Mountains in the at545

[LargeMargeInBaja]

Originally Posted by BrandinoBeatz

What revs should I keep my 1994 international Thomas vista fill size bud transmission at with the at545 when going through mountains?

.
Descending, I stay below 2,200rpm.
As the engine nears 2,200rpm, I apply the brakes to slow to about 1,400rpm, then allow gravity to slowly accelerate to near 2,200rpm.
Then, I slow the rig again.
.
The fatal mistake:
* maintaining constant braking.
That heats the brake components while depleting your air.
Bad idea.
.
At the bottom of a descent, at a traffic control, I shift to 'NEUTRAL' so I can remain immobile without engaging the brakes.
Hot drums can warp, requiring extensive repair or replacement.
.
How do you know you warped your drums?:
* your brake pedal vibrates, and
* the brakes 'catch' on those high-spots, and
* your mechanic books a vacation to Maui.

[djdalfaro]

I have a DT408/AT545 in my 94 3800. If you need manuals, they're in the link below, as well as the tuning directions for the P-Pump. FWIW I've climbed 6% grades in my bus loaded at 23k lbs. Just watch your temps and pull over as needed. I use the throttle pull cable to speed up idle to help cool the engine while parked.

Marge's instructions above are exactly how I descend as well.

https://drive.google.com/drive/folde...81juA93UoGL22I

[Jolly Roger bus 223]

i have a driveline shop near me thats is reliable and quick if you have the correct parts and know the length you want.
dont know whats up your way anymore.
havent lived there since 2000 and at that time it was more about work , raising kids and keeping my stuff running and not a chance to have fun customizing a vehicle except for my wifes saturn at the time i just about ripped everything computer out of it just to keep it running.

[BrandinoBeatz]

Hey cadillackid I had a few question on swapping out my at545 that’s in my 1994 IH Thomas vista!, I tried to message you but says it’s full so I will post on here if you see this, I am looking to either swap with mt643 ( I hear that is compatible and won’t take much to swap out) or I had a idea of putting a a2000 in it? Is that even possible?
(I do have air brakes)

[BrandinoBeatz]

Would you say I should keep the at545 if nothings wrong with it ? Or go ahead and swap ?

[magnakansas]

i have a cummins 5.9 mechanically injected with at545. My plan is to swap to a 2000 series 5speed or 6speed. This will take money and time. overall I think the driving experience will be more enjoyable. the fuel mileage will increase. I will be able to cruise at 60mph. engine rpm will drop a little.

my current transmission seems to operate as designed, but is best suited for in town stop and go up to about 50 mph.

william

[RolesvilleMarina]

From my thread and reading some others those with older buses can either attempt to go mechanical (MT643) if the engine is compatible for one

My T444E is not so I went the 2000 route

HOWEVER

the 2000 is an electronic transmission. In MY case my bus already had the updated wiring harness on it being a 1999. 1997 (late year) through 1999 vistas had the updated harness.

So I bought a whole another IH 3800 long bus with a 7.3 and an A-2000 trans and all the "bits" required and swapped it all between my bus. Then sold my "donor bus" with MY AT545 as I told you.

I followed Cadillackid Redbyrd thread which if you have not read you you need too... FOLLOWED by MY thread "Transmission options"

reading BOTH, and IN THAT ORDER, will fill in a LOT of the questions you are askings... the answers are already there


In an older bus without the proper harness for the TCM Cadillac Kid talks about using just a "box" he made to read the throttle position sensor and says that's all you "technically" need to make it work.

He is a perfectionist, and amazing the work and help he gives, so he wasn't happy and he did even better later on.. again read the thread.

BUT it is possible to put in an allison 2000. it would be better to do so.

since I cannot on advice on HOW to pull this off since i kinda "cheated" I can't say how to do it

I can help you slap the A-2000 in your vista in a day though.. May not need driveshaft work as I did not..

but the electronics... the computers

you need to read the threads, then ask..

also there are now others I heard sell kits/harnesses but I dunno who/what/cost

sure it would be ideal to do A-2000 swap..

