tranny temps

[bansil]

Ok so I have an A545 I know it slips with out lockup option.
I noticed sunday that at 55mph flat ground temp was around 180/190 engine temp(since tranny cooler is in radiator)
On a few smaller hills,giving throttle to maintain speed that engine temp(per gage) engine temp would be close to 200,but the tranny temp climbed quickly to over 220,I backed out and once it settled down to cruise speen temp dropped quickly to 190.
I know 180/190 is best to evap water molecules but I don't want to "varnish" or burn tranny fluid.
Tranny is full and has good color and no burnt smell.
I will be adding trany cooler/s to manage temp.
What is normal for this trans,hell 230 on gage is "buried" just curios....what say ya'll?

[sdwarf36]

Since I just put a tranny temp gauge this spring, my observation is that outside air temp has alot to do with the overall temp. ( Stock Ford tranny-cooler in the rad + small factory aux cooler.) I've done the same 200 mile trip and had the average temp vary 10-15 degrees from running in the day to running at nite. The heat of the day I'm running 185-drop the air temp 15 degrees and its 170-175. Worse was towing up a 1 mile hillclimb at 20 mph towing a trailer-210 degrees.

[chev49]

i dont want to go much over 200 or so on the temp gauge.. the main thing is to not floor the gas petal when its clear that the bus won't go any faster anyways up a hill.. its also why its a good idea to keep watch of the engine temp gauge.. the bus can always be parked for a bit while it cools off in the hills...
my son in law drives occasional trips to games, etc in the winter and he said he just keeps the acc petal on the floor all the time while going up hills... course it aint his bus... i think this is one of the reasons busses frequently have reman trannies when they are sold.. mine did.

[opus]

You really dont want to hit 200.

[chev49]

prefer 180.
allison site says trans should be properly warmed up before operation.
like that is going to happen in normal school bus operation...

its a good idea for people to read about trans operation on that site. fwiw

[bansil]

mmm according to page 21 of the manual:

sump fluid,minumum continuous=100*
sump fluid,typical continuous=200*
converter out fluid,maximum=300*
retarder out fluid,maximum=330*
sump fluid,maximum=250*

So I need to see where the gage is located and see where the temps are being taken

[caseythenose]

Tranny fluid can lose its lubricity in one mile on a hard pull.
Literally, start a transmission that is perfect with hot fluid, burn it on a hard pull...and one mile later it is toast.

100% synthetic fluid will prevent a ton of issues from heat.
The synthetic ATF retains its "goodness" into the 400 degree realm. (Your gaskets melt at that temp)

Have any of you heard the RV people that say to pull the trans out of OD (and out of lockup in many cases) on the hills? LOL

[opus]

Originally Posted by caseythenose

Have any of you heard the RV people that say to pull the trans out of OD (and out of lockup in many cases) on the hills? LOL

So thats why that sticker is on the dash. ;)

[bansil]

I am getting ready for a trip that is going to be hard on the tranny for sure.

It is the grade into Boone NC on HY421 it's not a long grade but at spots it's 12-19%.

Plan is to go slow,keep engine about 1800 RPM and 1st or 2nd gear...that coupled with all 5 heater fans on high...and stop if needed.

I have searched with no luck ...what is the "correct" way to drive up hills with 5.9 and the A545?

I have seen mention that the A545 has full pressure at 2400 RPM (thats kinda high isnt it?)

What would be ideal for rpm for keeping air moving from fan?

I have added a few electric fans I had laying around to try to keep air moving when bus is moving slow

Good thing I have a 190 amp alt. with all the fans on I'll need it of course the alt will make the engine work harder

Also it was a 95* day when I had the initial heating up..or original post.

It will be about 50* cooler when we head out.

I have recon'd the hill and possible pull offs, and planning the drive during the slowest traffic times with work schedules and class schedules.

Fingers crossed

[GreyEagle]

Take care of that tranny....... Here are a few links with good info........ I figgured you'll need it , if you get up that hill!!!!! LOL Enjoy your trip...

DOWN-LOAD-ABLE ....... http://www.allisontransmission.com/serv ... 1321EN.pdf

http://www.allisontransmission.com/publ ... onType=All

http://www.messb.com.my/allison_at_545.html

School Bus, Intercity Bus and Shuttle Bus Rating
Net input power 235 hp (175 kW)
Net input torque 445 lb-ft (603 N·m)
Vehicle weight Up to 30,000 lbs (13,608 kg) GVW

[bansil]

Thank you
I have the 2 pdf manuals
The last link is neat...there is a deep pan availble

[bansil]

SO READING THIS

ENGINE INTERFACE



Acceptable full-load engine governed speed

2400-4000 rpm (diesel)
3200-4000 rpm (gasoline)



Minimum engine idle speed
(with transmission in drive)

500 rpm


Which I have seen reference to keep rpm's at 2400 for loads so tranny gets full line pressure....cruising at 1800/2000 is actually slipping more under load...correct?

I am rethinking this now and plan to try to keep the rpms up and see how that works, since tranny doesnt have lockup...hell the guy I got it from and the mechanic said when you pull out give it hell until you get upto speed...makes since now

[GreyEagle]

Originally Posted by bansil

SO READING THIS ENGINE INTERFACE

.hell the guy I got it from and the mechanic said when you pull out give it hell until you get upto speed...makes since now

Makes sense to me....... give her hell. Drive it like you stole it!!!
floor it at the bottom of the hill and don't let up until you reach the top .......... or all hell breaks loose!

[bansil]

Originally Posted by GreyEagle

Makes sense to me....... give her hell. Drive it like you stole it!!!
floor it at the bottom of the hill and don't let up until you reach the top .......... or all hell breaks loose!

I reckon we could just camp on the shoulder of the road for a few days...pretty scenary

[caseythenose]

Originally Posted by opus

So thats why that sticker is on the dash. ;)

Not with a lockup torque converter.

If your vehicle will maintain lockup in high gear and will not oscillate in and out of OD all the way up, the best thing to do is leave the shifter alone. Period.

There is less heat in the fluid, less shock to the drivetrain and the engine is right in its zone.

[GreyEagle]

Quote

I reckon we could just camp on the shoulder of the road for a few days...pretty scenary....

Whenever my DW ask about..

What are we going to do if we break down? I answer .......... Pull off to the side of the road, set up a mail box and plant some flowers.

[bansil]

it's the little details that worry people

so right now I plan to add a couple electric fans to help out that big azz factory fan(so I don't have to rev it to keep air moving)
all heaters on high,drive a gear low and possible water mister system rigged up....If I spray motor with cleaner before the mountain,engine should be sparkly clean by the top

whatch the gages (maybe install aftermarket add ons I do'nt trust the factory ones,not enough sweep in them)
relax and pull over when hot and idle up to cool it off...woop 2 weeks to go gotta get busy

[GreyEagle]

Now you're thinking....... (and possible water mister system). Have seen these on several different vehicles....... If you can keep the engine cool, the trans will be cool also..... just how cool is that?

[crazycal]

Those temps seem a little high. I only reached those on long climbs coming back home. I picked up 4 gallons of Dextron at Walmart. Just going to drain and fill. When I hit the hills, I try to keep my rpms over 2000. I think the TC heats up more when you baby the throttle. Pure speculation on my part.

[bansil]

That's my speculation also and from what I have read