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Old 03-21-2010, 01:22 PM   #1
kris's66lwb
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100 mph

i got a 100 mph speedo to relpace my 85 mph speedo but i want my milage too be correct how can i accomplish this task ? or is there even a way
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Old 03-21-2010, 01:39 PM   #2
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Re: 100 mph

The speedometer gears in the transmission have to be right for the rear end gears and tire size. As long as the speedometer itself is working properly, it will show the right speed. Seems like with age/use the internal spring in the speedometer can get weak and they sometimes need to be recalibrated.

However, given correct gears in the transmission and speedometers that work properly, the 100MPH speedometer is a direct swap for the 85 MPH unit.
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Old 03-21-2010, 09:24 PM   #3
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Re: 100 mph

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Originally Posted by Pyrotechnic View Post
The speedometer gears in the transmission have to be right for the rear end gears and tire size. As long as the speedometer itself is working properly, it will show the right speed. Seems like with age/use the internal spring in the speedometer can get weak and they sometimes need to be recalibrated.

However, given correct gears in the transmission and speedometers that work properly, the 100MPH speedometer is a direct swap for the 85 MPH unit.
Yea x2! Ya it is possible to roll em back just never actually done it lol!
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Old 03-21-2010, 02:14 PM   #4
kris's66lwb
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Re: 100 mph

thanks i knew that already i need to knw if there is any way possable to make the odomerter read the milage on my current speo mine has 28xxx and the new one has 42xxx miles how can i roll or advance the new one to match my truck current mialge
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Old 03-21-2010, 04:12 PM   #5
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Re: 100 mph

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Originally Posted by kris's66lwb View Post
thanks i knew that already i need to knw if there is any way possable to make the odomerter read the milage on my current speo mine has 28xxx and the new one has 42xxx miles how can i roll or advance the new one to match my truck current mialge
Oops I read your post wrong. Not sure how to do it, but I know it can be done. I don't think it's illegal because trucks this old are mileage exempt.
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Old 03-21-2010, 04:14 PM   #6
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Re: 100 mph

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... because trucks this old are mileage exempt.
Not everywhere
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Old 03-21-2010, 02:48 PM   #7
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Re: 100 mph

if i remember correctly i believe that rolling it at all is a felony
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Old 03-21-2010, 03:41 PM   #8
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Re: 100 mph

It is against the law I believe, but I'm honest and have no problem setting one to the correct mileage. It can be done if you take the scroll wheel thingy apart, but I can never remember exactly how to do it. I have to figure it out again every time. It's always been Camaro speedos though, but I'd imagine it would be basically the same.
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Old 03-21-2010, 09:11 PM   #9
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Re: 100 mph

cool thanks i dont rele care about the law implications becuase who else is gunna know and who would care espically if its the correct mileage right
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Old 03-21-2010, 09:25 PM   #10
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Re: 100 mph

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who else is gunna know

You just advertised on the world wide web.....
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Old 03-21-2010, 09:28 PM   #11
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Re: 100 mph

eh o well right im sure the cops got bigger fish to fry
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Old 03-21-2010, 09:42 PM   #12
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Re: 100 mph

LOL u never know jk man you should be fine
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-'79 3/4 ton "Big Yellow Bananna" Lifted 4spd. 39.5 TSL Swampers, The money Pit
-'86 K5 Blazer Silverado 6.2 4" lift 35"s
-'95 Ext. Cab Shorty 4" Tuff Country rolling 35" M/T's
-'83 Monte Carlo T-Tops. 126,500 Original Miles
-LATER
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