I will help either way

[RolesvilleMarina]

Originally Posted by magnakansas

i have a cummins 5.9 mechanically injected with at545. My plan is to swap to a 2000 series 5speed or 6speed. This will take money and time. overall I think the driving experience will be more enjoyable. the fuel mileage will increase. I will be able to cruise at 60mph. engine rpm will drop a little.

my current transmission seems to operate as designed, but is best suited for in town stop and go up to about 50 mph.

william

how do you plan to do the leccy parts

the TCM needs inputs the older buses don't give

there are work arounds and I hear companies sell the harness etc if you give them your Vin??

any thoughts?

the mechanical part of taking out the AT545 and putting in the A-2000 is a piece of cake and simple hand tools

[magnakansas]

The vin will do nothing in my case. So no point bothering. Go bock and read through Cadillac kids redbyrd thread on his transmission swap.

There is fellow that will supply me with a new TCU, wire harness, and throttle position sensor.

In my case I will likely build/modify my own harness.

There is no input from my engine, it doesn’t have electronics
William

[magnakansas]

I will use a 2000 series with a #3 housing. Closest direct swap. There is a fellow that Cadillac worked with. We/I am using a throttle position sensor that I believe Allison used with the 3000 series transmission with mechanical injection diesels. Same fellow also supplies TCU that is new. I think the TCU is one that can be had for the Chevrolet that uses the 1000 series. I am not certain about that. At a later point I am going to try to integrate a variable geometry turbo. When the transmission is ready for a shift, the turbo will be commanded to back down on boost- reduce engine torque- I think I can even incorporate some sort of throttle down during shift with a solenoid or linear actuator in the throttle linkage. I expect this to be a five to ten year endeavor.

William

[cadillackid]

Originally Posted by magnakansas

The vin will do nothing in my case. So no point bothering. Go bock and read through Cadillac kids redbyrd thread on his transmission swap.

There is fellow that will supply me with a new TCU, wire harness, and throttle position sensor.

In my case I will likely build/modify my own harness.

There is no input from my engine, it doesn’t have electronics
William

let me guess jason at transmissiontuner dot com.. if so then I fully recommend him!!



this goes for the other post looking to put a 2000 series in a 94 that doesnt have the J1939..



what you will need to do is fashion up a throttle linkage to get throttle position into the transmission.. there are a few ways to do it..



if you buy a transmission, wiring harness and TCM from a newer bus as a set, it will be a "J1939" throttle, meaning its looking for throttle position from a data link.. this is what the mnid 97 and older engines lack,



CAC (custom automatic conversions) makes a throttle box in which you piggyback wire into your existing throttle pedal circuitry.. it measures the voltage and creates a J1939 data message that approximates to throttle position 0-100..



I have one of those boxes laying in a drawer.. that is the route I went on my redbyrd before I discovered my engine contained the native J1939 link (the Redbyrd TRANSformation) thread.. it did work but me being a perfectionist didnt like the operation of my transmission when running cruise control.. I had no downshifting because the pedal never moved.. it stayed in the '0' position all the time so I had to always punch the pedal on hills so kind of defeated cruise control..



the other method is a mechanical to electronic throttle box.. I believe the way Jason does it is takes a mechanical cable that is pulled in and out of a box that translates to a resistance.. his box is designed to connect to a TCM that is set up for analog or "auto" throttle .. generally this box will not work with an OEM TCM that looks for J1939 throttle only.. (he sells pre programmed TCM's as well as harnesses as well).. he may have a J1939 boix, I havent asked him for awhile..



with this type of scenerio yuo would fashion a bracket to anchor the cable housing and then a linkage you would connect physically to the arm on your pedal.. a J1939 scan tool is paramount for this as you would nbeed to see how the trans sees the throttle position as you floor and release the pedal so you can adjust your geometry (geometry is how far up or down the shank of the pedal and where to place the anchor on the dash frame) so you can achieve as close to 0 throttle off pedal and 100% throttle reading to the trans when floored..


this method also will give you lackluster results running cruise control as the pedal is always at 0% even when climbing hills and the engine is working its arse off..





the next method is to do it all electronically with either a commercially sourced J1708 to J1939 converter or you can build your own..



even the 1994 T444E engines have J1708 (its whats on the 6 pin gray connector under the dash).. in this data stream are several data points of note..


