Some Pics Of The Rs

[Rob]

I have asked my wife to try to dig back into the archives of Cat's sales to discern the sales numbers of 1693/D-343 series engines of all variants sold to Mack trucks encompassing the years 1970-1980. The sheet that I have identifies four engines from a certain block of production and shipment from Peoria to Hayward, CA. Since it has been identified there were a few, but limited number of these trucks, (RL755LST) series produced, it would be nice to further the investigation. Of particular interest to me would be the amount of survivors, and of those, original survivors. My particular truck is completely original with the exception of the interior of which I have nearly rebuilt complete. All major components are original to the truck and the engine has been rebuilt with an out of frame major. It leaks oil terrible from the excessive use of red silicone sealant everywhere that has pushed out.

Something of particular interest to me is the "P6" engine designation my chassis appears to be built with. The Mack literature lists this engine at 375hp, yet when I've ordered parts, (gaskets/seals) from the Caterpillar dealer in Peoria, the serial and arrangement numbers rate the engine at 425hp. I've not discerned this disparity as of yet. I've never pulled anything with the truck and the clutch is so weak it slips when bobtailing up a hill. It was driven here from Paducah, (sp)? KY without problem but it had difficulty pulling the hills in southern IL due to clutch slippage.

Until my purchase I'd never seen an RL series tractor before. This truck was acquired to install my V-12 Detroit into. Upon seeing the straight rail frame, and literally disintigrated cab from rust, I almost did not purchase the truck. Either my inherent stupidity, or profoud fortitude caused me to make the purchase anyways. Being cold and having a nice barn to hide it in for a couple of months bought me some time to concoct an acceptable story before I informed "Momma" as it was early November; (you guys can appreciate this I'm certain).

I feel I made the right choice by bringing this one home. I purchased a 26,000 mile ambulance cab for a replacement. had it media blasted clean inside and out, welded up some unneeded holes in the floor and cowl, then etch and epoxy primed everything. I have gone no further for about two years now.

This investigation is "renewing" my interest.

Rob

[Rob]

Best i can tell,the truck was originally registered to Robert (bob) Eckstein Round Lake Beach,IL i tried the DMV as well,no help at all there. I tried peopleseach,just about all i could think of,but if he has passed,that would explain a lot. Tried a lot of the local Mack dealers in the area as well,all i got was the old "our records don't go back that far" routine. I had just about exausted everything i could think of,which is how i happened on Bigmacktrucks.com,i figuered if anyone knew anything about this truck,it would be on here!..................Mark

Think I've posted this before:

[bullhusk]

I went to the Brockway web sight and found the seven pictures of the Brockway Superliner. I don't see any resemblance at all to the Mack Superliner except for the CA47 cab. Maybee I am looking at the wrong prototype. I must admit that it seems as though Mack may have pilfered the Superliner name. Then again Mack used the liner term long before Brockway. They used to call the early H models highliners. I think the liner term even preceded freightliner.

If you don't see a resemblance? then you must be looking at the wrong prototype! The term liner was also used on the R model International R190 R200 R220 an so on back in the 50's an 60's they called them Roadliners

[rhasler]

Found another:

RL755LST 35444 Built 7/21/77, CAL49 Cab, 1693 Engine, RTO12513 Transmission, SSHD Rear Drive Axles, RSA380 Rear Suspension

[other dog]

If you don't see a resemblance? then you must be looking at the wrong prototype! The term liner was also used on the R model International R190 R200 R220 an so on back in the 50's an 60's they called them Roadliners

And they called these Sightliners.

[other dog]

Think I've posted this before:

Here's another picture I found in this Mack book-

[vision386]

Here's another picture I found in this Mack book-

Thanks for posting that Tom,thats the one i was looking for,figures its in about the only Mack book i DON'T have LOL!.......Mark

[other dog]

Thanks for posting that Tom,thats the one i was looking for,figures its in about the only Mack book i DON'T have LOL!.......Mark

You're welcome, it's available at www.motorbooks.com, and probably available and cheaper at amazon.com.

