5 700r4 transmissions killed in 50 mi. how can this happen?

I just finished a F1 build for a buddy of mine. 350/ 700r4 He got the trans from a local re builder. Trans one was set up by a good mechanic and the shifter was installed by the owner. It died first time it tried to shift into od. Trans guy said it was set up wrong, but rebuilt it. We trailered the truck to him for set up of linkage and fluid. Next one, same thing, owner did the R&I trans guy rebuilt it again, and same thing happened. Now the trans guy is doing the R&I, but it's happened again.........3 more times. The fresh shinny truck is back in the overcrowded trans shop. The guy hasn't charged anything, has paid the towing, and insists it's not the ****** itself, but something is wrong with the kick down geometry. He has changed all the brackets and set it up himself. WTF? Is the trans guy an idiot? is there something else that can cause the failure. When it goes it shifts into od and pretty much freewheels, blows fluid out the vent. On the third trans Jeremy just drove it home the last mile. lost third and second, limped in in first.

Has any one had any thing like this happen?

The hood did fall on Jeremy's hand and broke his thumb in the first ten minuets we were working on her ............just sayin,

 

It's all in the TV cable.... how it's mounted, how it operates, how it was installed and what was used.

 

That's what the trans guy says.......you'd think he could maybe fix it?

 

exactly!

 

After the 1st one, was the converter checked ? Lost mine a few yrs ago. Friction material came apart due to a faulty NEW converter.

 

I would try another trans guy, if hes been through it that many times then I would ***ume he dont know what the hell he is doing! Transmissions dont just fail like that 5 times in a row. After it broke twice I would find someone else to rebuild it but thats just me.

 

I had a run of bad luck with a 700r. My 54 chev pickup had one when I bought it. It shifted and pulled good. Pulled motor and ****** for clean up amd paint. Reinstalled and just quit wouldnt do anything. So I had a spare out of a truck with about 200k on it but again it shifted before being pulled out. It would go into all gears but would just stop. Let it set for about 1 hour and it would work again. Bought one from a guy I know who does rebuds and it seems to be fine. I wonder what the hell happened with the last 2.

 

I've blown up and destroyed my fair share of 700r4s.

A. TV Cable set up

B. A bad builder once.

Like Waddayacare said, the TV Cable is so critical on these that if something is of with the set up, it will ruin it in a heart beat.

Check out bowtieoverdrives.com, I put their TV cable kit on and I've never had an issue with a TV set up again. Put the plate and cable on, let it ratchet itself out by pushing the gas pedal down, and never worry about it again.

 

The T.V. cable set up and geometery is EVERYTHING on a G.M.overdrive trans. Lokar makes a kit for the T.V. cable (it's not really a "kickdown") and an attachment that corrects the geometery at the carb arm. Not everybody likes their stuff, but it works everytime.
Like I said a bit ago, that isn't a kick down cable. It's a T.V. cable or Throttle valve pressure cable. It literally tells a the fluid coming out of the pump what pressure to opperate all the functions at throughout the trans. If it's not right, lifespan is measured in minutes. Period.

 

We finished my dad's '58 Chevy pickup equipped with a 700R4 two years ago, and I can count the number of times we have driven it. I have pulled the ****** out 3 times, the valve body out 5 times, used three different builders, and ****** fluid measured in drums not gallons!! The TV cable is adjusted correctly, and functions properly. The first one went bad because I did not have the lock up converter. The second one had an egg shaped case internally. The third one almost works, but does not go into O.D. All the time. I am going to give it one more try, and if I can't fix it, a TH 350 is going in it.

 

Common problem! Heat kills a 700R4. A 700R4 runs alot cooler with a lockup convertor.

Another common problem due to an early case. The earlier 700R4 cases warped due to heat. This is why I say run at least an "MD8" case.

T.V. cable improperly adjusted and/or incorrect pivot ratio on the carb for the T.V. cable.

Find someone that know what they're doing with setting up the T.V. cable. It also helps, especially if you don't know how to set the cable up correctly, to adjust the cable by ****** line pressure with a gauge. A good ****** shop (that knows what the hell they're doing) can do that.

 

I have been thinking a 4 or maybe 5 speed swap.

 

And people wondered why I didn't use one.

 

Sounds like your ****** guy is going out of his way to help you. But if after that many times going into it and not finding what is wrong,best bet is to find a ****** mechanic that can. Only used one 700r4,lasted a month,never want another one.

 

They work great once a few small details that differ from a "standard" auto trans are worked out. They just don't have the wiggle room for screwing up the settings that a Turbo 350 or such has.
Personally, I MUCH prefer my Tremac TKO 5 speed.

 

Good info. I installed one in my 33 Chevy and will be firing it up for the first time soon. I'll have my ****** guy come over and double check my work.

 

This site explains just how important the TV cable adjustment is on the 700r4 and the correct way to set it up. As stated above this is absolutely critical and if not done correctly will fry the transmission in a very short time. The 700 has gotten a bad reputation because of this issue. Most failures can be directly traced to an incorrect geometry of the linkage that controls the cable.
http://www.tvmadeez.com/article/index.php

 

I second what themoose said... I have bought and installed their kick down set up, and it worked perfectly. Well worth the money,

 

Like imports and mechanics in the 70's.... too much intimidation!

I've been running AND racing GM overdrives for years without any issues. It's no different than tackling your first flathead, you do research. You learn just how it's suppose to work and that's how you do it! Trust me, it's not rocket science!

But for those that do not want to learn, you can always go to a manual valve body then there will be no T.V. cable to deal with.

 

tv cable right ? tcc in operation ?
I use these instead of electric
http://www.transmissionpartsusa.com/700R4_Transmission_TCC_Lock_up_delay_valve_p/001-000035937.htm

 

yep ^ I put one in for a guy a few years back, set it up by line pressure as per builder. That thing worked like a champ right out of the box.

 

Thanks guys. Its out of my hands how the owner handles it. I've been around this stuff for a while. Never heard of this many failures. But yes for now the truck is getting a 350.

 

I am surprised no one mentioned setting the TV cable by use of a pressure gauge,having been down that road with a 700R4 I can tell you the simple way of setting a 700R4's cable is not the right way USE A PRESSURE GAUGE here is a good article you 700R4 owners should save http://67-72chevytrucks.com/vboard/showthread.php?t=526152 Now that I am back to my Ford roots I have another transmission the AOD which also needs to be set with a pressure gauge to make it live.

 

Trans has pressure ports on it, seems like after 3 or 4 rebuilds the damn gauge would pay for itself.

 

has the failure ONLY occurred in OD?

that will answer a lot of questions.

 

Wrong motor/trans setup for the truck, it misses the ford drive train!

 

I pulled a 700R4 from my local junkyard,had it rebuilt by a local guy put it in my coupe and set up the TV cable by the directions found on line at Bowtie Overdrives. I have Bowtie Overdrives linkage adapter for the Edelbrock 1405 . No problems at all in almost 12,000 miles. I'd get a different guy to rebuild , get the correct geometry for your carb ,aset up the TV cable yourself.

 

I pulled the motor/trans out of my old truck after driving it to where I parked it to pull the motor, and haven't messed with the TV cable at all. I figure to leave it that way, that's another way to handle it. 40,000 of the 100,000 miles on it are mine anyways.

 

X2 on Bowtie Overdrives

 

Blow out your cooler and lines when it is re-installed.. A slightly plugged cooler gave me headaches with a 700r4.