1. TPS - threottle position. 0-100% of actual pedal position
2. Engine Load - an approximation of the engine's load factor 0 - 100%
3. Cruise Set speed. when cruise is active shows as the set.. or 0 if cruise is off
4. Cruise Active. shows as engaged or disengaged..



these parameters also exist in J1939 as well...

using a translator you can run an OEM J1939 allison TCM (like would be on a modern bus).. and you can translate the data from your J1708 into J1939 parameters and send them to the transmission.. sometimes when cruise is engaged you can simply send the engine load factor in place of the actual pedal position.. modern TCM's recognize that cruise is on (since you tell it thats the case).. this method is the hardest if you dont know how to write code, but is the easiest if you do..

you use a pair of these devices..
https://buy.advantech.com/OBD-Adapte...-BB-HD3-A3.htm


and then run the data through a raspberry pi or such and write a program to make the data translations.. I think there is some coding stuff in my redbyrd trans thread...

I have a few of those advantech devices (their earlier versions) and they work well...



you could also build your interfaces using ELM325 (J170 and ELM327(J1939) chips and roll your own raspberry pi hat...



since i write code for everything from my work stuff to my home HVAC to my busses.. it seems like a rather easy method..


just some things to think about..
-Christopher

[magnakansas]

That throttle position sensor... I think, from what I have seen, can be set up so that if there is a cruise servo connected to the throttle linkage, the throttle posiiton sensor will read the change as the cruise system is modulating the throttle.

one of the things I am going to have to work out is how to use throttle position, intake boost level, and see if that is enough to figure calculated load. I suppose i need to look at turbine pressure also...... and engine rpm.... The thought is two possible ways.... a look up table and on the fly calculation combination of both? dunno.

I think getting drivability issues worked out to a fine point is always difficult. IF you do it well.

I have been looking at Li'l black box, I think is an arduino based control for the holset 351 and holset 300 variable geometry turbos.

an interconnection between throttle position, rear axle road speed input, engine rpm will come from torque converter speed, intake boost, EGT, possible exhaust manifold pressure,

I am thinking the throttle position needs to be connected directly to the injection pump, by pass all the linkage....

maybe this needs its own thread

william

[cadillackid]

on the 12 valve, you always have a mechanical input to the engine.. the T444E doesnt.. on the 12 valve the pedal actuates the pump input.. which is where id keep it.. if you want to run VGT and electronically control a mechanical engine.. id just hop up a 24 Valve that already has most of what you would install with a matrix iof little black boxes..



putting cruise on 12V will not require any kind of load factor or cruise data be sent to the allison, as the allison will treat it like its being driven straight.. you can formulate some trans control with a box like engine load and kickdown (maybe trigger kickdown based on an output from an EGT gauge)..


as far as enginbe load... IH does it fairly simople from what I can tell..


on a diesel (unlike a gas car).. the throttle is simply an RPM setpoint.. notice if you sit in the seat of a diesel in neutral you can oress the pedal halfway down and the engine wont run away to the rev limiter.. on a gas car it will...



on a mechanical its a valve stop in the pump that slows the fueling down when it reaches the throttle setpoint .. and fuels heavier the firther you get away from that setpoint..



this is how diesel Lugging comes into play.. low RPM yet you have the throttle way down.. its goingto fuel as heavy as it can to try and reach that setpoint.. a gas car at half throttle wont fuel any more than whatever fueling precentage the map calls for at that TPS and RPM..



so IH looks at how heavy it is fueling when you are away from the setpoint and it tempers the data.. it also looks at how much from minimum fuel it takes tio hokd it at the setpoint and then adds a nominal amount like 10%.. so at idle its like 18-24% with the A/C on.. and like 17% A/C off..



