Bird
Rest in Peace
Personally, I never did like the twin I-beam Fords used, but I guess they were pretty good or Ford wouldn't have stayed with them so long.
trailer tire pressure
- Thread starter Whatswrong
- Start date
- Views: 8161
clemsonfor
Super Member
I Dont love them, but dont hate them either. I think you get more travel than the 2wd chevy wishbone front end or whatever they call it from similar generations.
But most of them tend to wear the inner front right tire, even when alingned
ModMech
Platinum Member
Any time you ask about tire inflation, a lot of speculation is involved.
To KNOW the best (most correct) inflation pressure for a given application you NEED to KNOW a number of factors:
1) Manufacturer's load-inflation chart for the EXACT tire make/model involved
2) LOAD on the tire, I mean measured by a scale, not a guesstimate
3) Speed you will be operating at
4) Accuracy of the gauge you are using
Obtaining the load chart is damnear impossible, more likely for trailer tires from a known quality supplier than automotive tires tho. You also need to be VERY careful to use the correct chart, the same make and model of tire can have multiple load ratings (D, E, F, G... XL etc) and you MUST use the correct table for the tire rating.
We almost never know the real load on the tire, scales just are not that common for the average trailer user. When in doubt, assume 100% rated load.
Speed, many tire charts actually state that "overinflation" is needed for higher than notmal speeds (70+ MPH), but also you MUST reduce the maximul allowable loads as well. Few people know about this and almost no one does it.
When did you last check your gauge for accuracy? Modern electronic gauges are available for reasonalbe cost that "self calibrate", they still need to be verified periodically. Our "master" gauge that I have had for 20 years recetly began reading 9 PSI high, it shows "0" when vented tho. We need a new gauge ASAP.
OSHA regs say that a tire inflated to less than about 80% of the recomended pressure is "under inflated" and consequently MUST be re-inflated in a safety cage. The BIG problem with that reg is OSHA does not understand tire charts, in a number of cases an inflation pressure of 75% of sidewall is perfectly ok and more than adequate to carry the load at legal speeds. The regs are correct if that would be 80% of the 75% manufacturer's suggested pressure and not the "cold max" as it is often interpreted.
Also, COLD MAX is just that, the MAXIUM pressure the tire is designed for "COLD" - at ambient temperature with no sun or pavement heating. The tire temp before the vehicle is driven any significant distance or speed. It does not mean the maxium pressure the tire was designed to have. At max load, max cold sidewall the tire pressure will read many PSI higher after being operated at speed and that is perfectly normal and OK.
To KNOW the best (most correct) inflation pressure for a given application you NEED to KNOW a number of factors:
1) Manufacturer's load-inflation chart for the EXACT tire make/model involved
2) LOAD on the tire, I mean measured by a scale, not a guesstimate
3) Speed you will be operating at
4) Accuracy of the gauge you are using
Obtaining the load chart is damnear impossible, more likely for trailer tires from a known quality supplier than automotive tires tho. You also need to be VERY careful to use the correct chart, the same make and model of tire can have multiple load ratings (D, E, F, G... XL etc) and you MUST use the correct table for the tire rating.
We almost never know the real load on the tire, scales just are not that common for the average trailer user. When in doubt, assume 100% rated load.
Speed, many tire charts actually state that "overinflation" is needed for higher than notmal speeds (70+ MPH), but also you MUST reduce the maximul allowable loads as well. Few people know about this and almost no one does it.
When did you last check your gauge for accuracy? Modern electronic gauges are available for reasonalbe cost that "self calibrate", they still need to be verified periodically. Our "master" gauge that I have had for 20 years recetly began reading 9 PSI high, it shows "0" when vented tho. We need a new gauge ASAP.
OSHA regs say that a tire inflated to less than about 80% of the recomended pressure is "under inflated" and consequently MUST be re-inflated in a safety cage. The BIG problem with that reg is OSHA does not understand tire charts, in a number of cases an inflation pressure of 75% of sidewall is perfectly ok and more than adequate to carry the load at legal speeds. The regs are correct if that would be 80% of the 75% manufacturer's suggested pressure and not the "cold max" as it is often interpreted.
Also, COLD MAX is just that, the MAXIUM pressure the tire is designed for "COLD" - at ambient temperature with no sun or pavement heating. The tire temp before the vehicle is driven any significant distance or speed. It does not mean the maxium pressure the tire was designed to have. At max load, max cold sidewall the tire pressure will read many PSI higher after being operated at speed and that is perfectly normal and OK.
