It’s Just A Pickup

[glimmertwin01]

once again sweet

[oldblue1968chevy]

amazing!

[Low Elco]

Are you still there, Bruce? Hope the truck is treating you well, I have a couple questions? On P. 13, you ran a vent line to the front of the truck from the tank. What did that go to? Having gas smell problems in the garage. Thanks in Advance, Chip

[Bruce88]

Originally Posted by Low Elco

Are you still there, Bruce? Hope the truck is treating you well, I have a couple questions? On P. 13, you ran a vent line to the front of the truck from the tank. What did that go to? Having gas smell problems in the garage. Thanks in Advance, Chip

Hi Chip
The vent line I ran to the engine compartment from the gas tank went to the vapor canister (I call it a charcoal canister), this is part of the evaporative emissions control system (EEC). You didn’t say what year truck you had and this could be the reason you have a gas smell problem in your garage.

First it needs to be said that all gas tanks need to be vented in some manor, important to say again all gas tanks need to be vented in some manner. If it’s not vented you will not be able to get the gas out of the gas tank to feed the engine without collapsing the fuel tank from the vacuum that would be created from drawing the gas out of the tank (very unlikely to create enough vacuum to collapse the tank normally you just starve the engine for fuel because it will not flow thru the line).

There are two different vent systems that can be found on the 1967 – 1972 trucks. The first one is found between 1967 – 1969, I would call this venting thru the gas cap. If this is the system you have the smell of gas in your garage could happen and there’s nothing you can do to prevent it. The smell of gas might not be as noticeable when the truck is parked outside but because the gas cap vents into the atmosphere and the vapors need to go somewhere it could be noticed outside also, but in a closed garage the vapors are more noticeable. Another problem that can be noticed with this vent system is when you have a full tank of gas and run over a bumpy road or going around a corner and the liquid gas gets up to the cap some gas could dribble out thru the vent hole and down the side of the truck. (Note changing a vented cap system to a none vented cap system without thinking about the whole vent system will not work, no you can’t just change the cap).

The other vent system (EEC) could be found on the 1971 – 1972 trucks (I can’t say all of them, it all depends on what state the truck was originally sold in and as always if the system was changed by someone back to vented cap system). Basically this system is not vented into the atmosphere thru the gas cap but the fumes and venting is thru the vapor canister. The canister collects any gas vapors and then when the engine is running any vapors that have been collected in the charcoal is drawn off and burned in the engine (you don’t have the smell of gas in the garage). You can change a (EEC) system to a vented cap system but you need to think about all the components of the system and where you block them off. You can’t change a vented cap system into a (EEC) without changing the gas tank and adding some components to make it a functional EEC system.

My truck is a 1972 that had an EEC system and I wanted to retain it even with the relocated blazer style gas tank and this is the reason I ran my vent line to the engine compartment.

My personal opinion is before making any changes to your fuel tank vent system you need to understand what all the various components do and make sure there all there and doing what their supposed to be doing to have a safe and functional system.

Hope you find this information useful and if you would like any additional information just ask.

Enjoy your build
Bruce

[68GMCCustom]

well I'm glad you post this. I was going to get the Magnaflow system but it looks like...to run the exhaust through the frame (lowered truck)... would take a lot of modification.

[Bruce88]

Originally Posted by 68GMCCustom

well I'm glad you post this. I was going to get the Magnaflow system but it looks like...to run the exhaust through the frame (lowered truck)... would take a lot of modification.

I would have to agree.
I tucked this exhaust as close to the frame as I could because my truck is lowered 2-1/2 inch front drop spindles and 4 inch drop springs in the rear. Any lower than this I think it would be a good idea to run it thru the frame and this exhaust kit just would not be suitable with out major modification so a custom exhaust would probably be more of a advantage and cost less in the long run.

[sourkraut]

great work bruce! wait till you hear the magnas with the x-pipe, it is awesome!

[Bruce88]

Sometimes the instructions are lacking, not existent or not compiled together in one place
There maybe the questions as to what the instructions said, omitted steps, what do I do next, or maybe just why am I doing this step.

