Speed-O/Odometer question

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Speed-O/Odometer question

April 30, 2019, 08:23:19 am

What drives the speedometer/odometer on my 97?

Mine is acting up, at about 35 mph it pegs the speedometer at about 95 mph.

Yesterday I checked the odometer and in 100 miles by Garmin Basecamp the odometer only advanced 25 miles.

Re: Speed-O/Odometer question

Reply #1 – April 30, 2019, 09:26:49 am

Most likely, since I haven't laid eyes on yours, a Hall effect device on the transmission. If you're very lucky all you have is a dirty plug in connection at one end or the other causing noise on that signal line, hence the Whoopee! speed reading.

My (our) speedometer unfortunately is dead and will require more aggressive troubleshooting, for which I have the equipment and skill set. Yay me.

Re: Speed-O/Odometer question

Reply #2 – April 30, 2019, 09:50:36 am

Quote from: Old Toolmaker – April 30, 2019, 09:26:49 am

Most likely, since I haven't laid eyes on yours, a Hall effect device on the transmission. If you're very lucky all you have is a dirty plug in connection at one end or the other causing noise on that signal line, hence the Whoopee! speed reading.
My (our) speedometer unfortunately is dead and will require more aggressive troubleshooting, for which I have the equipment and skill set. Yay me.

Thanks, so I will be looking for something with a pair of wires attached to it on the output side of the transmission?

Re: Speed-O/Odometer question

Reply #3 – April 30, 2019, 10:04:36 am

The speedo in my 95 was acting up like yours. I replaced it from Lauderdale speed shop in florida. They were great with easy install direction and set the odometer. Give them a call.

Re: Speed-O/Odometer question

Reply #4 – April 30, 2019, 10:14:38 am

Quote from: joeszeidel – April 30, 2019, 10:04:36 am

The speedo in my 95 was acting up like yours. I replaced it from Lauderdale speed shop in florida. They were great with easy install direction and set the odometer. Give them a call.

Thanks, might they have a different name? Google did not find that name.

Re: Speed-O/Odometer question

Reply #5 – April 30, 2019, 10:19:14 am

Steve,

Try them-- assume yours is a VDO: Instrumentation Repair - Lauderdale Speedometer

Re: Speed-O/Odometer question

Reply #6 – April 30, 2019, 10:25:16 am

Quote from: wolfe10 – April 30, 2019, 10:19:14 am

Steve,

Try them-- assume yours is a VDO: Instrumentation Repair - Lauderdale Speedometer

Thanks Brett that worked

will it say VDO on the back?

Re: Speed-O/Odometer question

Reply #7 – April 30, 2019, 10:52:49 am

Old Toolmaker ---- If your 92 is like our 91, check the signal generator that is connected into the xmition at about the 10:00 O,clock position. Ours has a gear driven "T" that drives the speedo signal and the cruise control signal. One time the speedo mini gen sender had to be replaced and another time the cruise control sender froze up and snapped off the pin that drives the "T". I have dealt with Steve at Speedometer Service in Scappoose, Oregon. I have gotten all of the pieces that I needed from him. His Phone No. is 800-634-2145. If the drive pin is snapped, PM me and I can give you some pointers on how to get the sheared off piece out of the xmition. I can also give you some help on how to test that mini gen sender. Happy troubleshooting and have a great day ---- Fritz

Re: Speed-O/Odometer question

Reply #8 – April 30, 2019, 11:25:24 am

Quote from: fkjohns6083 – April 30, 2019, 10:52:49 am

Old Toolmaker ---- If your 92 is like our 91, check the signal generator that is connected into the xmition at about the 10:00 O,clock position. Ours has a gear driven "T" that drives the speedo signal and the cruise control signal. One time the speedo mini gen sender had to be replaced and another time the cruise control sender froze up and snapped off the pin that drives the "T". I have dealt with Steve at Speedometer Service in Scappoose, Oregon. I have gotten all of the pieces that I needed from him. His Phone No. is 800-634-2145. If the drive pin is snapped, PM me and I can give you some pointers on how to get the sheared off piece out of the xmition. I can also give you some help on how to test that mini gen sender. Happy troubleshooting and have a great day ---- Fritz

So far, on a Saturday, I checked for voltage and found it. I'm kinda hoping to one of these days, fire up the generator, hook up the oscilloscope and take a drive and see if I have pulses. Early on I crawled underneath and looked at the sending unit(s) because I have a report of the cruise control coming and going.

Right now my excuse for not doing anything is that I need to finish cleaning the Rockwood for sale. That's my excuse and I'm sticking with it. That and my cardiologist told me to slow down some more, as I tried to "push" myself cleaning out the Rockwood.

FWIW, a stripped sending unit drive is on my nightmare playlist.

Re: Speed-O/Odometer question

Reply #9 – April 30, 2019, 11:54:18 am

Be aware that we are discussing spedo signals from two VERY different transmissions here: Hydraulic 4 speed on the U225 and Electronic 6 speed on the U270.

Re: Speed-O/Odometer question

Reply #10 – April 30, 2019, 12:19:01 pm

Quote from: wolfe10 – April 30, 2019, 11:54:18 am

Be aware that we are discussing spedo signals from two VERY different transmissions here: Hydraulic 4 speed on the U225 and Electronic 6 speed on the U270.

