V6 (1994-2004) Mustangs Technical discussions on the 3.8L and 3.9L V6 torque monsters

speedometer needle jumpin

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Old 01-21-2008, 08:04 PM
  #1  
Stang_1995
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Default speedometer needle jumpin

hey.
i have a 1994 mustang w/ 3.8L v6, A/T. recently got for my 16th birthday.
i was drivin a few nights ago and i hit a bump in the road, not a big one.. just a small bump in the highway and i looked down at my speedometer and noticed that it dropped from like 70 down to 40 or so and then back up to 70 and as far as i know it's accurate now. is this a common problem in mustangs? or is my speedometer just actin up?

I am soon going to take my stang into a mechanic just to get everything looked at.. tune up.. all that fun stuff.

thanks for the advice.

Matt "Stang_1995"
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Old 01-22-2008, 02:12 AM
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SilvrStang
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Default RE: speedometer needle jumpin

Try taking it off and readjusting the needle thats poppin.As far as tune up just do it yourself man. You will save time and money.

Fuel Filter- 10 bucks
Air Filter- 40 bucks(K&N)
Plugs+Wires ( 80 bucks)
Oil Change(20 bucks)

Someone add something else If Im missing it
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Old 01-22-2008, 06:48 AM
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jthorn9
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Default RE: speedometer needle jumpin

My 95 5.0 gave me the same problem. It started about 2 months ago, the speedo would just randomly drop, then would recover, but last week, after getting my rebuilt tranny installed, around halfway home it droped to zero, and never came back. Went to my trusty shop I always go to, they pulled my speedo gear and there were several chips in the teeth, Greg, the owner, said it's not uncommon for older cars speedos to quit working because speedo gears do wear out over time. Well he ordered another one for me, however, the problem still wasn't fixed, I still have to check my old tranny to see if I can't salvage the speedo drive gear from it. If I can, that should fix my problem. Point is, all these pieces are made out of plastic and will wear down over time. It may also be that the sending unit that connects to the speedo gear is bad, or that a needle was knocked out of wack, point is, there are a lot of different small things it could be.
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Old 01-22-2008, 11:15 AM
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6Stang99
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Default RE: speedometer needle jumpin

Mine did that the day after i swapped the stock gauges w/white face gauges. It was really sticky and jumped from spot to spot. I took the gauge cluster back out and pulled the needle out a tiny bit so there is a little gap between the needle itself and the face of the gauges. This allows it to move freely with no friction from rubbing. Maybe your speedo needle was a little loose and the bump knocked it down to rub on the gauges. It's really easy to take them out and check. If you don't know how just go to your local autozone or something and buy the haynes repair manual for your year stang. I have one and that book is like my bible.
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Old 01-22-2008, 09:32 PM
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Stang_1995
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Default RE: speedometer needle jumpin

thanks so much. i'll just do that lol. i've been wantin to get more into cars and this looks like a really good way to
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Old 01-22-2008, 09:33 PM
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Stang_1995
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Default RE: speedometer needle jumpin

my dad got me the Haynes book when he got me the car lol. i look through it regularly. very good source of info
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Old 01-22-2008, 09:35 PM
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Default RE: speedometer needle jumpin

I see.. i'll give it a good look and see what the gears look like..

damn this would be a lot easier if it wasn't 17 degrees outside right now
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Old 01-23-2008, 01:19 AM
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Fink
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Default RE: speedometer needle jumpin

the haynes book is good but sometimes it gives you steps that you dont need. i recently just replaced my passenger side exhaust manifold and the book said that i had to remove the tranny dip stick and tube... never did that and i still got it in. but that book is pretty much king for anything that has to do with fixing your car.
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Old 01-23-2008, 01:22 AM
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Default RE: speedometer needle jumpin

also try and fix everything u are capable of when fixing your car. i saved 80 bucks/hr with just my manifold.. took me and my dad 3 hours to take out and replace it
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Old 01-23-2008, 03:18 PM
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Stang_1995
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Default RE: speedometer needle jumpin

yea lol thanks.. but it's a bit hard to get stuff out and work on it when it's below freezing constantly :P it's startin to drive me crazy haha
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