Centramatics Follow-up

[SeaLevel]

We've only put about 35 thousand miles on our Airstream since adding the Centramatics. No problems so far, and Jackson Center didn't comment on them last summer when we stopped to have our running gear checked out before heading to Alaska.

[Tireman9]

I covered valve hole issues in my blog but basically the hole in the wheel will be either 0.456 +/- 0.005" or 0.625 +/- 0.0075

[Salvagediver]

Originally Posted by Mollysdad

Yes, I have the 15" Sendel T-2 that came stock on my Airstream and many others. I too got into the weeds on the hole size, but the Dill 902-W dropped right in.
The issue with the rims (my truck rims have the same problem) is the area where the stem installs is a machined cavity, so a standard (416) type valve stem won't work because you can't get a wrench in the cavity to tighten the nut. I tried. Even the washer under the nut was too big to drop in the stem area, forget the wrench. The 902-W has what's known as a "shoulder nut" meaning the part the socket goes on is raised above the rim bottom.
The Dill 902-W's were also available in different heights, so I wanted the one which was shortest, so it didn't scrape a curb; while still being tall enough to allow the TST 507 to screw on. I believe the generic stem is 1 1/4" and that was fine.

Thanks! I was eyeballing and liking that shoulder nut thinking I could get a socket on it, even though I have some specialty thin wall types. Also appreciate knowing the 1-1/4" will work.

One more factoid: the newer Rams are supposed to eventually get a software update that will allow integration of trailer tire monitoring system with the truck's system. I believe you could put three or four trailers into memory. I'll stick with the separate monitor for the trailer since I can't remember how to page through all the readout options on the instrument panel...duh.

[Salvagediver]

Originally Posted by Tireman9

I covered valve hole issues in my blog but basically the hole in the wheel will be either 0.456 +/- 0.005" or 0.625 +/- 0.0075

Thanks. Pretty tight tolerances. I recall reading some pre-CNC Royal Ordnance prints once upon a time that had "FTF" tolerances listed. I had to ask; the answer: "File To Fit."

[GCinSC2]

Originally Posted by Salvagediver

Thanks. Pretty tight tolerances. I recall reading some pre-CNC Royal Ordnance prints once upon a time that had "FTF" tolerances listed. I had to ask; the answer: "File To Fit."

FTF, that made me grin. Sounds like an explanation for what ever is ahead of you.

[jeffmc306]

Originally Posted by Salvagediver

...One more factoid: the newer Rams are supposed to eventually get a software update that will allow integration of trailer tire monitoring system with the truck's system. I believe you could put three or four trailers into memory. I'll stick with the separate monitor for the trailer since I can't remember how to page through all the readout options on the instrument panel...duh.

Salvagediver, I’ve been following a thread on the HD RAM forum about retrofitting the hardware on my 2019 RAM 2500 to enable the TTPMS feature. Here’s a link with all the parts and steps.

After reading that you need to reprogram the BCM yourself (dealer won’t touch it), I decided to go with a TST system. I’d prefer to have it “built in” but it’s just not worth the effort. It’s a shame the option was delayed.

By the way, I did go to Discount Tire yesterday and got the Dill stems installed (thanks to MollysDad for the tip). I was watching the Tire Tech’s reaction when he took one of them apart and nodded his head reacting to the tall nut. He did have to dig to find a socket to fit it.

They did a great job and I was out of there in an hour (two techs worked together on it). I will definitely go back to Discount Tire when the Firestone Transforce AT’s on the RAM wear out - can’t wait to get a set of Michelin Agilis tires.

[Tireman9]

Originally Posted by Salvagediver

Thanks. Pretty tight tolerances. I recall reading some pre-CNC Royal Ordnance prints once upon a time that had "FTF" tolerances listed. I had to ask; the answer: "File To Fit."

Well most of the wheel dimensions have similar tolerances. Wheel mfg has to be accurate as the standards have to ensure proper "fit" when assembling the tire and valves to the wheel with parts made anywhere around the world. There are industry "Go -No go gauges available to wheel companies and most use them as if found out of tolerance it basically results in a recall of all wheels made in that production run if it si something like the wheel diameter where the tire seats. There is no way to check the measurement in the field for 15" or 16" etc as the actual location of that 15" is at the intersection of a vertical and an angle machined surface. That point is actually inside the metal.


Here is what wheel companies machine too.

[Salvagediver]

Originally Posted by Tireman9

That point is actually inside the metal.

Day-um! I didn't realize that there was that much engineering in a wheel! I'll look at them differently now. Lesson learned (again): Don't assume anything; and don't buy crap alloy aftermarket wheels (even though I don't have any interest there).

