That’s cool you got this fixed. The needle bounce is likely some kind of binding in the sleeve as you suspect.

I am a little late to this thread. For future reference you can build up these cables by brazing them with a propane torch and brass wire. Get the tips clean and flux them up with borax laundry booster.

My dad helped me fix my Volvo speedo when I was 16 this way. RIP dad. The tip had broken off and he made a new one by silver soldering a square steel shaft to the end of the cable. The speedo worked again but it bounced. I never figured out why (I was just a kid and just kept driving the car). Reading your thread it occurred to me the cable was too long. Dad must have rebuilt it a tad too long and it was binding in the sleeve. That thing is like a big spring so it slingshots as it binds and makes the needle oscillate.

Bouncy needles can also be remedied with greasing the entire length of the cable. But I bet you’ve done that already. Likely it needs to have it is either too long or too short by a tiny amount. You can test the theory by loosening the yoke a bit and backing it out while driving it.

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79 300TD “Old Smokey” AKA “The Mistake” (SOLD)
82 240D stick shift 335k miles (SOLD)
82 300SD 300k miles
85 300D Turbodiesel 170k miles
97 C280 147k miles

Did some troubleshooting on the bouncy needle today, yes it seems like the inner cable is a tiny bit too long. Loosening the nut and pulling the dash cluster out makes the needle run smooth and the cruise work perfectly.

I added some o-rings around the post to stand it off a bit, only works if the cluster is pulled out. Ground a very small amount off the end of the cable and now it works great with the cluster out and is marginal when pushed in. It worked then bounced again, then I tugged back on the outer cable a bit and it ran smooth.

Going to trim the inner cable a tiny bit more tomorrow and hopefully that will do it.

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1993 300D 2.5L Turbo

I decided something was up so rather than trim it further I grabbed my remaining half a cable and decided to attach it to the cluster, spin it with a drill, and move the cable in and out. Turns out that it ran the smoothest when it was under a little pressure, so something was up if the replacement was happier loose.

Pulled the inner cable and it turns out mine doesn't have this ferrule thing and it must have been rubbing against something when the cable nut was tightened.

Sliced it off so only the regular square end was present and now it runs super smooth

Attached Thumbnails

 

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1993 300D 2.5L Turbo

Thanks for sharing! Glad you nailed it.

__________________
79 300TD “Old Smokey” AKA “The Mistake” (SOLD)
82 240D stick shift 335k miles (SOLD)
82 300SD 300k miles
85 300D Turbodiesel 170k miles
97 C280 147k miles