The Chrysler Minivan Fan Club Forums banner

Winter wheel swap - heat disbursement between front brake caliper and steel wheel

2K views 9 replies 6 participants last post by  Road Ripper 
#1 ·
I am requesting some opinions from folks who may have expertise on wheel compatibility and/or safety experts.

I gave my teen sons my 1999 Chrysler Town & Country. We are in Wisconsin and this will be their first ever season of winter driving. Wanting to give them every possible advantage in snowy conditions, I have been shopping for and bought ($200) a set of four winter tires on rims. They came off of a 2009 Dodge Caliper and are basically new.

60257



The specs are nearly a perfect match. The only differences (as far as I can tell) are in the center bore diameter (4.4 mm difference) and a 6 mm difference in positive offset. Below is a side by side chart I put together with the specs from wheel-size.com.


60256


In order for the winter steel wheels to fit over the "hub lip" and sit flush on the front, I will need to increase the center bore from 67.1 mm to 71.5 mm (there is no "lip" on the rear brake drums so the wheels should sit flush and not need any modification). This coming weekend, I will pull out my die grinder shave 2.2 mm off of the center bore of the fronts. I do not believe that doing so will have any meaningful effect on structural integrity or wheel balance.

My question however, is regarding the offset. The factory chrome wheels have a 40 mm positive offset. The steel replacements have a 46 mm positive offset. If my understanding of offsets is correct, this means the wheels and tires will be situated 6 mm "in" toward the vehicle. This small difference is negligible and should have little, if any, impact on the bearings or vehicle performance. It WILL however, decrease the gap between the wheel and the brake calipers. By my measurement (I could not find a factory measurement) the current spacing between the outside of the front brake calipers and the inside of the factory chrome rims is 11 mm. The same gap with the steel wheels installed will be 5 mm. The steel rims shouldn't flex under stress or anything (at least not 5 mm), but my concern is heat dissipation.

Any thoughts? The point is probably moot because my sons will not be making trips long enough to heat the calipers up that much. And the sub freezing winter temps here should further moderate any heat concerns. But if/when we do get those couple of unseasonably warm weeks, might this be a problem?

Please feel free to tell me I am overthinking this and the wheel transfer should be fine. Or more importantly, if I am overlooking something that could potentially be a problem.

Thanks in advance.
 
See less See more
2
#2 ·
The rear drums have a 71.6mm hub too. Personally, I would get wheels with the correct hub bore. The hub is designed to support the weight of the vehicle, while the stud and lug nuts are only supposed to keep the wheel torqued down onto the hub. The hub bears radial loads, while the wheel studs deal with axial forces.

The offset isn't very important in consideration for brake clearance. I have +25mm offset and my wheels would strike the caliper if I didn't use 1/4" wheel spacers. It is the shape of the face of the wheel that will impact the caliper, those appear to arch outwards away from the hub which should be good.

There might be a hub adapter somewhere for purchase in the internet.
 
#3 · (Edited)
NO! STOP! DO NOT GRIND OUT THE CENTER BORE!
The center bore is what holds the weight of the car. Since your concern is safety for your kids, don't do something that could cause them to have a wheel snap off. Get the tires remounted on proper fitting wheels.
 
#4 ·
^^ yes, 2.2mm (while is not much) is probably close to the thickness of the steel wheel plate - if you eliminate most if not all of the "lip" that fits on the hub, the wheel will loose considerable rigidity in the bolt circle. The plate face can flex more without the structural bend...

Is this going to cause an imminent failure? probably not but from stand point of safety it's not good.

Also, if you plan on grinding the wheel bore, do all 4 (after test fitting the first one)- you don't want to be driving in snow with mismatched front spare...

BTW, heat transfer only occurs between rotor/drum and wheel, brake caliper / bracket do not make contact with the wheel.

IIRC, positive offset is to the outside of wheel center (vs negative - inside) so +6mm offset will put the rubber 1/4" wider spaced and will gain 1/2" track (which doesn't benefit bearings but adds stability) and as you say is probably negligible.
 
#5 ·
Negative offset moves the wheel out, positive offset moves it inwards. Zero offset would be the hub/lug mating surface centered in the wheel.
60259
 
#6 ·
The only way those wheels would work is if you used 1/4" thick spacers on each wheel, to get the center hole of the rim out past the hub "snout". Although that will make only the wheel studs/nuts support the weight of the van, I ran mine this way in front without anything failing. I had to do it because I put 4th gen van front suspension/brakes on my 3rd gen, and the 3rd gen wheel spokes would hit the calipers with brand new brake pads.

