Reply
 
Thread Tools Display Modes
 
Old 09-11-2019, 05:14 PM   #11
Mini-Skoolie
 
NovaTRON's Avatar
 
Join Date: Dec 2016
Location: Seattle
Posts: 26
Year: 1995
Coachwork: Thomas
Chassis: Oshkosh
Engine: Cummins 5.9 12-valve
Rated Cap: 26
Here is the sensor/sending unit from the AT545



(try this again- sorry still learning to use this site)
Here is the sending unit/sensor on the MT643



I haven't pulled the sensor out of the MT643 yet to compare, but the mechanic says they are "2 different types of sensors" , so I'm not sure if pulling the Tone Ring gear off of the AT545 is the way to go or not..
Attached Images
File Type: jpg signal-2019-09-11-142728.jpg (138.5 KB, 26 views)
File Type: jpg signal-2019-09-11-142728-3 (1).jpg (84.7 KB, 22 views)
File Type: jpg 20190905_141751 (1).jpg (173.1 KB, 22 views)
NovaTRON is offline   Reply With Quote
Old 09-11-2019, 06:20 PM   #12
Bus Nut
 
Join Date: Jun 2015
Location: Asheville, NC
Posts: 287
Year: 1999
Coachwork: American Cargo 14'L x 7'8"W x 7'H Box
Chassis: Ford E350 Cutaway
Engine: 7.3L Powerstroke
Rated Cap: 11500 lbs
Quote:
Originally Posted by NovaTRON View Post
Here is the sensor/sending unit from the AT545



(try this again- sorry still learning to use this site)
Here is the sending unit/sensor on the MT643



I haven't pulled the sensor out of the MT643 yet to compare, but the mechanic says they are "2 different types of sensors" , so I'm not sure if pulling the Tone Ring gear off of the AT545 is the way to go or not..
There is no tone ring in your AT545 show in the picture. It uses a gear that meshes with the gear of the transducer you are holding in your hand. This transducer adapts transmissions that originally had a mechanical speedometer cable to an electronic speedometer.

A tone ring has very coarse, square teeth that are not meant to mesh with anything. It is a non-contact solution that relies on changes of a magnetic field (or more precisely, reluctance). That's what your mechanic tried to convey; two completely different principles. You would have to get the correct AT545 tone ring from somewhere else like fleabay or a junkyard.

BTW, that conversion box I was talking about is called ERA and costs $180.
alpine44 is offline   Reply With Quote
Old 09-11-2019, 06:50 PM   #13
Mini-Skoolie
 
NovaTRON's Avatar
 
Join Date: Dec 2016
Location: Seattle
Posts: 26
Year: 1995
Coachwork: Thomas
Chassis: Oshkosh
Engine: Cummins 5.9 12-valve
Rated Cap: 26
Quote:
Originally Posted by alpine44 View Post
.....

BTW, that conversion box I was talking about is called ERA and costs $180.
Thank you! I'll look into this solution, which may be the best bet, including if I ever end up changing my rear end gear ratio.
NovaTRON is offline   Reply With Quote
Old 09-11-2019, 06:57 PM   #14
Bus Nut
 
Join Date: Jun 2015
Location: Asheville, NC
Posts: 287
Year: 1999
Coachwork: American Cargo 14'L x 7'8"W x 7'H Box
Chassis: Ford E350 Cutaway
Engine: 7.3L Powerstroke
Rated Cap: 11500 lbs
Quote:
Originally Posted by NovaTRON View Post
Thank you! I'll look into this solution, which may be the best bet, including if I ever end up changing my rear end gear ratio.
To answer your previous question: The adjustable Thomas/Ametek speedometers have the dip switches visible from the rear in a cut-out. I have the instructions for the adjustment if you need them.
alpine44 is offline   Reply With Quote
Old 09-11-2019, 09:19 PM   #15
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 11,860
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
Ok .that was the device I tried to describe previous was a gear to electric conversion.. now take the sensor out of your 643 and how down the hole? Is that a worm gear like the hole shown or is it the course gear alpine talks of which is a tone ring..

So right now how is it set up? The moved the sensor from your 545 and screwed it into your new 643 and your speedo reads double speed?

The 4 wire sensor is what was OEM on your bus correct? I’d the 2 wire that’s in the at545?
Any part numbers on that 2 wire sensor or where it came from?

What I’m trying to figure out is what was on the bus originLly and which one was new with the new trans?
Reason I ask about it is if he cobbled together wiring to make the 4 wire sensor work when the 2 wire sensor was oem that could explain issues..

Sounds like alpine has you covered better than I at this point.

Although that 2 wire sensor intrigued me as I am working on another bus project where one just like that would be the ticket so if it has any numbers or where you got it from please do tell
cadillackid is offline   Reply With Quote
Old 09-11-2019, 10:17 PM   #16
Mini-Skoolie
 
NovaTRON's Avatar
 
Join Date: Dec 2016
Location: Seattle
Posts: 26
Year: 1995
Coachwork: Thomas
Chassis: Oshkosh
Engine: Cummins 5.9 12-valve
Rated Cap: 26
Quote:
Originally Posted by cadillackid View Post
Ok .that was the device I tried to describe previous was a gear to electric conversion.. now take the sensor out of your 643 and how down the hole? Is that a worm gear like the hole shown or is it the course gear alpine talks of which is a tone ring..

So right now how is it set up? The moved the sensor from your 545 and screwed it into your new 643 and your speedo reads double speed?

The 4 wire sensor is what was OEM on your bus correct? Iíd the 2 wire thatís in the at545?
Any part numbers on that 2 wire sensor or where it came from?

