Speedometer Jumps with new Cable I am Perplexed.

[James E Vining]

The Winne (71 D-20) had a Seized up Speedometer and the cable Broke at teh Tranny connection so I removed the Speedo and used Marvel Mystery oil in the Oiler Cup located just up from where teh cable attaches and let it sit a couple days each day checking and adding oil if the cup was empty, In teh end i got it spinning nice and smooth and I even tested it and ran it for a while with a Drill and a Piece of the broken cable and It was smooth from 10 MPH to 70 MPH I coudl not get my cordless drill to spin any faster, I did that a few times just to make sure it was lubed up good and working properly.
I bought a cable (not the Original Part #) but a 120" one that had the same attachment ends on it  (5/8 at Speedo and 7/8 at Tranny)
I am thinking there could pe a possibility of teh Cable Itself ( Inside Piece that spins) may be a little bit to long in turn putting extra pressure on the Brass Piece in the Speedo itself?
I tested it yesterday with rear wheels off ground and from 0-20 it jumps dramatically between the 2 and I can feel it in the cable, when I remove the cable from the Speedo the cable spins smoothly no Binding or jumping and when I checked the Speedo it was fine again using the drill.
Now the Collar on the Cable itself is at the Speedo end (meaning you can only remove it by pulling it from Speedo end, I even removed the cable and greased it and reinstalled the cable in the Housing
I did notice when I was attaching the Cable and Housing to the tranny it seemed like the cable itself was a bit long so that should be the end I cut any off of if I need to, since the speedo end is set by the collar

[Surfinhurf]

Sounds like the speedo is still "Stiff" .  You can spin it with a drill but that is direct drive.  Your speedo cable will have some flex if the speedo does not move freely. Is your cable square plastic with a steel cover?

[pvoth1111]

Sounds like the cable is binding up

[James E Vining]

I double checked the Speedo by hand and it is super free as a matter of fact I can spin it with my hand and it spins a bit after I let go so thats not it.
I finally found the Tranny End of the cable was sticking out about 3" from end of 7/8 threaded coupler which I would think should fit into tranny gear just fine but for some reason when I  really paid attention as I inserted it I found that it was binding up so I cut off about 1/2" of the cable and it works great now, all I can think is that it was causing the cable to be pushed up to the speedo which there is no extra room due to the collar on cable and must of caused extra pressure on the brass Speedo Piece not to mention put a bind inside the cable housing.
It now works quite well, Jumps a real minor amount about 2 MPH at 10 MPH but after that its smooth, I even greased the cable extra well making sure to get as much grease inside the housing as I could just to be safe.

I am not sure what exactly was causing the cable to bind in the tranny gear and last time I pulled a Tranny gear unit the tranny dumped a bunch of fluid on my head and into my eyes, which it took me about 2 weeks to get my hair back to normal.
I may be pulling the gear just to figure it out as It is irritating me not knowing why it is binding up in there, I removed the broken off piece from the previous cable so it has me wondering 
But for now the cable is working much better and I have a speedo I can actually read now LOL

[James E Vining]

Sounds like the speedo is still "Stiff" .  You can spin it with a drill but that is direct drive.  Your speedo cable will have some flex if the speedo does not move freely. Is your cable square plastic with a steel cover?

No My cable is all Steel, looks like the ground down the round (cables as it appears to be many smaller cables wrapped to be a larger one) cable to make Square ends so they fit into the Square Speedo and Tranny sections.

Oh BTW I must not of specified when I spun the Speedo with drill I had Oiled it and checked it by using a small end off of broken cable and then again I tested it in MH with someone sitting in cab and I was under MH connected to cable at the tranny end to see if it was jumping still and it did not when using the drill, Since I have a variable speed drill I could run it as low as 10 MPH and as high as 70 MPH

[DaveVA78Chieftain]

I have a hunch the square hole in the speedometer gear in the transmission may be rounded off.

Dave

[James E Vining]

Thanks Dave, But last nightish I was running it in gear (With rear wheels off ground of course) and the speedometer was working great, I could tell it was shifting into second at about 15 or so and 3rd at about 30 or so.
I think(Hope anyway) that the tranny part is ok and not rounded off.

[Brownfamily]

My speedometer jumps at all speeds + or - 10-15mph. What is the bet way to service?, lube, etc?

[DaveVA78Chieftain]

What is the bet way to service?, lube, etc?

Lube would be the best place to start

[Oz]

But not Jiffy Lube...