it fuels less than called for in the map when you over shoot.. overshoot the RPM too much and the engine actually shuts off.. (the T444E, DT466E will actually shutdown until they get close to the setpoint by TPS.. 700 RPM at 0%.. with an AT545 theengine rarely shuts down long.. wioth a manual or a lockup trans ive had my engine shutdown going downhill long enough my EGT gauge was at like 150f .. literally colder than the coolant around the cylinders..


the allison base maps are speed (tailshaft speed) vs throttle.. you never want to set a shiftpoint so high that at that throttle position the engine reaches its setpoint and backs off completely and the trans never shifted. you usually want to shift close to that engine RPM setpoint.. and then downshift a bit higher.. but not so close that you cause hunting back and forth


then there are outside factors such as kickdown request where the transmission will downshift to the lowest gear it can without getting close to the maximum RPM for the inout shaft.. (engine RPM).. when the kickdown request is cancelled then the trans resumes its normal shift schedule..



on most TCMs an input can be triggered that will call a different shift schedule.. maybe you want a pseudo Tow/haul mode where you run up-pressure (be very very careful editing TAPs you can scatter the trans).. and later shifts with early downshifts for when you are in the mountains.. maybe in those cases you want you shift points slightly above your throttle theoreticakl setpoint so you can hold gears and then release them by letting off the pedal a bit.. with a wide downshift you wont trigger a downshift right away..


I use EFIlive and tunbe my wn shift maps...



back to the T444E that was mentioned here.. on the T444E it is a drive-by-wire engine.. the oedal is nothing more than a rheostat that provides return voltage back to the computer from 0-5 volts.. a 5 volt reference along with its own reference ground and then the returnb signal wire are used to tell the computer how far you pressed the pedal. . 2 other wires exist which are a switch that lets the comoputer know your foot is off the pedal.. if it sees this switch open yet sees no TPS movement, the throttle is disabled and the check enginbe light turns on..



when you use cruise control with an engine like this, the pedal just sits there.. (unless you install aftermarket cruise).. the factory cruise is all electronic internal and the pedal stays at 0%.. like any cruise you can floor it to override the cruise if you want but it wont cancel it..



so if you were using an aftermarket throttle (not an engine data link) you have no TPS data to send to the cruise unless you translate the J1708 to J1939 and send it in a data link...

[magnakansas]

I am going read this multiple times and think about this so I can absorb all the information.


william

[cadillackid]

sorry magna i can be buzzkill at times.. i did make a mistake in that post.. you want to downshift LOWER than your upshift for that throttle position..



so if you lose speed you will downshift to a lower gear.. and the Upshift from the lower gear back to your original should be above the downshift..



so say you are in 4th gear and losing speed.. the trans will drop to 3rd.. and then the 3-4 upshift point will want to be somewhat higher than the 4-3 downshift so you have a chance to run-out that lower gear to gain back speed..



dont be afraid of this stuff.. most times people never touch it... I only did because I really didnt care for the provided shift schedule in either of my TCMs.. my rear is over geared so the tendency of the TCM;'s to always get me in a lower RPM higher gear (like a car) resulted in alot of lugging and high EGT.. so I built my own shfit tables..

[magnakansas]

NOt a buzzkill in any way...... not at all

I dig your posts.... just that some times I think I have to think carefully about everything you said....

I dont want to miss any bits of information.

I would love to live in the same neighborhood as you... I think I could learn and I would be able find and give some assistance to the more physical projects.

It can be a huge help mentally when one of my friends comes over to just hang out during a project.

custom shift tables..... it is like like race parts "just bolt on" HA never just bolt on. Custom trans/engine/rear end gears = custom programming


william

[cadillackid]

Originally Posted by magnakansas

It can be a huge help mentally when one of my friends comes over to just hang out during a project.

THIS!! is the truism of the decade!



one of my friends used to do that.. or i was at his house. (before he found the man of his dreams and dropped off the face of the earth)..


we were always at each others' houses building or wrenching or tuning something!



whether it was one of my hotrods or his hotrods.. or HVAC.. we both love to build HVAC so it seemed our houses probably have the best and most advanced HVAC in our neighborhoods..



