JamesC

iTrader: (5)

The colors may not be exactly accurate, but I "believe" the tooth count is. Any additional info is appreciated.

3.23's up require a blue 7-tooth drive gear, plus the following driven gear:

18 tooth (p/n 3987918) Brown = 3.23
19 tooth (p/n 3987919) White = 3.42
20 tooth (p/n 3987920) Blue = 3.45
21 tooth (p/n 3987921) Red = 3.73
22 tooth (p/n 3987922) Gray =3.77

3.08 has an 9-tooth drive gear.

Some how-to's for swapping the gears into place:

https://www.thirdgen.org/forums/faq-...eter-gear.html

http://sethirdgen.org/t5speedo.htm

And from DSM where I found a lot of info: https://www.thirdgen.org/forums/tran...en+gear+sleeve

If your speedo cable is leaking at the trans and you replace the sleeve, note the following thumnail or your leak will likely continue (the sleeve for TH350, T-5 and Super T-10 can be found in the link in post #2):

JamesC

maroon88iroc

iTrader: (7)

mods you guys REALLY need to make this a sticky i have spent alot of time researching this and this post by jamesc pretty much sums it up and the links to how to change them is AWESOME!

btw here is the site that you can order the gears from. i didnt see it in your post jamesc.

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

anesthes

iTrader: (12)

These part #'s are for mechanical speedo's. (I know, I ordered them yesterday) They are 1pc large plastic gears with integraded rod. If you have an electronic VSS you need just the gear end that slides over the metal shaft.

Does anyone have the part #'s for the VSS gears?

-- Joe

Kevin91Z

iTrader: (1)

22 tooth is for 4.10 gears, as I just swapped in a 4.10 ratio 9-bolt, and used a 22 tooth gear. The 21 tooth is for 3.70/3.73. 3.77's would be close enough to use the 21 tooth.

Pat Hall

iTrader: (31)

Hey guys. I was curious to see if I could find any of the metal shaft speedo gear stuff, so I grabbed my f-body parts manual and plugged some part #'s into the gmpartsdirect website, and they do have a couple of things that are still available. 1. Part# 14090580-Gear W/Shaft, Sleeve, Seal-19 Tooth-White: $30.75. 2. Part# 14090595-Gear W/Shaft-22 Tooth-Gray: $15.75. They also have both drive gears available pretty cheap. 1. Part# 14053347-Gear-9 Tooth-Red: $4.04. 2. Part# 14071731-Gear-7 Tooth-Purple: $4.02. I guess if you're looking for just the gear itself to slip on the end of a VSS unit, finding a good used one is still the cheapest way to go. If you need a complete, metal shaft, mechanical drive assembly for a 3.42 geared car, part# 14090580 is somewhat reasonable, considering it'd be brand new. Somebody seriously needs to start reproducing the metal shaft driven gears! I've looked just about everywhere on the web, and they just don't exist. PATC-Raptor corp. has just about every speedo gear ever produced for GM, Ford, and Mopar, except for these. They also carry brand new VSS's for the 700r4's, but no dice for the T5 VSS's.

JamesC

iTrader: (5)

This from the above website:

Speedometer gears for a Chevy TH350 transmission with 26 inch tires and 4.10 gears. 7 tooth drive gear and 22 tooth driven gear. We also have 8, 9 and 10 tooth drive gears, and 17, 18, 19, 20, 21 and 22 tooth driven gears. (The driven gears also fit Super T-10 and Chevy T5 transmissions.)

JamesC

anesthes

iTrader: (12)

I'd double check with gmpartsdirect and make sure they actually have them. I went through this a month or two ago, and nobody had them in stock anymore. INCLUDING patc. I ended up finding what I needed out of a v6 trans, but still.

-- Joe

Pat Hall

iTrader: (31)

The V6 cars in the junkyard are a great place to find the white, 19 tooth driven gear that's correct for the popular 3.42 rear ratio. I've managed to snag 2 or 3 of them from those. Most of them had the metal shaft too, so they work on the VSS units.

