I'm in 700r4 trouble.

[1970pelle]

I really haven't wrapped up my new crate engine install and Oh no! What has happen which is my fault. I had to convert the 700r4 lock up to a different style set up, being the removal of the under dash control unit(ECU) what ever.
I used a TCI kit, the install was easy. So I thought while I had the pan off anyway, why not add a couple of items. Thinking I have a known good trans that has a resent rebuild. Again Thinking. Why not change with some of the Corvette trans parts that TCI sells. I buys a sevro kit and a TV valve something. Well during my install of that valve that the TV cable contacts I didn't assemble it correctly. And blocked the valve from moving. I only drove the truck maybe 2 miles max to the muffler shop. And I was creeping at that, because of the open headers. That I didn't pay attention to that where blowing hot exhaust directly onto the trans cooler lines.
I pulled the pan, its covered in a very nice shade of black. And a pile of silver in the corner. I think for a moment find my mistake. Fix it and test drive.
I take it out and run it up to see if it will shift at any speed. It finally shifts at 35 mph and just about rips everything apart. It throws the belts, barks the rear tires. knocks any dirt or dust left on the truck off.
So now I will be pulling the trans for a rebuild, probably trashed a new tranny cooler.
I can just hear it now, why did you buy a new truck ?

Ken. in the dog house.

[kalbert]

An incorrectly adjusted or malfunctioning throttle valve is bad news, it'll wipe all the friction material off the clutches in just a couple shifts.

Those race car parts are hell in a pickup. Hard on u-joints, splines, axles, you name it! I drilled out the holes in the separator plate and blocked the accumulators in one and uffda, that was fun for about twice. That transmission lived out the rest of it's short life in a 3500lb Camaro instead of a 5500lb pickup.

All my favorite 700's have had the TransGo SK700 kit in them. It fixes all the common complaints of slides, bumps, and runaways and makes all 3 shifts feel tight but not hard. Have used a couple of other TransGo kits over the years and they are all very well engineered. When you go through yours, get one of these kits. They're not cheap, but worth every penny.

It has instructions for lockup without electrics, that part I wouldn't recommend, but the rest of it is superior to anything else. It's not a fault of the kit that the non-electric lockup is poor, it's just that non-electric lockup in general is poor. Fluid can flow to the lockup circuit in 2nd gear. The lockup solenoid allows that fluid to dump to the pan until it is energized, then it directs it the rest of the way to the piston to apply the clutch. All of the non-electric lockup tricks I have seen block the dump circuit so anytime there is enough pressure in 2nd gear or above the converter clutch is applied, sometimes weakly.

[1970pelle]

Yea if your going to play, you will have to pay. So out comes the trans when I finish up the honey do list I had just started on. I'll be riding a while longer which isn't all that hateful. Its prefect riding season here. On the good side all the bolts are fresh and with the new style cross member trans removal will be much simpler.

Ken. (soon to have a lightened wallet)

[1970pelle]

I'm going to get some Boo's for this. But I'm going to put a 400 turbo in the truck for the time being. And rebuild the 700r4 after I finish the bathroom remodel, kitchen update, and some more tile floors. Which will be next summer for sure.

Ken

[RUN GMC]

Originally Posted by 1970pelle

I'm going to get some Boo's for this. But I'm going to put a 400 turbo in the truck for the time being. And rebuild the 700r4 after I finish the bathroom remodel, kitchen update, and some more tile floors. Which will be next summer for sure.

Ken

NO BOOs or judgements here bro.......you do what you have to do just keep on working at it or on it.....in the meantime you will be able to enjoy/experiencing driving it............

[1970pelle]

Yea twice in the last week I have had to ask my neighbor to use his truck. To pull my trailer to pick up a couple of bikes and a few sheets of sheet rock.

I was thinking how much highway driving really do. And it not very often anymore, with Jacksonville growing as it is. The speed limits have dropped and most roads. The longest trips are to Daytona, and I always go the back way. Down here we call it running across Hunered, Its really route 100 east. All you can do is laugh. A damn Yankee. Been here more than 20 years.


Ken

[kalbert]

Originally Posted by 1970pelle

I'm going to get some Boo's for this. But I'm going to put a 400 turbo in the truck for the time being. And rebuild the 700r4 after I finish the bathroom remodel, kitchen update, and some more tile floors. Which will be next summer for sure.

Ken

Nah, the 400 is a fine piece of machinery. Sturdy, simple. The vacuum load sensor on the 350/400 is far superior vs the throttle valve on the 700. Vacuum is a way way better indicator of engine load than throttle position. Because of this the 400 can shift like smooth butter when you're taking it easy and have a nice firm pop when you get into it.

[1970pelle]

I have pretty much decided on the TCI unit. And with Thanksgiving coming so quick, I'll have both boys around to help me out. I'll hang onto the 700r4 for a rainy day. I most likely will take the new parts out and sell them if undamaged.

I need to have a garage sale, will all my mock up parts. And take offs, and stuff I have accumulated over the years. I need the room for Harley parts.


Ken

[hatzie]

Try this thread on the ThirdGen F Body board.
http://www.thirdgen.org/forums/carbu...c-control.html

[1970pelle]

Originally Posted by hatzie

Try this thread on the ThirdGen F Body board.
http://www.thirdgen.org/forums/carbu...c-control.html

That link has some good info and diagrams. I used all TCI parts in my failed 700r4. My issue was me being far sited, and not double checking my work. I'm getting old. Talked with my speed shop guy and he shot me a decent price on a new TCI unit. I'm thinking hard about that.

Ken

[hatzie]

None of the Kits on the market do a super good job. Gm didn't either.

The best solution for smooth driveability would be a modified B&M VSS controller kit.
Adding an ACDelco 212-331 GM Original Equipment Automatic... with a Standard Motor Products DSV31 Spark Delay Valve in the vacuum hose in series with the control wire. The PAK CON connector for the vacuum valve.

You positively need a brake pedal lockup override. If you don't have cruise control you can use the cruise terminals on the brake light switch in series with the control wire to cut the lockup. If you have working cruise a 5 terminal Mini ISO relay could be wired to the brake lamp wire between the switch and the column with the relay switch terminals in series with the lockup control.

A Beuler BU-508TD Mini ISO time delay relay with the switch contacts added in series with the control wire would give your control signal a slight delay to prevent the engage-disengage-engage hunting that happens even with the GM factory controllers. Placing this inline with the control wire would give you a two second to three hundred second state change delay.

I would think mildly adjustable ON control hysteresis could easily be part of the TCUs on the market but it doesn't seem to be... unless the POT on the B&M controller is this type of control.

It wouldn't be rocket science to build a controller with a PIC or ATMEL that would take inputs from an override switch, 12v from the brake pedal, 2K/4K selectable VSS, MAP and, a multi-turn Pot for inputs.
Control would be based on a small table to turn the clutch on above 45mph with the hysteresis applied to the ON signal based on the resistance of the Pot. Off would happen from the Vacuum switch contacts opening, VSS dropping rapidly, Brakes applied, Override switch, or VSS below 45mph.

Combine this with a cheapie controller for an inside the pan harness and control solenoid.