My winter setup on my 3rd gen was steel 16" wheels from a 2004 Ford Crown Victoria/Mercury Grand Marquis. I had to grind out the hub centerbore a mm using a grinding stone bit on a router, using an old hub to test fit now and then to keep the fit snug. The wheels stuck outwards a little farther than the stock wheels, but put the edge of the tire even with the outside of the fenders. I bought the wheels with Bridgestone Blizzaks already on them, used off of craigslist. The Blizzak WS-60's were awesome in everything. We tried Firestone Winterforce on our RWD Magnum and they sucked! Car would barely move on ice or hard-packed snow. Replaced those with Blizzak DMV3 and was quite happier. Big difference. I would only use Winterforce on an AWD vehicle, and be careful with them because they still aren't good on hard snow/ice.

You can go down to 15" wheels and not worry about brake clearance, if that helps your choices. I run 15's on my 4th gen van (Ford Explorer wheels with the hub bore ground out to fit). I test fitted wheels in a junkyard to find what worked before buying.
 
#7 ·
There are adapters that will allow you to change from one center bore size to another. They are pretty thick and have enough of a center bore perch to take the weight off the lugs and put it on the hub where it should go. But since the OP was talking about grinding on wheels to get them to fit, I'm assuming he doesn't have another $50-$100 per wheel handy or would like to avoid dumping a lot into the old van. Remounting them on the stock wheels will be much cheaper, and safer because you will retain all stock wheel dimensions.

Wish I had a pic of the old Civic when it's wheel snapped off because of a ~1mm center bore gap. If that happens with a barely 1,000 lbs car, what do you think a 2 ton van will do to some grinding imperfections?
 
#8 ·
There are lots of rims being tossed out by the repair shops as tires are removed from them (purchased through kijiji or whatever) to put over properly fitting rims. Maybe check with a couple of repair shops to see what they are throwing out.
Too small a hole is a problem, spacers being available when too large.
 
  • Like
Reactions: Road Ripper
#9 ·
Thank you all first for your responses. More importantly, thank you for genuine focus on the safety and wellness of my sons.

When I put my calipers on the hub "snout" it measured out 69.8 mm, so the actual amount of steel I would be taking out was barely over 1 mm from the circumference - so little that almost 1/2 of the center flange would remain on the steel wheels. I just didn't think it would affect the structural integrity enough to be a safety issue.

Here is the kicker: Last year, we found an identical 1999 T&C Limited (with bad transmission) - same color, same interior, same everything. We stripped it of all usable parts (including body panels) and are storing them up in the garage rafters. After stripping the parts van, we sold the catalytic converter, scrapped the rest and still made money (maybe $50) on the deal. But it was a great father/son(s) project. Soooo, I actually do have a spare set of stock 15 spoke chrome rims I can swap these winter tires on to. I really didn't want to use them for the swap because they have decent (2/3 tread) Michelin's mounted. I was just thinking that in the long run, the "summer" tires will be more apt to wear out than the winter tires. Plus, I drive a 2001 and much prefer the 15 spoke wheels "look" to my factory wheels - so in the back of my mind, I was kind of coveting the 15 spoke chromes for myself at some point. :)


60272



Your experiences notwithstanding, I am still not convinced that my original plan to grind 1.5'ish mm out of the center bore on the steel wheels would have resulted in a significant safety issue. And if it were my van, I would have taken the chance in a heartbeat. But given that the sole focus of my life (my sons) will be driving it, I will not take the chance. I don't know if I was being cheap so much as practical. It will only cost $100-120 to swap the winter tires onto the old rims.....and that is what I will do.

Again, thank you all for taking the time to respond and setting me straight.

Happy Holidays to all.
 
#10 ·
I wouldn't swap the tires over to the chrome Limited rims. I have a set of those too, and I had to fix the beads because of corrosion from them being used in the winter. The tires wouldn't hold air. Once the beads were cleaned up, there were voids where the corrosion ate away the aluminum/chrome. I had to fill all of those in with JB Weld, file/sand smooth and painted the beads (one one rim the entire center section/interior) with POR-15 (epoxy paint). Then a coat or two of spray paint over that to finish. After it all dried, I had good tires mounted and balanced with sticky weights (clip-on weights will eat the beads again) and they haven't leaked at all since. That was 8 years ago. I only use those wheels in the summer, clean and polish the chrome over the winter, and wax them before the next use.

I put those wheels on my 2004 Limited for a while. The front calipers do hit the spokes, so you have to use 3/8" spacers. I think I finally bought some 5mm spacers for a Dodge Challenger on ebay, and those fit pretty well. You might have to use longer wheel studs in front, as I replaced my front hubs and was able to fit Ford Taurus studs into the hubs.

I like steel rims for winter tires. They won't corrode as much as aluminum and cause tire leaks, the steel clips from wheel weights won't make extra corrosion from different metals, and if you hit a curb the rim will bend instead of breaking a chunk out or cracking and stranding you with a flat tire. They're cheap and easy to maintain, and easy to make look decent with hubcaps. I first went looking at the U-Pull junkyards and bought up enough full-size steel spare tires to use for snow tires, then I found the set already mounted on those Crown Victoria wheels that were easy to make fit.
 
  • Like
Reactions: Special Edy
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top