that's what I found - I took the speedo out, opened/cleaned it up, checked everything etc but still had the issue

took a dremel to the tcase end and trimmed just a little bit off to get that 'just right' amount of tension - no problems since then. for anyone having this issue (the odometer works but the speedo needle doesn't, sticks, bounces, etc) i'd suggest trimming a little bit at a time off the tcase end. I would use a dremel/cut off wheel to avoid fubar the end of that cable by using sidecutters etc.

at least in my experience, the problem isn't at the speedo if the odometer is working correctly - it can be solved w/o taking the speedo out or dash off

 

There are revolving magnets in the speedo when they start to loose their magnetism they can bounce.
So if your cable is good your options are a speedo shop or get a Crown replacement if you want the CJ look or go to an aftermarket speedo.

 

Been fighting that one myself. Took the speedo out and cleand it then spun it up with a drill and it was rock solid at 60mph. Put it back in and bounce by 10 mph. Took the speedo cable off at the transfer case and hooked it up to the drill. Solid 60mph and solid at every other speed I tried. Kinda lost as to next steps.

 

step 1...pull drive train. step 2... install drill. (sorry couldn't resist)

 

Thanks for the insight guys. I'll try the drill to rule out the speedo itself. Also seems that if while running the drill, I push in on the cable I should be able to see if the cable length is putting undue pressure and making it bounce.

 

Thanks for the insight guys. I'll try the drill to rule out the speedo itself. Also seems that if while running the drill, I push in on the cable I should be able to see if the cable length is putting undue pressure and making it bounce.

DOH! Why didn't I think of that? Thanks, will try that tonight! :highfive:

 

So I tried the drill, which must be run in reverse like your un-screwing. First the cordless which would only get me to 25mph. Then I switched to the variable electric and was able to get up in the 75-80 range (you know, average Jeep cruising speed ). The speedo showed a smooth needle at all speeds and as I varied it. I tried pushing and pulling some on the cable as it was running but that didn't seem to make any difference! So now I'm stumped again. That just doesn't make sense! Any thoughts guys?

 

If you already tried trimming your cable, putting some graphite powder in it to lubricate it, made sure that it is run well so that there are no tight bends then I suppose it is possible that the drive gear inside the transfer case is slipping a little. They are plastic and just friction fit to the shaft. I have heard of guys taking it apart, scoring it and reinstalling it with some jb weld. But I would double check everything else first.

 

Install coil springs instead of leafs. Bounce gone.. Lol. Mine only bounces when the road is rough. I've read that sharp bends in the cable can cause bouncing too

 

I don't think theres any sharp bends, it's ran like it was stock. But I'll check that. The speedo driven gear is brand new, as is the cable.

 

I don't think theres any sharp bends, it's ran like it was stock. But I'll check that. The speedo driven gear is brand new, as is the cable.

I mean gear on the output shaft of the tcase. Might try trimming a bit more of cable?

 

But it was fine before. I had a little bounce in a small range but now it's all over the place. It even slows down when you accelerate. And when I had things tore down and was counting the teeth on the drive gear I did not notice any heavy wear. I could try trimming some more but it doesn't seem like theres too much, I mean it slides in easy and it's not hard to turn the nut on. Maybe I can leave the nut loose a couple turns, tape it in place, and try driving it.

 

Maybe I can leave the nut loose a couple turns, tape it in place, and try driving it.

This. I left the cable loose from the speedo enough that it wouldn't bounce until I could trim it.

I will say though, I bought a cable from Napa for a 55-57 Chevy Bel Aire, fit like OEM, and better than the Crown/Omix offerings ..

 

Maybe you could even find some big washers or plastic spacers to keep the nut from pushing the cable in too far.

 

While examining the t-case end up close as it goes in, I noticed the cable stopped entering while the cable sleeve still had a tiny bit to go before the rubber ended bell mated with the gear housing. So I tried grinding off about 3/32" or so. It did seem to help a little at higher speeds but it still bounced and even decreased speed when I mashed the pedal some everywhere else. So I'm going to try an extra rubber washer first. Then if that doesn't solve it I'll grind a bit more off, maybe an 1/8". If that doesn't work I'll add the washer back in. Basically shortening the cable up a little at a time. I think maybe the cable needs to just free float without any access drag or pressure. The cable will push in some but will only pull out till the ball at the speedo end hits the cable sleeve, so I think that end is good. (I hope!)

 

Well to add to this search for a solution, I tried a new cable. One from Omix-ada this time instead of Crown. It made no difference. And I still had to trim 1/4" off the end of this one also.

 

Omix-Ada, Crown, Rugged Ridge and Outland are all the same people.

 

Omix, R.Ridge, and Outland are but I believe Crown is on it's own. The two cable were different, in color and design.

 

This is a picture I took of the box. This worked perfect, still using it today, a couple years later. Took the picture Feb 6, 2014.

 

Yep. I couldn't believe they had that cable in stock, but he said they had a guy that does classics in the area so he gets a few of them, so they keep them in stock.

 

I picked up the Bel Aire cable. It fits my cj and seems to be a quality product. I think i must have something wrong with my speedo. The further i drive the slower it reads.

 

Well keep us posted if you make any progress. Theres gotta be an answer! :laugh2:

 

Okay, the quest is still on. I was thinking after everything I've tried, maybe it's the drive gear in the t-case. I'll check it out next time I have the t-case out. So I did. Drive gear looks good, as does the new driven gear. But I noticed inside the case on the back wall of the speedo gear housing that there is an index divet, and then 2 off center wear marks. Now when I took this apart a few years ago I never seen any guide pin on the old driven gear, though it looks like there should have been one. However in all the diagrams of the Dana300 I've looked at, none show any centering pin of any sort.
Has anyone ever noticed this or seen any pin? It seems as though a pin would hold the gear centered and rotating smooth. The drive gears end just has a hole where something could ride in. My t-case was never opened since the factory until 2012, but it could have worn away I suppose. Never found anything in the case itself.

 

Very interesting. I have the same exact problem - slight bounce pretty much all the way through the speedo BUT does not bounce with a drill. Mine also has cruise control so I have 2 cables and a servo. I tried various things from speedo back to the tcase so I gave up assuming it had to be in the tcase. I will try to look into mine to see if i can see or get a pic of the inside. Thanks for not giving up and sharing your findings!

 

Yep, your welcome. This is the million dollar Jeep question. It seems to work fine and smooth with the drill, at all speeds, but when connected back to the tcase things go wacky. I sent an email to Novak to see if they have any ideas on the divet. The more I look at it I'm guessing it's just the center point of the bit they used to drill the larger, maybe 3/4" clearance hole. Because when you rotate the driven gear housing position based on the tooth count, the shaft isn't centered anyways. But something made those two off center wear marks.
So I'm thinking maybe sand off the end of the driven gear, maybe 1/32", so it doesn't touch the case at all. Maybe it's catching the edge of a wear mark ever so little and it interrupts the speed of rotation and gear mesh with the drive gear.

 

When I dealt with an erratic speedo needle I got a new, speedo cable for my year/model CJ, confirmed the length to the original (I may have had to trim it slightly) then I used a good graphite, lubricant along the whole length, and of course, ensure it only had gentle curves from speedo to transfer case. Been very smooth/accurate since.

 

Just a note, they make 2 different inner cables, one is wound clockwise the other counter clockwise. If you have the wrong one, it will act like it is unwinding and spring back, which can cause a bounce...that one took 2 years to figure out. Tim

 

. Interesting- where did you get one wound the correct way?

 

Interesting. I'll have to compare my factory cable to the Crown and Omix cables I have.