[rhasler]

I have asked my wife to try to dig back into the archives of Cat's sales to discern the sales numbers of 1693/D-343 series engines of all variants sold to Mack trucks encompassing the years 1970-1980. The sheet that I have identifies four engines from a certain block of production and shipment from Peoria to Hayward, CA. Since it has been identified there were a few, but limited number of these trucks, (RL755LST) series produced, it would be nice to further the investigation. Of particular interest to me would be the amount of survivors, and of those, original survivors. My particular truck is completely original with the exception of the interior of which I have nearly rebuilt complete. All major components are original to the truck and the engine has been rebuilt with an out of frame major. It leaks oil terrible from the excessive use of red silicone sealant everywhere that has pushed out.

Something of particular interest to me is the "P6" engine designation my chassis appears to be built with. The Mack literature lists this engine at 375hp, yet when I've ordered parts, (gaskets/seals) from the Caterpillar dealer in Peoria, the serial and arrangement numbers rate the engine at 425hp. I've not discerned this disparity as of yet. I've never pulled anything with the truck and the clutch is so weak it slips when bobtailing up a hill. It was driven here from Paducah, (sp)? KY without problem but it had difficulty pulling the hills in southern IL due to clutch slippage.

Until my purchase I'd never seen an RL series tractor before. This truck was acquired to install my V-12 Detroit into. Upon seeing the straight rail frame, and literally disintigrated cab from rust, I almost did not purchase the truck. Either my inherent stupidity, or profoud fortitude caused me to make the purchase anyways. Being cold and having a nice barn to hide it in for a couple of months bought me some time to concoct an acceptable story before I informed "Momma" as it was early November; (you guys can appreciate this I'm certain).

I feel I made the right choice by bringing this one home. I purchased a 26,000 mile ambulance cab for a replacement. had it media blasted clean inside and out, welded up some unneeded holes in the floor and cowl, then etch and epoxy primed everything. I have gone no further for about two years now.

This investigation is "renewing" my interest.

Rob

Rob,

During this investigation I have come across 3 pairs of RL755LST chassis, each pair representing a separate GSO. The first built in 1972, serial numbers 011230 and 011231 used 11GB91068P49, one pair, 35358 and 35359 use 11GB91253P5 while 35443 and 35444 used 11GB91253P59 (P59 being the same as P5 except for the addition of an oil temperature sending unit). 35358, 35359, 35443, & 35444 likely used the same Caterpillar engine arrangement since the oil temperature sending unit was supplied by Mack. I think this might account for the 4 engines your wife found were sold to Mack in this time frame.

As far as the engine ratings, I can't really speak to that other than to speculate that there was perhaps some kind of a campaign or field service program to uprate them later on. All of the stuff I've seen from the Mack system shows 375 HP for the engines in all 6 trucks.

In regard to Bob Eckstein's truck, if it isn't one of the last four produced then I would suspect that it is actually an RS755LST that was converted to an RL755LST. I don't know exactly what differences the two models would have or if such a thing would be possible. With the information that Mark had about the interior I plan to check some collision books if they're still around and see if I can find a part number or arrangement for the Oxblood interior. If so I may be able to cross reference the engine arrangements and the interior arrangements and narrow down the search some more. I don't recall seeing any built with the cab mounted A/C, but I'm sure the truck underwent extensive modification before reaching it's final configuration.

[Rob]

Rob,

During this investigation I have come across 3 pairs of RL755LST chassis, each pair representing a separate GSO. The first built in 1972, serial numbers 011230 and 011231 used 11GB91068P49, one pair, 35358 and 35359 use 11GB91253P5 while 35443 and 35444 used 11GB91253P59 (P59 being the same as P5 except for the addition of an oil temperature sending unit). 35358, 35359, 35443, & 35444 likely used the same Caterpillar engine arrangement since the oil temperature sending unit was supplied by Mack. I think this might account for the 4 engines your wife found were sold to Mack in this time frame.

As far as the engine ratings, I can't really speak to that other than to speculate that there was perhaps some kind of a campaign or field service program to uprate them later on. All of the stuff I've seen from the Mack system shows 375 HP for the engines in all 6 trucks.

In regard to Bob Eckstein's truck, if it isn't one of the last four produced then I would suspect that it is actually an RS755LST that was converted to an RL755LST. I don't know exactly what differences the two models would have or if such a thing would be possible. With the information that Mark had about the interior I plan to check some collision books if they're still around and see if I can find a part number or arrangement for the Oxblood interior. If so I may be able to cross reference the engine arrangements and the interior arrangements and narrow down the search some more. I don't recall seeing any built with the cab mounted A/C, but I'm sure the truck underwent extensive modification before reaching it's final configuration.

