New speedo cable, new gear, etc but speedo still bouncing

[Jimmmmmay]

Hey guys,

I'm one of those guys that has a bouncing speedo in my Challenger. I ordered and installed a new OER cable from classic industries. Before I put the cable in I lubed it like crazy with graphite. I also changed out the speedo gear in the transmission because the one that was in there was too small for 3.73 gears and I made sure to clock the pinion housing to the correct location for a 38 tooth gear. If I hook a drill up to the cable under the bottom of the car and run it counter clockwise the speedo sweeps nicely and holds steady, so I don't think it's a speedometer issue. It also feels like the speedo gear is engaged, because I can't spin it in the transmission either. Everything seems to be the way it's supposed to be, but when I actually drive the car the speedo bounces a bit and also doesn't go above 30mph.

The ONLY thing that I can think of is that it's something to do with the main shaft on the transmission. It's an A833 4 speed tranny... I don't know any history on the transmission or what it might have come out of. If I've ruled out the speedo, cable, plastic gear, and the pinion housing clock location what the heck else do you think it could be? At this point I'm totally stumped and don't really know what else I could easily check. Any ideas would be greatly appreciated. I'm getting sick of using my phone on the center console to see how fast I'm going. Every time I make a right hand turn the phone slides off the center console and falls between the seat

Thanks

-Jim

 

[BcudaChris]

Hey Jim, I've gone around with the bouncing speedo on a few E-bodies (all std cluster). Every time it has been the sludged up grease that used to lube the speedo movement. I've never tried the drill trick, but I would think the drill probably has more torque and acceleration behind it than the speedo drive in the trans and the sludged up grease doesn't even try and slow it down.

Mr. Heaterbox (he's findable the internet) can probably get it going for you, if it is your speedo.

FWIW, you might be over thinking it. That symptom is pretty typical of 45-49 yr old grease in these movements. I'd send the speedo out before I'd tear into the trans.

 

[halifaxhop]

When you changed the gear did you set the housing in the right range?

 

[DetMatt1]

When you changed the gear did you set the housing in the right range?
View attachment 63631

He said he clocked it. The speedo in my ‘67 Imp is a bouncer too but it doesn’t start bouncing until around 55 and evens out again above around 75.
Oh yeah, E body consoles are all but useless.

 

[halifaxhop]

Then I am thinking it is gummed up myself, does not take much to do it either. Really nothing else left, seriously doubt it is in the trans. I had a piece of dust on mine where the cable goes into the spedo between the bearing and the spedo drive? Sucked finding that and you really have to whatch how to clean it dam things are delicate.

 

[Jimmmmmay]

Thanks for all the replies guys. I was messing with it a bit more last night with a drill (again) and now I'm thinking you're right about it being a speedometer issue. I noticed after hooking it up to the drill that if I spin it while sort of pushing the cable in at low speeds, it seemed better. If I wasn't pushing on the cable while spinning, it started bouncing a bit at low speed. So now I'm thinking it's a speedo issue and like BcudaChris said these things are ~50 years old. Just wanted to make sure I was checking all the right things and covering all the other bases. I really don't want to send the speedometer out or get a new one and go through the trouble of removing and installing it only to find out it's something else.

 

[halifaxhop]

Here is something to try use denatured alcohol on the area the cable goes in, be carefull you do not want it on the face it will damage the printing. Just spray it on a rag and wipe it off and see if it improves. If so oil it with something light like 3 in 1 oil or sewing machine oil sparingly.

 

[BcudaChris]

Good Luck Jim, dropping the steering column makes getting the speedo out MUCH easier.

Let us know how it comes out. I'm particularly interested to hear if you have success with Halifax's method. I tried to clean and re-grease the 1st one I messed with by myself, but didn't have proper tools and went about it like I knew what I was doing and trashed the thing.

 

[Jimmmmmay]

Good Luck Jim, dropping the steering column makes getting the speedo out MUCH easier.

Let us know how it comes out. I'm particularly interested to hear if you have success with Halifax's method. I tried to clean and re-grease the 1st one I messed with by myself, but didn't have proper tools and went about it like I knew what I was doing and trashed the thing.

Just wanted to finish this story... It's over a year later and I took the whole dash out to replace the old and sketchy dash wiring harness, cracked dash pad and put a new OER speedo in... wouldn't you know it, the speedometer doesn't bounce anymore. Kind of an anti-climatic ending I guess. But I learned every single piece of how an ebody speedometer works! The one thing I did notice is that holding the original speedometer upside down the needle went to about the 10-15 mph mark and stopped while the new one didn't move, so it looks to me like the old one is just a bit worn out.