Re: [Chrysler300] Jumping Speedo Needle
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Re: [Chrysler300] Jumping Speedo Needle

Yes Rich .. There is a spinning brass bushing/ bearing  in there that receives the square end on the drive cable . It spins in the die cast housing . In earlier ones there is a cap --looks  like the drain on side  of water valve but male . It is to oil that bush , via a small felt .  It was greased  at assembly but grease always gets dry and hard . It is often all that is wrong with speedo ( learned that the hard way -- after pulling apart whole thing and wrecking it the first time ) . That and atf into cable . Has to spin totally free at speedo head as if nothing is connected to it . I think if you have speedo out you can get oil into the space around spinning bushing by putting face down and putting oil around it into space while turning it . ( without getting the plug out ) WD 40 or penetrating oil might help , then like 10 weight . Or atf . I think you are right .. Later ones they greased or oiled and then put in plug like a core plug by denting center . Save .05$ . Any messing with inside of speedo head rarely turns out well . Very touchy to calibration .. Not just at one point , across whole dial can be ok one end off other end non linearly. I think but am not sure 1000 rpm there is 60 mph on all cars . ( actual number can be checked ) . I Used drill and whittled wood square like large toothpick to check ( approx) it worked ok after freeing it up . If friction there cable winds up a little against friction then snaps forward causing ~ 5-10 jump in mph number . Repeat !! Especially cold weather . Sometimes odometer is stuck or broken ( plastic !) much older ones are metal , mopar replacement parts , 50's -- at least once i used a metal one , nos off ebay to fix / replace that  plastic one, but forget years that crossed .  When odometer jams it usually breaks free from input drive by stripping a plastic gear in there , but sometimes can go snap , snap snap as teeth jump . .. Makes speedo jump very regularly , you can tell this one as Odometer does not move , eventually teeth wear off . Speedo works again after a while but no odo . Sometimes better to just accept that . If you get into the spinning magnet scraping etc , very hard to fix. That scraping shows as huge 30+ mph jumps off zero even when going slow . Can stop the scraping by careful bending  but then calibration all off . At that point goes to pro if you have not by then wrecked it .. I think scraping is caused by wear in input bushing lets the part sag and hit . Half the magnet device is supported only by that same bushing . Has to stay square and centered . That sort if means it is worn out ? 
Been there on these! Good luck !

Sent from my iPhone

On Nov 8, 2015, at 5:17 PM, 'Rich Barber' c300@xxxxxxx [Chrysler300] <Chrysler300-noreply@xxxxxxxxxxxxxxx> wrote:

I happen to have two ’63-’64 instrument panels out and disassembled.   Each speedometer assembly has a small hole on top of the threaded stub where the speedo cable attaches.  But the plug in the hole does not appear to be removable.  It is neither Phillips-head or slotted.   They have a small hole in the center of the plug that looks like a sharp punch had been used to set a plug in the hole, perhaps to locate and fix the position of the rotating shaft.  I don’t think these holes are very tiny Allen-head sockets bit I will pursue cleaning and experimenting.


Anyone know a little more about this assembly detail?


I can get each speedo up to 12 MPH with a little spin on the shaft and both seem smooth after 50+ years.


Rich Barber

Brentwood CA (Light rain-TBTG)


From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On Behalf Of 'Gary Nelson' gnelson@xxxxxxxxxxxx [Chrysler300]
Sent: Sunday, November 08, 2015 10:13 AM
To: Josh <josh@xxxxxxxxxx>; Chrysler300@xxxxxxxxxxxxxxx
Subject: Re: [Chrysler300] Jumping Speedo Needle



Josh, there is a product called Chain Life (also for cables), brand name, Champions Choice. It is a foaming lube (aerosol), that clings under sever pressures. Internet search brings up several brands. I suspect private label packaging by Champions Choice. Some are called chain/cable lube. Everyone should have a can on the shelf.


Another point about speedo lubing. On the back of speedo where cable attaches, there is a small lube cap that is knurled to grip and unscrew. You have to grip with pliers to get it unscrewed.  It is vertical and hard to get at (get a light and crawl in), with speedo in dash. inside that small cylindrical cap there is a felt wick that dried out years ago.  It is essential to remove the wick and soak in light oil (10 w, 3 in One, etc.), and a couple of drops in the opening where wick was removed. This lubes the shaft going into the mechanism. A must do.



AKA, The Parts Doc



Sent: Saturday, November 07, 2015 7:06 AM

Subject: [Chrysler300] Jumping Speedo Needle



Hello guys,

My 300D speedometer needle is starting to jerk around just a little.

I'm guessing something needs lube? Can you guys offer any suggestions?




Posted by: John Grady <jkg@xxxxxxxxxxxxxxxxx>

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