700r4 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

wessscott · 10-31-2004, 09:22 PM

I recently purchased a 1970 C10 with a 700R4 installed. The problem is the speedo does not work. I was told that you could buy an adapter to convert the 700R4 electric signal to an analog signal. If any one knows where to purchase or what else can be done please let me know.

Longhorn Man · 10-31-2004, 10:39 PM

Some research would be needed, (info may pop up on this thread now) but the 700R4 originally had a mechanical speedo drive, so all you have to do is rob an older 700R4 vehicle of it's tail shaft and gear drive.

Huck · 10-31-2004, 10:43 PM

A converter is available but is like $300. It takes the pulse from the trans and converts it to a mechanical driven cable to your speedo. I would tend to opt for converting the 700R4 back to mechanical drive. Try bowtieoverdrives and I believe they can send you the necessary parts for under $100.

**passthebuck** · 11-01-2004, 12:03 AM

you can also get an electric speedo from Autometer that'll do the job. My retro install of a 700r4 was from a 91 something & it still had a mechanical speedo

Project1970 · 11-02-2004, 12:57 AM

All you need is the sleeve, the drive and driven gears, the seals, and the clip for the drive gear.

I've gotta go with the Autometer this time around, though, because the ECM for the LS1 needs the speed signal.

10-31-2004, 09:22 PM	#1
wessscott Registered User Join Date: Oct 2004 Location: Fayetteville, NC Posts: 41	700r4 I recently purchased a 1970 C10 with a 700R4 installed. The problem is the speedo does not work. I was told that you could buy an adapter to convert the 700R4 electric signal to an analog signal. If any one knows where to purchase or what else can be done please let me know.

11-01-2004, 12:03 AM	#4
passthebuck Sisyphus was my mentor! Join Date: Sep 2002 Location: Carleton Place, Ontario CANADA Posts: 984	you can also get an electric speedo from Autometer that'll do the job. My retro install of a 700r4 was from a 91 something & it still had a mechanical speedo __________________ passthebuck #5642 -TWO 1967 GMC 910's. One with L6/3-on-the tree and the other with 355 w/435hp & a 700r4. -a 2013 Honda Civic as my "sensible" car

11-02-2004, 12:57 AM	#5
Project1970 14.1 @ 96MPH Join Date: Jul 2001 Location: Mesa, AZ Posts: 2,811	All you need is the sleeve, the drive and driven gears, the seals, and the clip for the drive gear. I've gotta go with the Autometer this time around, though, because the ECM for the LS1 needs the speed signal. __________________ Project1970 - LS1 Swap Complete!

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10-31-2004, 10:39 PM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Some research would be needed, (info may pop up on this thread now) but the 700R4 originally had a mechanical speedo drive, so all you have to do is rob an older 700R4 vehicle of it's tail shaft and gear drive.

10-31-2004, 10:43 PM	#3
Huck Senior Member Join Date: Jun 2001 Location: Shelbyville, KY Posts: 3,269	A converter is available but is like $300. It takes the pulse from the trans and converts it to a mechanical driven cable to your speedo. I would tend to opt for converting the 700R4 back to mechanical drive. Try bowtieoverdrives and I believe they can send you the necessary parts for under $100.



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