1970 Cadillac Ambulance wheels/rims

John Zicha

PCS Member / EMT / PARAMEDIC
We are in search of front and rear rim/wheels for our 1970 Caddy. The ones on it now were put on just to move it around.
 
Your looking for the heavy duty gm wheels they were used on taxi cabs ,police package cars and the commerical chassis. I do have a pair of the disk wheels here I would trade for the older 60 set of drum brake wheels.
 
I have a set of 4 or if needed 5. But I am on the left coast and these are pretty heavy , with shipping might not be worth it?
 
Caddy 1970 Bible says they are 15" Kelsey Hayes wheels
https://www.gmheritagecenter.com/do...formation-kits/Cadillac/1970_Cadillac_VVI.pdf

I got a Federal Reserve Dollar that says the same wheels went on every GM pickup & van leaving the factory in 1970 unless Commercial tires were ordered on the vehicle, and another Federal Reserve Dollar says that wheel is still available as a new part from multiple wheel dealers such as Frey The Wheel Man for reasonable money.
 
Wheels

A regular caddy rim is a available but I have never seen commercial chassis / limo rims being made. Up to at least 76 the CC rims are a heavier cross section and the spokes are riveted verse a regular wheel that is a bit lighter and has welded spokes. They interchange with no problem but they are diffrent rims.
 
........ and I would want to know that the Cadillac wheel covers will stay on them. I would definitely stick with OE in this case. They are available.
 
Page 7 or 8 of the PDF I put up clearly shows ALL Caddy including 9 passenger limo leaving the factory on the same Kelsey Hayes wheel. Only difference is the 9 passenger left on a larger tire.

I seriously doubt any coach manufacturer had a rim plant.

I'll also go as far as saying possibly a Coach builder MIGHT have put a COMMERCIAL 15" tire on a COMMERCIAL 15" rim as a price adder. If they did they put that tire on a Kelsey Hayes rim.

Commercial rims have a thicker dish and 3 or 4 rivets securing each spoke to the wheel. Wheels were shrunk onto the dish when they were made, trued and then riveted.

A standard 15" tire such as LR78-15 of that time frame will not mount on a COMMERCIAL 15" rim, and a COMMERCIAL 15" tire will not mount on a 15" passenger rim.

This is not to be confused with Chrysler product. Chrysler offered an optional Police/Taxi Service wheel & tire package. Chrysler factory wheels had a lighter dish. I don't recall if Chrysler P/T rims were riveted or welded, but I know where to find 6 of them if I need to check. Chrysler also offered a P/T service rear end and suspension option in that time.
 
All Series 75s, and anything built on Cadillac's commercial chassis, shared the same heavier, riveted commercial chassis rims. Cadillac supplied these wheels to the coach builders from 1956 through the end of the commercial chassis in 1984 as part of their commercial chassis package with several modifications to the wheel during those years which corresponded to their modifications to the standard Cadillac wheel. Every other Cadillac model used the lighter, welded, wheel. This has been well documented.

I will take you up on your bet regarding them being the same as used on all pickups and vans Walter!!
 
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Page 7 or 8 of the PDF I put up clearly shows ALL Caddy including 9 passenger limo leaving the factory on the same Kelsey Hayes wheel. Only difference is the 9 passenger left on a larger tire.

I seriously doubt any coach manufacturer had a rim plant.

I'll also go as far as saying possibly a Coach builder MIGHT have put a COMMERCIAL 15" tire on a COMMERCIAL 15" rim as a price adder. If they did they put that tire on a Kelsey Hayes rim.

Commercial rims have a thicker dish and 3 or 4 rivets securing each spoke to the wheel. Wheels were shrunk onto the dish when they were made, trued and then riveted.

A standard 15" tire such as LR78-15 of that time frame will not mount on a COMMERCIAL 15" rim, and a COMMERCIAL 15" tire will not mount on a 15" passenger rim.

This is not to be confused with Chrysler product. Chrysler offered an optional Police/Taxi Service wheel & tire package. Chrysler factory wheels had a lighter dish. I don't recall if Chrysler P/T rims were riveted or welded, but I know where to find 6 of them if I need to check. Chrysler also offered a P/T service rear end and suspension option in that time.

you might want to rethink some of this.I do know a 890 x 15 tire will go on any 15 in wheel, ford, dodge or GM. the heaviest duty rim GM put out was the 3 rivet one. for passenger cars. it may have had the same rating as the 1/2 tone pickup. that I do not know. but I do know that i have l78 x15 bias ply tires mounted on the commercial wheels on my 72 combo.

there has always be some concern about radial tires on standard wheels. but it's all talk. not proven to be true.
 
