TH350 to 700R4

[BobbyK]

The TCI one is what I run.
I did have a problem with the diaphram switch(black box in pic.), I've since bypassed it and now manually engage the lock-up of the Torque converter, via a switch.

[big dump]

Well, I wasn't aware that Painless had a kit until earlier today, but I went ahead and bought this one from them, because my friend has a sponsorship with them on his car, and they've always treated him well. I spoke with one of the tech guys over there this afternoon, and decided to go that route. A little more expensive, but I'm sure like everything they build, it will be good quality..

http://www.painlessperformance.com/w...ject+Object%5D

[68K30]

I have a 700R4 and a NP205 behind my 454 in my 68 K-30I moved the crossmember and the transfer case frame mount back 5/8", redrilled afew holes and that was it. There was enough travel in the splines the make up the difference, I have a 14 bolt rear and a non-standard driveshaft in the front, but it was an easy swap. The TV cable adjustment is critical and was a little tricky on the big block,after market tv bracket and som engineering but it works, the lockup is real easy, find a 1984 or 1985 Chevy truck or suburban and get the vacuum switch that is mounted by the brak booster, the brake switch under the dash and the plug on the trans and find a schematic for the 85 truck, real simple install and it works great.

Hope this helps
Bill

[68K30]

In my last post I forgot to mention that I also installed the Advanced adaptors shorter output shaft.

[big dump]

That makes more sense, thanks. Almost done with this swap, just waiting on the lock-up wiring, which should be here today, and have to install/adjust the TV cable. I really don't like projects like this, under the vehicle, crap falling in your face. Be glad to have this one finished up. Pictures to come..

[Wildstreak]

Originally Posted by big dump

I really don't like projects like this, under the vehicle, crap falling in your face. .

me too, when I can, Im just going to trailer it to a mechanic to adjust the tv cable properly. Ive heard it was really hard to do. But if you do it and its not so bad I might giver er a try :P

[big dump]

I don't know, because I don't have experience with it yet, but I would suspect that it's a matter of knowing what the distance of travel is for the cable that pulls the plunger, and making sure that at WOT that amount of travel is achieved. I was planning on measuring the travel in the cable, then setting the distance on the throttle side to match. I think that would get me in the right area, then it's probably just a matter of test driving/adjusting. The TV cable has a good bit of adjustment on it by depressing the D-shaped button on the side. Someone chime in if I'm way off on this..

[Dusty71blazer]

What are you using to connect the cable to the carb, this has to be specific too, like in this picture...


Here are a few links that I have bookmarked on this...

http://www.purplesagetradingpost.com...o/700R4p1.html
http://www.tciauto.com/Products/Inst...ble_adjust.htm
http://www.cpttransmission.com/tech_tvcable.htm

Happy reading

[Dusty71blazer]

Here is some more info & a linkage kit that's supposed to make it easy, kinda pricey.... not sure if I'll go this route when I get around to doing this swap, depends on how much $$$$ I have to spend..

http://www.tvmadeez.com/

[SeventyOne]

Took this quote from:http://www.cpttransmission.com/tech_tvcable.htm


WARNING: PERMANENT DAMAGE WILL OCCUR IF THE T.V. CABLE IS NOT ADJUSTED OR HOOKED UP.

THE DAMAGE WILL OCCUR WITHIN A FEW FEET OF DRIVING THE VEHICLE!

Does anyone think is a little extreme? How would they expect you to road test a vehicle and check shift points if you cannot drive more than a few feet?

Anyways, anyone thought of using this:

http://www.tciauto.com/Products/GM/gm_4L60E.asp

[Dusty71blazer]

Originally Posted by SeventyOne

Anyways, anyone thought of using this:

http://www.tciauto.com/Products/GM/gm_4L60E.asp

Looks like that would save alot of headaches!

I want to eventually do this swap (700r4). I would also like to someday upgrade to fuel injection. I'm starting to think that they should be done at the same time- the money saved on the linkage & lock-up kit will go a long way toward buying a used TPI setup off of ebay. I'm not trying to thread jack here but anyone considering doing both swaps should consider this... Any thoughts??

