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 Transmission Problem 2000 International
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Mark23290
Senior Member

United States
63 Posts

Posted - 09/19/2013 :  1:13:11 PM  Show Profile  Reply with Quote
Looking for suggestions, I have a 2000 International with a Alsion AT 545. The bus is on the third transmission in two years. Just had a new one installed and I have less then 100 miles since it left the garage and it is clunking between 1st and 2nd on the upshift and sometimes like shutters and jerks the whole bus as it downshifts.. The upshift really clunks or shifts hard. Is there any sensors or something telling it to do this? I can not imagine another bad transmission right off the shelf.



Feeeling very frustrated.
Any suggestions or ideas are greatly apprecited--- even making it a pontoon is starting to cross my pea brain.....

Mechan1c
Top Member

USA
674 Posts

Posted - 09/19/2013 :  2:22:19 PM  Show Profile  Reply with Quote
Is this the same bus that has the unknown buzzing going on??
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Mark23290
Senior Member

United States
63 Posts

Posted - 09/19/2013 :  5:33:29 PM  Show Profile  Reply with Quote
Yes it is. I'm wondering if the electronic modular on left side of the trans could be faulty.

I spoke with a guy at Alison and he said the modulator should kick out about 1/2 throttle if I remember what he said. Mine does it when its to the floor. ( Had key on and took modulator out and visualized the plunger kick out ). As the guy said to test it.

But any advise here is greatly appreciated. I seen older posts where the Alsions are bad for shifting hard and I'm wondering is it just me...
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bluebirdvision
Top Member

USA
992 Posts

Posted - 09/19/2013 :  6:27:21 PM  Show Profile  Click to see bluebirdvision's MSN Messenger address  Reply with Quote
All our 545s shifted hard, our last units were built in 2001.. they shifted terribly hard up until about a year before the district traded them in, THEN the garage figured out that by adjusting the modulator they were able to make them shift a little "easier"

Shane Kirley
New York Bus Sales Delivery Driver. (I know its not much, but its a start)


Facebook Page: Blue Bird Corporation Fans
https://www.facebook.com/home.php?sk=group_212311114614&ap=1


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Mark23290
Senior Member

United States
63 Posts

Posted - 09/20/2013 :  05:19:29 AM  Show Profile  Reply with Quote
quote:
Originally posted by bluebirdvision

All our 545s shifted hard, our last units were built in 2001.. they shifted terribly hard up until about a year before the district traded them in, THEN the garage figured out that by adjusting the modulator they were able to make them shift a little "easier"



How did they adjust the modulator? It's just a bolt holding a clip on the side of the tranny?
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Mark23290
Senior Member

United States
63 Posts

Posted - 09/20/2013 :  07:05:34 AM  Show Profile  Reply with Quote
How can you adjust the electronic Modulator? Do you have any reference to relays or wiring diagrams. I took the modulator off last night and the plunger kicked out when the accelerator was about floored. The tranny at slow speeds also will shutter which I'm thinking its hunting for the right gear. I have a 97 International 444E same set up and it shifts and runs so much smoother almost cant tell its shifting at all.

BTW you guys rock when it comes to information. I have learned alot thru the site.
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Wolf0r
Top Member

USA
2177 Posts

Posted - 09/20/2013 :  08:30:51 AM  Show Profile  Reply with Quote
I have a test harness I built with a dome light bulb. Hook it across the modulator so see if it is getting powered up when you give it throttle. The buzzing might be a defective relay. GMCV in that year had problems in that area. Some even came from the factory missing the modulator relay.

“The good thing about science is that it's true whether or not you believe in it.”
Neil deGrasse Tyson
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Mark23290
Senior Member

United States
63 Posts

Posted - 09/20/2013 :  10:26:29 AM  Show Profile  Reply with Quote
Do you think the relay mounted on the left side at the foot (there are three of them.Its the middle one) could be causing the issues? It does buzz all the time. I unplugged it and now have plugged it back in. The bus ran the same with it in this morning. Is there a way the layman without a computer can reset the ecm?