I always like to see instructions that I would call the (KISS) system (Keep It Simple Stupid) with plenty of pictures. When bringing together a number of parts from different manufactures to accomplish a task and their instructions don’t seem to work together, there’s always the possibility there not going to or will need modification in order to work and they just didn’t think about that or wanted to address it.

The installations of a 700R4 transmission in or trucks seems to be a popular modification, but there’s plenty of confusion about the TV cable setup that may prevent some from wanting to do this transmission installation. If you break the setup into small chunks/steps this may help in eliminating some of the major confusion.

First you have to determine what engine the installation is going to be used on. This installation is going on a SB Chevy, carbureted engine, that was not setup for a 700R4 transmission with a TV Cable (not a computer controlled 700R4 or fuel injected engine).

I took some screen shots from different web sites and have modified some of them for clarity/understanding (more than I will list here) hope they don’t mind (smile). Here are some links to some of the instructions that I used to help compile this post. http://www.bmracing.com/PRODUCTS/Bui...-TH-700R4-4L60 you will find a PDF file (Installation Instructions Transpak Part Number 70235) See page 12 & 13. And http://www.tciauto.com/Products/Inst...ble_adjust.htm

One of the steps is to create a attach point for the TV cable to the throttle lever on the carburetor. Your carburetor probably doesn’t have a hole for this; the hole would have to meet the geometry shown in the instruction figures and all the measurements they talk about is to assure that it meats those requirements. (I highlighted the measurements in blue in the below picture) The simple way to meet all the geometry requirements is to obtain a (TV Cable Bracket Corrector Kit) their made for many carburetors. Rochester, Edelbrock, and Holley from a number of different sources I happen to be using one by Sonnax Performance (part # AS3-03K) for Edelbrock/Carter Carburetors.

One thing you might have to change on the corrector kit is the throttle cable end. Their made for a clip-on throttle cable and may need to be changed to a ball-type throttle cable stud depending on what kind of throttle you have. I had to change mine to ball-type and decided to use the upper hole that worked better with my throttle bracket. I also had to trim my throttle bracket to clear the corrector lever (just peculiar to my throttle bracket).





Next is to locate the TV cable bracket in relationship to the attach point on the throttle lever, meeting the geometry requirements (highlighted in green in the above picture). There are loads of different brackets that you may have, most will require some kind of modification to work. Just because the bracket you buy or use say that it fits a 700R4 TV cable doesn’t mean that it locates it in the correct location. The opening in the bracket for the TV cable is the same for a 350 transmission or a 700R4 transmission but are located in different positions depending on what transmission you are using. I used a ½ inch X 1-1/2 inch X 3-1/2 inch long aluminum block that I drilled and tapped some holes in to attach it to my throttle bracket moving it outboard and down to meet the correct geometry. If you’re using a steel bracket you might have to cut it to locate the opening then weld it or fabricate a complete bracket to do the job. As far as how far aft the bracket should be located I would say a minimum of 2 inches aft of the attach point to lets say 6 inches aft of the attach point as long as you maintain the 90 degree angle on the cable with the throttle lever attach point straight down from the throttle shaft (reference the 55 degree angle in the first picture)

This is the hardest part of the installation with so many different brackets out there and you will have to figure out how to make it work. This geometry relationship is important and needs to be maintained for everything to work right. So take your measurements and figure out if the bracket mounting location needs to be moved and figure out how to do it. You never know your bracket may not need any modification (I kind of doubt it). The installation definitely gets simpler from this point forward (smile)

Before someone jumps in and says that my throttle cable is not a straight pull in the below picture. The throttle cable pull is not as critical as the TV cable geometry and with the ball-type attachment and it being a cable it will compensate just fine for the less than straight pull.



With there being so many different TV cables, with different lengths, I would recommend using a universal TV cable that can be adjusted and it will not dictate the mount location. You can find one at Summit Racing or JEG’S mine came with my TCI 700R4 transmission package.