[big dump]

Dusty,

I'm fuel injected, running a standard GM TBI factory style injection setup, so my linkage is just like what you posted above. The measurements may help. I may make up a cardboard template or something and try to use it to measure up behind. So far, I just pushed in the D-Shaped button, and pulled out the adjustment so that when I have WOT, the cable is maxed out (plunger all the way in on the tranny). Haven't tested it yet, everything is ready minus putting transmission fluid in (need a new dipstick, just found out that the TH350 one will not work).

[Dusty71blazer]

Originally Posted by big dump

Dusty,

I'm fuel injected, running a standard GM TBI factory style injection setup, so my linkage is just like what you posted above. The measurements may help. I may make up a cardboard template or something and try to use it to measure up behind. So far, I just pushed in the D-Shaped button, and pulled out the adjustment so that when I have WOT, the cable is maxed out (plunger all the way in on the tranny). Haven't tested it yet, everything is ready minus putting transmission fluid in (need a new dipstick, just found out that the TH350 one will not work).

Yeah, your life is alot easier because of that.. do you have the computer controlling the torque converter lock up?
Who did you have reprogram your computer? did you use all stock wiring, etc?

[big dump]

I had the computer chip flashed by Affordable Fuel Injection, and purchased a TBI harness from them also. I would have re-used the stock engine harness that I bought with the TBI unit, but it was pretty thrashed, so rather than re-build it, I just bought a plug and play from them. The lockup isn't computer controlled, it's a stand alone harness that I bought from Painless. The 4th gear solenoid is vacuum controlled, and it also comes with a new brake switch with 4 terminals to control the lock-up as well. I've heard good things about it. P/N 60109, link above..

[Dusty71blazer]

Sounds like a sweet set-up, thanks for sharing your info- I don't know what way I'll end up going but I know that Fuel injection is in the plans somewhere! Maybe I'll have to steal the TBI off of my Sub

[Dying2Live]

I've always adjusted the kickdown where the end of it's range is the end of the range of the throttle cable's travel. It's always worked well for me.

[big dump]

Well, I got everything buttoned up, and took it for some test drives (short, 2 miles max) trying to get the TV cable set up correctly. The first few, I had the tension set too strong, in other words, a shorter cable, and the 1-2 shift was too hard and at too high an RPM ~2,500. The 2-3 shift felt good, and the 3-4 shift felt good but I thought it was too aggressive so I adjusted again.

I tried both methods described online, maxing out the cable adjustment (pulling toward the TBI), and then shortening with WOT, as well as minimizing the adjustment (pushing toward the transmission), and then letting the TV cable 'ratchet' out under WOT and both forms of adjustment netted me the same length of cable, which transitioned into soft shifting from 1-2 and 2-3, however, from 3-4 under this adjustment the transmission shifts into gear, then clunks.

My thought is that I either don't have the TV cable adjusted correctlly, I have the wrong length TV cable, or the custom bracket that I made has improper geometry. I think that I need to measure a stock vehicle to get the length between the throttle shaft center of the TBI, and the plate that the TV mounts to. I'm not sure if that geometry affects the TV, and I figured that it was adjustable for that very reason however I'm not comfortable driving it until I get it worked out.

Anyone have 'stock' measurements of the distance from the TBI throttle shaft center pin and the front of the TV plate? Any other thoughts?

[SeventyOne]

Bigdump - I found a shift indicator that has D-3-2-1 at classicparts.com.

http://www.classicparts.com/1971-72-...info/91%2D357/

Question for anyone using the Advance Adapter output shaft (i.e. no spacer) - does the 700r4 trans pan interfere with the front driveshaft where it exits the transfercase? Also what are you running for headers if you moved the engine forward?

[71RestoRod]

Originally Posted by SeventyOne

Question for anyone using the Advance Adapter output shaft (i.e. no spacer) - does the 700r4 trans pan interfere with the front driveshaft where it exits the transfercase? Also what are you running for headers if you moved the engine forward?

The pan comes close (within ~ 1/4") but doesn't interfere. It does unfortunately preclude your ability to use a deep aluminum trans pan.

If you move the engine forward you can use Camaro or early G-Body headers. These work great with an auto trans. The passenger side gets tight with the transfer case but you can route the exhaust up and over the case.

[SeventyOne]

Originally Posted by 71RestoRod

The pan comes close (within ~ 1/4") but doesn't interfere. It does unfortunately preclude your ability to use a deep aluminum trans pan.

