Community Forums

tom chelbana · 06-11-2021, 01:46 PM

On You Tube the trucks use their GPS for the speedometer and there were no issues other then the loss of speedometer when disconnected.
Newmar Man

R.Wold · 06-11-2021, 01:53 PM

Quote:

Originally Posted by Rev. Roy

Thanks Tom! Someone raised the concern of the transmission being controlled by the speed sensor. Am I wrong in my thinking that the transmission shift-point is controlled by the RPMs not the speed? It's been too many years since I did engine/transmission work.

Quote:

Originally Posted by tom chelbana

On You Tube the trucks use their GPS for the speedometer and there were no issues other then the loss of speedometer when disconnected.
Newmar Man

The output to the speedo is just that. Everything else is internal so the trans still knows what’s going on, it’s just the feed to the speedo that you are eliminating.

NCC-1701A · 06-11-2021, 02:19 PM

Thanks for the post, Tom.

For those that don't have a GPS or other Speed option, there are Apps for cell phones that work very well. When the lin lines in my 2007 Journey went bad and had my dash gauges jumping all over, I downloaded a Speedometer app and used my phone on the dash as the speedometer to get through until I got new Lin Lines and installed them.

Ken C · 06-11-2021, 03:10 PM

Are the location and pictures of a 4000 series trans location? If so, does anyone know if the 3000 is in the same or similar location and look the same?

tom chelbana · 06-11-2021, 04:46 PM

Yes the picture is of a 4000 series trans. Have been under a number of Newmar coaches with 3000 series and looks very much like the photo of the 4000. Someone posted it was on the passengers side of the coach between engine and trans. Still waiting for someone to use disconnect so we can all travel safer and better know this will get us to a shop or home. This problem could go back to 2014 to today but we will have to see if older coaches have this problem too.

Newmar Man

Dutch Star Don · 06-11-2021, 09:30 PM

I would love for this to be the answer, and like Tom said, someone needs to test it. With that said, a Tiffin owner, with a friend at Cummins called and asked him. He wasn't definitive, but said, disconnecting the speedometer would keep the trans from knowing when to shift. He recommended calling Brandee Hanson at the Allison distribution center. My firend has dealt with her in the past, she is very knowledgeable. Here is her response. I wish it was better news....we really need someone to try it.

To: Brandee Hanson <Brandee.Hanson@westernstarnw.com>
Subject: Fwd: DEF Head failure

Hello Brandi,
Will the Allison 3000 transmission shift if you disconnect the Speedo cable?

On Jun 11, 2021, at 11:45, Brandee Hanson <Brandee.Hanson@westernstarnw.com> wrote:

Jeff,
If you disconnect any of the speed sensor connectors from the transmission it will go into “fail safe mode” and lock into a gear.

Thanks,

Brandee Hanson | Western Star Northwest – Ridgefield, WA | Service Estimator/Advisor
(360) 887 – 7500 x 7554 | Brandee.Hanson@WesternStarNW.com

tom chelbana · 06-11-2021, 09:42 PM

The video on You Tube is showing the speedometer cable being disconnected on a manual transmission to allow the truck to continue to travel after the DEF codes and check engine on so without someone disconnecting the sensor for the speedometer we will wait to see. As many coaches that are experience this problem we should have an answer very soon. One won't have anything to lose if the coach has the DEF codes on plus check engine light to take the speedometer cable off. Hundreds of coach owners are waiting to see if this is the temporary/emergency is the answer.
Newmar Man

wagonmaster2 · 06-11-2021, 10:38 PM

Quote:

Originally Posted by Dutch Star Don

I would love for this to be the answer, and like Tom said, someone needs to test it. With that said, a Tiffin owner, with a friend at Cummins called and asked him. He wasn't definitive, but said, disconnecting the speedometer would keep the trans from knowing when to shift. He recommended calling Brandee Hanson at the Allison distribution center. My firend has dealt with her in the past, she is very knowledgeable. Here is her response. I wish it was better news....we really need someone to try it.

To: Brandee Hanson <Brandee.Hanson@westernstarnw.com>
Subject: Fwd: DEF Head failure

Hello Brandi,
Will the Allison 3000 transmission shift if you disconnect the Speedo cable?

On Jun 11, 2021, at 11:45, Brandee Hanson <Brandee.Hanson@westernstarnw.com> wrote:

Jeff,
If you disconnect any of the speed sensor connectors from the transmission it will go into “fail safe mode” and lock into a gear.

Thanks,

Brandee Hanson | Western Star Northwest – Ridgefield, WA | Service Estimator/Advisor
(360) 887 – 7500 x 7554 | Brandee.Hanson@WesternStarNW.com

Any information on what does "lock into a gear" mean? Which gear, does the transmission just pick a gear or maybe it Low gear and never shifts up as you accelerate? Really scarey situation either way. As stated, hopefully someone will have to use this procedure to find out, but still hopefully no one has to endure this.

tom chelbana · 06-11-2021, 11:36 PM

I have posted on the Allision forum the question to Tom Johnson who has over 40 years experience with Allision the question being what effect would disconnecting the speedometer sensor have on trans? Do you see any other problems with disconnecting speedometer cable under the conditions we are talking about?
Newmar Man

GKU · 06-12-2021, 06:41 AM

Following with Interest!!

arlawbob · 06-12-2021, 06:48 AM

Is there a thread that discusses where I can get a back up DEF head?

weighit · 06-12-2021, 07:04 AM

Quote:

Originally Posted by arlawbob

Is there a thread that discusses where I can get a back up DEF head?

I asked Tiffin about ordering one for my coach, they said they had no spare units to sell. Would pull one off the production line of new coach builds if a repair shop called to let them know we were stuck and not drivable.

mahdi · 06-12-2021, 09:28 AM

Anxiously following

Dutch Star Don · 06-12-2021, 10:05 AM

Quote:

Originally Posted by weighit

I asked Tiffin about ordering one for my coach, they said they had no spare units to sell. Would pull one off the production line of new coach builds if a repair shop called to let them know we were stuck and not drivable.

Tiffin is now restricting the sales of all spare parts, unless you are broke down and an authorized service center orders them. I'm sure this will change when the parts flow gets better. My friend with an Allegro Bus, bought the spare DEF head part that goes bad, before they implemented this new policy.

Personal Opinion.....I'm getting tired of Covid being the excuse for everything that goes wrong, and many just being lazy. Maybe if people weren't paid more to stay home, then go to work, this would quickly end!