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Mark23290
Senior Member

United States
63 Posts

Posted - 09/20/2013 :  10:48:33 AM  Show Profile  Reply with Quote
BTW This is in a 2000 International AM Tran T444E 145,000 miles on her.
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Wolf0r
Top Member

USA
2177 Posts

Posted - 09/20/2013 :  11:56:45 AM  Show Profile  Reply with Quote
I don't know on the reset. Here is how the modulator is setup.
[URL=http://s229.photobucket.com/user/nixbus/media/IC_modulator_zps888772fa.jpg.html][/URL]

“The good thing about science is that it's true whether or not you believe in it.”
Neil deGrasse Tyson
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Wolf0r
Top Member

USA
2177 Posts

Posted - 09/20/2013 :  12:14:07 PM  Show Profile  Reply with Quote
TSI Number: 97-08-02

TSI Date: March, 1997

Subject File: ELECTRICAL

SUBJECT


Allison AT/MT Transmissions Used with International T 444E, DT 466E and 530E Engines

APPLIES TO



Vendor: Allison
Model: 1000 3000 4000 8100 8200 8300


DESCRIPTION


Vehicles equipped with International T 444E, DT 466E and 530E engines and Allison AT or MT transmissions may experience harsh (abrupt) 1-2 or 2-3 upshifts. Kit part number 2500739C91, containing a switch and installation hardware, is available to eliminate harsh (abrupt) upshift complaints. The switch is wired into the transmission modulator control relay and activated by the throttle pedal resulting in a faster ON signal to the transmission modulator control relay.

I know it's dated 1997 but this may fix your troubles.

“The good thing about science is that it's true whether or not you believe in it.”
Neil deGrasse Tyson
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Mark23290
Senior Member

United States
63 Posts

Posted - 09/21/2013 :  07:26:56 AM  Show Profile  Reply with Quote
Did some checks and the modulator seems to be working. The buzzing relay I switched them and it still buzzes. Found that with the relay in the change transmission filter light comes on. The new tranny also had a new filter put on.
Guess I will have to take it back in and have them put a computer on it and make sure the computer is telling it the right things.. From reading it seems these Alsions are bad for this, but I have never had problems like this before.
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mastertech
Advanced Member

228 Posts

Posted - 09/22/2013 :  09:07:56 AM  Show Profile  Visit mastertech's Homepage  Reply with Quote
We had issues like this on the late 90"s re's. Sometimes the relays were actually wired wrong and doing just the opposite of what they were supposed to or the ecm was on/off cycling the modualtor even at full throttle.( you had to actually test drive with a test light on the modulator to find this as it wouldnt do it in the shop) Installing the throttle pedal kit fixxed the issues but you had to check them from time to time as the silly toggle switch they used could sometimes get knocked out of position by the drivers foot.
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Mark23290
Senior Member

United States
63 Posts

Posted - 09/24/2013 :  1:49:33 PM  Show Profile  Reply with Quote
Well took it back to the shop who did the install, and they say it is fine. That is is just setup tighter then the last tranny.
I mean you can here a clunk between 2-3 like a hammer tapping metal. It goes thru the gears fine.
So I'm not sure as which way to proceed....
And it sure likes to hunt for the right gear pretty frequently. The buzzing relay does not cause any change installed or out. Same with disconnecting the modulator from the side of the tranny.. Any suggestions???
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jperkins
Active Member

USA
41 Posts

Posted - 10/23/2013 :  8:23:51 PM  Show Profile  Reply with Quote
I think tech-one or sams if still in buisness made modulator kits which were brackets mounted to fuel pedal and a cable modulator to replace electric modulators I installed a lot of these kits when I worked for detroit diesel allison dist. they smoothed up some shifting complaints the electric mod. is just slam on at 60 percent throttle and off at 45 percent if working right the cable style feathers the mod. on
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tigger2
Advanced Member

USA
281 Posts

Posted - 10/24/2013 :  04:43:32 AM  Show Profile  Reply with Quote
We had a 1997 Chevy gas box truck with an AT545 donated to band, that had harsh up-down shifts that was vacuum operated. We ordered a cable modulator from Vally truck parts and welded a bracket onto the throttle pedal and adjusted the travel. Now it shifts fine we could find nothing wrong with the engine vacuum or the modulator.
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