speedometer needle bounce
Race Director
Joined: May 2001
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From: Democracy is two wolves and a lamb voting on what to have for dinner. Liberty is a well armed lamb contesting the vote.
St. Jude Donor '10
Re: speedometer needle bounce (ray77vette)
My speedo bounced really bad, right before it quit. A new cable didn't fix the problem, so I had it rebuilt.
Race Director
Joined: Oct 2002
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From: Smalltownville Michigan
Cruise-In 5, 6 & 10 Veteran
St. Jude Donor '09
Re: speedometer needle bounce (ray77vette)
The speedo system on C-3's isn't too complex.. It's the Gear, 2 cables, xducer, the speedo head and the gear in the trans....I noticed that my lower cable acted stupid and that made mine flop. I repositioned it for a good angle and secured it. GTG no more flop
Team Owner
Joined: Jul 1999
Posts: 65,492
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From: Orange Park Florida
Re: speedometer needle bounce (ray77vette)
I fail to see how a U joint could make the speedo bounce....assuming it's in the rear suspension, not some addition to the speedo cable....
I will assume no cruise controll...pull the speedo cable, and examine for any signs of wear....it only pulls from one end, the other is fixed in place by an adaptor....usually up top....the cables themselves are common and easy find in a parts house....
the shroud needs cleaned out and any carbon/graphite lube or old dried oil needs be cleaned out, I just use carb cleaner and a air jet...blow it out....
if it's still acting up, you need do the nasty...pull the speedo head....and fix that....it's fairly easy....do a search and find my previous posts on how to do this....
GENE
I will assume no cruise controll...pull the speedo cable, and examine for any signs of wear....it only pulls from one end, the other is fixed in place by an adaptor....usually up top....the cables themselves are common and easy find in a parts house....
the shroud needs cleaned out and any carbon/graphite lube or old dried oil needs be cleaned out, I just use carb cleaner and a air jet...blow it out....
if it's still acting up, you need do the nasty...pull the speedo head....and fix that....it's fairly easy....do a search and find my previous posts on how to do this....
GENE
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Team Owner
Joined: Sep 2003
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From: eville in
Re: speedometer needle bounce (turtlevette)
man oh man, for a u-joint to throw off the speed-o, the bind and release would ge un real :banghead: :banghead: like gas.brake,gas,brake
i'd think you would feel or hear :eek: the joint before it could bind so bad as
to send that much harmonics back threw the driveline :eek:
i'd think you would feel or hear :eek: the joint before it could bind so bad as
to send that much harmonics back threw the driveline :eek:
Racer
Joined: Oct 2000
Posts: 429
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From: Oak Harbor WA
Re: speedometer needle bounce (ray77vette)
Recommend you replace the speedo cable (my '74 had a two-piece cable). My speedo didn't bounce, but it sure did squeek. The new cables fixed everything. A lot easier than pulling your entire speedo, too. Hope that will fix your problem. I'd avoid squirting any lube in the old cable, or any additional lube in the new cable. The cable spinning sometimes acts as a pump and works any excess lube right up into your speedo, and gunks it up, plus looks bad with goo spots in your dash's centerpiece. A cable's not very expensive, and should last 20 years.
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From: Exiled to Richmond, VA - Finally sold my house in Murfreesboro, TN ?? Corner of "Bumf*&k and 'You've got a purdy mouth'."
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St. Jude Donor '06-'10, '13
Re: speedometer needle bounce (kenko74)
I had the same problem and it was the cruise control transducer that was causing it. So, after you lube the cables, if the problem does not go away, look at the transducer and see if it is stiff to turn.
Mine locked up and tore the end of the cable.
Mine locked up and tore the end of the cable.
Melting Slicks
Joined: Feb 2003
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From: Auburndale Florida
2025 C2 of the Year ('64-'66) Finalist - Unmodified
St. Jude Donor '03-'05-'06-'07-'09
Re: speedometer needle bounce (ray77vette)
My speeometer use to bounce on my 72. Pulled the cable off at the transmission end and sprayed some penetrating oil in the end. I held the cable above the car, higher than the head piece in the dash. All in an attempt to satuate the cable as far as I could w/o removing or replacng it. Then I lowered it and let it drain. Did this a few times and you would not believe the gunk that came out. The cable was dry, dirty and rusty. After letting it drain over night I sprayed some white grease into it. No more problems, quiet and steady! WD 40 or 30 wt oil would work OK.
A note of caution, you do not want any oils or solvents to enter the head or speedometer housing, so be careful when trying to satuate and re-oil
Good Luck
Mark :party:
A note of caution, you do not want any oils or solvents to enter the head or speedometer housing, so be careful when trying to satuate and re-oil
Good Luck
Mark :party:
Advanced
Joined: Nov 2003
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From: rochester ny
Re: speedometer needle bounce (comp)
i pulled one out of an '80 olds...it was the same as my vette.
all of the above was good advice: check cables for tightness at transducer and lubricate upper cable. problem should go away.
all of the above was good advice: check cables for tightness at transducer and lubricate upper cable. problem should go away.
Drifting
Joined: Mar 2001
Posts: 1,411
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From: St. Louis, Missouri
Re: speedometer needle bounce (mga1x)
To add to what has already been stated: If you have cruise control, you'll have two cables, an upper (CC transducer to speedometer) and lower (CC transducer to transmission. If you find out that the lower cable is your problem, about 90% of time it's caused by a bad transducer binding and not allowing the cable to turn at one end while the transmission is trying to turn the opposite end.
The CC transducers are a universal GM item. Some may have add ons for dashboard lights, etc. but these can easily be removed. Salvage yards have them for about $20 - $25.
The CC transducers are a universal GM item. Some may have add ons for dashboard lights, etc. but these can easily be removed. Salvage yards have them for about $20 - $25.
Race Director
Joined: Oct 2002
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From: Smalltownville Michigan
Cruise-In 5, 6 & 10 Veteran
St. Jude Donor '09
Re: speedometer needle bounce (BSeery)
I had the same problem and it was the cruise control transducer that was causing it. So, after you lube the cables, if the problem does not go away, look at the transducer and see if it is stiff to turn.
Mine locked up and tore the end of the cable.
Mine locked up and tore the end of the cable.
[Modified by Aflac, 4:40 PM 12/17/2003]
