Tire Pressures

[IMDSailor]

Why do the inside tires of my drive axel run 5 deg warmer that it's outside mate? All 4 are pump to 88psi cold. When driving the inside pair get to 103 deg and the outsides run at ~98 deg. Oddly enough the temps are all very close, the inners temps are higher than the outer but not dramatically so. I should also mention that the pressure seems to peak at 104psi on the inside pair, the outside pair don't reach that.
I'm running 19.5in Goodyear 670RV made in 2010.
No Tag.
I have a TST 510 system.
Aswell, as others had recommended, in the TST fourm, I've set the High Pressure alarm for the rear axel at 103 deg. So with the heating issue I'm in almost constant alarm. Thank you to the inventer of the mute button, lol.
My initial conclusions are that 1. there is an issue with the rear axel or 2. the pressure alarm is set to low.
I'm thinking 1 but hopeing for 2.

Thanks,
Stewart

[Wanabee FTer]

I suspect it is because the rear inner wheels are closer to the rear brakes then the rear outer wheels. Also more air is available for the rear outer wheels to cool down.

JMO

[Dunner]

I see the same with mine. Lack of air circulation on the inner tires.

[CLIFFTALL]

The alarm could be set for 106. That's 20% above 88. As far as the temps. They are pre set at the factory for 158 so I don 't think you have a problem but it is a good question and I will look forward to you getting an answer. You may have had better luck on the TST thread as Dan would pop in. Send him an email if you need to.

[IMDSailor]

Thanks for the replies guys. If we accept that the pressure difference is due to being closer to the breaks and lack of air flow, therefore cooling, does the difference in pressures create a unsafe condition? or should the outsides be pumped up to meet the inside pressure? or is the ebb and flow of tire pressures factored in to the grand scheme of things?

[CLIFFTALL]

Originally Posted by IMDSailor

Thanks for the replies guys. If we accept that the pressure difference is due to being closer to the breaks and lack of air flow, therefore cooling, does the difference in pressures create a unsafe condition? or should the outsides be pumped up to meet the inside pressure? or is the ebb and flow of tire pressures factored in to the grand scheme of things?

All tires on the same axle should be the same pressure when cold.

[IMDSailor]

Originally Posted by Clifftall

All tires on the same axle should be the same pressure when cold.

Thanks Clifftall, In my own defense I did know and do that. LOL. I will increase the upper limit on my TST. I was concerned that I had reached my upper limit and will now approach the new limit and those limits are set for a reason. I guess the fact that the pressures are the same by pair indicates normal oprations and a balanced rig, which is a good thing.

Thanks again for the responses.

Your humble student,
Stewart

[Dunner]

Just got out my TST bible and for my 507 system, it says:

"We recommend you leave the temperature setting at 157° - Tires typically fail between 180-200°"


"Typically for tire pressure, they should be set 15% above and 10% below what you run in your tires."

(The paper says 157° and the booklet says 158°)

[IMDSailor]

Originally Posted by Dunner

Just got out my TST bible and for my 507 system, it says:

"We recommend you leave the temperature setting at 157° - Tires typically fail between 180-200°"


"Typically for tire pressure, they should be set 15% above and 10% below what you run in your tires."

(The paper says 157° and the booklet says 158°)

Hi Dunner, yeah got that too. But herein lays the rub. At 15% above is 103psi. The inners seems happy at 104psi.

[Dunner]

Stewart, what is the difference between inner and outer pressures?

I've also notice my trailer and outside tires run hotter on the sunny side by 5-10°.

[IMDSailor]

Please Note. In my original Post I was useing degrees, thats should read PSI, not deg. Here is the corrected version.
I can be kinda stunned sometimes, lol.

Why do the inside tires of my drive axel run 5 psi higher that it's outside mate? All 4 are pumped to 88psi cold. When driving the inside pair get to 103 psi and the outsides run at ~98 psi. Oddly enough the temps are all very close, the inners temps are higher than the outer but not dramatically so. I should also mention that the pressure seems to peak at 104psi on the inside pair, the outside pair don't reach that.
I'm running 19.5in Goodyear 670RV made in 2010.
No Tag.
I have a TST 510 system.
Aswell, as others had recommended, in the TST fourm, I've set the High Pressure alarm for the rear axel at 103 deg. So with the heating issue I'm in almost constant alarm. Thank you to the inventer of the mute button, lol.
My initial conclusions are that 1. there is an issue with the rear axel or 2. the pressure alarm is set to low.
I'm thinking 1 but hopeing for 2.

Thanks,
Stewart

Sorry for any confusion while trying to help.

[Dunner]

I don't remember now how much my PSIs differed, but I wanna say they tracked with the ° change.

[CLIFFTALL]

Originally Posted by Dunner

Just got out my TST bible and for my 507 system, it says:

"We recommend you leave the temperature setting at 157° - Tires typically fail between 180-200°"


"Typically for tire pressure, they should be set 15% above and 10% below what you run in your tires."

(The paper says 157° and the booklet says 158°)

Your bible for the 507 is different that the bible for the 510. Watch this you tube. It says 20 %.

http://www.youtube.com/watch?v=f3Qs4...e_gdata_player

[Dunner]

I know tires should be set cold, but wouldn't it be better if they were at the same psi when you're driving down the road? Each would be supporting the same load?