Are you telling me the signal for the speedometer is built into the transmission? My desire to learn new things ended when manufacturers began selling you stuff while retaining ownership of their intellectual property.

Re: Speed-O/Odometer question

Reply #11 – April 30, 2019, 06:02:36 pm

Our 91 GV has the 4 speed Allison ( model 647??) which has the gear box inserted into the xmition. The drive pin connects the xmition gear to the "T" gear box which has the speedo sender and the cruise control sender inserted into it. It is difficult to see and I would have had to do some thing drastic to get to it if I didn't have my pit to work in. Have a great day ---- Fritz

Re: Speed-O/Odometer question

Reply #12 – April 30, 2019, 06:14:44 pm

My speedometer died about 4 or 5 years ago. Took it to a speedodmeter shop near Tacoma, WA. They keep it overnight and said that they couldn't fix it. Inside was all corroded. New one was going to run around $200. I found one on ebay for $80 bucks and replaced it myself. Pretty easy to set using GPS. Mine was doing the exact same thing as Super8mm.

I really would have preferred the old analog odometer to the new digital one.

I've held on to the old one planning to pull it apart just to look at it. Just so happened to run across it yesterday and pulled it apart. Not easy to get open without doing damage to the black ring that attaches the works to the housing.

Took a bunch of pics. Hopefully someone gets some enjoyment out of em'.

see ya
ken

Re: Speed-O/Odometer question

Reply #13 – April 30, 2019, 06:23:11 pm

Mine was replaced at 14 years by rbark. Previous owner

Re: Speed-O/Odometer question

Reply #14 – April 30, 2019, 07:42:02 pm

Thanks Ken, mine has a digital ODO but it matches the Tach but from my pictures I cant tell what brand it is.

did you do any testing to see if it was the speedometer head or the sensor on the tranny?

Re: Speed-O/Odometer question

Reply #15 – April 30, 2019, 07:47:05 pm

Quote from: fkjohns6083 – April 30, 2019, 06:02:36 pm

Our 91 GV has the 4 speed Allison ( model 647??) which has the gear box inserted into the xmition. The drive pin connects the xmition gear to the "T" gear box which has the speedo sender and the cruise control sender inserted into it. It is difficult to see and I would have had to do some thing drastic to get to it if I didn't have my pit to work in. Have a great day ---- Fritz

We too have the Allison MT643 four speed. And I did the reading because I want to know and I have lots of down time to fill. The thing that got me when I crawled underneath was the location of the right rear jack. Just too convenient for my partner. "It was an accident. Honest."

I was a really good toolmaker, and part of that was looking for everything that could go wrong.

I too wish I could purchase a replacement VDO speedometer with the analog odometer, but I'll settle for being able to insert my own current mileage.

Re: Speed-O/Odometer question

Reply #16 – April 30, 2019, 08:07:38 pm

Quote from: Old Toolmaker – April 30, 2019, 07:47:05 pm

I too wish I could purchase a replacement VDO speedometer with the analog odometer, but I'll settle for being able to insert my own current mileage.

Give North Hollywood Speedometer a call. I used them all the time back a few years to replace the VDO speedo faces (Km to miles) and change gears on the ODO of my grey market imports. They are really good. If you have a VDO speedo part number for a like coach, it would help.

North Hollywood Speedometer Repair | NH Speedometer

Pierce

Re: Speed-O/Odometer question

Reply #17 – April 30, 2019, 09:23:30 pm

Quote from: Super8mm – April 30, 2019, 07:42:02 pm

Thanks Ken, mine has a digital ODO but it matches the Tach but from my pictures I cant tell what brand it is.

did you do any testing to see if it was the speedometer head or the sensor on the tranny?

I'd be very surprised if yours isn't a VDO. At least that's all I've ever seen. At least in the older coaches. Let me rephrase that senior coaches.

I didn't do any troubleshooting after the SpeedO shop said mine was corroded and it worked after I installed the new one (and still does).

see ya
ken

Re: Speed-O/Odometer question

Reply #18 – April 30, 2019, 11:12:44 pm

Quote from: Pierce & Gaylie Stewart – April 30, 2019, 08:07:38 pm

Give North Hollywood Speedometer a call. I used them all the time back a few years to replace the VDO speedo faces (Km to miles) and change gears on the ODO of my grey market imports. They are really good. If you have a VDO speedo part number for a like coach, it would help.
North Hollywood Speedometer Repair | NH Speedometer
Pierce

Thanks Pierce, I am going to the coach tomorrow to check for storm damage and will look at it and see if I can get a make and model of it.

Re: Speed-O/Odometer question

Reply #19 – April 30, 2019, 11:13:54 pm

Quote from: kenhat – April 30, 2019, 09:23:30 pm

I'd be very surprised if yours isn't a VDO. At least that's all I've ever seen. At least in the older coaches. Let me rephrase that senior coaches.

I didn't do any troubleshooting after the SpeedO shop said mine was corroded and it worked after I installed the new one (and still does).
see ya
ken

OK, Thanks Ken

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