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Mack 85,000-pound Tandem Axles Available


kscarbel2

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Holy! That's cool! That's quite the beast. What motor in it?
 
It didn't have a tilt hood originally?


No it had a steel hood that is sitting on the bed in the first photo

During the initial restoration the all the mechanicals where taken care of, the cab was gutted. The dash was replaced to add factory air. Air ride seats were also added.

7.8 ford 210 hp
Allison MT643
4.88 gears, Detroit lockers in each rear axle

It could use more horsepower and an overdrive

After the tilt hood was added the entire suspension was rebuilt. All 6 springs have had there capacity reduced, shocks were added to the rear and air bags to the front.

Now my seat barely moves

I still toy with the idea of an overdrive
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There were two of those trucks at NAS Norfolk when I was there. Don't know what they were used for other than test weights for the CH-53 helicopter squadron at the other end of the ramp. Both ran but were routinely moved via these helicopters out across the bay and brought back.

Dog.jpg.487f03da076af0150d2376dbd16843ed.jpgPlodding along with no job nor practical application for my existence, but still trying to fix what's broke.

 

 

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18 minutes ago, james j neiweem said:

This thread took a turn down a rabbit hole.🙂

Yes, but for a refreshing change it did not go negative, and a lot of useful information acquired/gained/learned.

All good to me when they do that.

Dog.jpg.487f03da076af0150d2376dbd16843ed.jpgPlodding along with no job nor practical application for my existence, but still trying to fix what's broke.

 

 

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2 hours ago, Rob said:

Yes, but for a refreshing change it did not go negative, and a lot of useful information acquired/gained/learned.

All good to me when they do that.

Agreed.

We can get the subject back on track if we can ever find a customer in North America that will actually order these new axles and see the truck.

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21 hours ago, kscarbel2 said:
I myself think this thread is great. Really like his ex-Navy Ford F-900 6x6 tandem.

Thanks, it certainly draws interest wherever I go, unfortunately it is resting now due to the virus causing all the events I go to this time of the year being cancelled

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On 3/21/2020 at 8:14 AM, bulldogboy said:
The Plymouth, MA Fire Department has a tanker built on the same F-900 6X6 chassis.

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It’s a 1990, looks like it also has a Marmon Herrington front axle and a tilt hood. It also looks like it still has the bench seat but the brush guard is gone.

Since the Navy ordered these trucks in small batches and each batch had slightly different specifications mainly pertaining to gear ratio, transfer case and the tilt hood.

If you have access to this truck I would like to see pictures of the data plates that are mounted on the lower portion of the inside of the doors

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Well here I go down the rabbit hole-What is the power plant and tranny.[emoji846]


Since the fire truck is not mine I can not be shore on the power plant but it is probably still the 7.8 ford with an Allison behind it.

The navy did like that combination because I have a second truck that has the identical combination

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Funny how guys who think they move real weight look at the 85K rear and first thing they think is now we need more power ??  Goldhofers move millions of pounds and they go very slow and if you look at the weight to speed to power needed ratio you will find it really takes not a lot of power to move, 85K rears would end up in the coal fields which is kinda  slow right now but word is may have a come back, logging could use 85K rears but only off road, don't know of any states that will permit 85K axle weights NC, FL and VA will give 50K but even that is limited, so big weight is mostly off road and slow does not take big power unless you just want to have big motor bragging rights and higher repair costs.  

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That's what I was thinking.These would be a good coal hauler or mining dump spec. And the MP8 is all the power you ever need there with low axle ratios.

Logging (at least up here) I don't think the road trucks would spec anything like that, and the off road trucks are using planetaries. Most of the road trucks are running 46's on 52,000 air suspension, but many still running rubber block.

As for power. I pulled 140,000 pound loads up and down 12% hills for many years with an E6 350 and they did the job just fine. Even did it once with a 300 plus. Having said that....I like power!! LOL. And often times big power means the difference between chaining and not having to chain up.

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20 hours ago, Bullheaded said:

That's what I was thinking.These would be a good coal hauler or mining dump spec. And the MP8 is all the power you ever need there with low axle ratios.

Logging (at least up here) I don't think the road trucks would spec anything like that, and the off road trucks are using planetaries. Most of the road trucks are running 46's on 52,000 air suspension, but many still running rubber block.

As for power. I pulled 140,000 pound loads up and down 12% hills for many years with an E6 350 and they did the job just fine. Even did it once with a 300 plus. Having said that....I like power!! LOL. And often times big power means the difference between chaining and not having to chain up.

Hopefully it's different these days but "big power" a few years ago had repair costs to go with it. I always liked the 676, and 300+ engines myself as they were on the threshold of enough to get the job done, yet not strong enough to tear themselves up prematurely.

People forget there was gillions of tons of freight pulled all over the world with less that 250hp in all grades and weather and it got the job done. Kind of like ring shank drywall nails I guess when screws became marketed for the purpose.

Dog.jpg.487f03da076af0150d2376dbd16843ed.jpgPlodding along with no job nor practical application for my existence, but still trying to fix what's broke.

 

 

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Was just talking about this with someone the other day. I spent many years in the bush with 38,000 rears in my 78 IH. I finally broke one axle shaft and I wasn't stuck or spinning. But the truck was bought used and was wore out already, LOL

Also drove a DM dump truck with a 237 and 5 speed Mack.

Probably why the highways were safer back then too. Well mostly because we were better drivers, but the average speeds weren't as high in days past.

Most of out trucks topped out at 55 MPH at 2100 RPM in the old days, LOL

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