Moog 81091 vs 81085 for RWD & Concerning Negative Camber

slypher25aussie said:

I recently bought a '07 QX56 RWD. The rear tires are HORRILY worn on the insides and both tires are visibly tilting inwards at the top like I have a negative camber. I suspect that the air shocks are toast and the original coils are struggling. Would this cause a negative camber? I didn't realize there were different coils for 4WD vs RWD. Moog says the 81091 is the correct coil for RWD and the 81085 that everyone recommends is for 4WD. My concern is that if I get the 81085, the rear will ride too high. Thoughts?

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Hello from Miami. I too have a SE RWD. my rear droops a bit. So I am looking at the Moog 81091 because that’s what fits. What did you end up doing? Thanks.

latinlau said:

Hello from Miami. I too have a SE RWD. my rear droops a bit. So I am looking at the Moog 81091 because that’s what fits. What did you end up doing? Thanks.

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So I actually bought both because I wasn’t sure. I tried the 81091 Gabriel shocks as I was trying to save money. Still didn’t like the ride height. Thought it was too low still. Swapped to the 80185 and also swapped in the Bilstein shocks. Big difference but now it rides too high in the back in my opinion. I wish I would have done the 80191 springs with the Bilstein shocks. Hope that helps.

Do you have rear air shocks? (I cant remember which trims/years do or don't) The reason I ask is because a sagging rear end is usually caused by failure of the air shocks...not the springs. New 80191 springs are still going to be soft and wont resolve your sag in that scenario. There are a couple of different ways to resolve this...but if you don't want to increase the ride height at all with the stiffer 80185, then you gotta either pony up and get new air shocks or just install some Firestone Coil Rite airbags (I would still replace the air shocks with standard shocks because they're probably toast anyways)

n8dogg said:

Do you have rear air shocks? (I cant remember which trims/years do or don't) The reason I ask is because a sagging rear end is usually caused by failure of the air shocks...not the springs. New 80191 springs are still going to be soft and wont resolve your sag in that scenario. There are a couple of different ways to resolve this...but if you don't want to increase the ride height at all with the stiffer 80185, then you gotta either pony up and get new air shocks or just install some Firestone Coil Rite airbags (I would still replace the air shocks with standard shocks because they're probably toast anyways)

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Yes I did have air shocks. My understanding is that when you delete the air shocks and replace with standard shocks, you need to beef up the springs as the factory springs were not meant to support the rear of the truck without assistance from the air shocks. The 80185 springs significantly increased the rear height and it looks a little funny now raised up in the rear.

slypher25aussie said:

Yes I did have air shocks. My understanding is that when you delete the air shocks and replace with standard shocks, you need to beef up the springs as the factory springs were not meant to support the rear of the truck without assistance from the air shocks. The 80185 springs significantly increased the rear height and it looks a little funny now raised up in the rear.

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Yup, you are correct...usually you would need the beefier springs and they do increase you height. I have the 4x4 drive and maybe the difference isn't as significant as it might be on a 2x4 rig, but there is an increase in ride height either way. I know it may have been an afterthought to mention it here, especially for you as you've already switched out parts, but to latinlau from Miami and any others who might be concerned about the increased height, I do think that keeping the original springs and just adding the Firestone airbags would probably do the trick. I tow a 28 ft travel trailer and I suspect that the Firestone airbags alone would not be enough, so in my case the stiffer taller springs were a very good match!

Excellent feedback. We have coils and its RWD. Had the front struts/coils installed and just the rear shocks(TRQ Amazon). Ended up with a raised front end. So we decided to go for the rear coils to begin with. I didn't know that there were two Moog models, hence my question. If purchased from Amazon, returning them should not be a problem. Also, we like the height in the front, even though we had to adjust the headlights to the max. Thanks to this chat, we are probably going with the Moog 81085. I did find a lower priced pair from Mevotech, but I'd rather go with a more reliable brand. Have a great one guys!!!