The oil temperature guage in mine is installed as the engine has a hydraulic retarder, (Brakesaver). Although mine was not connected during my drive home, I reconnected it up and pulled the trolley valve to actuate it and proptly put a little over a gallon of engine oil on the floor quickly. Very easy to figger out why it was disconnected. The oil cooler on these engines when equipt with the retarder is very large. I understand the engine oil heats quickly under engine braking power as the heat generated is dissipated in the oil cooler.

The tag that is drive riveted to the engine block is from the Caterpillar Tractor Co. itself. It is not a Mack tag added later on. The serial number and arrangement numbers are stamped into this tag. There are no other accompanying markings pertaining anything to Mack Trucks at all. The dash gauges consist of the normal ones plus oil temp, "Brakesaver" application pressure, pyrometer, and a big Cole-Hersee switch for operating the glow plugs as the engine is indirect ignition. The keyswitch in the dash is nothing more than that. It does not operate the starter motor. To shut down the engine you pull a traditional knob from the dash.

Both of my RL700 series trucks show on the line setting ticket roof mounted A/C units and both truck had the support bars welded in the upper cab structure. They looked identical although the 74 RL797 used a "Kysor" unit, and the 78 RL755 used a "Red Dot" vendored unit. Funny that the 74 uses a rotary type compressor, (Sanden, I think) yet the 78 uses a two cylinder York compressor. Both trucks were built with "Kysor" shutters although the 74 has a clutch fan and the 78 is rigid. The shutters are missing from the 74 but still present and operating on the 78.

That oxblood interior is nice but overwhelming. Although the seat covers and door cards emulate this same scheme as close as possible I'd rather have a medium dark gray as more to my style. I'm not totally against staying as original as possible but really have no plans to sell the truck so may personalize it a little. I understand the economy of operating one of these engine is worse than "piss-poor" so that's really not an option.

Guess it is pretty to look at and is much quieter that the females I reside with.

Rob

[rhasler]

I missed the A/C unit on your truck Rob. After looking back there is one more RL755LST that appears to have been the only one ordered on that GSO. It was 28683. It shows to have a Kysor A/C unit, shows an optional interior trim package (doesn't say what color), Mack camel back rear suspension (9 leaf springs, two piece rubber bushed trunnion) and Mack differentials (4.50 ratio), spoke drive axle wheels and disc aluminum steer axle wheels, 11GB91251P19 engine assembly, and RTO12513 transmission. It looks like most of these items match what was remembered about it by several sources. This might be the one.

[Rob]

Here is mine the night I got home with it. Had to grab these off the net cause I lost the computer with about a hundred photos of this truck before tearing into it.

Rob

[vision386]

I missed the A/C unit on your truck Rob. After looking back there is one more RL755LST that appears to have been the only one ordered on that GSO. It was 28683. It shows to have a Kysor A/C unit, shows an optional interior trim package (doesn't say what color), Mack camel back rear suspension (9 leaf springs, two piece rubber bushed trunnion) and Mack differentials (4.50 ratio), spoke drive axle wheels and disc aluminum steer axle wheels, 11GB91251P19 engine assembly, and RTO12513 transmission. It looks like most of these items match what was remembered about it by several sources. This might be the one.

Sure sounds like it,maybe,just maybe this is the one!............Mark

[Rob]

Here is a link with a photo of my truck in it's former working life.

Rob

http://www.baxmeyerconstruction.com/

[David]

So, if I'm following this correctly, there were seven of these trucks with cat engines? Two have been distroyed, Rob's, the one for sale on ebay and three unacounted for? I've really enjoyed reading this thread.

[rhasler]

So, if I'm following this correctly, there were seven of these trucks with cat engines? Two have been distroyed, Rob's, the one for sale on ebay and three unacounted for? I've really enjoyed reading this thread.

