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Discussion Starter #1
I installed some of the Vision Warrior wheels on my PM about a year ago. In order to fit them to the PM's axles you need to use 'hub rings', essentially a few millimeter thick shim that adapts these wheels to the PM's axles. Hub rings are, to my understanding, common.

A few weeks ago I was descending the E side of Monarch Pass in Colorado. Often I'll just find the right gear and let the PM idle us down the passes, but on that day, and on that grade, I couldn't find a gear that wouldn't just wind right out. It's a steep road and traffic is hauling. So I ended up using the brakes a lot on the way down.

Toward the bottom, approaching a corner that I needed to be going slower into, I burned down on the brakes to scrub some speed. In so doing the front end of the PM really started to shake and thump and feel, to be blunt, downright terrifying. The symptoms pretty much exactly matched what I know of as 'hot spots', when a rotor is warped and pulses as it passes through the caliper. There were a few more corners left that I had to brake hard for, and on each of these the pulsing/shaking/thumping got progressively worse. If I didn't know better I'd have thought the lug nuts on the wheels were loose. Or gone.

Once things leveled off I pulled over and gave each front wheel a lateral tug, checking to see if something in the suspension was loose or broken. Everything felt solid. After a few minutes, presumably during which things had cooled considerably, we resumed travel. We covered several other passes later that day, and the next, and these symptoms never returned.

When we got back home I stopped by the dealer and had them inspect the brakes, thinking that hot spots are easily remedied. Dealer said the brakes looked pristine, no warping whatsoever. Huh.

So that started me thinking about what the pulsing/shaking/thumping could have been, if not hot spots. And the hub rings are what came to mind, largely because they're made of some sort of nylon.

I went to the tire shop that installed the wheels and tires, and told them what you've just read above. Then asked if it was possible that all of the heat from braking could have softened up the hub rings, maybe distorted them, and allowed the wheels to move elliptically under braking once things were really hot. Both techs I talked to said that yeah, sure that could happen. They put the van on a lift and pulled the wheels off to inspect the hub rings, and they also looked pristine.

So I'm kind of at a loss on how to fix this. I know that it's rare -- Monarch is the only pass in CO that's caused this issue to date. But the pulsing/shaking was so violent that I don't want to send my sweetie out on a trip and wonder if she's going to make it back. I want to solve this, on general principal if for no other reason.

If it's not brakes, and not the hub rings, and the suspension feels tight, what else could it be?

My gut tells me that even though the hub rings look like new, they are the culprit in that they could soften up to cause these symptoms, then firm back up when cool.

Any thoughts/suggestions appreciated.
 

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Discussion Starter #3
Get a new set of hub rings? They are pretty cheap!

That seems closer to kicking the can down the road than solving it though. If it happened once it'll happen again.

I found a place that'll machine a set out of steel, but they want $100. Putting this out there in hopes of getting some confirmation that I'm on the right track before spending the $$$.
 

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The whole point of hub rings is to prevent wheel wobble. They make them in aluminum too.

The heat must have made the rings go soft. Then when cooled, they worked again.
 

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Discussion Starter #5
The whole point of hub rings is to prevent wheel wobble. They make them in aluminum too.

The heat must have made the rings go soft. Then when cooled, they worked again.

The guy at the tire place looked and looked and even made some calls when I was there, and couldn't find the size needed for the PM in anything other than nylon/plastic.
 

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I am guessing the hub rings center the hub for perfect alignment during the lug tightening and once the lugs are tight I doubt the tire could get into an elliptical pattern. If that happened re-centering seems even more doubtful. I have to believe it WAS your brakes. What would do that and return to “normal” is the puzzle. Parable: I own the poster-boy of vehicles for warped rotors, a third generation Toyota 4 runner. It can do a similar thing to what happened to you. Heat them up and it will almost scare the #*&%&^$% out of you but later it is almost imperceptible. After about 4 sets of Toyota Rotors at their $$$ price each (my daughter owned it then) I went into my parts guy and bought the cheapest China iron disks ($16 each!) and they are still on the thing 40K miles later! Lesson? I planned to change them every few months so "don’t spend a lot” was my idea. Why did they last? I don’t have a clue. But it was your brakes.
So try this.
1. $100 is not a lot to have the steel centering rings made and find out if that works. It’s a safety issue and I don’t cheap out on that. Do it.
2. When that doesn’t work change out the rotors AND pads for a good replacement (not the China ones yet!) set from Wagner, Raybestos, or whatever your local parts guys can get. Don’t even think about the OEM as that will teach you nothing.
 

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I have a set from early Sprinter (t1n) to Promaster if you want them you can have them for nothing. When I was looking I thought I found them online in steel or aluminum but I'm not positive. I did find many, many sources however. Some sizes are more popular than others of course. If you want mine I can measure them up for you.

They measure 79mm/83mm (79 is the inside for the Promaster, 83 the outside.
 

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The guy at the tire place looked and looked and even made some calls when I was there, and couldn't find the size needed for the PM in anything other than nylon/plastic.

Have you considered that may be by design, or intentional?

Some car and light truck wheels I've installed were lug centered, and not hub centered like some reference materials suggest. I would "guess" that it's not necessarily a good idea to do both at same time if the alignment wasn't perfect. A soft nylon or plastic ring can give (compress) some, whereas a steel one won't as much. Any misalignment could cause high stresses.

