Quote: Originally Posted by 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 I just called our AC Delco dealer and the 18 tooth brown driven gear part # 12554183 shows up as obselete. I have decided to go another route. My bird now has 3.23 rears and 26.25" tires and a blue 7T drive gear and a 22T white gear. Speedo is way too slow. I normally would require a 7T drive and an 18T driven. I am tired of searching for the 18T. my calculations show 7T/22T combo=.318(currently have) 7T/18T combo= .388(desired) 9T/22T combo= .409(next best one) Speedo will show fast for sure but I am hoping not drastic. If I can get it within 5km I am happy. I will post my findings.

i have the same problem. i found brown driven gear off of ebay but it's the old, long plastic style which i believe is for a mechanical speedo. I have a electric speedo with VSS. in the days coming up i'm going to try and modify it and cut an interference fit D hole to fit it. when i succeed i'm gonna have one heck of a write up. the brown gear for electric VSS systems are dang near impossible to find. i know PATC sells the white ones and another color.

Yes I tried that...didnt work, might if you use a lathe. BUT I did find a used brown gear, put it in and guess what speedo was still too slow, I ended up putting in a red drive gear and my original white driven gear and speed is close to bang on. so Im not sure if half this stuff here is incorrect or if some specs are diff. from car to car.

what combination can i use for a 4.56 gear and a 26" tire?

With the common 7 tooth drive gear found in our T5's, the calculator I used calls for a 25 tooth driven gear, which I'm pretty sure doesn't exist. If you could find any place that offers a 6 tooth drive gear, then a 21 tooth driven would do the job.

Which gear combo you need is VERY affected by what size tire you're running. Most of the gear combos on this site are usually based on a 245/50/16 size tire. Here's link to the calculator I always use to figure out my speedo gears. It's handy because it has the tire size calculator and speedo gear calculator side by side on the same page, so once you figure your tire size, then you can figure the speedo gears. You also have to know how many teeth are on your speedo drive gear. For T5's it's either 7 or 9 teeth, 700r4's are 15 or 17 teeth. All my combos have worked out perfect using it. http://www.5speedtransmissions.com/calculators.html

i found one for a mustang t5, that wouldnt work or will it?

Not 100% sure if it would work or not. I know the input shafts are vastly different on the Ford T5's, but there's probably a real good chance that the output shaft diameter might be the same size on both GM and Ford T5's. A good business to contact with T5 questions is Hanlon Motorsports. They can probably tell you if it would work or not. But yeah, if you can find a 6 tooth drive gear that fits, then all you'd need to do is dig up a 21 tooth driven gear and you'd be all set. If your speedo is cable driven instead of electric, that makes it even easier to find the driven gears since the all plastic driven gears that fit the old Muncies and T10's fit the T5 mechanical speedo bullet too. The electronic style gears that fit on the metal drive shaft with the D-shaped hole are always harder to come by compared to the all plastic gears.

I'm restoring a 1989 z28 in the process of building a 383 i have 273 gears what do you suggest

Will a 4th gen T5 VSS driven gear work in a 3rd gen T5?

just to update, I did find a use brown driven at a tranny shop, installed and speedo was still out, I ended using my original white driven and changed the the driver to a red. So for some reason all the data and calculators didnt mesh with my set up. But I got it now within 2 kms, so I am happy. I also still have the brown VSS driven gear If someone cant find it anywhere, Id take 20 canadian and that would include shipping within canada, US shipping probably 25 would cover most of the continent.

I just got done changing from 3.08 drive/driven gear combo in the trans to a 3.45 drive/driven gear. My problem is when putting shifter block back on, I set it up in N but buy the time the tailshaft becomes seated, the shifter block moves into the 4th gear position. Any ideas on what i can do to prevent the shift bar from moving?

I have a question, I have an '89 camaro t5 tranny from an z28 iroc. I don't know what the rear end gears were.. but the drive gear is RED, I am wondering what the teeth count is of the drive gear..