What Iím trying to figure out is what was on the bus originLly and which one was new with the new trans?
Reason I ask about it is if he cobbled together wiring to make the 4 wire sensor work when the 2 wire sensor was oem that could explain issues..

Sounds like alpine has you covered better than I at this point.

Although that 2 wire sensor intrigued me as I am working on another bus project where one just like that would be the ticket so if it has any numbers or where you got it from please do tell
No sensors were moved. The 2 wire transducer/sending unit with the pencil gear (pictured) was the original on the AT545.

The 4 wire sensor/sending unit came with the MT643 and was straight connected right to speedometer, though with just 2 wires, and is now giving me the doubled speed & distance.

Without pulling it out to look, I'm assuming this 4 wire sensor on the MT643 is the type that uses a Tone Ring (but that's also what I assumed about the 545 -which contradicts every thing I had read up until now)

Sounds like the Electronic Ratio Adapter (ERA) is the easiest fix for this job.

Oh and here is a pic of speedometer - if that helps anything
NovaTRON is offline   Reply With Quote
Old 09-12-2019, 06:04 AM   #17
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 11,860
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
Ok now I’m understanding. That 4 wire sensor may not give a signal compatible with your speedo also. I’d love to see a pinout of it as I’ve only ever seen 3 wire not 4.
So that 2 wire is what was originally in the bus as OEM.
So yours may be opposite of my issue. My 545 had a tone ring my 643 a gear.
And the new endeavor I’m working on has a gear and needs a tone ring. I need a sensor like your 2 wire.

You could swap the gear and ring from trans to trans.. I’m not sure what that box posted is, I couldn’t find it, I’ll have to scroll back through the thread to see if it is special.

This is the speedo cal unit I use and it works great.
https://www.summitracing.com/parts/d...SABEgLeR_D_BwE
cadillackid is offline   Reply With Quote
Old 09-12-2019, 11:41 AM   #18
Mini-Skoolie
 
NovaTRON's Avatar
 
Join Date: Dec 2016
Location: Seattle
Posts: 26
Year: 1995
Coachwork: Thomas
Chassis: Oshkosh
Engine: Cummins 5.9 12-valve
Rated Cap: 26
Which unit should I go with???

Quote:
Originally Posted by cadillackid View Post
Ok now Iím understanding. That 4 wire sensor may not give a signal compatible with your speedo also. Iíd love to see a pinout of it as Iíve only ever seen 3 wire not 4.
So that 2 wire is what was originally in the bus as OEM.
So yours may be opposite of my issue. My 545 had a tone ring my 643 a gear.
And the new endeavor Iím working on has a gear and needs a tone ring. I need a sensor like your 2 wire.

You could swap the gear and ring from trans to trans.. Iím not sure what that box posted is, I couldnít find it, Iíll have to scroll back through the thread to see if it is special.

This is the speedo cal unit I use and it works great.
https://www.summitracing.com/parts/d...SABEgLeR_D_BwE
I could swap the gear and ring from trans to trans, but it seems using a calibration unit would be much easier/faster- though does requires another purchase.

The Abbott unit cost $180
ERA (Electronic Ratio Adapter)¬* Your Speedometer Solution

While the Dakota Digital unit is $80
https://www.summitracing.com/parts/d...SABEgLeR_D_BwE

Are these both going to accomplish the exact same thing? that is- re-calibrate/ adjust the ratio of the speedometer signal.

Anyone have an opinion on which unit to go with?

NovaTRON is offline   Reply With Quote
Old 09-12-2019, 12:43 PM   #19
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 11,860
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
I am using the dakota Digital unit on my red bus.. it can take in and custom adjust about any type of speed signal into any type.... it has a mode where you can drive a known speed... ie a GPS or follow other vehicle with calibrated speedometer.. and you can live-adjust the signal ratio up and down till your speedo matches..





your 2 pin adapter with a gear on the end? is there any part number on that? i really Need to buy one Just like that but have been googling and cant find that beast... where did you get that? was it OEM to your Bus?
cadillackid is offline   Reply With Quote
Old 09-12-2019, 01:01 PM   #20
Mini-Skoolie
 
NovaTRON's Avatar
 
Join Date: Dec 2016
Location: Seattle
Posts: 26
Year: 1995
Coachwork: Thomas
Chassis: Oshkosh
Engine: Cummins 5.9 12-valve
Rated Cap: 26
Quote:
Originally Posted by cadillackid View Post
I am using the dakota Digital unit on my red bus.. it can take in and custom adjust about any type of speed signal into any type.... it has a mode where you can drive a known speed... ie a GPS or follow other vehicle with calibrated speedometer.. and you can live-adjust the signal ratio up and down till your speedo matches..





your 2 pin adapter with a gear on the end? is there any part number on that? i really Need to buy one Just like that but have been googling and cant find that beast... where did you get that? was it OEM to your Bus?
Sounds fairly simple to install/adjust. And it saves $100 over the Abbott unit.

That 2 pin adapter is the OEM to the bus (as far as I know) . You can see some numbers in that picture, but they look too worn-out to be readable.

It's certainly possible that I could get that part back, though it is a bit of a drive for me.. I left the AT545 at the shop that did the swap/conversion- they are holding it for me for a short time until I determine if I can sell it for any core value, if not, they are just going sent it to scrap.. I've just had too much other things going on to even want to look into it.
NovaTRON is offline   Reply With Quote
Reply

Tags
at545, mt643, speedometer

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 12:05 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.