One step/instruction missing was on setting the universal TV cable length. First attach the cable down at the transmission and secure with a metric bolt. Then press the reset tab on the auto adjuster and push the slider in flush with the adjuster (see the first picture in this post) pressing the reset tab and pushing the slider flush with the adjuster can be done after the adjuster is installed in the bracket it’s just simpler now. Now install the adjuster in the bracket. Slide the inner tube on the TV cable housing in or out to get the best fit not riding on anything or to tight riding on the trans or eng. Then slide the inner tube out about a ½ inch and tighten the locking nuts (the ½ inch that you move it out is to allow the auto adjuster to move forward). Once the nuts are tightened you will not be able to adjust the cable housings length again, there is a compression sleeve inside the nuts that will crimp down onto the inner tube. This tube has to be locked before the auto adjuster will work correctly.

Another missing step. Is where to set the adjustable cable sleeve stop on the cable before moving the throttle to wide open throttle? With the cable thru the plastic cable clip, slide the sleeve stop up to the clip (throttle should be at the idle position). Now pull the cable so that the stop is approximately ¾ of an inch away from the clip then slide the stop to the clip and tighten the set screw (you can release the cable now). I would call this a pre-set position; the ¾ inch dimension is just approximate it could be any where between ½ inch to 1 inch. This pre-set position is needed for the cable auto adjuster to work

The adjustable cable sleeve stop you see in the pictures is a custom one that I made out of some 3/8 HEX stock and some set screws. The adjustable cable sleeve stop that comes with the universal TV cable will work just fine but I wanted something a little more custom.



A quick review before I move the throttle to wide open throttle and let the auto adjuster do its work and do the final adjustment/setting of the TV cable.

(1)The attach point on the throttle lever meets the geometry requirements.
(2)The TV cable bracket is located to meet the geometry requirements.
(3)The slider on the auto adjuster is pushed in flush on the adjuster.
(4)The Universal TV cable length is set/locked to length.
(5)The adjustable cable sleeve stop is in the pre-set position.
(6)The carburetor choke is in the off position (not interfering with throttle going to WOT).
(7)The throttle return springs are removed (to make it easier to move the throttle).

If you can’t answer (Yes) to the above steps your not ready to do the final setting of the TV cable.

Of course I answered yes to all the above (smile) Now move the throttle to the WOT position. You might hear some clicking from the slider moving forward on the auto adjuster. After you move the throttle to the WOT position the slider should have moved forward from the flush position it was set to prior (there’s no dimension that it needs to move just that it moves forward). The TV cable is now adjusted/set; there are no other adjustments that need to be done. If the slider on the auto adjuster did not move forward in this step try increasing the pre-set dimension of the cable sleeve stop.

I did not try to address using a factory TV cable because there are so many and each one requires their own specific auto adjuster mounting bracket to a specific carburetor and there is normally no way to set the cable sleeve stop (the cable stop is normally swedged on the cable, not adjustable). If you want a factory installation you need to get the carburetor, mounting bracket, and TV cable for that specific set up.

I also did not try to address a Lokar style custom TV cable installation because I’m not doing that installation and would not have any pictures and where all the geometry requirements talked about would apply, the final cable setting is a little more complicated because it doesn’t use an auto adjuster. Trying to keep it simple (smile)

For those that are interested the throttle bracket and TV cable bracket that I used and had to modify was from JEG’S part number 15152 & 15229 .

Now the only question I have is where to post this in the forum. I think the above information would be useful along with the installation instruction listed in the beginning of this post to any one that’s trying to set up a 700R4 TV cable on a carbureted engine. It is part of my build and could be of benefit to the general forum members so I’m posting in my build thread and will create a link to it in the FAQ section.

Hope you find it beneficial in understanding and doing a TV cable install

Now that I’ve been lying around long enough to let my body recover/rest from the last few weeks work on the truck I need to get out there and work on it (smile)
Enjoy your build

[N2TRUX]

Originally Posted by Bruce88

Now the only question I have is where to post this in the forum. I think the above information would be useful along with the installation instruction listed in the beginning of this post to any one that’s trying to set up a 700R4 TV cable on a carbureted engine. It is part of my build and could be of benefit to the general forum members so I’m posting in my build thread and will create a link to it in the FAQ section.

Great write up. I copied this to the FAQ forum- 700r4 TV cable install (Carb Motor) LINK

[Bruce88]

Originally Posted by N2TRUX

Great write up. I copied this to the FAQ forum- 700r4 TV cable install (Carb Motor) LINK

Thanks N2TRUX

I did create a thread in the general FAQ section (700R4 TV cable setup on a carbureted engine) with a link to this post/build thread. Was trying not to wasting forum space in double posting.

