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Posted

Running LT tires at 40 psi can be dangerous because it is too low of a pressure and heat can build up which in turn could cause a blow out. Most of time when going from a P rated tire to a LT tire about 45 psi is what will carry the same load as a P rated tire at 35 psi. Also the max psi of 80 does not mean much for a half ton truck, the only people who would need to come close to that PSI is a 3/4 or ton truck carrying a heavy load and/or towing a heavy load.

Can you point me to this information on tires please

Posted

Can you point me to this information on tires please

Go to Toyo's website and download their Tire Inflation Guide. You basically look up what poundage your OEM tires are supposed to handle at the OEM psi, you then divide that by 1.10. Take that number and then find the size LT tire you are running now and find what psi that the carrying weight corresponds to. It is usually around 45 psi. 40 psi is not dangerously low or anything but anytime you run a tire with too low a pressure then excess heat can build up which can cause the tire to come apart, though rare it can happen.

Posted

Running LT tires at 40 psi can be dangerous because it is too low of a pressure and heat can build up which in turn could cause a blow out. Most of time when going from a P rated tire to a LT tire about 45 psi is what will carry the same load as a P rated tire at 35 psi. Also the max psi of 80 does not mean much for a half ton truck, the only people who would need to come close to that PSI is a 3/4 or ton truck carrying a heavy load and/or towing a heavy load.

Now I'm confused?

E rated tires are for loads usually an 8ply tire.

P rated tires are exactly that passenger vehicle tire.

LT tire is a light truck usually under 3/4 ton and is suited for light loads 1/2 to 3/4 ton trucks.

 

Now the psi rating on a tire is what the tire can max handle, this does not mean you should run your truck at those numbers. Your drivers door jamb has recommended tire pressure listed for front and back tires, as well as cold tire ratings.

Running a LT tire, you should be ok from recommended truck's tire pressure up to 45 psi.

Running an E rated tire can handle much more psi as it is usually a 8 ply tire used manly for loads and towing.

 

The amount of psi pressure you apply to your tires, should always meet the trucks recommended psi from driver's door jamb, and never exceed the max rating from installed tire.

 

My recommendation are 32-38 psi max for p tires. LT tires 35-48 psi max. E rated tires 35-55 depending on load being moved.

 

Thxs

  • Like 1
Posted (edited)

After sending a email voicing my concerns this is what I got back, i highly doubt they are going to do anything for me without costing me a arm and a leg. Lemon law for WI is 4 trips to the dealer and im on 2, I highly doubt they will take it back and look at it again. I sent a video of it happening and apparently my console shaking and the stuff on my seats shaking is with-in spec, granted its not nearly as bad as some of the videos ive seen on here, but still annoying

 

oe9hQII.png

Edited by grizz_wi
Posted

After sending a email voicing my concerns this is what I got back, i highly doubt they are going to do anything for me without costing me a arm and a leg. Lemon law for WI is 4 trips to the dealer and im on 2, I highly doubt they will take it back and look at it again. I sent a video of it happening and apparently my console shaking and the stuff on my seats shaking is with-in spec, granted its not nearly as bad as some of the videos ive seen on here, but still annoying

 

oe9hQII.png

Have an independent tire, and front end repair companies review your shake/vibration and let them attempt a repair, then you send a registered letter of defect to GM from your owners manual that you need your truck repaired. Then seek a lemon lawyer, or attorney. Get a video of your truck shaking!

 

You have this under control, when you are prepared and stay in control!

Posted

Now I'm confused?

E rated tires are for loads usually an 8ply tire.

P rated tires are exactly that passenger vehicle tire.

LT tire is a light truck usually under 3/4 ton and is suited for light loads 1/2 to 3/4 ton trucks.

 

Now the psi rating on a tire is what the tire can max handle, this does not mean you should run your truck at those numbers. Your drivers door jamb has recommended tire pressure listed for front and back tires, as well as cold tire ratings.

Running a LT tire, you should be ok from recommended truck's tire pressure up to 45 psi.

Running an E rated tire can handle much more psi as it is usually a 8 ply tire used manly for loads and towing.

 

The amount of psi pressure you apply to your tires, should always meet the trucks recommended psi from driver's door jamb, and never exceed the max rating from installed tire.

 

My recommendation are 32-38 psi max for p tires. LT tires 35-48 psi max. E rated tires 35-55 depending on load being moved.

 

Thxs

LT is just a light truck designation it doesn't dictate load rating. LT ratings breakdown like so: F rated tires are 12 ply equivalent, E rated tires are 10 ply equivalents, D rated are 8 ply, C are 6. Passenger or P rated tires are 4 ply equivalent. Ply equivalents don't tell you anything about the actual load rating. These are the numbers that follow like 125R or 126Q. The number is it's load rating and the letter is the speed rating you can find the charts on line for each but you would have to contact the manufacture for the correct pressure for your exact tire, the charts on Toyos website are for their tires specifically but pretty close in general probably within 1-3 PSI.

Posted

I have a question and anyone can feel free to chime in on this.

Out of the 727 pages of information generated by pissed off GM customers, how many accumulated problems

With these trucks have we compiled?

1. Vibrations

2. Frame beaming/ cab mount issues

3. Preload incorrect on pinion

4. Tires,rims,tires and tires

5. Front wheel bearings

6. Ring and pinion/ carrier assembly

7. Driveshaft

8. AFM

9. Aftermarket exhaust

10.

