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[GMCnet] Wheel and tire recommendations [message #301238] Sat, 28 May 2016 22:34 Go to next message
rod utterback is currently offline  rod utterback   United States
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Registered: April 2016
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Junior Member

Hello All,

I am wrapping up my initial coach repairs (purchased 3/17) which included but certainly not limited to bearings, brakes and shocks. Now I am ready to tackle wheels and tires. I was shocked to read the warning sticker inside the glovebox warning not to use radial tires since I see 6 all-steel radials (on 16.5 rims not stamped radial).

A parallel effort is upgrading the a/c dash system to R134a.

What does experience say is the most cost effective choices regarding both?

My ultimate goal is a roadworthy vehicle by June 15. I have inspected and/or repaired all subsystems in the “house” along with engine cooling and charging systems refurb. Fuel system (tanks, hoses, pump, switching, etc) repair will begin after a/c and tires. I do all the work myself so I’m learning first hand about the entire vehicle. While not hoping for a roadside breakdown, I think this knowledge will be invaluable if my luck goes in that direction.

Tired but happy (73 days and counting) + ($3k purchase + $3k in parts)

Rod

1973 26 ft. Canyonlands 86k miles
455 ci carb
San Diego

Sent from Mail for Windows 10

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Re: [GMCnet] Wheel and tire recommendations [message #301240 is a reply to message #301238] Sat, 28 May 2016 23:24 Go to previous messageGo to next message
roy1 is currently offline  roy1   United States
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Look close at the rims it is possible they are later rims that someone swapped out. If so there will be an R stamped in the part number. Non radial rims with radial tires can have a tendency to crack. It would be easier to charge the a/c with duracool rather then flush the system.

Roy Keen Minden,NV 76 X Glenbrook
Re: [GMCnet] Wheel and tire recommendations [message #301241 is a reply to message #301238] Sat, 28 May 2016 23:25 Go to previous messageGo to next message
Adrien G. is currently offline  Adrien G.   United States
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Location: Burns Flat, OK 73624
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Rod,

There's been a lot of write up on tires and rims.
Steel rims 16" if the centers are shaped just like the 16.5" rims are, with a 4.567" ( 4-9/16") center.
Alum rims, check with Jim K. at Applied GMC. a few choices there.

Tires, your choice of load range "E". Do a forum search.

On the AC, if it still has a partial charge, I would add Duracool 12a. R134a requires a flush and oil type change
save the hassle, unless it need to be opened up.

FWIW.



Adrien & Jenny Genesoto 75 Glenbrook (26-3) Mods LS3.70 FD / Reaction Sys / 80mm Front&Intermidiate / Hydroboost / 16" Tires / Frame Rebuild / Interior Rebuild Yuba City,Ca. Text 530-nine-3-three-3-nine-nine-6
Re: [GMCnet] Wheel and tire recommendations [message #301242 is a reply to message #301241] Sat, 28 May 2016 23:40 Go to previous messageGo to next message
A Hamilto is currently offline  A Hamilto   United States
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Adrien G. wrote on Sat, 28 May 2016 23:25
...Steel rims 16" if the centers are shaped just like the 16.5" rims are, with a 4.567" ( 4-9/16") center. ...
To expand on that a little, the "truncated cone" shaped rims won't clear the front calipers. They need to be "bowl" shaped: http://www.gmcmhphotos.com/photos/gmcpicx/p38755-after.html
Re: [GMCnet] Wheel and tire recommendations [message #301243 is a reply to message #301242] Sun, 29 May 2016 06:51 Go to previous messageGo to next message
tphipps is currently offline  tphipps   United States
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Location: Spanish Fort, AL
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The 'bowl' shaped rims will work for all wheel positions. They must be on the front for brake caliper clearance. The 'cone' shaped rim will work on the back four, the brake drums will fit.
If you up-grade to 80mm calipers on the front, no steel 16" rim will properly clear the caliper. You will need either American Eagles or Alcoas.
Disclaimer: I did a test fit of these possible combinations when I up-graded to 80mm. You could make OEM 16" steel rims fit, if you added the available spacers. But, this does add additional expense and work to the swap.
Evacuate the A/C system and add Duracool or similar product. You will have better results.
Enjoy your ride.
Tom, MS II


2012 Phoenix Cruiser model 2552 KA4CSG
Re: [GMCnet] Wheel and tire recommendations [message #301249 is a reply to message #301238] Sun, 29 May 2016 14:17 Go to previous messageGo to next message
JohnL455 is currently offline  JohnL455   United States
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Switching an R12 system to 134a is a Downgrade not an upgrade. It was designed for R12 not 134a. If it is still holding R12 after XX years ( compute lbs/year loss rate) and if it only needs to be topped I would top with R 12.

John Lebetski
Woodstock, IL
77 Eleganza II
Re: [GMCnet] Wheel and tire recommendations [message #301265 is a reply to message #301238] Sun, 29 May 2016 23:11 Go to previous messageGo to next message
Scott Nutter is currently offline  Scott Nutter   United States
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Hey Rod.
Where in San Diego are you?
I'll be in Solana Beach till June 6th. Let me know if I can help.
Scott. Cell 858 212 8760


Scott Nutter 1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final drive, Quad bags, Dave Lenzi super duty mid axle disc brakes, tankless water heater, everything Lenzi. Alex Ferrera installed MSD Atomic EFI Houston, Texas
Re: [GMCnet] Wheel and tire recommendations [message #301310 is a reply to message #301249] Tue, 31 May 2016 09:17 Go to previous messageGo to next message
TR 1 is currently offline  TR 1   United States
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JohnL455 wrote on Sun, 29 May 2016 14:17
Switching an R12 system to 134a is a Downgrade not an upgrade. It was designed for R12 not 134a. If it is still holding R12 after XX years ( compute lbs/year loss rate) and if it only needs to be topped I would top with R 12.


+1... Would not put 134a in an R12 system under any circumstance. Your system will not cool as well, and unless you do a proper conversion, (which is difficult, expensive and time-consuming) the life of your AC components will be reduced.

People make out like R12 is impossible to get, but most areas have cans available on craigslist for around 25 bucks a can, or you can buy it on Ebay. If you are concerned with using R12 because of the regulatory aspect, you can get a 609 certification online for I think 20 bucks. It's an online test.. Takes all of 10 minutes. Test basically says "Do everything you can to prevent release of R12 into the atmosphere". If you can understand that concept, you'll pass.

I have not had experience with any of the R12 substitutes (Duracool, Freeze12, propane as a refrigerant, etc...) as I have always just used R12 in older cars that call for it. However, as long as the R12 substitute does not contain 134a, (Some of them actually do) I would consider that over converting to 134a.


Mark S. '73 Painted Desert, Manny 1 Ton Front End, Howell Injection, Leigh Harrison 4bag and Rear Brakes, Fort Worth, TX

[Updated on: Tue, 31 May 2016 09:28]

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Re: [GMCnet] Wheel and tire recommendations [message #301312 is a reply to message #301238] Tue, 31 May 2016 09:27 Go to previous message
TR 1 is currently offline  TR 1   United States
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Registered: August 2015
Location: DFW
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Actually, R12 may be a little more right now ($30-35 a can) because it's spring.... R12 prices seem to spike during spring/summer. My point being buy what you need now, and then if you want to stock up on a few cans, wait till fall/winter.

Mark S. '73 Painted Desert, Manny 1 Ton Front End, Howell Injection, Leigh Harrison 4bag and Rear Brakes, Fort Worth, TX
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