Need Your Advice

[Free Bird-SKO]

Our cruising speed on flat ground is around 60, limited by gearing (4.78:1 axle). When the roads are steep enough to have "slow truck" lanes, we are holding the same pace as the slow trucks in them with us. Outside of mountain climbing, it's rare to drop below 55 on hills.

I've got my eye out for a deal on a lower ratio axle swap, I expect that 70 on flat ground would be no big deal with 4.10:1 ratio.

I swapped a 4:30 for a 4:10 in my 93 short bus, mighta gained a few mph on the flats but nothing on the hills. I can still hit 2600 rpm and only be doing 50. This is about what I expected, the harder you push the AT545 the more it slips. I have a 5spd Spicer and most of the trimmings sitting here waiting for me to get them installed, then I expect to see some big changes. I should be seeing 60mph at 2200.
The 545 trans is a good unit for picking up school kids but I can't recommend it in a cross country machine. I'm well satisfied with my Cummins and I can juice it up if needed but I think it will handle my little bus just fine the way it is.

 

[EastCoastCB]

I swapped a 4:30 for a 4:10 in my 93 short bus, mighta gained a few mph on the flats but nothing on the hills. I can still hit 2600 rpm and only be doing 50. This is about what I expected, the harder you push the AT545 the more it slips. I have a 5spd Spicer and most of the trimmings sitting here waiting for me to get them installed, then I expect to see some big changes. I should be seeing 60mph at 2200.
The 545 trans is a good unit for picking up school kids but I can't recommend it in a cross country machine. I'm well satisfied with my Cummins and I can juice it up if needed but I think it will handle my little bus just fine the way it is.

I've got a 545 with a 3.42 ratio.

 

[Free Bird-SKO]

Hmm, perhaps my 545 is toast.
How many miles on yours and which bus is it in?

 

[EastCoastCB]

Hmm, perhaps my 545 is toast.
How many miles on yours and which bus is it in?

I've got super high gearing at 3.42.
Its in a 99 Thomas 5 window with a 190hp Cat 3126. Its got less than 100k on it but the at545 has a reman tag on it so its newer than the bus.

 

[Free Bird-SKO]

No kidding you're high geared, probly do 35mph in low gear!
Awesome on the freeway if the transmission can hang in there.
Did you buy the bus with that gearing?

 

[EastCoastCB]

No kidding you're high geared, probly do 35mph in low gear!
Awesome on the freeway if the transmission can hang in there.
Did you buy the bus with that gearing?

Yeah my bus is a rather odd duck. Came with a 5" lift kit from the factory, too.
The bus came with highway gearing but was apparently regeared even higher probably when they replaced the original transmission. Originally it came with 4.10.
Doesn't seem to slip as much with the highway gears. I don't get near as much slip as other buses I've owned or driven/ridden.

 

[Free Bird-SKO]

Makes me wonder if the 545 could have been beefed up during the rebuild.

 

[EastCoastCB]

Makes me wonder if the 545 could have been beefed up during the rebuild.

Its just a reman from Allison.

 

[railbus5]

Highly unlikely the tranny is an AT 545. My 2002 BB has an AT 2000.

 

[o1marc]

Highly unlikely the tranny is an AT 545. My 2002 BB has an AT 2000.

Charlie, Did he just say you don't know what you're talking about?

 

[cadillackid]

Josh definitely has more patience than I do

He has traveled all over the country in a 7.3/AT-545 equipped Vista. I would go nuts...

I travelled the country in a 7.3/AT545 till I blew up the AT545.. travelled the country in a 5.9(DT360) / AT545. till i blew up that AT545...


now I travel the country in 7.3/A1000. and a 5.9(DT360)/MT643, havent blew those up yet..

 

[PNW_Steve]

I travelled the country in a 7.3/AT545 till I blew up the AT545.. travelled the country in a 5.9(DT360) / AT545. till i blew up that AT545...


now I travel the country in 7.3/A1000. and a 5.9(DT360)/MT643, havent blew those up yet..

Yours doesn't count 'cause you never stopped to visit us

 

[cadillackid]

Highly unlikely the tranny is an AT 545. My 2002 BB has an AT 2000.

its a AT545 ive ridden EC's bus.. its a 99 and the AD2000 wasnt out yet when it was built...

-Christopher

 

[cadillackid]

Yours doesn't count 'cause you never stopped to visit us

Ha! i forgot about the AT540 i have that STILL WORKS after being heated up to 350+ degrees in the cascades....



lol i didnt stop to visit anyone really on that trip.. it was early august in a bus with No A/C and it was cool outside.. i wasnt gonna wait for it to get hot again so I hauled arse home

 

[EastCoastCB]

Highly unlikely the tranny is an AT 545. My 2002 BB has an AT 2000.

I've seen 01's and 02's with either. Even heard of a few 03's with 545's in em. https://www.schoolbusfleet.com/forum/topic.asp?TOPIC_ID=17402