Speedo Drive Gear
05-07-2009, 02:29 PM
#1
Thread Starter
Join Date: Mar 2008
Location: California
Posts: 32
Speedo Drive Gear
I'm looking for a '90-'93 transmission because the one in my '87 finally gave out. I was looking at the paragraph below taken from ModernDrive.com. It says the speedo drive gear changed from 7 tooth to 8. this isn't the small plastic gear you swap out at the end of the speedo cable when you upgrade your rear end gear. Those are around 18 tooth deals. Is it something deeper inside the tranny? Thanks guys, see below:
"1990 to 1993 .... the speedo drive gear was changed from 7 tooth to 8 tooth. The 8 tooth was a step backwards when installing lower rear axle ratio greater than 3.55 as the driven gear is limited to 21tooth count. Yes, 23 tooth gears are available but do not last long as the teeth are thin and do not mesh correctly."
"1990 to 1993 .... the speedo drive gear was changed from 7 tooth to 8 tooth. The 8 tooth was a step backwards when installing lower rear axle ratio greater than 3.55 as the driven gear is limited to 21tooth count. Yes, 23 tooth gears are available but do not last long as the teeth are thin and do not mesh correctly."
05-08-2009, 05:11 PM
#4
5th Gear Member
Join Date: May 2007
Location: Pittsburgh
Posts: 2,459
The speedo drive gear is on the output shaft INSIDE the transmission, it is a 6 tooth gear unless you buy an after market 7 tooth which is meant for 373 conversions. The speedo cable gear is what is 18-2x teeth and when using the 7 tooth drive gear for 3.73s a 21 tooth cable gear is necessary. A stock 6 tooth drive gear with a 21 tooth speedo cable gear is what is used on 3.55 calibration.
7 and 8 teeth drive gears are not in a stock t-5
7 and 8 teeth drive gears are not in a stock t-5
05-08-2009, 05:52 PM
#5
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Join Date: Dec 2005
Location: Lil' Rhody
Posts: 22,376
The speedo drive gear is on the output shaft INSIDE the transmission, it is a 6 tooth gear unless you buy an after market 7 tooth which is meant for 373 conversions. The speedo cable gear is what is 18-2x teeth and when using the 7 tooth drive gear for 3.73s a 21 tooth cable gear is necessary. A stock 6 tooth drive gear with a 21 tooth speedo cable gear is what is used on 3.55 calibration.
7 and 8 teeth drive gears are not in a stock t-5
7 and 8 teeth drive gears are not in a stock t-5
pre 90 was 7 tooth, 90-up is 8 tooth
05-08-2009, 08:46 PM
#8
5th Gear Member
Join Date: May 2007
Location: Pittsburgh
Posts: 2,459
I'm not saying your lieing or anything, but my trans was never opened. Nor was the brand new tremec t-5 that I bought, BOTH had a 6 tooth speedo gear in them. Besides why would they sell a 7 tooth gear as a precise 3.73 conversion piece.
http://www.latemodelrestoration.com/...0%201&comp=LRS
Like I said, do you know from experience taking apart trannies and counting teeth? or did you just read this on a website. I know for a fact that mine is a 6 tooth. I don't mean to be a dick or anything, but are you sure you counted the teeth right if you did take one apart?
http://www.latemodelrestoration.com/...0%201&comp=LRS
Like I said, do you know from experience taking apart trannies and counting teeth? or did you just read this on a website. I know for a fact that mine is a 6 tooth. I don't mean to be a dick or anything, but are you sure you counted the teeth right if you did take one apart?
05-08-2009, 08:56 PM
#10
Banned
Join Date: Dec 2005
Location: Lil' Rhody
Posts: 22,376
1990 to 1993 the stock Ford production V-8 WC T-5 was upgraded with stronger 3.35 gear set by increasing the nickel content to produce a harder, stronger gear. 2nd and 3rd gear ratios were decreased slightly tp provide more torque to the rear wheels. Synchro linings on 3rd, 4th were improved by changing from fiber linings to carbon fiber to further improve the friction surface resulting in better high rpm shifts. A longer throw shifter was installed to "make shifting easier". The speedo drive gear was changed from 7 tooth to 8 tooth. The 8 tooth was a step backwards when installing lower rear axle ratio greater than 3.55 as the driven gear is limited to 21tooth count. Yes, 23 tooth gears are available but do not last long as the teeth are thin and do not mesh correctly. Torque rating jumped to 300ft/lbs.
