What speedo gears
06-26-2017, 10:49 AM
#1
What speedo gears
New here and my first post. I have a 1992 auto 700r4 with 2:59 rear. I just picked up a Dana 44 with 3:33 gears to swap with the Dana 36. Can someone tell me what speedo gears I will need to make the speedometer read correctly? Thanks in advance.
06-26-2017, 11:18 AM
#2
15 DRIVE, 40 DRIVEN and a VSS for the 40 tooth. These would be considered maybe ideal for a 3.33 with "stock" 2.75/40 tires. Shouldn't be an issue. the gears are harder to find than previously and they sometimes demand higher pricing. It's very doable !!
06-26-2017, 11:45 AM
#4
No - the DRIVE (GRAY) would work but the 40 tooth is for an older "cable drive" mechanical speedometer.
Keep shopping!!
GM# 25513047 should be correct for the DRIVEN using the VSS. GM# 10456089 for the VSS or an equivalent from the after-market.
Keep shopping!!
GM# 25513047 should be correct for the DRIVEN using the VSS. GM# 10456089 for the VSS or an equivalent from the after-market.
Last edited by WVZR-1; 06-26-2017 at 11:48 AM.
06-26-2017, 12:00 PM
#6
06-26-2017, 12:17 PM
#7
Speedo Gears
I still have many in stock - email and I will check. Not sure what to charge for either the drive or driven - what do you think is fair ? greg
06-26-2017, 04:05 PM
#11
I ordered the 15 tooth grey gear and the 40 vss. Thank you for the info! But still need the 40 driven gm# 25513047. Like it was said earlier they are hard to find. Can anyone post a link where I can order one? Thanks again for the help.
06-26-2017, 05:42 PM
#12
Team Owner
This place had them at one time. Not sure if they still do, but its worth a shot.
https://transmissioncenter.net/
Also not sure if this helps, but I made the same swap years back and I used the driven gear for a 3.31 gear car (45 teeth). This allowed me to use the existing drive gear in the tailshaft which made the job simple. The trade-off was that the speedo is off a small amount, but we're talking less than a percent. That being said, I can't imagine that gear is any easier to locate.
https://transmissioncenter.net/
Also not sure if this helps, but I made the same swap years back and I used the driven gear for a 3.31 gear car (45 teeth). This allowed me to use the existing drive gear in the tailshaft which made the job simple. The trade-off was that the speedo is off a small amount, but we're talking less than a percent. That being said, I can't imagine that gear is any easier to locate.
Last edited by TA; 06-26-2017 at 05:48 PM.
06-26-2017, 06:18 PM
#14
Team Owner
06-26-2017, 06:25 PM
#15
Ok. Thanks for the replies. At least now I have an idea of what it looks like. Seems odd to me though that there are plenty of gears for the older th350 and 400's but not for the 700r4.
What was the 40 tooth gear originally on? Maybe I can try to find it by make and model.
What was the 40 tooth gear originally on? Maybe I can try to find it by make and model.
06-27-2017, 02:02 AM
#16
The C4 Corvette uses a C4-only driven gear for the C4-only VSS sender. It is NOT generic "700 R4" stuff. What makes the C4 Corvette set-up different is the tailshaft housing (which holds the VSS) that accommodates the driveline beam, which is unique to C4 Corvette. The output shaft has two holes in it for the drive gear clip. One hole is for C4, the other for everything else that the 700 was used in.
The driven gear has a "D" shaped hole in it that fits on the VSS drive shaft. I have a Dk Green driven gear I never used. Brand new. I forget what the teeth count is.
The driven gear has a "D" shaped hole in it that fits on the VSS drive shaft. I have a Dk Green driven gear I never used. Brand new. I forget what the teeth count is.
The VSS driven gear isn't just a C4 thing. Full size Buick, Chevy, Olds, Camaro and F'bird also.
06-27-2017, 09:21 AM
#19
Use the time to maybe inspect the 3.33 for needs of bearings/seals/clutch-pack or whatever. You've lots to do if you intend this to be a pleasant experience.