The red drive gear is usually a 9 tooth count. Kinda strange to have that drive gear in an Iroc, or Z/28 T5. It's commonly used when the rearend ratio is 3.08, which is the ratio that came in pretty much ALL the L03(305 TBI) powered RS Camaros with a manual trans. I've seen a few Irocs with 3.08's, but it's sorta uncommon. The more common drive gear is the blue, or purple colored 7 tooth one, which comes with 3.23 or numerically higher rearends.

hello, i am in need of your brown 18 tooth gear if you still have it.
i will pay with paypal. my email is backlash43@yahoo.com
thanks,
don

i got a t 5 um is thier any way i can beff it up like mack it any stronger im plaing to swap out my moders and like i k it put out to much tq for it to handel also the ingen i have in it nowe has just enuff to f with it um i dont wana go back to a\t and t56 are to exspincev
any idas no i dont wana go to a turbo 350 or any thing like that that will chew my gas up its my daly driver

I'm afraid my understanding of much of the above is limited, but it appears that you're off topic. Perhaps posting your question in the general forum would generate better results.

JamesC

Holy cow, I don't normally nitpick about another poster's grammar too much, but jeez, did you even finish elementary school?

Holy mother of god, put down the wrenches and open a book.

i found a brown gear, it still reads slow. i went from a 3.42 to a 3.23. the 18 brown is closer than it was but is still about 8 mph off. i guess i will try to find a 17 tooth....if they made one. 1991 rs 3.1 5 speed 15 inch tires.

Hello all. I have a 1991 z28. It has a t 5 I got from eBay in it. I just swapped rear ends this weekend with a 4.56 2000 trans am. There is a vss on the tranny. My speedo now reads 160km hour when I'm doing 100 km hour. I think that makes it like 45 miles out. Any idea if I can just change the gear on the vss itself and what gear it would be ? Where could I get it?

Hello cubby. I used an online speedo gear calculator and came up with a few combos. The first thing you need to figure out is how many teeth you have on the speedo drive gear that's on the output shaft of the trans. The 2 most common tooth counts are 7 and 9. 7 is usually a dark blue or purple color, 9 is usually red. When I did the calculations, I entered the standard 3rd gen Z/28 tire size(245/50/16). With a 9 tooth drive gear and 4.56 rearend gears, you'd need a 32 tooth driven gear, which I don't think even exists. With a 7 tooth drive gear, the driven needs to be 25. That might also be either non-existent or damn hard to locate. PATC Raptor corp. sells drive gears that fit the T5. You could check their site and see if they offer a 5 or 6 tooth drive gear. If so, that'd make it much easier to locate a driven gear that'll match up. With a 6 tooth, you'd need a 21 or 22 driven, 5 tooth would require an 18 tooth driven. Figure out what drive gear you have in your T5 and also let me know what your actual rear tire size is. If your rear tire isn't the standard 3rd gen size, that'll change the tooth count you're gonna need. This might be a tough problem to straighten out since the factory never offered 4.56 as a rearend gear, so that makes it hard to get the proper speedo driven gear. If you can't manage to get the right combo for your existing VSS, the other option would be to buy an adjustable VSS unit that fits the T5. I've seen them on PATC's site, but I'm not sure if any of them work with a T5. You'd have to look on their site or send them an email I guess. Hope this info at least points you in the right direction!

Hey Pat thanks so much for the reply. Ya I think it's going to be a tough one. I'm going to check that website you suggested and see what they have. Also there is a GPS option for approx 250$ that I may try out to see if it's compatable. I'll post the results. Thanks again

Glad to be of help! Also, I forgot to mention, if you end up going with an aftermarket, adjustable VSS, make sure it has the correct PPM (pulses per minute) to be compatible with your computer. If I remember right, 3rd gen computers require 2000 PPM, whereas 4th gen and newer ones call for 4000 PPM.