Kevin91Z

iTrader: (1)

This website lists speedo gear combinations:
http://www.hanlonmotorsports.com/t5speedo.asp

However its a Ford T5 website, and GM's dont have a 6 tooth or 8 tooth. Their info says 19 tooth for 3.42/3.45, and 20 tooth for 3.55, and 21 tooth for 3.73 with a 7 tooth drive gear.

mxcrazed

What would you do for a 2.73?

Pat Hall

iTrader: (31)

Don't take this the wrong way, but the first thing I'd do is chuck the 2.73 rear in favor of 3.08's or better. You're gonna go through a lot of clutch discs running 2.73's with a manual trans. To figure what driven gear you'll need though, you can use the calculator at this site. http://www.5speedtransmissions.com/calculators.html. With a 7 tooth drive gear, it calls for about a 15 tooth driven gear, which I'm not even sure is available. With the red, 9 tooth drive gear, you'll need either a 19 or 20 tooth driven gear depending on your tire size.

mxcrazed

How do I figure out the margin of error and where can I find a good variety of speed-o gears? I have 28" tires plus 1 red and 1 blue driven gear I guess ill go figure out what drive gears I have. I would do something about rear but it will probably be an ls1 rear eventually. Thanks for all your help pat!!!

Pat Hall

iTrader: (31)

I'm guessing that since you have an 87 Firebird, you probably have the electric VSS type speedo sender. If so, you'll be kinda hard pressed to find driven gears. Nobody so far has been able to point out a place that sells the VSS style gears new. According to that calculator, with 28" tires, you'd need an 18 tooth driven gear along with the red, 9 tooth drive gear to get an accurate speedo reading. The 18 tooth gear was used in cars with 3.23 rears, so if you could find a member that's parting out a T5/3.23 car, you'd be able to get the gear you need. Most of the V6 powered T5 cars got 3.42 rears, which used the white, 19 tooth gear, but some of them got 3.23's, so you've probably got a fairly good chance of being able to get the gear you need. The reason I referred to the V6/T5 cars is that they seem to be way common in the junkyards, so that's probably your best bet for finding that gear. You might want to check and see what gear you have in there now. The 18 tooth is usually brown in color.

mxcrazed

It is a mechanical setup with the 85 mph speedo, I guess I'll switch the selector shaft when I get the speedo gears in they are easy to find on google and I could also use a 10/20 combo and get the same accuracy. I have had the drive and driven confused I have red and blue drive gears how many teeth are those? I'm really a noob to this lol

tb55chevy

Your not a Noob just confused like me and everyone else with this black art.

Blue is 7 tooth
Red is 9 tooth

I myself am trying to figure out what to run in my T5 with the 4:11's in my 9 inch I just installed. If anyone knows please let me know. I am running a Mechanical speedo it was a 3:4? rear before.

Thanks.

mxcrazed

Thank you tb55chevy I guess I need a 18 tooth brown drive gear, it is possible that is whats in there I believe the last car it was in was a 700r4---->T5 swap so it could have been recalibrated. to answer your question you figure out your drive and driven gear by plugging your information into the calculator that pat supplied a link to on 4/9/08 above. not all gear combos will be possible not round to the nearest whole number and that is your driven gear (if both gears are available)

Pat Hall

iTrader: (31)

You guys have got it made since you're both running mechanical speedos. The TH350 style driven gears and "bullet" insert work great in a T5, and they're all over ebay for dirt cheap. You can't run a 10/20 combo because the only 2 drive gears available for the GM T5's are the 7 and 9 tooth gears, so your best option would be a 9/18 combo for those 2.73's. You have to remove the tailshaft housing to change the drive gear, it's mounted on the output shaft by a clip, and it's pretty easy to do while the trans is out of the car. Hey tb55, the most common speedo gear combo for 4:11's is 7/22, at least with a 245/50/16 size tire. You can plug your tire size into that calculator, and it'll tell you which combo will be closest. There's a tire size calculator on the left, and the speedo gear calculator on the right.

