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Topic: speedometer issues (Read 1669 times) previous topic - next topic

Re: speedometer issues

Reply #20 –
Stump, I read your post along with several others. I'm just gonna look at the sending unit to see if I can find anything wrong. I don't intend to remove or disassemble it because it's currently working. When it stops working I'll start removing and disassembling things after I troubleshoot. I was just trying to educate myself ahead of time by reading old posts on here. In my experience it's usually difficult to troubleshoot something that's still working... and I really hate breaking stuff that still works

Re: speedometer issues

Reply #21 –
Quote from: RRadio –
In my experience it's usually difficult to troubleshoot something that's still working... and I really hate breaking stuff that still works.
Scott, Here's a troubleshooting flow chart to help you out:


Re: speedometer issues

Reply #23 –
@Scott,

I can't say for sure but I'd bet money that your speedometer is your problem. Mine worked intermittently for about a year before it died completely. The original analog (milage) speedometers seem to have a limited life. Replacement is in your future. The good news is that while it's still working you have time to find one on ebay at a reasonable price. The bad news is my tachometer just died a week or so ago. So you have that to look forward to.

see ya
ken

Re: speedometer issues

Reply #24 –
[ The bad news is my tachometer just died a week or so ago. So you have that to look forward to.]

Ay Yi Yi!

Re: speedometer issues

Reply #25 –

Don't mean to steal this thread but I have speedometer problems also. I have attached a photo (I hope) of the part I think is bad. This mounts on the transmission and it might be called the mini generator. Anyways the sort drive cable's end that looks like an old speedometer cable slides into this piece but it just seems to turn freely as if the female socket is worn out.
Anyways what is the proper name for this part and where can I find one?
[/quote]

Re: speedometer issues

Reply #26 –
You're not stealing the thread. You're exactly on topic with speedometer issues.

Re: speedometer issues

Reply #27 –
Quote from: Jerryetc –
Anyways what is the proper name for this part and where can I find one?
Jerry,

Identifying and locating obscure parts for old motorhomes can be a challenge.  It is helpful to provide as much info as possible when asking for help.  In this case, you might specify what transmission you have - I'm guessing it is a Allison MT643 - and what engine.  I would also like to see a more "zoomed out" photo, so I can see what the other end of the electric wire looks like, and what the drive cable looks like (both ends).  Photo of the attachment point on the transmission would be nice.

I think your best bet might be a really good (local to you) "speedometer shop", if such things still exist.  Back in the day, these shops used to specialize in making/supplying adapters to mate any transmission to any speedometer.

You could try a Allison transmission shop, but they will probably say it is not a Allison part, so can't help you.

Without a part number of some kind, a online search will be difficult.  You will find lots of parts that look similar to yours, yet might not work at all.  Besides having to mechanically screw together correctly, the part also has to be electrically compatible.  The mini-gen "generates" a electrical signal that must be translated by the speedometer into MPH.  The frequency or voltage or whatever of the mini-gen and the speedometer must match.

Wish I could be more help.  The thread linked below shows the "process" a Barth owner went through to find this kind of part.  In the long run, it might be easier to just install a new aftermarket speedometer.  Do you have cruise control?  Does it still work?

Hall Effect Sensor - VSS Sensor - Speedometer Ratio Adapter - Topic

Re: speedometer issues

Reply #28 –
Chuck & Jeannie, Thanks for your response. I will try to get the photos later today. For now, to answer some of questions, the cruise still works, the transmission is a 4 speed Allison ( I'll try to get the numbers when I take the photos) the engine is a Cat 3208. I have sent the speedometer head and what I thought was the generator to, I think, Texas Speedometer and they said they checked out fine. I have put off troubleshooting the problem for over a year and have been using my GPS as a speedometer. Of, I had no oedometer.
 On your suggestion of a new speedometer, will it come with the generator and adapters to connect it to my transmission and cruise?
Thanks again.

Re: speedometer issues

Reply #29 –
Quote from: Jerryetc –
On your suggestion of a new speedometer, will it come with the generator and adapters to connect it to my transmission and cruise?
I don't know - my speedometer still works, so I have not researched that subject.

The engine and transmission info will be helpful to anyone trying to answer your questions.  You should add these to your signature.

You might try using the Forum "Search" function - it will often provide the exact answer you seek.  Try searching for "new speedometer", or perhaps "replacement speedometer".  See what other members have done in this situation.  For instance:

'93 U300 speedometer

Re: speedometer issues

Reply #30 –
The Speedometer/Cruise  Control  "T" fitting turns out to be a Bendix Product.  Am going to visit a Allison Dealer soon to find out if they have a cross over to it, since Bendix is long gone.

Re: speedometer issues

Reply #31 –
Jerryetc  ----  I had very good service from Steve @ Portland Speedo Service for solving my speedo problem.  After doing the troubleshooting that he recommended, I ended up replacing the mini-gen sender on my Allison 4 speed.  The new mini-gen sender is an "isspro  P/N R 8970, date code 2415".  Give Steve a call @ 1-800-634-2145.  I'm sure that he can help you thru this.  Have a great day  ----  Fritz

Re: speedometer issues

Reply #32 –
Fritz, Did your mini-generator look similar to mine?

Re: speedometer issues

Reply #33 –
Thanks to all for your help. I took Fritz"s advice and called Steve at Speedometer Service in Portland. It  appears that my drive pin may be the problem, but I am mailing both the mini-generator and the drive pin to Steve and he going to check it, fix it or replace it. Also Chuck I am going to take your advice and expand my coach information on my page.

Re: speedometer issues

Reply #34 –
Jerry,

Glad you found some help on your speedo problem.

I see you have added the coach data to your signature.  Excellent!  You might double-check your transmission model number.  Most of the Allison 4-speed model numbers start with a "6", and most 6-speed model numbers start with a "3" or a "4", which is really kinda bass-ackwards when you think about it.
 

Re: speedometer issues

Reply #35 –
Thank you Chuck. I changed to 643. I don't know where that 463 came from.