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700R4 problems

mplogic

1/2 ton status
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May 7, 2002
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Phoenix, AZ
Just finished the SB400 swap into my 89 Blazer. The engine is running beautifully but my tranny started acting up on the test drive. It's not shifting until almost 3800rpm. All the gears are still working you just have to buzz it up really high to get to them. My mechanic suggested it sounds like the TV is sticking. Anyone encounter this before or have any other suggestions?
 
Yes, you need to adjust the TV cable....pretty easy really. On the throttle bracket (bolted to the top of the intake manifold near the firewall on the driver's side) you'll have the throttle cable and the TV cable for the tranny. What you need to do is: there is a "button" on the TV cable where it goes through the back of the bracket. Push that in, then with your hand, cycle the tbi/carb to all the way open, then let it go back to closed.....that will adjust your TV cable and you'll be good to go.
DON'T drive your 700R4 with it slamming shifts at 3800rpm /forums/images/graemlins/shocked.gif You'll be sure to blow it up that way. /forums/images/graemlins/deal.gif
 
Ah, thanks. Easy fix. It's shifting much better now but actually feels a little early, maybe I'll try adjusting that back a click or two. Of course I did just make rather drastic changes to the horsepower and torque curves, think that will effect how the tranny shifts or should I be able to just adjust it out a bit more?
 
The guy who rebuilt my tranny was telling me that half the 700r4's that are brought to him for bench rebuilds are full of good clutches, steels, seals, pumps, etc... and he wonders how many think to clean the govenor or adjust the TV cable before they pull it. What kind of power are you running out of the 400? I just had a 700r4 rebuilt with all the upgrades to go behind about 350 HP. I'm wondering how long it will hold up. Anyone else have any good longevity stories with a little above stock horsepower and pre 89 700r4?
 
As I understand it, they are pretty close to a 350turbo in strength.

I'm not pushing any serious horsepower, more of a torque monster. Not sure where I am in the numbers either, anyone in Phoenix have a dyno I can borrow? /forums/images/graemlins/smile.gif Using a .040 over 400SB, my '89 heads, headers, a mild Extreme Energy dual grind cam (258/262 or thereabouts), stock TBI, and running approx 9:1 compression. The idea was to get my beast moving with as little pedal as possible and so far it seems to have done the trick. I'd imagine a torquey motor is just as hard on a tranny as a high horsepower motor is though? We'll see how she holds up.
 

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