Can my 5.9 and AT545 pull a 9k van?

[EastCoastCB]

Originally Posted by cadillackid

I never thought a locking transmission made much difference.. then I changed out to one and wow!! its like a whole different bus.
-Christopher

told ya so!

[natedlee]

Originally Posted by turf

capacity of the trans is both weight and hp.



even though you are at the weight limit, you're still under the hp limit with a stock 5.9. you can probably add 40 ponies and still be under your limit.



i'd try to turn up the afc on your fuel pump a bit first before swapping into a 643, but eventually you'll want something different.



i've run my 545 for 5-6 years now and i'm swapping in a locking transmission now.

Ok I read about this mod in passing. Can you explain how it's done, or point me to a decent resource to read up on it?

Which trans are you getting now?


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[natedlee]

Originally Posted by turf

that trans cooler is standard on all buses. you'll need an additional one.

the biggest short coming of the 545 for towing is the fact that it doesn't have a locking torque converter.

what does that mean?? when you go up and down hills, you go faster and slower.
a non locking transmission (at545) keeps a constant rpm and slows down. the difference (slipping) is lost as heat in the transmission.
a locking torque converter doesnt slip. if you slow down the rpms go down.

long uphills with the non locking transmission will create tons of heat and will be the death of the 545.

i am a huge fan of the 545, i have one on my bus, i tow 3k lbs, and abuse the **** out of my transmission dragging my trailer up and down the rockies.

towing has probably indirectly cost me a few thousand in repairs already. i have replace my manifold (cracked by heat), rebuilt turbo, added gauges, overheated, new fan cltuch, new water pump, new thermostat....and now a new transmission.

i'm in the process of replacing my 545 with a 1545, a locking version of the same transmission.

thats a fluid to fluid trans cooler, so your water temp and trans temp will be real similar.

check out my thread when i added the cooler.
http://www.skoolie.net/forums/f33/ad...545-14363.html

Thanks dude. I'll be reading up on your story for sure.


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[natedlee]

Originally Posted by cadillackid

I never thought a locking transmission made much difference.. then I changed out to one and wow!! its like a whole different bus.
-Christopher

Which one did you upgrade to?


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[cadillackid]

Originally Posted by natedlee

Which one did you upgrade to?


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I upgraded to an allison 1000 (mildly Built up) 6 speed.

thread on it is the redbyrd transformation under short busses
-Christopher

[Tango]

Don't forget these trannies have a torque limit as well.

[Lazy Mountain Man]

The MD 3060 is a great transmission but it may not be practical for older coaches since it uses electronic controls. To convert you not only need the transmission but the ECM, VIM, wiring harnesses and a throttle position sensor. It's totally possible but it does get a little complicated. It's best to try to get the whole system out of wrecked truck or bus so everything works together.

[bluebird90]

I honestly think your bus is under powered and under transmissioned for towing that van. The van alone may weigh up to 7000 lbs. One big concern is braking. You must have a remote braking system for the van, it's the law.
Also, the bus is not that heavy in the back, the van could put you in a jackknife situation especially in the wet. You would be better with an R E bus.

[EastCoastCB]

There's GOT to be a reason there aren't RE tow trucks.

[bluebird90]

That,s because when a tow truck is towing the weight of the towed vehicle is on the rear axle of the tow truck, when flat towing there is no additional weight on the bus.( I maintain about 15 tow trucks of different types and believe me, many of them a skittish in the wet.)
Hence making for low traction on the rear. The long overhang of many buses compounds that by leverage.

[bluebird90]

Forgot to mention, I drove a bus just like that for a while. That thing was very skittish in the wet. Almost took the rear wheels off the ground in a panic stop a few times. .If you do use this bus, put some weight in the back.

[natedlee]

Originally Posted by bluebird90

Forgot to mention, I drove a bus just like that for a while. That thing was very skittish in the wet. Almost took the rear wheels off the ground in a panic stop a few times. .If you do use this bus, put some weight in the back.

Well all my heavy stuff is in the back (or will be) actually. Water tanks, generator, battery bank, kitchen, etc. IF I tow it will at least have that going for it.


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[Stuntmanmitch]

Originally Posted by turf

thats a nice info sheet about the 545.

if you look at any other bus with any other transmission spec, they will be higher. the 545 is the bottom of the barrel as far as common school bus transmissions/ conversion buses.

the MT643 is rated 60K lbs
the MD3060 is also rated at 60k lbs capacity.

the 545 is a great tranny for in town large vehicle use. as far as a highway cruiser/tow platform its the least robust choice we skoolie owners have.

30K may be the capacity, i'm am at 80% of capacity around 24k and have had my share of problems.

Thanks for this info. I have the 5.9 but with a MT643 (11window TC). I will want to pull my car or truck on a trailer in the future, at most I'm thinking 6k lbs. I'm looking into trans coolers now.


That van is sweet!

[natedlee]

Originally Posted by Stuntmanmitch

Thanks for this info. I have the 5.9 but with a MT643 (11window TC). I will want to pull my car or truck on a trailer in the future, at most I'm thinking 6k lbs. I'm looking into trans coolers now.


That van is sweet!

I think I may be upgrading to the MT643 at some point. So many things I want to tow!


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