  • Like 1
Posted

I have a question and anyone can feel free to chime in on this.

Out of the 727 pages of information generated by pissed off GM customers, how many accumulated problems

With these trucks have we compiled?

1. Vibrations

2. Frame beaming/ cab mount issues

3. Preload incorrect on pinion

4. Tires,rims,tires and tires

5. Front wheel bearings

6. Ring and pinion/ carrier assembly

7. Driveshaft

8. AFM

9. Aftermarket exhaust

10.

My buddy's friend was over, we were shooting the shit about cars and stuff he entions he works for a dealer as a servicemanager.

Well I almost fell over my self, boy did I have questions for him.

I asked him about the vibration issue happening on these trucks, well he told me there's an issue without a doubt.

He says they all have the clunky transmission, and weird shifting issues, but the vibration issue is real.

He says out of every 10 trucks sold, he is dealing with 3 trucks with vibration, shaking issues.

 

Some are worst then others, and he metioned about new bushings coming out, as well as new body mounts too.

He also says the exhaust flapper was an issue for some trucks, but this is only part of the issue.

In most cases, he has asked GM for assistance to get them into a different truck, as he had no solution to correct the vibration issues for most after many attempts.

  • Like 2
Posted

UPDATE: Just got a call back from my CEM (Customer Experience Manager) They swapped out tires and wheels with another truck and the vibration was still present. He said they have direct contact with a "subject matter expert" who had them swap the left front hub, vibration still present. Next it looks like they will run the truck on a lift in 2WD and 4WD to find out where it is. I am just happy that after over 20 days out of service GM is finally accepting that it is NOT a tire issue. The word that the PicoScope gave them today is excessive lateral runout. Which to me would be a tire issue. Not sure what components can be effected by lateral runout aside from Tires and Brakes.

 

Im now in a Yukon rental and guess what.....It Does NOT Vibrate!

Posted

UPDATE: Just got a call back from my CEM (Customer Experience Manager) They swapped out tires and wheels with another truck and the vibration was still present. He said they have direct contact with a "subject matter expert" who had them swap the left front hub, vibration still present. Next it looks like they will run the truck on a lift in 2WD and 4WD to find out where it is. I am just happy that after over 20 days out of service GM is finally accepting that it is NOT a tire issue. The word that the PicoScope gave them today is excessive lateral runout. Which to me would be a tire issue. Not sure what components can be effected by lateral runout aside from Tires and Brakes.

 

Im now in a Yukon rental and guess what.....It Does NOT Vibrate!

Interesting, I believe you may be the first that said the pico scope is saying lateral run out issues. Let us know what they find if anything.

  • Like 2
Posted

My dealer had the truck for another day today, said they were going to do all sorts of tests. Got it back, was told "performing as designed"..the SOBs even scratched my rims again too! I sorta knew that they would say this after "consulting" with GM.

Wrote GM today, guess I will start the bullshit with GM now.

The service writer did not even write the complaint down right.

Posted

My dealer had the truck for another day today, said they were going to do all sorts of tests. Got it back, was told "performing as designed"..the SOBs even scratched my rims again too! I sorta knew that they would say this after "consulting" with GM.

Wrote GM today, guess I will start the bullshit with GM now.

The service writer did not even write the complaint down right.

 

I had to complain to them about documenting the issue correctly all 3 times i went in. Made them rewrite the invoice. They were not very happy with that. After that they threw my aftermarket parts up in my face, told me that i voided my warranty and any repairs that they would do iwould have to pay out of pocket for. Following that conversation i called the 1-800 GM cystomer service number to complain about how i was treated. The following day after they contacted the dealership they returned my call stating word for word what the dealer told me about voiding ny warranty. Complete bullshit and i am done with them, decided to try and figure it out myself.

  • Like 1
Posted

I have 18s. The part that has me confused is it doesn't always do it.

 

I have a 15 Z71 that came stock with 18's and good years, it also vibrated intermittently over about 68 mph. I put 20's on it with BFG All terrain t/a ko2's and it shook the teeth out of my head, but not all the time. Had them damn things balanced 3 times, It got a little better but was still there. It really seemed magnified with the 20's on it. After fighting with the dealer who refused to service the truck because I had aftermarket tires and exhaust on it. I put the 18's back on in no particular order and the vibration was almost nonexistent, until they did the service and rotated the tires. Out of both sets of tires I had each balanced 3 times by either the dealer or the local tire shop. As of right now the vibration is minimal but is still there, talk about wasting 2k on wheels and tires, that you cant use, on an off road edition pick up truck that comes from the factory with radial tires....WTF :wtf:

 

So what happens when you have to get new tires??? Go through the whole horseshit circus again?? :banghead:

Posted (edited)

Just an update

got another opinion or rotate and balance attempt at a independent tire store.

And after 30min. and 50$ my truck rides better than it has in a while.

so it seems you can get different results from different techs and tire machines.

still got the low speed vibes from bumps etc, but anything over 45 is smooth as it was when new.

A sense of relief for sure. I'm feeling so much better about this truck.

o, btw im still riding on the stock SR-A's

Edited by Gofas
Posted

More than a few have noticed reduced vibration for a week or so after being up on a lift to have the tires rotated and or balanced. Hopefully yours stays that way.

  • Like 2

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