Page 7 or 8 of the PDF I put up clearly shows ALL Caddy including 9 passenger limo leaving the factory on the same Kelsey Hayes wheel. Only difference is the 9 passenger left on a larger tire.

I seriously doubt any coach manufacturer had a rim plant.

I'll also go as far as saying possibly a Coach builder MIGHT have put a COMMERCIAL 15" tire on a COMMERCIAL 15" rim as a price adder. If they did they put that tire on a Kelsey Hayes rim.

Commercial rims have a thicker dish and 3 or 4 rivets securing each spoke to the wheel. Wheels were shrunk onto the dish when they were made, trued and then riveted.

A standard 15" tire such as LR78-15 of that time frame will not mount on a COMMERCIAL 15" rim, and a COMMERCIAL 15" tire will not mount on a 15" passenger rim.

This is not to be confused with Chrysler product. Chrysler offered an optional Police/Taxi Service wheel & tire package. Chrysler factory wheels had a lighter dish. I don't recall if Chrysler P/T rims were riveted or welded, but I know where to find 6 of them if I need to check. Chrysler also offered a P/T service rear end and suspension option in that time.


The statement that I have highlighted above, is absolutely incorrect. Any 15" tire will mount on any 15" rim, provided that the width of the tire is within the tire manufacturers recommendation concerning the width of the rim. The only "commercial 15" tire" that I have any knowledge of was a tire that was supplied to the Cadillac Division for specific use on ambulance chassis. That tire was labeled on the side wall of the tire, "AMBULANCE SERVICE". When you went to your local tire dealer to purchase replacement tires for an ambulance, they would order in 6 or 8 ply tires, and they only came as a white wall, and they didn't have any special markings on them, other that the tire size and the ply rating. To add to this, the only black wall heavy duty (6 or 8 ply) tires, were those that came on Cadillac commercial chassis that was delivered to the body builder. If you insisted on a black wall tire, then they would mount the white wall side on the inside of the rim. Today, the only tires that you can purchase for a commercial chassis, is by finding the weight rating of the tire at a specific psi (pounds per square inch of air pressure).
 
Paul, we gonna have us a fist fight on this.
In 1964 I had a half ton Cheby pickup on standard wheels and tires that could devour a set of rear tires in 4000 miles due to the Positraction rear end. I was NOT a happy camper with this situation.

Walt at Scanlon Tire explained very meticulously that the wonderful folks at GM were putting car wheels and tires on the pickups. He sat one of my tires next to a 15" COMMERCIAL 670-15 and showed me the differences, including weight of the tire.

Fine, put the COMMERCIALS on the truck, and I'll swallow hard at the counter when I pay. WRONG says Walt, COMMERCIAL tire will not mount on a passenger car rim. Being a smart young punk, I look at the numbers on both casings and mention they both say 15. Walt handed me a ruler. COMMERCIAL 15" tires have about ½ inch more hole in the middle. They also will not seal on a standard 15" passenger car wheel. A 15" COMMERCIAL tire will not seal on a car wheel either.

The 2 rims I bought for the rear end of that truck set me back $45, 1965 dollars. I also got a hell of a lot more service miles out of the COMMERCIAL casings and had them retreaded twice. It was a damn expensive lesson in 65, and I still remember it.

I learned a lot more lessons from Walt as time went on, some expensive and some free of charge. What back I have left is in some part due to Walt teaching me how to pick a wheel & tire up rather than doing it my way.

When tire measurements switched to letters & numbers from numbers only the wheel diameter number is the same diameter as a passenger car wheel.

I will continue to stay with the position GM half ton pickups and vans left the factory with passenger car sized tires for a long time into the 70s. 3/4 ton and up were floating axles and either 6 0r 8 bolt rims depending on the axle.
3/4 & 1 ton wheels are also hub weight bearing, not wheel bolt weight bearing.

GM, Ford & Dodge bolt holes will line up on 3/4 ton and 1 ton but the center holes are different diameters.
 
Wheels

Walt at Scanlon Tire explained very meticulously that the wonderful folks at GM were putting car wheels and tires on the pickups. He sat one of my tires next to a 15" COMMERCIAL 670-15 and showed me the differences, including weight of the tire.

64 Chevy and GMC 1/2 ton trucks all used 6 lug wheels. 3/4 ton and up is a 8 hole. All american cars of that era are 5 lug..
 
