Cascade Crew

Quasi-Traction · Posted: Tue Oct 21, 2008 3:26 pm Post subject: Speedometer Gear.

Need the correct driven gear for a 3.42 rear ratio, for a T-5.

Also need the retaining clip for the gear and 10mm bolt that goes on a T-5 trans. Mine weeps fluid without it.

Willing to pay shipping. Thanks.

Twilightoptics · Posted: Tue Oct 21, 2008 4:12 pm Post subject:

You must forget that I work in a transmission shop LOL.

Plus... you need to know what drive gear you have before you can get the appropriate driven. Is it blue? If so it's a 7 tooth. Then just use the online calc with your tiresize to specifiy the proper driven.

If it's a 7 tooth and you're going to run those Wheels from Alphius (245/50R16) that's a 25.6 tall tire. Yeilds a 19 Tooth Driven gear with 3.42 butt gears.

alloy · Posted: Tue Oct 21, 2008 5:03 pm Post subject:

Paul's right about the gears if that's the correct tire size. A blue 7 tooth drive with a white 19 tooth driven yields a .368 ratio. Optimum ratio is .375, but .368 is as close as your going to get.

If Paul can't supply them for you, here is where I buy my gears for my T56 speedometer cable drive conversions. I purchase the parts on Ebay from Pactrans, then email Trudy and ask her to combine shipping for me. They ship very fast and Trudy has always been very helpful to me.

I don't have any spare gears in stock right now to help you out with, but I do have a spare T5 drive gear clip around here somewhere. The hold down bolt is just a plain 6mm bolt. Nothing special about it. I've got many in my bolt pile if you need one. I also always use a new driven gear sleeve. There is an o-ring both inside and outside of the sleeve, and it's just best to get a new one so you don't have any leaks. I had a inside o-ring go bad on me and it emptied my trans in less than a day. One day no leaks, the next day big red puddle and almost empty trans.

Hope this helps.

19 tooth driven gear (fits a T5)
http://cgi.ebay.com/ebaymotors/Chevy-TH350-Speedometer-Driven-Gear-19-Tooth-Gears-350_W0QQcmdZViewItemQQ_trksidZp1713Q2em153Q2el1262QQcategoryZ33727QQihZ004QQitemZ140098001529

7 tooth (blue) drive gear
http://cgi.ebay.com/ebaymotors/GM-T5-speedometer-drive-gear-with-7-teeth-Chevy-T-5_W0QQcmdZViewItemQQ_trksidZp1713Q2em153Q2el1262QQcategoryZ33727QQihZ004QQitemZ140115939750

Speedo driven gear sleeve retainer
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=140004242129

Driven gear sleeve (housing-fits T5) http://cgi.ebay.com/ebaymotors/Chevy-TH350-Steel-Speedometer-Gear-Housing-350_W0QQcmdZViewItemQQ_trksidZp1713Q2em153Q2el1262QQcategoryZ33727QQihZ004QQitemZ140134295485

Quasi-Traction · Posted: Wed Oct 22, 2008 5:14 am Post subject:

All the information is very helpful.......

Right now I'm running pretty close to a 25" tall tire (235/60/15's).

my problem is I don't know exactly what I have in the trans right now as a drive gear.

The trans came out of a car with 3.23's and a the tire size is the same for what I have now. I changed the drive gear last year with one Rod gave me, and it seemed to read fairly accurately within a few MPH all the way up in excess of 100mph.

Dan, I'm absolutely certain that the retainer for my T-5 is a 10mm head, and its a real fine thread, the retainer itself has fingers on it, the ebay part you listed looks like one I looked at from Raptor Transmission, which isn't the same.

The O-rings may be the cause of the leak, so I'm sure I'd do well to replace those.

Twilightoptics · Posted: Wed Oct 22, 2008 6:31 am Post subject:

Usually the ones with fingers are for the larger automatic speedo housings inserts.

Manual trans are usually just a little piece of flat bar with a notch out of one corner.

Look inside the hole, is the gear blue/dark purple? If so it's a 7 tooth.

a 6mm bolt thread is a 10mm head. Bolt are listed by their diameter not their headsize :O)

If you can't find that gear you can come swap the one you have out for the one in the chevette.

Quasi-Traction · Posted: Wed Oct 22, 2008 12:08 pm Post subject:

Ok, looks like I have a 7 tooth drive (purple colored)

and my driven gear is a 21 tooth (Red colored)

I know my retainer had fingers on it. I had it at one time, but I've misplaced it at some point, and now I don't know where its at.

I guess I don't read very well early in the morning (or at all... Rolling Eyes

) Raptor is PATC, and Dan's a machinist, therefore speaks in thread size/pitch, not bolt head size like I do.

O ring came out with a spit in it. Probably my leak source. Will any O-ring that fits do, or is there a spesific one for the gear sleeve?

alloy · Posted: Wed Oct 22, 2008 4:23 pm Post subject:

Right now you have a .333 ratio. With the tire size you have you need a .388 Get an 18 tooth driven gear to go along with the 7 tooth drive and you will be set.

http://cgi.ebay.com/ebaymotors/Chevy-TH350-Speedometer-Driven-Gear-18-Tooth-Gears-350_W0QQcmdZViewItemQQ_trksidZp1713Q2em153Q2el1262QQcategoryZ33727QQihZ023QQitemZ360090916986

The problem with replacing the outside o-ring only is the seal on the inside is probably really old also. I think it's $9 from PATC for a new sleeve. Money well spent. And the retainer is $2, might as well grab one of those also.

Going by bolt head size will eventually catch up with you. I saw a plastic bolt size checker at Lowes the other day. You might grab one of those for a few bucks. Makes it easy to tell what your working with.

chevymad · Posted: Wed Oct 22, 2008 5:44 pm Post subject:

LOL Chris. Bolts are never sized by the head. Always by the thread. Even for those of us not machinists. You can find lots of bolts with various size heads and the same size thread. There's no real standard. Anyway, something you'll have to get used to.

alloy · Posted: Wed Oct 22, 2008 5:52 pm Post subject:

And to add to what Brandon said, bolt length is called out by the shank and threads only. The head is not included when specifying bolt lengths.

Quasi-Traction · Posted: Wed Oct 22, 2008 7:22 pm Post subject:

looks like I'll be replacing the whole sleeve, and a 19 tooth driven gear. Not sure if I should buy the retainer from em. I'd like to have it, even though my cable has a threaded collar.

PATC said that the new sleeve comes with the O-ring from what I could tell.

Thanks for your help guys!

Twilightoptics · Posted: Wed Oct 22, 2008 10:52 pm Post subject:

The retainer holds the bullet in. The cable screws onto the bullet.

BigDaddyVu · Posted: Fri Oct 24, 2008 8:07 pm Post subject:

I bought a wc t-5 and installed it in my t/a but forgot to swap the speedo gears from my other tranny. I have a 3.73 ratio and my speedo is off you can have it for free if you pay for shipping. the car i got it from has a 3.42 ratio posi.