700R4 nightmares

[Woody Burban]

I rebuilt it 1st time with a Monster Kit and 1650 stall Tourque converter. Blew valve, shredded it. I rebuilt it again, had trouble shifting 2-3rd. Replaced TV cable, adjusted it with pan open, made sure compressed perfect. Drove and tuned it. 1,000 miles began jumping 4-3 and ran it just in 3rd, then heavy vibration on highway at 1800 RPM. Blew 4 & 3 today.

I’m so F’ing tired of this issue, it’s only a 1500 and my mechanic said the 35” tires may be to much for the trani.

Now I need to get it on the road again. I was gonna buy a reman, Monster Trani 700R4 and stock torque converter and drop it in.

At this point Ive though about just moving to Standard! Is this possible.

Any ideas? 460LE?
Thanks
Woody

 

[yevgenievich]

Either make sure axles regeared and have a good 700r4 build, or switch to 4l80e or th400. If it is monster transmission , I would avoid their build.

 

[Vbb199]

Monster transmission has alot of bad reviews.

Perhaps you should have one built and have a reputable mechanic install it and setup the TV cable with the appropriate throttle linkages and tune the line pressure with a gauge vs a throttle setting.

 

[Vbb199]

And for a 35" tire, you'd want around a 4.56 gear to match a 700r4's ratios well.

 

[CheemsK1500]

If you don't care about fuel economy, and want an automatic that is practically bulletproof, the TH400 is the way to go. The lighter duty TH350 is pretty durable as well, with the right upgrades. They are also pretty straightforward to install, since a vacuum line, and shift linkage is all that is needed to make them work in your truck. The 4L60e and 4L80 can be made into good transmissions, but most of them require some sort of computer to shift them, unlike the 700r4's TV linkage. The only time I'd recommend a modern GM automatic, is if you had a modern LS to go in front of it.

 

[SquareRoot]

Nv4500 and miles's of smiles.

 

[Vbb199]

You can run a 4L80e or 4L60e on lightswitches from a hardware store to make it shift if you wanted to lol its just switched power solenoids on the VB that see <this> vehicle speed at the ecm and sends a 12v signal to the shift solenoid to make it shift


Or run a full manual valve body and you won't need a single electrical wire to make it shift

 

[CheemsK1500]

You can run a 4L80e or 4L60e on lightswitches from a hardware store to make it shift if you wanted to lol its just switched power solenoids on the VB that see <this> vehicle speed at the ecm and sends a 12v signal to the shift solenoid to make it shift


Or run a full manual valve body and you won't need a single electrical wire to make it shift

True, though I've thought converting an automatic to a semi-automatic kind of defeated the purpose of having an automatic in the first place.

 

[Vbb199]

True, though I've thought converting an automatic to a semi-automatic kind of defeated the purpose of having an automatic in the first place.

Automatics never disengage from the motor, torque is constantly applied vs a manual where it's disengaged, even if it's for .5 seconds on a slam shift

Thats more for racing though haha doesn't apply here I don't think

 

[Woody Burban]

Thanks guys, I’ve had it with repairs, spoke to the wife, new truck $70K plus. Probably gonna have a great local mechanic drop an LS in with a new trani this summer. For now have him order a 700R4 new and drop it in tune with pressure gauges, not the (lawn mower throttle control TV Cable). I would love to go Standard 5spd, anyone seen a good thread on this?
Woody

 

[Vbb199]

I don't know what your setup is under the hood whether it be tbi, carb, or something else, but if it's tbi, presumably the original throttle valve bracketry is there, if not... could be the incorrect geometry

If that valve pressure isn't set correctly it'll burn the trans up in short order

Very short.


Plus +++++ you have to purge and flush the cooler lines after you burn one up before installation of the next , too


@SquareRoot and @Frankenchevy both have installed standard 5 speeds in their trucks, they have threads I believe on their nv4500 swap

 

[CheemsK1500]

If you go the NV4500 route, it will be easier If you get one out of a GM truck it will pretty much be a bolt on affair for either a small block or an LS (transfer case will likely need an adapter though). A Dodge one can be adapted to fit too though. You will also likely need new drive shafts, due to length differences. The hardest part will probably be finding a compatable clutch pedal assembly. For cosmetic reasons, I'd also suggest modifying or replacing the steering collum. Having a dead collum lever and indicator in a floor shift truck just looks silly.

 

[gmbellew]

I don't know what your setup is under the hood whether it be tbi, carb, or something else, but if it's tbi, presumably the original throttle valve bracketry is there, if not... could be the incorrect geometry

If that valve pressure isn't set correctly it'll burn the trans up in short order

Very short.


Plus +++++ you have to purge and flush the cooler lines after you burn one up before installation of the next , too


@SquareRoot and @Frankenchevy both have installed standard 5 speeds in their trucks, they have threads I believe on their nv4500 swap

in addition to the above advice , if the speedo is VSS the DRAC needs to be corrected for tire size to make the speedo correct or TCC lockup will be all messed up on the highway.

 

[Vbb199]

Yea that thing will be a dog if it's not geared right for 35" tires and goes into lockup, however it gets signal to engage in lockup whether it be via an ecm (87-91), or a vacuum controlled solenoid, if your axle ratio doesn't match the tire it'll burn up the 700 in short order too. They don't like heat at all.

I've proven myself that if you match your ratio to the tire size, bearing in mind how a 700r4 likes to operate, it'll stay cool and be happy, even when loaded at or above it's max capacity for towing.

Like me and my suburban, it's a R1500 with 3/4 ton suspension, with a 4.10 ratio and 31" tires, healthy small block, it never just lugs the transmission and gets it real hot towing or empty. It's always happy.

Really 4.56 would've been bullet proof coverage for my 700r4 and a 31" tire, but as it is now, with a 4.10, it's running 2500rpms at about 80mph according to my tach

 

[Woody Burban]

I think I have 3.73 stocks in the rear, would 4.10 or 4.56 improve the 35” tire problem?
I can rebuild an engine or build ya a house, but Trani and gears are not my wheelhouse.
Thanks everybody!
Woody