Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: wa_desert_rat on September 28, 2015, 12:56:24 pm

Title: VDO Speedometer Sender for 643 Allison
Post by: wa_desert_rat on September 28, 2015, 12:56:24 pm
My sender has gone Tango Uniform and the VDO speedometer (installed by a PO) now reads about 50% of actual speed. Does anyone know the part number for the sender? Do I need to provide more information? Nothing on a Google search leaped out at me.

Craig
Title: Re: VDO Speedometer Sender for 643 Allison
Post by: red tractor on September 28, 2015, 03:51:36 pm
Before I would condemn the sender I would check the drive assembly pins and also for grease as they often do not get greased not sure which cruise control you have but some also have their sender on the same adapter
Title: Re: VDO Speedometer Sender for 643 Allison
Post by: Twig on September 28, 2015, 04:05:03 pm
It is gear driven. One on the sender and a pencil gear that drives both the speedo and cruise. I would look there first. Replaced the pencil gear on my '87.
Title: Re: VDO Speedometer Sender for 643 Allison
Post by: wa_desert_rat on September 28, 2015, 09:59:21 pm
Before I would condemn the sender I would check the drive assembly pins and also for grease as they often do not get greased not sure which cruise control you have but some also have their sender on the same adapter
Can take the assembly apart without all the transmission fluid coming out? I actually do suspect the drive assembly. I have managed to take a photo of a plate that appears to give its s/n and hoping that I can get the appropriate part from Allison.

Craig
Title: Re: VDO Speedometer Sender for 643 Allison
Post by: red tractor on September 29, 2015, 10:43:17 am
You can take the adapter off of the pencil gear and disassemble it first and check the drive pins the pencil gear assembly can be removed without losing fluid
Title: Re: VDO Speedometer Sender for 643 Allison
Post by: Dakota Slim on September 29, 2015, 11:04:49 am
I think I have the same problem. Can someone post a photo of the drive assembly or point me to a mechanical drawing?
Title: Re: VDO Speedometer Sender for 643 Allison
Post by: red tractor on September 29, 2015, 11:11:57 am
You will find it on the passenger of the transmission towards the driveshaft end toward the upper part of the transmission
Title: Re: VDO Speedometer Sender for 643 Allison
Post by: wa_desert_rat on October 01, 2015, 08:06:01 am
On our U225 I think the speed sender is on the driver side at the forward end of the transmission. There is a metal placard next to the connector that gives the data to be able to order the new parts. The sender is fully mechanical and gear driven (according to my mechanic). I sent him a photo of the placard and he thinks he can order a new part. The cable that connects to the transmission is pretty thick.

Photo is of my placard.

Craig
Title: Re: VDO Speedometer Sender for 643 Allison
Post by: Bill Willett on October 01, 2015, 12:59:31 pm
Google, Woodward Mini Gen and see if this is what you need.