I believe the takeaway is: get a new speedometer assembly from an '84 or earlier 123 diesel automatic. Ebay that puppy, they were $50-$150 when I was looking.
If this is the noisy one, even better. Alternatively, try taking it apart and cleaning it up first. Took me about 30 minutes to dismantle, clean, and reassemble mine the first time, so it's not a big commitment. I used synthetic bicycle grease I already had. -Tim On 6/3/10, andrew strasfogel <astrasfo...@gmail.com> wrote: > CORRECTION: Should have written "OK - what is the takeaway message from all > that learned discussion? Am I doomed to forever have an inaccurate > speedometer that reads too high (in mph and miles covered), or is there hope > for an affordable fix?" > > > On Thu, Jun 3, 2010 at 2:50 PM, andrew strasfogel > <astrasfo...@gmail.com>wrote: > >> OK - what is the takeaway message from all that learned? Am I doomed to >> foreever have ain inaccurate speedometer that reads too high (in mph and >> miles covered), or is there hope? >> >> >> On Thu, Jun 3, 2010 at 12:57 PM, Dillon, Meade M CIV >> SPAWARSYSCEN-ATLANTIC, >> 53310 <meade.m.dil...@navy.mil> wrote: >> >>> Sho'enuf, hat tip to Rolf (and Mitch). For a 123.133 the EPC shows that >>> the speedo and the diff changed for '85, but no changes to the >>> transmission speedometer gears. >>> >>> -Max >>> >>> -----Original Message----- >>> From: mercedes-boun...@okiebenz.com >>> [mailto:mercedes-boun...@okiebenz.com] On Behalf Of Rolf >>> Sent: Thursday, June 03, 2010 10:51 AM >>> To: Mercedes Discussion List >>> Subject: Re: [MBZ] ISO a fix for lousy fuel economy in a W123 >>> turbodiesel - with an incentive >>> >>> I know for a fact that the speedo is matched to the rear diff and not >>> the transmission alteast in the W123 chassis. Feel free to research it. >>> >>> -Rolf >>> >>> On 06/03/2010 10:46 AM, Dillon, Meade M CIV SPAWARSYSCEN-ATLANTIC, 53310 >>> wrote: >>> > I think that the issue is the drive gearing may be the same, but the >>> > gear which drives the speedometer (in the tail of the tranny) varies >>> > to match the differential. >>> > >>> > The EPC can answer this question... >>> > >>> > -Max >>> > >>> > -----Original Message----- >>> > From: mercedes-boun...@okiebenz.com >>> > [mailto:mercedes-boun...@okiebenz.com] On Behalf Of Rolf >>> > Sent: Thursday, June 03, 2010 10:38 AM >>> > To: Mercedes Discussion List >>> > Subject: Re: [MBZ] ISO a fix for lousy fuel economy in a W123 >>> > turbodiesel - with an incentive >>> > >>> > That is pretty much correct. The speedo is based on the rear diff not >>> > the trans. The automatics are all the same (for the w123) gearing and >>> > all the four speeds end in 1:1 gearing. The manuals differ from year >>> > to year based on engine and reivisions. >>> > >>> > -Rolf >>> > >>> > On 06/03/2010 10:35 AM, Mitch Haley wrote: >>> > >>> >> Jim Cathey wrote: >>> >> >>> >> >>> >>> No, I correct myself. The speedometer is attempting to measure >>> >>> wheel >>> >>> >>> > >>> >>> RPM, but it's tapped at the tranny tailshaft. The 85 tranny is >>> >>> _expecting_ to have a lower tailshaft RPM for a given road speed, >>> >>> and >>> >>> >>> > >>> >>> so gears up the speedometer tap to make up for it. >>> >>> You put that tranny in a car with a shorter rear end, and the >>> >>> tailshaft RPM is higher than expected, and so is the speedometer >>> >>> output. >>> >>> >>> >> I thought the MBZ way was to have the trannies all alike, and match >>> >> the speedometer head to the differential gearing. >>> >> >>> >> Mitch. >>> >> >>> >> _______________________________________ >>> >> http://www.okiebenz.com >>> >> For new and used parts go to www.okiebenz.com To search list archives >>> >>> >> http://www.okiebenz.com/archive/ >>> >> >>> >> To Unsubscribe or change delivery options go to: >>> >> http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com >>> >> >>> > >>> > _______________________________________ >>> > http://www.okiebenz.com >>> > For new and used parts go to www.okiebenz.com To search list archives >>> > http://www.okiebenz.com/archive/ >>> > >>> > To Unsubscribe or change delivery options go to: >>> > http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com >>> > >>> > _______________________________________ >>> > http://www.okiebenz.com >>> > For new and used parts go to www.okiebenz.com To search list archives >>> > http://www.okiebenz.com/archive/ >>> > >>> > To Unsubscribe or change delivery options go to: >>> > http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com >>> > >>> >>> >>> _______________________________________ >>> http://www.okiebenz.com >>> For new and used parts go to www.okiebenz.com To search list archives >>> http://www.okiebenz.com/archive/ >>> >>> To Unsubscribe or change delivery options go to: >>> http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com >>> >>> _______________________________________ >>> http://www.okiebenz.com >>> For new and used parts go to www.okiebenz.com >>> To search list archives http://www.okiebenz.com/archive/ >>> >>> To Unsubscribe or change delivery options go to: >>> http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com >>> >> >> > _______________________________________ > http://www.okiebenz.com > For new and used parts go to www.okiebenz.com > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > _______________________________________ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