If you move the engine forward you can use Camaro or early G-Body headers. These work great with an auto trans. The passenger side gets tight with the transfer case but you can route the exhaust up and over the case.

Perfect thanks for the response - your chassis look sweet btw. Mine's in the "before" stage and hope it will look like yours once completed.

[big dump]

71, Thanks for the link. I have some updates, I'm hoping to have it running well this weekend..

[SeventyOne]

Cool. Looking forward to hearing how you figured out the tv cable.

Another thing that I thought of for those that moved the engine forward is radiator hoses - guessing the stock ones won't work. Anyone have working part numbers?

[olblue60@aol.com]

I have just finished this mod in my 67 panel 4wd 72 drivetrain. There are two ways to do it. I would be happy to speak on the phone, but with my two finger typing skills, It would take me forever to type. Its easy! I'm just a carpenter. If interested, Pm me for my phone #. Good luck.

[big dump]

Well I haven't posted in a while because I've been taking a break after being frustrated with this seemingly simple process of adjusting the TV cable.

Let me start by saying that I am a confident fabricator, and Industrial Designer by trade, so I have a good understanding of how to build things in general and make them work. I have built two different custom brackets to mount the TV cable/Throttle cable, with the same results even with two different geometries. I have followed all the posts and write ups I've read online about TV cable geometry with no success. The symptoms that I had as a result were stacked shifting, shifting too soon, or too late.

I finally decided that since there are companies out there with more experience that have done the 'math' on these systems that I would just order up a bracket and cable system complete. I picked one up from Bowtie Overdrives (link below) and installed a new spring into the plunger in the transmission, which meant dropping the pan again and re-installing, installing a new TV cable, modifying the Throttle linkage on the TBI to accept the TV bracket and cam that comes with it, and also sandwiching the plate in between the TBI unit and manifold (which cannot be done without bending the return fuel line coming out of the back of the TBI because it will hit the 90° flange on the plate, picture below).

http://www.bowtieoverdrives.com/cata...php?ITEMID=326

I also ditched the OEM throttle cable in favor of a universal unit from Lokar, which has also proven to be more of a PITA than it seems to be worth with this setup. The issues that I'm having now are that in order to get full WOT on the TBI through the pedal (thus properly adjusting the TV cable), I have to tighten the throttle cable up so much that it doesn't allow the butterflies to fully seat back down into the TBI causing a fast idle.

In addition, despite the fast idle which I'm sure I can fix with a spring on the other side of the linkage or maybe playing with the throttle cable a little more, I'm getting a very violent shutter between overdrive and third gear under partial throttle just trying to cruise on the freeway. I'm afraid at this point that I'm going to severely harm the transmission if I continue to adjust/test without a clear direction going forward.

I know that everything installed on the transmission is correct, does this still sound like a TV cable problem or could it possibly be a TCC lockup issue? I'm confident that I have the lockup installed correctly and getting proper vacuum as well. Any suggestions? I know there are a couple others out there with TBI and 700R4, anything I'm missing here?

[71RestoRod]

As far as the WOT issue is concerned, I had the same problem and solved it by bending the Z-shaped rod on the throttle peddle to get more throw out of it before bottoming out.

Regarding the TV setup, just guessing... but sounds to me as if your TV geometry is still off. The cam that you installed for the TV changes the rate that the pressure is applied in relation to throttle position but shouldn't affect the total range of motion.

Just a thought, but try this to verify that your geometry is on:

Measure total cable movement for both your TV and throttle cables. Using a sharpie pen, mark the TV cable at the point where it exits the cable housing, then move the throttle to WOT and mark the throttle cable where it exits its housing. With the throttle at WOT, measure the distance from the housing to your mark on the TV cable, then release and measure the distance from the throttle housing to the mark on the throttle cable.

I have a similar Bow Tie cam on my throttle body. When I measured my cable movement, I came up with total movements of 2-1/4" on the throttle and 1-3/8" on the TV cable. Not saying that yours should be identical, but one would think it ought to be close... at least the 1-3/8" total throw on the TV cable.

Have you hooked up a pressure gauge? The best advice for not hurting anything is to make sure you have a rise in pressure immediately off idle. If you are cruising in OD at part throttle and not pulling any line pressure you'll cause damage for sure. Setting the TV relative to WOT is dependent on having your geometry spot on. If it's off, you may be running part throttle w/ no line pressure.