twigger

So my 91 has the electronic speedometer and I would like to swap gears. My problem is besides buying an expensive Dakota box do I have any other options?
I thought I read somewhere that you can change out the reluctor ring to recalibrate the signal to the vss to get the speedometer to read correctly but I have been unable to locate such a device. Any help is much appreciated thanks!

JamesC

iTrader: (5)

Simply switch out the drive and/or driven gears with the correct ones. You may be able to purchase what you need from the site below:

http://www.transmissioncenter.net/sp...n_______va.htm

JamesC

jmd

iTrader: (4)

the '91 does not have a reluctor ring on the output shaft.

It has a drive gear just like a car with mechanical speedo. The VSS has a driven gear.

Go back and read the sticky threads about speedo gears and review the site James linked.

twigger

Thank you for the link James!

I have read the sticky through multiple times. I was confused because when I went to try and buy speedo gears here locally I talked to 2 reputable transmission shops and speed shop that all they do is speedometer calibrations and all 3 places told me there are no gears to change out and I had to recalibrate the sensors output with a box. I know another local guy who used a Dakota box to recalibrate because he told me the same thing. I suppose it would have been easier for me to get off my lazy *** and jack my car up and take a look. If I just have to change out the two gears I am more than happy about that thank you!

Just curious if any, which transmissions came with a reluctor ring?

Tuned Performance

iTrader: (92)

http://www.facebook.com/pages/Virtua...02207606487557

Ray just got one of the dakota digital in, user rcar7395.

JamesC

iTrader: (5)

No thirdgens.

JamesC

RCAR7395

iTrader: (124)

Thx man, yep I got a Dakota $30 shipped in USA, Untested but guaranteed. Lmk if interested
Thx
Ray

twigger

RCAR7395 I think I just found a new friend, thanks for the help guys!

RCAR7395

iTrader: (124)

lol , still got it, so lmk or send pay pal below to secure it. I have 3 or 4 people asking about it and only have 1 ! Thx man ! Add my Virtual Junkyard facebook to yours if u have it. Lots of pics of stuff i have for sale there too !
lmk
Thx
Ray

twigger

PM sent.

jmd

iTrader: (4)

'89 was the earliest for GM trucks.

twigger

So does anybody have any ideas where I might find those speedometer gears? I tried calling the guys at the above link and they said that the 40 tooth driven gear is no longer available for transmissions equipped with the electronic speed sensor.

twigger

Okay I talked to 6 transmission shops and 2 dealers in three states and all come back saying that the black 40 tooth driven gear is no longer available. So if im not mistaken my only option now is the Dakota box?

jmd

iTrader: (4)

it's possible to fab. one. what's your tire size?

twigger

Its a 315/35/17 which I believe is a 25.7 inches tall.

chevman24

iTrader: (1)

Heres a site I found that has the gears.
http://www.transmissioncenter.net/sp...n_______va.htm (oops i posted the same link the moderator did)

I got my driven gear from summit. I also have the early style gears though.
TCI has them as well.

twigger

Summit, that website and TCI cant get those driven gears for the sensor type, I have called them all.

chevman24

iTrader: (1)

Damn that sucks. Got any salvage yards nearby? You would only need the driven gear, since all of the Drive gears are still available. Have you tried thirdgenranch, hawks, or YoungsFbody?
I would think they would be able to find something for you. No one could tell me that with all those salvage Camaro's and Firebirds they bring in that they dont have any gears laying around. Most probobly go with the transmission though.

Found this on ebay...39 tooth driven gear
Its close..http://www.ebay.com/itm/SPEEDO-DRIVE...item43a2c404c4

jmd

iTrader: (4)

If you're running those with a 3.42, a 40 tooth won't give you an accurate speedo. Grab a 42 which I think is available. If you're talking a different rear gear, then say it.

twigger

Chevman24, thanks I will try them tomorrow. Im not sure if many models came with a 40 tooth I will see if I can find one though.

According to the figuring speedo thread. https://www.thirdgen.org/forums/tran...eedometer.html
posts 5 and 10 they say for a 3.42 rear end, which im using, and a 315/35/17 I should be using a 15 and 40. I might be able to get by with a 15 and 41 but I dont know.

I dont know if its possible but if my math is right I should be able to use a 17 and a 45 combo if they go together?

chevman24

iTrader: (1)

This calculator will give you the exact gears. http://www.bgsoflex.com/speedo1.html
He may be right about your speedo gears. The correct gears for 3.73s is a 15 drive and 44 driven with a 25/26 inch tall tire.

Addition; the 15 drive 40 driven is correct for a 3.42

jmd

iTrader: (4)

Here's what you have:
25.7" tire, 3.42 rear, 15 tooth drive gear, 40 tooth hypothetical driven gear.

Here's a combo GM used in production vehicles:
25.7" tire, 3.45 rear, 15 tooth drive gear, 42 tooth driven gear.

Every time I have used the GM speedo gear combos and checked them against mile-markers, "your speed is" signs, and other newer vehicles, they have been dead-nuts accurate. So, I keep plodding along with accurate speedometers. Your choice.

That would be even further from matching production combinations.

Tuned Performance

iTrader: (92)

just noticed today in the new corvette central catalog they have the vss gears

the 40 is p/n 534204

http://www.parts123.com/parts123/yb....rt~A2~cadefibF

Tuned Performance

iTrader: (92)

but with driven gears 40-45 you need a different vss. standard motor parts have the best price for vss usually around $50-$65