Lots of time spent on upside down 5 gallon buckets, pop bottles, beer bottles, Pizza boxes...



tools everywhere, grease everywhere, football games on the garage TV...
then there was always that time when you figured it out and so it was time of a sat night to see how loud we could squeal the tires.. or how far could the coal roll!...





as for custom shift tables.. not everyone need go that far.. I do because the busses are customs.. like many do classic rest-o-mod cars thats the busses for me.. a bus will never be my home or my long-term sleeper.. sure i may drive them lots.. but 99% of the nights out there they are parked in a hotel parking lot while I sleep inside the building.. so for me if it takes me forever to swap a trans or build a motor.. or if I blow something to pieces.. its simply a reason to build it back better because im not on a schedule..



if the red bus is broken ill drive the dev bus.. if the dev bus breaks i drive the Superior.. and the superior is a loadstar Superior.. it wont break.. it just wont..

[Jolly Roger bus 223]

chistopher i hope it doesnt but everything old breaks ?
not to give you you bad vibes.
hope all goes well.
i get to play with a 1940 fuel oil boiler converted to natural 1 year ago and has never been correct?
fun stuff?
oh and i have trends on annnexaire units to sell to the govt.
sorry work before life.

[cadillackid]

Originally Posted by Jolly Roger bus 223

chistopher i hope it doesnt but everything old breaks ?
not to give you you bad vibes.
hope all goes well.
i get to play with a 1940 fuel oil boiler converted to natural 1 year ago and has never been correct?
fun stuff?
oh and i have trends on annnexaire units to sell to the govt.
sorry work before life.

work before life == my life!.



love that old boiler! all old stuff breaks sometimes!.. OK but really I just had to say because its a superior and a loadstar it wont break!( literally when I first started dreaming of owning my own bus (when I was a teen).. a loadstar superior was my all time Bucket-list bus.. as life went on i figured id never find one.. then I did! ha! LOL


good ole CAST IRON boilers when cared for will just go! is it a Steamer or Hot water?



I worked on a few steamers that were coal converted to Nat .. at least one is still running (in old churches)..


thiose thigns were BEASTS.. the conversion burner was an external device.. that essentially just blew flames .. big ones.. into the bottom of the firebox.. it would turn on with the Thermostat call and shut off with the T-stat or the pressretrol.. those old systems ran 6 PSI!! it did have an electric chimney damper to help increase the efficiency when it was off..



last time i worked on one of those was in like 1997.. last year I got a call from an old guy.. said he founf my number scribbled on a note in the maint shop.. the note had 2 phone numbers.. "furnace guy".. which he said rang disconnected.. and "smart furnace guy chris" which rang to my cell (yes ive had the same number since 1994 or so...).. was all in a panic because it was cold in the church and the furnace wouldnt light.. he took the cover off and found the spark ignitor was pretty much destroyed....



"well im niot much help now BUT.. I do remember putting a spare ignitor in a shallow desk drawer in a metal desk that say in the room next to the boiler.. I labelled it as boiler ignitor.. im sure that desk is long gone and im sure that piece has been used but maybe the box is still there and we can get the part number.. and ill try to get you one"..



I heard rustling around and dude picked the phone back up.. well the box is here.. and there is what looks like a Brand new ignitor in here!.. he sounded more excited than when someone's kid is born..



"it takes just the spark plug wire and 2 screws.."..


OK let mne put it on..


I hear tools and metal covers..


" how do I turn it on? "


recycle the power breaker in the little grey box that resets the unit's timer


.. I hear a fan come on.. (inducer)... I hear the screeeeaaaaaak of the damper opening.. I hear CLick!! ZZZZZzzzzZZZZ..!! BaWoooosh!!! Woaoaooaoo!! I knew right then that ole boiler would live to see another day...



"oh my god.. its running.. its really running!.. you really are the smart furnace man!"...


ha!! wow that was a blast from the past.. I think that old burner was either a gabriel or a Beckett conversion burner...

[Jolly Roger bus 223]

its a steam boiler in a dry cleaners.
and if you hear the news about the camp lejeune lawsuit its actually the dry cleaners they are trying to blame for the contaminated water.