It looks like most (maybe all of them?) were located in Illinois, I'm assuming due to the Caterpillar connection. I'm not sure the one on eBay is an RL755LST. I did find some listings for 1674 engines as well while researching which I didn't delve into too much, but I think the 270 HP rating listed for the eBay truck is more in line with that engine. There were 5 RL753LST chassis listed (1674 engines) all built between 6/23/71 and 6/25/71. They must have really cranked those trucks out.

On a side note, was Bob Eckstein's truck "Phantom 309"?

[Rob]

Yes, Bob Eckstein's truck was "Phantom 309" after Red Sovines' hit single.

Rob

[Rob]

I remember two long hood R model dump trucks in the Peoria area with 1674 engines but it has been years since I've seen them. They were blue in color is all I really remember but they were aluminum frames. Seems like they belonged to Heinz Bros. Construction but not certain.

I didn't know what an "RL" series truck meant in those days.

Rob

[rhasler]

I think the RL753LST were probably all ordered/owned by the same company. They look like they're all spec'd the same. Page 1000 rear suspension, RT9509A transmissions, so probably not the ebay truck. Probably safe to assume that the eBay truck is either RL755LST 11230 or 11231 which were both built in 1972, maybe re-powered with a smaller engine.

[bullhusk]

There was a guy in Jackson NJ back in the 80's that had a LJ Mack tandem tractor 205 turbo Mack motor Candy Red color he also called it "Phantom 309" His son had a R700 Mack with a Mack V8 same color thay used to haul flat beds an S- Jersey Sand out of Claton's sand pit in Lakewood. Anybody from Jersey remember those trucks?

Ernie DS

[Rob]

I think the RL753LST were probably all ordered/owned by the same company. They look like they're all spec'd the same. Page 1000 rear suspension, RT9509A transmissions, so probably not the ebay truck. Probably safe to assume that the eBay truck is either RL755LST 11230 or 11231 which were both built in 1972, maybe re-powered with a smaller engine.

That could be cause Heinz has dozens of trucks of all types.

Rob

[Superdog]

This truck was for sale awhile back in WI,probably still there cause he was asking quite abit for it.It's a RL753LST,with a 1674 in it.I'm pretty sure the ad said it was a 1971.

[vision386]

It looks like most (maybe all of them?) were located in Illinois, I'm assuming due to the Caterpillar connection. I'm not sure the one on eBay is an RL755LST. I did find some listings for 1674 engines as well while researching which I didn't delve into too much, but I think the 270 HP rating listed for the eBay truck is more in line with that engine. There were 5 RL753LST chassis listed (1674 engines) all built between 6/23/71 and 6/25/71. They must have really cranked those trucks out.

On a side note, was Bob Eckstein's truck "Phantom 309"?

Rhasler,yes Rob is correct,Bob Eckstein had the truck lettered as "Phantom 309" after the popular country song,its hard to see,but if you look closely you can see the lettering above the Mack letters on the grille..............Mark

[Lmackattack]

I missed the A/C unit on your truck Rob. After looking back there is one more RL755LST that appears to have been the only one ordered on that GSO. It was 28683. It shows to have a Kysor A/C unit, shows an optional interior trim package (doesn't say what color), Mack camel back rear suspension (9 leaf springs, two piece rubber bushed trunnion) and Mack differentials (4.50 ratio), spoke drive axle wheels and disc aluminum steer axle wheels, 11GB91251P19 engine assembly, and RTO12513 transmission. It looks like most of these items match what was remembered about it by several sources. This might be the one.

That sure matched the closest to what Mr Hall and others have commented on. I would have to say thats the vin for that truck... Got to give you a big thanks for all this searching. Its itntresting that all this data is availible for one of the rare truck models. Not sure if that makes it easy or harder to find but you made it happen. yes that Truck was Phantom 309 noted on the nose of the hood.

this has been pretty cool searcing for all these cat powered trucks...Thanks again

[Rob]

That sure matched the closest to what Mr Hall and others have commented on. I would have to say thats the vin for that truck... Got to give you a big thanks for all this searching. Its itntresting that all this data is availible for one of the rare truck models. Not sure if that makes it easy or harder to find but you made it happen. yes that Truck was Phantom 309 noted on the nose of the hood.

this has been pretty cool searcing for all these cat powered trucks...Thanks again

Let's keep going on this to see how many still exist. So far, mine is the only known survivor with a 1693 still under the hood.

Rob