SnoKing
TDR MEMBER
I thought some of the really heavy haulers had double reduction axles?
I think they do in some applications, rarely ever see one up here. A lot of extra parts and higher cost involved.
Going with deeper gear ratios and making it up with the transmission is more cost effective. You figure if each of the tri-drives is 23,000 lb rated then you have 69,000 lb drives.
I see tandem trucks with 46,000 lb rears routinely haul loads grossing 200,000 lbs or more in an off road situation.
Just checked Meritor and they make single reduction tandems up to 58,000 lb so in a tri-drive they would be 87,000 lb. It could have those in it maybe....
My personal best was years ago....
Equipment involved was...
Power Unit
1980 GMC Astro 9500 Cabover Sleeper with an 8V92 Detroit Diesel 430 hp. 13 speed Fuller transmission, 38,000 lb rockwell rears on Reyco 4 spring suspension. 3.90 ratio
Single frame truck with 1" redi-rod placed through the frame before, center and behind the rear suspension to keep the frame from spreading.
Trailer
1979 Great Dane 45' tandem spring ride flatbed converted to an open top bark hauler with 8 1/2' sides and a top swing rear gate.
Highest Vehicle Gross Weight that I hit was 142,000 lbs. From Portage, Maine to East Millinocket, Maine using US Route 11. Have a look at where that is. We routinely weighed up from 110,000 to 125,000 lbs....but if the bark was just the right density it was a lot heavier and we filled the trailers every trip...
Frame on truck would flex enough to throw shifter out of gear if you hit a bump just right. No Jake Brake, just knowing the road, using your momentum and some skill. If a Moose stepped out in front of you had to just hold the line because it was insanity to swerve with that kind of weight.......That was my training....
Apologies to the OP for the threadjack.
That's a shame, Mike, and yes "free(not fair)trade" is a cruel joke perpetrated on us peons. Where I lived back East I watched as Ingersoll Rand, Bethlehem Steel, Mack Truck(to some degree), a whole slew of paper mills, and various other good paying industrial jobs were flushed away for the "service economy". It brings utter devastation. Shameful.
My apologies to JR as well, I've hi-jacked him before....he must be getting used to it as he joins in on whatever we veer over to.....![]()
Bethlehem, PA? We've done some wheelin over in that area on a few occasions. Might be going back this summer if we can find the time in between our trip to West by god Virginia and Wyoming.
No worries on the detour, I value a good conversation more than the direction it goes.
My personal best was years ago....
. Have a look at where that is. We routinely weighed up from 110,000 to 125,000 lbs....but if the bark was just the right density it was a lot heavier and we filled the trailers every trip...
When brother and I had shop in British Columbia
Brings back some memories.......Used to do powertrain rebuilding.....There were 2 guys that brought their tractors in for 2weeks over Christmas holidays every year. They got full rebuild of 18speed (bearings , main shaft , and full replacement of backsection.) Full rebuild of 46000lb rears including gear sets. This was the only time the trucks were down long enough to comfortably do this work. They from experience started breaking hard parts(twisting mainshafts and backsection countershafts, chunking gear sets etc) at about 18months and could not make 2 years.
They were V8 Cats that were putting down 2000lb/ft (back in 90's). These truck hauled wet bark from one plant to another, a total of 6miles one way. 3miles up to a plateau , then 3 more miles up to second mill. (not sure the grade but it was more than7% 2 lane). There were no scales and they routinely weighed in between 160 and 180K.
I remember taking the one Pete for a test run and it would smoke the tires if you laid into it in high gear at 50mph.
They did not mind paying and were extremely happy to make it year to year without major breakdown