Building a Tandem Axle Farm Truck?

[Stompin Tom]

What's your registered gvw on them?

I believe in Alberta your 23000 kg on drivers, 7300 on steering for 30,300 kg total gvw

 

[skegpro]

What will a guy notice steering wise from tandem to tridem in same wheelbase trucks?

 

[Stompin Tom]

What will a guy notice steering wise from tandem to tridem in same wheelbase trucks?

Well, first your wont have the same wheelbase, the tridem will and has to be longer, there are minimum wheelbase specs for a tridrive.

A tridrive will always give you more push with steering, you really wont notice it on dry pavement, you will notice a bit on gravel especially if your turning sharp with any kind of speed, but where you really notice it is in winter with slippery conditions. Its more something you have to be aware of, dont approach sharp turns or approaches with a full head of steam, back off a bit before sharp corners, give your self a bit of room for error.

 

[skegpro]

Well, first your wont have the same wheelbase, the tridem will and has to be longer, there are minimum wheelbase specs for a tridrive.

A tridrive will always give you more push with steering, you really wont notice it on dry pavement, you will notice a bit on gravel especially if your turning sharp with any kind of speed, but where you really notice it is in winter with slippery conditions. Its more something you have to be aware of, dont approach sharp turns or approaches with a full head of steam, back off a bit before sharp corners, give your self a bit of room for error.

I think in Alberta 260" is the shortest tridem body job you can register.

I have a tandem that is a 268"........

Just wondering if a 260" tridem would have the same turning radius as a 260" tandem

 

[sirkdev]

It will be close for sure more drag and forward push with the tri, think of pulling a tridem trailer vs tandem just not as nimble.

 

[Stompin Tom]

I think in Alberta 260" is the shortest tridem body job you can register.

I have a tandem that is a 268"........

Just wondering if a 260" tridem would have the same turning radius as a 260" tandem

wheel base is a bit tricky, its apples and oranges with tandems and tridrives. When you measure a tandem its from the center of the steering axle to the center point between the two drive axles, or the rotation point. With a tridrive you measure from the center of the steering axle to the center of the middle axle.

So in reality the turning radius for a 268 tandem should be slightly larger than that of a 260 tridrive, but it also depends on brand of truck and how much wheel turn they have.

 

[skegpro]

wheel base is a bit tricky, its apples and oranges with tandems and tridrives. When you measure a tandem its from the center of the steering axle to the center point between the two drive axles, or the rotation point. With a tridrive you measure from the center of the steering axle to the center of the middle axle.

So in reality the turning radius for a 268 tandem should be slightly larger than that of a 260 tridrive, but it also depends on brand of truck and how much wheel turn they have.

Lol

 

[f150truck]

alberta weights

http://www.transportation.alberta.ca/4777.htm

 

[Murminator]

Lol

Bah who need fuel tanks LOL

 

[skegpro]

What is everyone running for transmissions?

Are these Eaton ultra shifts any good?

Allison automatic?

13 or 18 speed eaton?

https://youtu.be/bJ1i5Bvujbg

 

[Cdnfireman]

What is everyone running for transmissions?

Are these Eaton ultra shifts any good?

Allison automatic?

13 or 18 speed eaton?

https://youtu.be/bJ1i5Bvujbg

FWIW, all our fire apparatus use the Allison automatics. The ladder trucks all weigh in at over 70k and rarely are there any transmission problems. And the trucks are not driven nicely at all. Full throttle starts, hard brake applications then hard on the throttle again. I’m amazed the transmissions stand up as well as they do.

 

[skegpro]

FWIW, all our fire apparatus use the Allison automatics. The ladder trucks all weigh in at over 70k and rarely are there any transmission problems. And the trucks are not driven nicely at all. Full throttle starts, hard brake applications then hard on the throttle again. I’m amazed the transmissions stand up as well as they do.

This is good info.

Do you find they spend a reasonable amount of time in the intermediate gears?

I have an older Allison 6 speed.

They seem to want to get to 6th gear real fast.

 

[the_real_wild1]

What is everyone running for transmissions?

Are these Eaton ultra shifts any good?

Allison automatic?

13 or 18 speed eaton?

https://youtu.be/bJ1i5Bvujbg

Most reliable is 18 speed eaton if you know how to drive and not rip out clutch brakes. I don’t like the Allison unless it is in my pickup. Usually reliable but if something goes wrong you can’t just get it fixed anywhere like the eaton 18 spd. Ultra shifts are “ok” but the electronics can be a real pita to deal with when something fails. The lower is just a standard trans with the add kms for the clutch. 18 spd is preferred over 13 speed.

 

[skegpro]

Most reliable is 18 speed eaton if you know how to drive and not rip out clutch brakes. I don’t like the Allison unless it is in my pickup. Usually reliable but if something goes wrong you can’t just get it fixed anywhere like the eaton 18 spd. Ultra shifts are “ok” but the electronics can be a real pita to deal with when something fails. The lower is just a standard trans with the add kms for the clutch. 18 spd is preferred over 13 speed.

So what would be the main benefit of having an 18 vs 13?

Other than being able to split the lower gears?

 

[the_real_wild1]

So what would be the main benefit of having an 18 vs 14?

Other than being able to split the lower gears?

Parts availability and just that, Being able split when needed. Everything with a 13 spd always seems to feel underpowered. Same with that Alison trans. Mack and Volvo have the nicest auto trans in the business IMO but if you get one of those make sure you get every bit of extended warranty you can. Newer Mack’s are nice to drive now. Not like the older trucks.

 

[skegpro]

What rear end ratios are guys running?

Got quoted a 4.11 and a 4.56.......

475 HP 1750 ft-lb at 1100 RPM

From what I gather reading inline I want to be able to cruise at 120km/hr at 1100-1200 rpm in 18th.......

My other concern is that I drive a metric **** tone of gravel rodes at 80 km/hr Soni also wanna be able to cruise that speed at the proper rpm.

I am thinking some of my concerns would be addressed with an 18 speed?

 

[the_real_wild1]

I have to add the disclaimer that I work on the stuff and have my class 1 but don’t drive professionally.

 

[skegpro]

Parts availability and just that, Being able split when needed. Everything with a 13 spd always seems to feel underpowered. Same with that Alison trans. Mack and Volvo have the nicest auto trans in the business IMO but if you get one of those make sure you get every bit of extended warranty you can. Newer Mack’s are nice to drive now. Not like the older trucks.

Good to know, I was king of wavering between the 13 and 18 speed.

Most of my trucks have a 9 speed Eaton in them.

And if I understand correctly I can drive an 18 speed exactly the same or split the shifts if I need the extra?

Sorry, not a pro.
Specing a truck is a daunting task.

 

[the_real_wild1]

More or less. Unless it is a heavy load the low range I don’t split. But they are there if you need.

 

[the_real_wild1]

The pros can weigh in on this too but just what I’ve found plus talking to guys.