At first I was a little underwhelmed by the dimensions until I had to pump the brakes after seeing that the dimensions were in millimeters...and then understood your point regarding a buried dimension after converting millimeters to inches. Thanks for this...but you're helping to expose my geekness since I like this sort of schtupff.

[Salvagediver]

Originally Posted by jeffmc306

can’t wait to get a set of Michelin Agilis tires.

Thanks, (I think) for another "time sump" of a forum to study!!! ...and for the tip on the Michelins; I love them on my elderly BMW and Porsche and now have to learn about the Agilis style. So, they are the pick of the Ram forum? (My sharpie paint over on the tire lettering is wearing off anyway.)

[jeffmc306]

You’re welcome! I hear you on the time sump. I only check in there when I need something so it’s not too bad. BTW, there’s a fellow AS poster over there, Gondul.

Guys on the AS forum love the Michelin Defender and the Agilis is the latest gen tire. I checked reviews on TireRack and found the Transforce AT #8 of 8 and the Michelin at the top.

[Tireman9]

Originally Posted by Salvagediver

Day-um! I didn't realize that there was that much engineering in a wheel! I'll look at them differently now. Lesson learned (again): Don't assume anything; and don't buy crap alloy aftermarket wheels (even though I don't have any interest there).

At first I was a little underwhelmed by the dimensions until I had to pump the brakes after seeing that the dimensions were in millimeters...and then understood your point regarding a buried dimension after converting millimeters to inches. Thanks for this...but you're helping to expose my geekness since I like this sort of schtupff.

Ya a lot of folks have no idea of the standards many Engineers live with on a day to day basis. Tires are not just rubber squirted in to a mold and baked most tires have 20+ different components and each component is made up of many different chemicals that have to be mixed and manufactures to precise levels day fater day or the property will change which can mean the performance of the tire may change.


The "fit" of the tire to the wheel is to the 3rd decimal (in inches). To tight and the tire will not mount centered on the wheel so you get bad ride or balance. too lose and their will be an air leak that can lead to tire failure.


In my work I discovered one major car co had a batch of wheels that were so large the tires would break the steel bead (ring of steel that holds the tire on the wheel). They had to do a recall. Another company decided to change the color of the wheels they had in stock so they re-painted the wheels but the extra paint thickness and texture messed up the seating of the tire on the wheels so they leaked air. They had to recall hundreds of new cars from dealership and change out the wheels.

[Salvagediver]

Originally Posted by Tireman9

Ya a lot of folks have no idea of the standards many Engineers live with on a day to day basis.

I hear ya - add OQE and finite analysis... One more thing, going out on a limb here I know, but I'm guessing you would not approve of the "starting fluid method" for mounting tires.

[GCinSC2]

Gimme that can of ether.

Stand back.

I saw a “tire shop” out in the country fix a tire on an old paper route truck. Nothing they had popped it until they ether’d it.

[Action]

Originally Posted by Salvagediver

I hear ya - add OQE and finite analysis... One more thing, going out on a limb here I know, but I'm guessing you would not approve of the "starting fluid method" for mounting tires.

Only if you start you engine with a crank.
Or buy the gasoline for your TV at a pharmacy
Or operate the single windshield wiper by hand

Technology has moved on. Partly for convenience and partly for safety. Please be safe.

>>>>>>Action

[Tireman9]

Originally Posted by GCinSC2

Gimme that can of ether.

Stand back.

I saw a “tire shop” out in the country fix a tire on an old paper route truck. Nothing they had popped it until they ether’d it.

I heard of someone falling out of a plane with no parachute and living too.


https://youtu.be/kHa9DyQ4-3A


https://youtu.be/RRQhCph_wMk

[GCinSC2]

Tireman9,

I was the innocent bystander. Clueless, just watching what happened.

Gary

[Salvagediver]

Received my Centramatics today - thought they would have a larger diameter, but am sure they will fit behind the alloys.

For the record, I mic'd the flange thickness: .0527" for those that besides me were curious. Phew, glad that's settled....want to talk about favorite hitches? Answer: No.

[GCinSC2]

DATA!

Hope all goes well.

[dznf0g]

Originally Posted by Salvagediver

Attachment 370670
Received my Centramatics today - thought they would have a larger diameter, but am sure they will fit behind the alloys.

For the record, I mic'd the flange thickness: .0527" for those that besides me were curious. Phew, glad that's settled....want to talk about favorite hitches? Answer: No.

Yeah, but, but, but the paint doesn't last.long, so subtract a few mil.

[Salvagediver]

Originally Posted by Tireman9

I heard of someone falling out of a plane with no parachute and living too.


https://youtu.be/kHa9DyQ4-3A


https://youtu.be/RRQhCph_wMk

The Laws of Physics will NOT be violated.