Speedometer Gear Failure Again

Ok today I changed another speedometer gear. This makes the 3rd time the shaft for the gear has broken off at the gear. I am refering to the shaft that is part of the gear. The gear itself is not damaged. What can cause this to continue to happen. Before the speedometer quit this time it was a little jumpy at low speeds. Is it possible that the cruise control transducer is trying to lock up causing the shaft to seperate from the gear? The only other part that is different is the gear housing was originally plastic, and it was replaced by the metal GM replacement part?

Help!:banghead:

Is your cable hard to turn? Did you check it for routing to make sure it's not binding somewhere?

DBuster....those old cruise devices get really dry grease in them, and need be pulled down very carefully to refresh them up....and redo the cables also....new wire and I use WD 40 on them, but plug up the shroud ends, fill it with solvent/carb cleaner, let it soak for a few minits, and blast it outta there from down lo, then up top.....get all that crap outta there.......then new wire if necessary the speedo will vary from either the cables/cruise servo, OR the speedo head itself....if the latter, it's another thread,

BTDT on many a car over some decades now.....vette is nothing really all that differant...it is just another chebby, right???

:gurney::evil::nuts:

WD40 is not a proper lubricant. Use some chassis grease on the cable, it will work much better than W(ater)D(isplacement)40

Twin_Turbo said:

WD40 is not a proper lubricant. Use some chassis grease on the cable, it will work much better than W(ater)D(isplacement)40

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TT, that is why I say soak the shrouds...that stuff dries out so bad in there from heat and such, I just can't see using it.....Kinda like me putting my power window, or manual window tracks back with NO lube of any kind, that shit dries out here like a plague, and totally useless....I not saying soak it muchly with WD or some other light oiley stuff, but freeking GREASE, not me my car been ok now with my treatment for some 15+ years now....

:bump::thumbs:

Your cruise transducer is trash. Get/have it rebuilt. Use red grease ONLY on speedo cables.

big2bird said:

Your cruise transducer is trash. Get/have it rebuilt. Use red grease ONLY on speedo cables.

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Thanks for the suggestions, & it's good to hear from BB.

The cruise control transducer is what I was starting to think. I just went by O'reillys and picked up a cable to bypass the speed control transducer. This will eliminate it & a bad cable problem. The speedometer is bouncing at the slower speed. If the new cable eliminates the bouncing, that will eliminate the problem I hope. I guess I need to order 2 more speedometer gears for backup. I was given 2 cruise control transducers last week. I guess I will pull them apart, and build a spare.

:beer:

Mid America sells a grease fitting that srews on to the cable so you can use a grease gun and push some grease throught the cable.

big2bird said:

Your cruise transducer is trash. Get/have it rebuilt. Use red grease ONLY on speedo cables.

Click to expand...

Why red grease? have been using chassis grease for years, never a problem. What's special about red grease apart from the color? Is it some kind of brand? Here the color doesn't mean anything, apart from maybe that one manuf. colors his blue, the other red and the next one green. For instance, mobil 1 synth is red but so is shell albida ep2 industrial grease.

Twin_Turbo said:

big2bird said:

Your cruise transducer is trash. Get/have it rebuilt. Use red grease ONLY on speedo cables.

Click to expand...

Why red grease? have been using chassis grease for years, never a problem. What's special about red grease apart from the color? Is it some kind of brand? Here the color doesn't mean anything, apart from maybe that one manuf. colors his blue, the other red and the next one green. For instance, mobil 1 synth is red but so is shell albida ep2 industrial grease.

Click to expand...

My speedometer shop gave me some, and was insistant that's all you should use. I'll stop by and see what it is specifically.

The grease is most likely a lithium complex base grease. Most automotive grease is made of a lithium complex, or a polyurea grease for factory filled sealed bearings. I would think that either one would work, and the color is usually a dye of some type. However they could use different base oils. Most greases are made with a 460 base oils, with the exception of higher speed ball bearings.

Got the speedometer cable changed today & bypassed the cruise control. The speedometer is still bouncing a little at 10 to 15MPH. Maybe this is normal. If the gear does not fail again, I will know that the cruise control was the problem.

While I had the speedometer cluster out I reset my needle to the correct reading. I took my WinALDL reading while driving and reset the needle. All I had to do was pull out on the needle, and it came off. Push it back on at the far left setting, & verify with WinALDL. It took about 2 times to get it right.