I'm wondering what you are calling commerical tires or wheels. Or what the mechanic was. Don't doubt what you were told. I have heard a lot of things myself that I beleved to be true till it was pointed out to me I was in correct. I have never seen a 15.5 tire 16.5 and 17.5 yes. They would be truck tires and could be labeled commerical. But for the automobile industry GM in particular on there commerical chassis they sold the standard tire was a a 890 x15 8ply tire. Mounted On there heavy duty rim which is easily ID. Buy the 3 rivet pattern holding the wheel to the rim. Trucks have nothing to do with this chassis as they have a different wheel.
 
Please note my comments in red below

Paul, we gonna have us a fist fight on this.

I see no reason to resort to violent behavior just because I don't agree with you. Possibly that is how you reconcile your differences with others, but it isn't the way that I deal with people. I deal with reasonable people reasonably, and unreasonable people, not at all. Thank you for advising me that you choose to be unreasonable.

In 1964 I had a half ton Cheby pickup on standard wheels and tires that could devour a set of rear tires in 4000 miles due to the Positraction rear end. I was NOT a happy camper with this situation.

Sorry, I don't recognize the brand "Cheby", however, I do recognize the brand Chevy. If your car 1/2 ton pickup could devour a set of tires in 4000 miles, and you recognize the problem as being the Positraction rear axle gear set, then why didn't you have the differential serviced by the selling dealership? The truck came with a warranty, with a minimum of 12,000 mile and 12 month, or a 24,000 mile and 24 month warrantee, depending on the exact date of manufacture.
One also has to consider the type of tire that was delivered with the truck. In 1964, tires were not known to get high mileage use, and it was common to replace OEM (original equipment manufacture) tires after 12,000 miles. If the truck was being driven by a 19 year old that had to be the first one away from the traffic light, and the first one to the next traffic light, it is very conceivable that the tires would be worn out in 4,000 miles. Tire longevity is all about how the vehicle is driven, both then and now. Another thing that will also effect the tire wear, because of how it is driven, is the differential ratio. Positraction was usually mated to 3.89 gear sets, which made for a very quick "off the line" performance. You didn't mention the engine that your truck had, however, it would have been extremely rare to have a Positraction differential mated up with a 6 cylinder engine.

Walt at Scanlon Tire explained very meticulously that the wonderful folks at GM were putting car wheels and tires on the pickups. He sat one of my tires next to a 15" COMMERCIAL 670-15 and showed me the differences, including weight of the tire.

The original standard tire on a C 15 model 1/2 ton pick up, was a 6.70 x 15 4 ply tire, and the optional tire was a 7.10 x 15 4 ply tire. The next size up from that, is a 7 x 17.5 commercial wheel and tire, that wouldn't fit the wheel studs on a 1/2 ton pick up, since it was for a much higher GVW (gross vehicle weight) truck.
There is a considerable difference in weight between a 4 ply tire, and a 6 ply tire, and even more, if it is a 8 ply tire. As you add ply's to a tire, the circumference of the tire will change to accommodate the additional ply's.

Fine, put the COMMERCIALS on the truck, and I'll swallow hard at the counter when I pay. WRONG says Walt, COMMERCIAL tire will not mount on a passenger car rim. Being a smart young punk, I look at the numbers on both casings and mention they both say 15. Walt handed me a ruler. COMMERCIAL 15" tires have about ½ inch more hole in the middle. They also will not seal on a standard 15" passenger car wheel. A 15" COMMERCIAL tire will not seal on a car wheel either.

Is it possible that in the intervening 42 years, that your memory has faded, and that what you actually were measuring was the 17.5 tire that came on the greater GVW trucks?

The 2 rims I bought for the rear end of that truck set me back $45, 1965 dollars. I also got a hell of a lot more service miles out of the COMMERCIAL casings and had them retreaded twice. It was a damn expensive lesson in 65, and I still remember it.

It is my speculation that the reason that you purchased new rims, was because what Walt sold you were a larger width tire that required a wider width rim, such as a 8.50 x 15 tire.

I learned a lot more lessons from Walt as time went on, some expensive and some free of charge. What back I have left is in some part due to Walt teaching me how to pick a wheel & tire up rather than doing it my way.

When tire measurements switched to letters & numbers from numbers only the wheel diameter number is the same diameter as a passenger car wheel.

I will continue to stay with the position GM half ton pickups and vans left the factory with passenger car sized tires for a long time into the 70s. 3/4 ton and up were floating axles and either 6 0r 8 bolt rims depending on the axle.
3/4 & 1 ton wheels are also hub weight bearing, not wheel bolt weight bearing.

