Question about speedo drive and driven gear

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Feb 10, 2002 | 10:29 AM

idrag2

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From: Texarkana, Texas, USA

Question about speedo drive and driven gear

Ok so I finally deside that I am going with 3.42's in my bird, my buddy GAVE me a good rear end....so I gotta use it.......ain't no gears like free gears....but anyway, Can anyone help me out with the tooth count that I will need to make my speedo right? Any help at all would help me out........BTW I have a 700R4 tranny, Thanks guys:hail:

Feb 10, 2002 | 10:40 AM

Jay 727

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From: FL

http://www.tciauto.com/tech_info/speedo_gears.htm

You'll need your tire diameter and drive gear tooth count in order to use the link above. It's the most accurate way I have found to get the right gears.

Feb 10, 2002 | 01:44 PM

idrag2

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From: Texarkana, Texas, USA

Ok I have no clue how many teeth are on the drive gear now.......but my tire dia...is 25.5

Feb 10, 2002 | 01:50 PM

Kevin91Z

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From: Orange, SoCal

Car: 1990 Pontiac Trans Am

Engine: 355 TPI siamesed runners

Transmission: Tremec T56

Axle/Gears: 12-Bolt 3.73

15 and 41. A quick search of this board found me that.

You should have a 17 now...

Feb 10, 2002 | 05:42 PM

idrag2

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From: Texarkana, Texas, USA

so right now I have 17 and 41..............but with 3.42 I will just have to change the drive gear.....15...

BTW right now I have 2.73's does this change anything?

Feb 10, 2002 | 06:05 PM

Jza

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From: Tulsa, OK

It's much easier to change a driven gear (one bolt), than a drive gear (have to remove tailshaft housing). Just a thought when picking out your gears.