Kevin91Z

iTrader: (1)

I'm running a 7/22 combo, as I said above in post #4.

TTOP350

iTrader: (8)

I need a scanner, so I can post all the GM tech book drive- driven gear and tire size info I have. 82-92

jimmy92rs

iTrader: (3)

Does anyone know where to get a VSS upgrade for 4.10 gears? I originally had 3.08s in the rear and now the speedo is off atleast 15-20 mph.

tilerob79

if i have a 700r4 with new 3.73s and posi , are all the parts #S the same as with the T-5
----------
and where can i get the parts?

JamesC

iTrader: (5)

No.

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

JamesC

MY_GTA

iTrader: (1)

"WOW" i think im even more confused than i was before i read all of this, ok question im doing the t5 swap this weekend and i want to have everthing ready, so im getting a t5 from a 91 firebird formula that had a 305 tpi so im guesing it had 3.08 gears, and im putting it in my 89 GTA 350 tpi w/ 3.27 gears, so what will i need? also will i need any connectors? anybody have part #'s

Kevin91Z

iTrader: (1)

You need a T5 VSS from an 86-89 Firebird, and you need to find a 7 tooth and 18 tooth speedo gears.

MY_GTA

iTrader: (1)

do you know a good place to get those items? would autozone or advance auto have those? and i would have to get a vss for a 86-89 305 tpi right? thanks for such fast reply. and just to make sure, the vss out of my 700r4 wont fit in the t5 right?

MY_GTA

iTrader: (1)

so if i order the 18 tooth gear does it come with a 7 tooth drive gear? cause im not finding a part# or even where to get the 7 tooth drive gear?????

Pat Hall

iTrader: (31)

If your donor T5 came from a TPI car, it's highly unlikely that it was running 3.08 gears. The only T5 equipped f-bodies I know of that ever came with the 3.08 ratio were the TBI cars. Chances are a 305 TPI car with a T5 got either 3.23 or 3.42 rearend gears, both of which used a 7 tooth drive gear. Take a flashlight and look in the speedo drive hole in the tailshaft housing. If you have a 7 tooth gear, the color of it will be either blue or purple. The 9 tooth gear is red, so it's pretty easy to see the difference. If you do end up needing a 7 tooth drive gear, PATC Raptor corp. sells them. They have an ebay store. It's only $12, and here's a link. http://cgi.ebay.com/ebaymotors/GM-T5...mZ140115939750 The hard part will be getting an 18 tooth gear that fits the T5 VSS. As far as I know, nobody sells them new, so you'll have to find a used one somewhere.

Kevin91Z

iTrader: (1)

Pat, the 305 5-speed TPI's could come with 3.08 drum brake rear or a 3.42/3.45 disc brake rear, depending on if it had the G92 option or not.

MY_GTA

iTrader: (1)

ok so if my t5 has a blue 7 tooth drive gear and the car it came out of had 3.23 gears then it will already have a 18 tooth correct? how can i tell what gears the car had from the t5? also will my computer have any trouble's considering it was set up for an auto? what about engine idle? man this stuff is confusing about these drive gears!

JamesC

iTrader: (5)

Your best bet is to yank the driven gear and take a peek--no guessing that way. No idea about the computer. Idle speed is around 600 or 700 rpm for a manual trans, IIRC.

JamesC

Hubes

So if you already have the right drive gear and you just need to replace the driven gear, do you have to remove the tailshaft?

JamesC

iTrader: (5)

No. The driven gear can be accessed from at the side of the tranny where the cable or VSS connects.

