700R4 speedometer gears? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

supermuble · 11-17-2006, 01:05 PM

Can you swap out the gears on an early 700R4 into a late model 700R4 with the electrical speedometer output? I want to use my 1989 speedometer gears on my 1991 700R4 and put it into my 1970 C10 with a straight 6 engine.

67ChevyRedneck · 11-17-2006, 01:40 PM

Not positive on this, actually it's mostly a guess... but I did just put one in my 67. I got a rebuilt one and had to swap speedo gears. You have to unbolt the tab on the tailashaft the holds the assembly in place, pull the assembly out, and then unbolt the 4 bolts that hold the tailshaft on. Pull the tailshaft off and you can see the exposed plastic (yeah plastic) speedo gear. It has a hook shaped clip on it, be sure to stick a screwdriver between the shaft and the clip or the L shaped piece WILL break off and parts stores DO NOT sell this part. You'd have to go to GM or a junkyard (lesson learned

) Slide the gear off, put it on the new tailshaft, line up the clip with the slot and slide the gear in place. Put the tailshaft back on (if the electronic one is different, use the manual one), bolt it back on, put the manual speedo gear stuff in, bolt the retainer clip back on, install tranny

49studebaker · 11-17-2006, 02:48 PM

I have been looking into the same issue. From what I've read, the newer 700r4 has a sleeve over the tailshaft that has the electronic speed pickup on it. I believe Redneck is right, just slide that off and you'll find the grooves for the old type speedometer (retainer clip) on the shaft. It seems either mech/elec. will work with either shaft, you just need the proper retaining clips,etc.

67ChevyRedneck · 11-17-2006, 02:52 PM

If I remember right, some tailshafts have 2 holes and some have one. Measure off the old tranny so the clip drops in the correct hole.

11-17-2006, 01:05 PM	#1
supermuble Registered User Join Date: Nov 2006 Location: Spokane, WA Posts: 12	700R4 speedometer gears? Can you swap out the gears on an early 700R4 into a late model 700R4 with the electrical speedometer output? I want to use my 1989 speedometer gears on my 1991 700R4 and put it into my 1970 C10 with a straight 6 engine.

11-17-2006, 01:40 PM	#2
67ChevyRedneck Hittin E-Z Street on Mud Tires Join Date: Nov 2004 Location: Greenville, SC Posts: 23,090	Re: 700R4 speedometer gears? Not positive on this, actually it's mostly a guess... but I did just put one in my 67. I got a rebuilt one and had to swap speedo gears. You have to unbolt the tab on the tailashaft the holds the assembly in place, pull the assembly out, and then unbolt the 4 bolts that hold the tailshaft on. Pull the tailshaft off and you can see the exposed plastic (yeah plastic) speedo gear. It has a hook shaped clip on it, be sure to stick a screwdriver between the shaft and the clip or the L shaped piece WILL break off and parts stores DO NOT sell this part. You'd have to go to GM or a junkyard (lesson learned ) Slide the gear off, put it on the new tailshaft, line up the clip with the slot and slide the gear in place. Put the tailshaft back on (if the electronic one is different, use the manual one), bolt it back on, put the manual speedo gear stuff in, bolt the retainer clip back on, install tranny __________________ Jesse James 1967 C10 SWB Stepside: 350/700R4/3.73 1965 Ford Mustang: 289/T5-5spd/3.25 Trac-Loc 1968 Pontiac Firebird: Project Fire Chicken! 2015 Silverado Double Cab 5.3L Z71 2001 Jeep Wrangler Sport 4.0L 5spd 2020 Chevrolet Equinox Premium 2.0L Turbo 2011 Mustang V6 ~ Wife's ride American Born, Country by the Grace of God 1967 CST Shop Truck Rebuild! My 1967 C-10 Build Thread My Vintage Air A/C Install Project "On a Dime" Trying my hand at Home Renovation! 1965 Mustang Modifications! Last edited by 67ChevyRedneck; 11-17-2006 at 01:41 PM.

11-17-2006, 02:48 PM	#3
49studebaker Senior Member Join Date: Nov 2005 Location: Victor, Montana Posts: 386	Re: 700R4 speedometer gears? I have been looking into the same issue. From what I've read, the newer 700r4 has a sleeve over the tailshaft that has the electronic speed pickup on it. I believe Redneck is right, just slide that off and you'll find the grooves for the old type speedometer (retainer clip) on the shaft. It seems either mech/elec. will work with either shaft, you just need the proper retaining clips,etc. __________________ 04 4x4 GMC Ext. Cab lifted 71 2wd GMC / Ramjet 350 ready for sheet metal 49 Studebaker pickup

11-17-2006, 02:52 PM	#4
67ChevyRedneck Hittin E-Z Street on Mud Tires Join Date: Nov 2004 Location: Greenville, SC Posts: 23,090	Re: 700R4 speedometer gears? If I remember right, some tailshafts have 2 holes and some have one. Measure off the old tranny so the clip drops in the correct hole. __________________ Jesse James 1967 C10 SWB Stepside: 350/700R4/3.73 1965 Ford Mustang: 289/T5-5spd/3.25 Trac-Loc 1968 Pontiac Firebird: Project Fire Chicken! 2015 Silverado Double Cab 5.3L Z71 2001 Jeep Wrangler Sport 4.0L 5spd 2020 Chevrolet Equinox Premium 2.0L Turbo 2011 Mustang V6 ~ Wife's ride American Born, Country by the Grace of God 1967 CST Shop Truck Rebuild! My 1967 C-10 Build Thread My Vintage Air A/C Install Project "On a Dime" Trying my hand at Home Renovation! 1965 Mustang Modifications!



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