700r4 speedometer drive gears
Thread Starter
Heel & Toe
Joined: Aug 2002
Posts: 23
Likes: 0
700r4 speedometer drive gears
I'm in the process of changing out the speedometer gears in my 700r4. Are the drive gears on the output shaft the same physical size with just the number of teeth different or they physically different sizes?
Le Mans Master
Joined: Aug 2000
Posts: 9,662
Likes: 7
From: Semper ubi, sub ubi
Cruise-In VI Veteran
Cruise-In VII Veteran
Re: 700r4 speedometer drive gears (satx79vette)
Don't hold me to this, but I vaguely remember reading that there was no difference in the speedometer gears, between different models of GM transmissions. Just different colored gears that corresponded to different rear end ratios.
Melting Slicks
Joined: Oct 1999
Posts: 2,581
Likes: 14
From: Tolar Texas
Re: 700r4 speedometer drive gears (satx79vette)
I don't know if they are different or not but I thought that I would post this speedo cal picture from salleechevrolet.com just in case you can find it useful. The 700R4 and 4L60 are the same other than the 4L60 is electronically controlled.
Also, http://www.smokemup.com has a really nice calculator for showing rpm vs. speed . . . etc.
Also, http://www.smokemup.com has a really nice calculator for showing rpm vs. speed . . . etc.
Burning Brakes
Joined: Mar 2001
Posts: 1,211
Likes: 5
From: Nashville TN
Re: 700r4 speedometer drive gears (MIKER)
Keep in mind as well that there are two different driven gear holders depending on what the tooth count is on the gears. You can order the stuff from a dealer or if you are tight with a transmission shop they might help you out.
Le Mans Master
Joined: Sep 2004
Posts: 5,116
Likes: 5
From: Livonia MI
I've done a few 700R4/4L60 swaps from a TH350, and both the drive/driven speedo gears swapped right over. Not sure if I transferred the driven gear housing as well, but didn't have to buy anything. As mentioned, the 4L60E version, is all electronically controlled. Actually wished I'd gone that way, as the tranny computer kits have come down a lot, and much easier to set up than messing around with the TV cable.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
I think the 350, 200, and 700 trans gears will exchange. The 400 has a larger diameter output shaft and I don't think that [drive] gear will transfer...but I'm not positive about that.
TCI has a calculator for determining correct gearset for your car.
http://www.tciauto.com/tc/speedo-info
When you use it, make sure that the number of teeth it recommends is actually available to purchase. The calculator will give you an answer, but that design part might not be made. You can try experiment with changes to teeth on both gears until you find what is available and what will work for you.
P.S. Buy TCI gears from Jeg's (or CF vendor), rather than TCI. I found that Jeg's kept adequate stock of most gears...while TCI did not! Go figure.
TCI has a calculator for determining correct gearset for your car.
http://www.tciauto.com/tc/speedo-info
When you use it, make sure that the number of teeth it recommends is actually available to purchase. The calculator will give you an answer, but that design part might not be made. You can try experiment with changes to teeth on both gears until you find what is available and what will work for you.
P.S. Buy TCI gears from Jeg's (or CF vendor), rather than TCI. I found that Jeg's kept adequate stock of most gears...while TCI did not! Go figure.
Intermediate
Joined: Sep 2011
Posts: 32
Likes: 0
From: Johnson City TN
As Dman535 stated, there are 2 different housings. I had to replace speedometer cable on a 700R4 in my 82 and broke the speedo gear (42 teeth) housing while removing the cable. The original speedo housing was plastic. I replaced it with an aluminum housing. Here's a site I used for information:
http://www.transmissioncenter.net/sp...n_______va.htm
http://www.transmissioncenter.net/sp...n_______va.htm
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