700R Throttle Cable Bracket

[Jerryt]

'86 Chevy K10, short box, 350, Edelbrock Intake and Performer carb, 700R (rebuilt). Someone had stuffed a 454 in which we removed (this is a project my 16 year old son and I are working on). We replaced with a rebuilt 350. I found a Throttle Cable Bracket at the local wrecking yard, but..............someone told me it is not the right one for a 700R and that I could do damage to the transmission if I didn't get the right one. Can you recommend an aftermarket Cable Bracket that would best suit our needs?

 

[Don M]

I strongly recommend that you buy the correct bracket for the carb that you will be running. If the geometry of the bracket is not correct the transmission will not function correctly and you will more than likely damage the transmission. That cable controls a lot of the functions of a 700r4, fluid pressure, shift points, etc.

This is a good explanation of the Throttle Valve and the Throttle Valve Cable (TV cable) functions. Essential reading for anyone working on or installing a 700r4.
http://www.tvmadeez.com/article/index.php

They also sell cable adjusters and carb attachments.

You will also want to install a switch to lock up the torque converter. This site has the parts and instructions to do that.
http://700r4.com/tech/tcc/index.shtml

There are other sites that supply these parts, I just happen to have these bookmarked.
Don

 

[Jerryt]

Hey Don:

Thanks so much for the referral to TVMADEZ. After talking with one of their techs today, I ordered their Throttle Cable & Throttle Cable Bracket kit. After a long time asking a lot of questions of local mechanics and no satisfactory answers, these guys seem to really know the 700R trans.

You also mention a torque converter lock up. What would this do for this truck? I'm not aware of the benefits.

Thank you so much.

Jerry

 

[Don M]

All torque converters have an inherent loss because the output is not directly connected to the input. A “lock up” equipped converter can overcome this loss by “locking” or directly connecting the input to the output inside the converter. The lockup is activated and deactivated by a solenoid inside the transmission. That’s what the electrical connection on the passenger side of the transmission is for.

Locking the torque converter when traveling at a constant speed in 3rd gear or overdrive will give you better fuel economy. My 87 truck has a 350 with a 700r4. If I’m traveling at a constant 60 MPH and with my left foot tap the brake pedal (unlocking the converter) the RPMs will jump 200 to 300. That’s how much power is lost in the converter.

A second benefit, and this is just my belief, I don’t know this to be fact and have never read anything that confirms this, is a transmission running with the converter locked generates less heat. Excessive heat will shorten the life of a transmission. Hopefully someone with more transmission knowledge will jump in and confirm this. (or tell me I’m wrong, won’t be the first time)

The 87s came with fuel injection controlled by an ECM and the ECM also controls the converter lockup. If I’m not mistaken the 86s also have an ECM even though they don’t have fuel injection, if so and the ECM is still in the truck you may be good to go by just sorting out the wiring. If ECM control is not feasible or you don’t want to mess with it, the second link I posted will lead you to a site that can supply the parts and instructions to make this work without an ECM.

Don

 

[David Hall]

Very Good Don,

The transmission generates more heat with the converter not locked because the fluid in the coverter is in a rotory motion and when the TCC (torque converter clutch) locks, spining 1 to 1 with the engine it changes to a vortex motion.