[VA72C10]

Awesome writeup as usual. I could have benefited with this when I had TV adjustment issues with my 80Z28 with a 700R4. Tried several brackets and cables available at the time (1997) but never got the shift I wanted even though the tranny was built right and built for firm shifts. Still drove it for 2 yrs and 30K miles but never LOVED the way it shifted.

[nuke1]

Looking great! Great write up, very informativce as usual!!

[C-10 Addict]

your pics and text would have been a great help on my install .I think we kind of get caught up in buying things that are supposed to fit and then don't fit right without modification.I got so frustrated with my cable bracket i ended up making my own to get it to fit. Again thanks for pointing out that lots of times we need to be prepared to modify things to get them to work on each individual application. Keep up the great work!

[BOZO]

Subscribing to a great thread

[DorianB]

Thanks Bruce for such great details. This is an advanced class in all the things I want/need to do to my truck!!!!

[msgross]

very cool build... nice detail on the pictures.

[Bruce88]

The long and short of it
Still tying things together and one of them is the driveshaft

The biggest problem that I’ve seen in the past in having a custom driveshaft made is easily overcome. It’s communication with the driveshaft shop prior to taking measurements; you could say being on the same page or not having any misunderstandings that can lead to the driveshaft being the wrong length or asking them to do something outside their capabilities. Once it’s made it’s too late to correct problems because it doesn’t fit right. Each driveshaft shop may take their measurements from different reference points, not to say that any one way to measure is better than another and they may have suggestions in overcoming other problems.

The driveshaft shop that I’m using had a nice little pamphlet in where to take the measurements from and also had a solution to the different yokes I was using between the transmission and the original driveshaft yoke. The simplest way to explain the difference between the yokes is the transmission yoke used inside retainer clips to hold the u-joint caps and the driveshaft yoke used clips on the outside of the u-joint caps. Decided to use a combo joint to solve the problem (part number 5-3022X Spicer or 3-3130 Neapco) that can be used to couple the two different yokes together.

This is not a high performance driveshaft installation it falls into the range of shorting the front driveshaft by approximately 3 inch’s because I’m using a 700R4 transmission and what I would say is minor rear suspension drop of 4 inch. Before someone asks what my exact measurements are I’m not going to be giving them, each truck could be a little different and that’s why it’s called a custom driveshaft (smile) you will need to take your own.





I think that this driveshaft will meet all my plans for the truck uses
Enjoy your build

[VA72C10]

You'll be rolling in no time now

[68GMCCustom]

I don't understand why some SWB trucks have a 2 piece shaft... and other SWB's have a 1 piece?

[oldblue1968chevy]

thats a 1 piece isnt it?..

[Bruce88]

Originally Posted by 68GMCCustom

I don't understand why some SWB trucks have a 2 piece shaft... and other SWB's have a 1 piece?

I really don’t know why, but it might have something to do with this truck being a standard light duty ½ ton and the more heavy duty trucks would have a one peace.

Originally Posted by oldblue1968chevy

thats a 1 piece isnt it?..

No that’s a two piece driveshaft there’s a u-joint just aft of the support bearing mount

[gcburdic]

Bruce....are the yokes about a half turn out of phase?

[Bruce88]

Originally Posted by gcburdic

Bruce....are the yokes about a half turn out of phase?

Not exactly sure what you are talking about, it might be just an optical allusion or that the transmission yoke is out of phase with the differential yoke. With a one piece driveshaft the transmission and differential yokes should be in phase. But this is a two piece driveshaft and with a standard u-joint between the front and rear shaft, the transmission and differential yokes will be 90 degrees out of phase with each other.

Hears a picture that you might be able to see it a little better

[propanemudtruck]

That's Purty.

The exhaust, the frame, the EVERYTHING looks so perfect and it's an absolute masterpiece.

Once again, nice work Bruce!

[mcbassin]

Originally Posted by propanemudtruck

That's Purty.

The exhaust, the frame, the EVERYTHING looks so perfect and it's an absolute masterpiece.

Once again, nice work Bruce!

Yep, it almost looks too nice to actually use!


Nice descriptions as always!