GM, Ford & Dodge bolt holes will line up on 3/4 ton and 1 ton but the center holes are different diameters.
 
Please note my comments in red below

Well geez, it;s sort of hard not to recognize RED.
Shoulda known Connecticut people got no sense of humor.

1964 Cheby bought from Frear Chevrolet, 1110 Stone Rd, Greece, NY- $1680- out the door including 4 ugly as sin mandated reflectors, 3" weight numbers & Sales Tax in November 63.
230ci 6 cylinder 3 on the tree 8 foot box, shade 510 green, gas tank in the cab behind the seat.

Only thing Frear ever covered under warranty was the leaking gas tank sender gasket that caused the cab to stink of gas which was costing me 23¢ a gallon, and dissolving the padding under the floor mat as it ran out the passenger door while the truck was parked. The truck was paid for leaving Frear's driveway, so they didn't see any need to do warranty work. The 24 year old driving it didn't give a rusty rat's azz about light to light street racing, but he did have a passion for moving along on open roads. He got to do all the light to light racing he wanted in a green Caddy, and got paid to do it.

The posi rear in a pickup in that time frame without a load on the truck would cause the rear tires to "chirp" when cornering. The dealer swore that was normal due to the posi locking and unlocking as the truck cornered. The second cute trick the Posi had was swinging the back end of the truck right 90° when taking off on ice.

You're right, factory tires were pure crap, might have been Rayon but I don't recall. Faded memory, well that covers a few young ladies, but not trucks. The second thing that was crap in 64 Chevy pickups was 3 on the tree shifters. You parked them in the gear you intended to leave in in Winter around here because they sure weren't shifting for the first half mile to a mile on a cold day if the truck had cooled off. I well remember being the fool under that truck in a 10° barn filing notches in the shifting shafts to get the bolts into the Hurst shifter arms. BTW, the little darlin who gave me a ride to work the next morning because the Hurst wasn't completed was named Kathy.

By January of 65 the truck also had a tarp over the box held down by LiftA dot fasteners that was replaced by a CabHiCap in Sep 65 that cost more to freight from Ohio than the cap cost. The truck also had a saddle tank tucked into the fender ahead of the L rear wheel that carried about 18 gallons of additional gas, and a single Hadley air horn. Girl in the passenger seat was named Joanne. She and the truck were both replaced in 66.

Best thing about 64 Chevy cabs was the designers moved the water leak that landed on your left knee in rain, and sent the water down past the cab vent in a manner that rotted cabs when the drain plugged.

Trucks, dogs, houses and women come and go. Trucks & dogs are memorable.

JE I've fought tires on and off rims more times than I can count in sizes from 4" up. 14.5 is a common commercial trailer tire, 15" 16", 16.5", 17", 17.5", 19" and 20" were all well used sizes. I also remain completely unconcerned by 2 and 3 piece rims, although for the last 10 years I insist on an air hammer breaker to dismount any 2 or 3 piece. It is rather fun to watch today's crop of "Technicians" run away from those tires.

Daniel, I'll have to take your word on bolt holes. I can still look at a dozen 17" GM 3 piece wheels but I have nothing left in 60s ½ ton. Thankfully it's been a while since I worked on a ½ ton Chevy. I do recall back then that the part number for all Chevy pickups, 2WD, front coil spring was the same. I also might still know where a few NOS coils from Caddy Ambulances sit.
 
some one left out the wail oil in the third member of the truck. that would lock up the cliches in it on a hard corner. so they got away with feeding you a line on that score. all it needed was the additive for the posi rear end.

but yes they did put 14.5 tires up to 12 ply on mobile homes and no you can't mount them on a 14 inch car rim. personal experience there.

but one has to remember the original question that was finding 15 wheels they put on the 70 GM commercial chassis they sold to aftermarket companies. which were the same shape as the standard wheel but heaver duty. the chassis was supplied with wheels and tires on it from GM. not shared by any other model in the GM line up. truck or car.

one doesn't want to confuse the new guys to the hobby. I admit guilty as charged
 
The statement that I have highlighted above, is absolutely incorrect. Any 15" tire will mount on any 15" rim, provided that the width of the tire is within the tire manufacturers recommendation concerning the width of the rim. The only "commercial 15" tire" that I have any knowledge of was a tire that was supplied to the Cadillac Division for specific use on ambulance chassis. That tire was labeled on the side wall of the tire, "AMBULANCE SERVICE".




I have one of these ambulance service tires. I have many 15' cc rims. No idea how to ship them tho.
 
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