brands is completely unacceptable.

 

[Mr. Merk]

Those tires look fine to me.

Are there any aftermarket arms?

The tires look sweet. Some guys even run 305/70s on the stock wheels, but apparently not without consequences.

There are tons of aftermarket arms on the market.

Sheared off ? Probably not, But would be interesting to see how it failed.
Btw,
Pittman arms are cast iron...

The stud breaks, not the arm itself.

 

[buellconvert]

That's awesome timing for that to happen wow could have been a lot worse!

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[Sickboy]

Good thing the arm failed when it did, could have been so much worse.
If you want to bombproof the IFS on a GM I would look to the sled pullers for some pointers. I would highly recommend Rare Parts pitman arm and idler arm braces. Kryptonite makes most of the rest of the parts you would need to rebuild the front end. I rebuilt the my '03 3500 back around 2014 using what both brands had available at the time. It was more costly up front but I knew it would stand up to many years of my abuse. 50k miles of daily driving, heavy towing, and countless 4WD full boost launches, and the front end was still tight when I sold the truck. Just putting out a set of options for you.

 

[Regcabguy]

PPE make some beefy parts for the GM's I've seen the stage 2's installed. What a difference. https://www.ppediesel.com/shop/stage3-forged-tie-rod-assemblies-gm-2001-2010-158031500.html

 

[SoTxAg06]

PPE make some beefy parts for the GM's I've seen the stage 2's installed. What a difference. https://www.ppediesel.com/shop/stage3-forged-tie-rod-assemblies-gm-2001-2010-158031500.html

Had those on a 2010 2500. They were worth the money.


OP, check out kryptonite, they have heavy parts for chevys.

KRYPTONITE PRODUCTS

KRYPTONITE STEERING AND SUSPENSION PRODUCTS

kryptoniteproducts.com

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[Mighty Dodge Ram]

Plenty of stories about 285/75-16s rolling off the stock rims when pressures are lowered. I went one size up from the stock 245s to 265s and am "happy" with them, but also considering the 255s when it comes time to change them out. On my last rig, I went with 285s and aftermarket rims but was never completely satisfied...the rims with less backspacing changed the steering characteristics. I like the factory rims on the 2500 HDs so no changing them out, I'll deal with the tires when it comes time.

 

[Mr. Merk]

Plenty of stories about 285/75-16s rolling off the stock rims when pressures are lowered.

Good to know. I was considering dropping them down to about 35psi when I take it off pavement

 

[Mighty Dodge Ram]

You'll probably be OK with 35 psi depending on how you "load" them up meaning speed during turns, the composition of the material you're driving on, etc. I'd be careful below 20 psi where you would typically be running them in sand.

 

[Mr. Merk]

Broke a belt on one of the 285s while pulling the trailer this past weekend. After much turmoil I finally pulled the trigger on some Toyo MT 255/85R16s.

 

[Mr. Merk]

worn 285/75R16 Terra Grappler vs new 255/75r16 Toyot MT. you can see the broken belt on the top of the 285

 

[Mighty Dodge Ram]

Those 255s look good, but is it the camera angle or are they already rubbing on the front bumper valance/air dam? I’ve read that others have trimmed off a triangular section due to rubbing while at full lock/compression.

Great choice in tires, good luck with them!

 

[Mr. Merk]

is it the camera angle or are they already rubbing on the front bumper valance/air dam? I’ve read that others have trimmed off a triangular section due to rubbing while at full lock/compression.

We'll see, wheel and camera angle might have something to do with it but remember the truck will be higher up as well. The wheel isn't centered in the tire.

 

[Mighty Dodge Ram]

My bad...thought this was an after shot with wheel/tire already mounted. ?‍♂️