JamesC

RockJay81

iTrader: (1)

is there any way to make a electro speedo on a 700r4 it would be great to do my speedo broke 3 times already in the past year

Kevin91Z

iTrader: (1)

Not that I know of. The 700R4 speedo VSS is a different size and will not fit.

webguy247

Another great site I think you guys should check out. I use em for parts and Art Carr is always friendly for answering questions when i call him.
California Performance Transmission

choekstra17

I noticed someone asked if they knew of any place that sold the driven gears for the VSS type T5. The company listed in the begining of the post does sell them. I just ordered the 22 tooth driven gear and 7 tooth drive geat to compensate my 4:10 gears. Again the website is http://www.transmissioncenter.net/sp...n_______va.htm
and I paid 42.00 for the driven and 15 for the drive plus shipping and it came to like 66.00 approx. Hope this helps

Chris

Scubaman7337

Hello, not sure if anyone can help. I have a 92 Firebird that I swapped from 700r4 to t-5 manual. The car has a vss, but the tranny has a 1" mechanical speed sensor. I purchased a 1" vss, but the driven gear is different. The vss has a D shaped shaft about 1" long, and all the gears I get have a square or round shaft that won't fit the vss. Does the gear just fit on the end of the vss, or do I need a gear with a shaft to work. And does anyone know which gear and where to find it. My car is 305 tbi, with 2.73 rear end. Any help would be much appreciated.

JamesC

iTrader: (5)

Welcome to TGO. Contact the company in the link immediately above.

JamesC

Hubes

the driven gear in my t5 is the one with the metal shaft through a plastic gear. is it possible to convert to an all plastic gear by changing the sleeve that holds it in to the other style? I have some plastic gears and a sleeve out of a muncie laying around, will they work? thanks

JamesC

iTrader: (5)

With the correct sleeve and plastic gear, I wouldn't see why not. Keep us posted.

JamesC

Hubes

ok, Im pulling the transmission before i put it away for the winter, so Ill let you know when I put it back together in the spring

Hubes

ok, I didnt actually try to put the gear in place but I compared the metal shaft gear to the all plastic gear. theres a bore in the tranny housing that the gear slides into and the diameter of the all plastic gear and the metal shaft gear is different at this point. there may be enough support in the gear housing, but i dont think an accurate speedo is worth the risk. to try to clarify since its hard without pics, if you look at JamesC's attachment in the 1st post, the little nub on the left of the gear is the part that slides in the bore and is a different diameter. hopefully that makes sense

Saabster

iTrader: (2)

Can someone explain to me how to get the correct speedo reading for a VSS equipped car with a 3.42 rear and 26" tires? I'm a bit confused by this thread, I know it's calibrated for a 3.08 from the factory given the year tranny I bought. Do I just need to change the whole VSS or are there gears I change?

JamesC

iTrader: (5)

Swapping from 3.08's to 3.42's will require both a drive gear (VSS) and driven gear swap. I'd phone the following company to inquire about parts:

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

JamesC

squatingeagle

i have a 91 305 tpi with a 3.08 rear but i just swapped to a 3.23 last week. rockauto.com has the 7 tooth drive gear and the 18 - 22 tooth gears as well cheap. i just ordered them both for about 10 bucks plus shipping. youll have to search the above part numbers to find the 18-22 tooth gears though. to search part #'s you have to click on the second tab. the 7 tooth drive gear is labeled as Speedometer Pinion Bearing under a 91 camaro z28 5.0. hope this helps

p.s. search all forums for rockauto discount codes they are posted all the time by other members

JamesC

iTrader: (5)

Very good to know.

JamesC

squatingeagle

JamesC in your experience, how is that t5 standing up to your 350? ive been thinking of doing the same thing, 350 and t5, but ive read some stuff that says the t5 wont last very long.

JamesC

iTrader: (5)

PM sent.

JamesC

GTA88t5

iTrader: (2)

Just found this online calculator. You just plug in what drive gear you have, what rear gear ratio you have, and what diameter tire you have .
http://www.bgsoflex.com/speedo1.html

Saabster

iTrader: (2)

By my math you need a 19.5 tooth driven gear with a 9 tooth driver. So pick a 19 or a 20. I'd go 19, that should make it a little fast.