I'd be careful regarding self-manufacture of parts unless I knew I was absolutely correct.



By the way, I doubt nylon rings could move tight lugs enough (or at all) to cause wheel to move relative to hub so as to cause vibration. What you describe sounds more like a brake issue to me that was associated with heat buildup. Just guessing though.
 

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Discussion Starter #9
I have to believe it WAS your brakes. What would do that and return to “normal” is the puzzle.

I agree.

But then I'm not inclined to throw money at something unless I'm reasonably certain that the problem has been identified.

I've had hot spots on many vehicles in the past. Living in the mountains almost makes it a sure thing, eventually. And once you get 'em they don't just go away -- you can feel them anytime you get the brakes warm, much less hot.

I've climbed/descended dozens of big passes since this episode, and have not felt one iota of pulsing on any of them.

As such I have a hard time thinking it was the brakes.
 

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Discussion Starter #10
I have a set from early Sprinter (t1n) to Promaster if you want them you can have them for nothing. When I was looking I thought I found them online in steel or aluminum but I'm not positive. I did find many, many sources however. Some sizes are more popular than others of course. If you want mine I can measure them up for you.

They measure 79mm/83mm (79 is the inside for the Promaster, 83 the outside.

Thanks for the offer. Tire shop has offered to replace the current ones for $10, which is probably about what it'd cost you to ship 'em out here. If I decide to go that route, I'll likely just have them pull a set off the shelf.

But I do appreciate the offer.
 

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I've been re-reading this thread. Is there any possibility that the lug profile on the wheel and the lug profile on the lug aren't the same? I find it hard to believe that the only thing keeping your wheel truly centered is a nylon ring but a little google research shows that this is actually the primary purpose of a hub centric ring. Still, if the lug nut and the wheel don't have the same profile because someone ordered the wrong lugs or wheels, then the wheels aren't getting as tight as they could.They will torque to the right value, but don't really have any holding power under stress as the contact between lug and wheel is a thin line, not the whole surface of the conical seat. I've seen this in the motorcycle world, not sure if it's a thing in the car and truck world.

This place has aluminum rings at $35 for a 4 pack, and custom size ones for $60 if there isn't a stock size that works.
 

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I think you are correct and if the lugs are correct the centering rings are just a precaution. Aluminum is obviously better than nylon as is the correct size center hole to begin with but they don't hold anything on they only help when you're mounting the rims (if everything else is correct).
 

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Have you considered that your anti-locking braking system came into play when you braked hard? This system will chatter like crazy in a emergency braking stop. This is caused by the brakes being pulsated to keep the tires from loosing traction to stop you in a shorter distance than when the tires loose traction with the road surface. Read in your manual about panic stops with the anti-locking brake system. This may explain why after you stopped the problem went away.

MLogan
2017 Trend MH
Smyrna, TN
 

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Brake disks can warp and then go back to normal. I had a 90's Chevy G30 C class that did that many times. I never liked the brakes on that van. Many years ago I had a 78 Mustang whose front rotors would warp and NOT go back to normal. Lots of pulsing thru the pedal. That became an expensive issue and eventually I traded the car in because of it. My 08 Ford E350 van and my Promaster have taken all those same mountain roads over the years with no issues. No drama and no signs of heat warpage. Much better brakes!
 
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Discussion Starter #15
Have you considered that your anti-locking braking system came into play when you braked hard? This system will chatter like crazy in a emergency braking stop. This is caused by the brakes being pulsated to keep the tires from loosing traction to stop you in a shorter distance than when the tires loose traction with the road surface. Read in your manual about panic stops with the anti-locking brake system. This may explain why after you stopped the problem went away.

MLogan
2017 Trend MH
Smyrna, TN


You deserve some sort of award.
 

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Just another thing to check: the symptoms sound similar to loose ball joints. Did the shop check other parts of the front end beyond the brakes and wheels? I have had an issue on my ford van where ball joints were worn and it created pulsing felt through the steering wheel at a specific speed and especially when braking downhill. It was just the right frequency of movement and I suspect pressure on the front end from braking that created the pulsing.
 

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I’m assuming the hub rings are spacers to get the correct offset, so that shouldn’t have any effect. It sounds to me like the brake pad tolerances we’re too tight and they heated up and swelled. I had that happen on a motorcycle at freeway speeds many years ago. It scared the crap out of me as the front end was literally shaking up and down.
 

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Discussion Starter #19
Just another thing to check: the symptoms sound similar to loose ball joints. Did the shop check other parts of the front end beyond the brakes and wheels? I have had an issue on my ford van where ball joints were worn and it created pulsing felt through the steering wheel at a specific speed and especially when braking downhill. It was just the right frequency of movement and I suspect pressure on the front end from braking that created the pulsing.

Ball joints were checked and are 100% fine.

Still no definitive conclusion on what caused this.
 

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FWIW My sprinter has Porsche Cayenne wheels modified to fit the sprinter hubs, When I bought another set to mount snows I "machined" out the center bore with a large hole saw chucked in my holehawg using a centering guide, then turned centering rings out of PVC pipe fittings on the lathe. These wheels also have aluminum offset spacers, Van now has 160,000 miles no issues. A theory about your wobble slash pulse; Stuck, sticky piston in a caliper, the long light application of brakes heating the assemblies perhaps sticking a piston, then hard braking showing up the unequal pressure, once temps and normal braking resumed the piston freed back up and the problem disappeared.
 
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