TPMS sensor questions

[GroovyGeek]

Why are there so many takeoffs being sold WITHOUT TMPS sensors? That makes some sense when only rims are being sold, but I am seeing many instances where rims+tires sets are sold without TMPS sensors.

Seems that the sellers are forgetting who the target buyer is - someone who does not want to spend a lot of money or time swapping wheels. If you buy a set of rims+tires as they came from the factory you can swap them in your driveway and be in your way. If you buy a set without TPMS the typical buyer would need to go into a shop, pay for the TPMS sensor, install, and balancing
and generally be in the hole for an extra $200+.

If I were swapping rims and tires and intending to sell the takeoffs I would never take the TMPS off, it should be much easier to sell them they way.

Am I missing something?

Sponsored

 

[OX1]

Any of you have issues getting a dedicated TPMS scan tool to "awake" the latest Ford sensors? I was always able to do this on a new sensor, even in the package. No longer the case, the new one's will not "wake up", until they are under pressure (inside tire).

 

[OX1]

Why are there so many takeoffs being sold WITHOUT TMPS sensors? That makes some sense when only rims are being sold, but I am seeing many instances where rims+tires sets are sold without TMPS sensors.

Seems that the sellers are forgetting who the target buyer is - someone who does not want to spend a lot of money or time swapping wheels. If you buy a set of rims+tires as they came from the factory you can swap them in your driveway and be in your way. If you buy a set without TPMS the typical buyer would need to go into a shop, pay for the TPMS sensor, install, and balancing
and generally be in the hole for an extra $200+.

If I were swapping rims and tires and intending to sell the takeoffs I would never take the TMPS off, it should be much easier to sell them they way.

Am I missing something?

A "good" shop can get sensors out (or swap them) without even removing inner bead. No need to rebalance really (unless you are leaving sensors out, permanently).

Just need a double bead ram/roller setup like this. This wheel is an extreme example, as it is an old school deep dish Bullitt. But can still easily get to sensor, without removing tire or rotating it on the rim (to require re-balancing).

MUCH easier even, on offroad tires with big sidewalls.

 

[greybrutus61]

I bought badlands tires and rims for my big bend . The local shop is charging 130 a wheel to put in sensors and to mount and balance them. they warned me that the computer may get improper messages about speed, braking etc, from what i read here , there should be no issues

 

[OX1]

I bought badlands tires and rims for my big bend . The local shop is charging 130 a wheel to put in sensors and to mount and balance them. they warned me that the computer may get improper messages about speed, braking etc, from what i read here , there should be no issues

For that kind of money, hope you are at least getting Road Force checked (and really, the full RF procedure done, if required).

 

[greybrutus61]

I don't know what you mean by road force procedure. Actually what is RF?

 

[BAUS67]

I don't know what you mean by road force procedure. Actually what is RF?

Road Force balancing has a drum that simulates the tire being in contact with the road hence the term Road Force. You can see it in the pic below.

 

[OX1]

Tire air pressure, belts, and rubber combine to make a continuous spring, all the way around a tire. It's what holds the wheel up, allows the tire to be "flatter" @ the point of road contact, and provides damping going over uneven terrain.

A road force balancer puts 1400 lbs of force into a roller, that simulates the tire being on the road. While the tire is rotating, the roller should remain in the same spot, if the tire's "springyness" is uniform (perfect) around the entire tire. Tires are not perfect, and some can have significant variations around the tire of where the roller will be, due to variations in this "springy-ness". This can lead to vibrations with tires acting like, they are out of round.

This variance is the maximum difference (in lbs-force) between the tire's spring constant, from one location, to another, around the circumference of the tire. A Road Force balancer, only made by Hunter Corp, measures this runout (or how much the roller moves in/out, away from the center of wheel/tire), and then calculates this difference (variance), as "Road Force", displayed in lbf.

You can have a tire that is "perfectly", dynamically, balanced (typically with higher weights though), but still horrible in "Road Force" numbers. Acceptable Road Force numbers vary quite a bit with tire type/size/construction, and drivers sensitivity to vibration. Hunter's "published numbers are 26 lbf for P type tires and 40 lbf for LT type tires.

My limits on a performance type tire are 10-12 lbf (Audi for instance, publishes a first harmonic limit of 18 lbf) https://static.nhtsa.gov/odi/tsbs/2013/MC-10123987-9999.pdf

On say a 35" (or less) in non-LT tire, I like to see 20 or less. On a 32"ish LT tire, say from a 3/4-1 ton, I like to see 25-30. This is not to say you can't get MUCH better. I just put 2 new tires on our 17 Escape, and without even doing the RF procedure (much more involved, and requires removing tire off rim, to do it 100% correctly, even with the new Elite series RF balancer), they both RF'd @ 2 lbf. Almost "perfect".

My new F250 though, vibrated like crazy right off the lot, with two of the tires "Road Forcing" @ 58 and 62 lbf.

Ford said their limit for the rear tires on a new F250 was 45 lbf (which they claimed they got them at or below that), but vibrations were not even close to acceptable for me. I ended up buying two tires on my own dime, as Ford would not do any better than those numbers. My final numbers on the 4 tires for this new truck were 7, 11, 17, and 22 lbf. It is 1000 times smoother then the day I picked it up.

 

[Boomhuck]

Oem Ford sensors can be bought for under $50 for a set of 5 several places on line.

Where online?

 

[B22-2023]

I don't know what you mean by road force procedure. Actually what is RF?

Road Force balance makes such a better ride on my trucks, I didn't know about it until last year and its all I do now except in a pinch on the road.

A shop called Ken's near you does it. Go in and ask them about it, especially for $130/tire if your current place isn't.

Sponsored