Bouncing of the needle is NOT normal. There is 27 year old lubricant in there. I would have the head professionally cleaned and calibrated. Most speedo shops charge $140 for this if you bring it in yourself. A bad speedo cable will also cause bounce.
I know it's $$, but I would clean/lubricate the cables, and have the transducer/head rebuilt, and be done with it. (Been there, done that):clobbered:

Bird,

I just put a new cable on it today. The cruise was bypassed. The problem is either in the gear housing, or the speedometer itself. I think I will run it to see if the gear fails again. I would doubt that the speedometer itself would be strong enough to snap the gear at the shaft. If it fails again I will probably replace the gear housing part that GM sold me. I still have the box to verify the number. The sad thing is that it cost 45 bucks. As far as a speedometer shop, I don't have one near me.

Dbuster, the speedo head is easy to work on and fix by yourself, not much to it really, just a small Radio Shak set of 'jewelers screwdrivers' and some patience on a kitchen table under good light and a mag glass if necessary.....

if so inclined, I can help you through it....BTDT many times....

Dirtbuster1 said:

Bird,

I just put a new cable on it today. The cruise was bypassed. The problem is either in the gear housing, or the speedometer itself. I think I will run it to see if the gear fails again. I would doubt that the speedometer itself would be strong enough to snap the gear at the shaft. If it fails again I will probably replace the gear housing part that GM sold me. I still have the box to verify the number. The sad thing is that it cost 45 bucks. As far as a speedometer shop, I don't have one near me.

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Since I had mine out, I also had it converted to 140MPH. $100
http://www.corvetteinstrumentservice.com/

mrvette said:

Dbuster, the speedo head is easy to work on and fix by yourself, not much to it really, just a small Radio Shak set of 'jewelers screwdrivers' and some patience on a kitchen table under good light and a mag glass if necessary.....

if so inclined, I can help you through it....BTDT many times....

Click to expand...

I would take alot of patience and a big magnifying glass for me. At least it's easy to remove.

Twin_Turbo said:

big2bird said:

Your cruise transducer is trash. Get/have it rebuilt. Use red grease ONLY on speedo cables.

Click to expand...

Why red grease? have been using chassis grease for years, never a problem. What's special about red grease apart from the color? Is it some kind of brand? Here the color doesn't mean anything, apart from maybe that one manuf. colors his blue, the other red and the next one green. For instance, mobil 1 synth is red but so is shell albida ep2 industrial grease.

Click to expand...

In the old days many things that were colour coded has fallen by the wayside. Grease colour coded blue was hi quality marine trailer wheel brg grease. That doesn't apply anymore, it's a crap shoot unless you buy from a quality manufacturer. I'm pretty sure that you want to use an oil or a very light grease for speedo type cables especially in colder climates.

Dirtbuster1 said:

mrvette said:

Dbuster, the speedo head is easy to work on and fix by yourself, not much to it really, just a small Radio Shak set of 'jewelers screwdrivers' and some patience on a kitchen table under good light and a mag glass if necessary.....

if so inclined, I can help you through it....BTDT many times....

Click to expand...

I would take alot of patience and a big magnifying glass for me. At least it's easy to remove.

Click to expand...

Yeh, they tend to have to be bigger as the year go by, damn small shit keeps getting small all the time....

:shocking::bonkers:

00fxd said:

Twin_Turbo said:

big2bird said:

Your cruise transducer is trash. Get/have it rebuilt. Use red grease ONLY on speedo cables.

Click to expand...

Why red grease? have been using chassis grease for years, never a problem. What's special about red grease apart from the color? Is it some kind of brand? Here the color doesn't mean anything, apart from maybe that one manuf. colors his blue, the other red and the next one green. For instance, mobil 1 synth is red but so is shell albida ep2 industrial grease.

Click to expand...

In the old days many things that were colour coded has fallen by the wayside. Grease colour coded blue was hi quality marine trailer wheel brg grease. That doesn't apply anymore, it's a crap shoot unless you buy from a quality manufacturer. I'm pretty sure that you want to use an oil or a very light grease for speedo type cables especially in colder climates.

Click to expand...

for sure, and so which is why I have used WD40 for decades now, and never an issue sometimes I have to re apply it after 6+ years...so what???

:devil: