700r4

[onefast95vette]

I put a 700R4 in place of my 4L60-E to take the computer out of the loop. Now the damn thing won't shift unless I stand on it, and even then I hit the rev limiter. The detente cable is set, it's got a B&M shift kit, all I can think is maybe the governor is bad. Any ideas?

 

[Hrtbeat1]

Shifting

Thats a little different. I've never heard of someone going from a 4L60E to a 700R4. But I guess it makes sense. The 4L60 uses the computer to control the shift points, while the 700 uses pressure regulated by the Throttle Valve cable. I would guess the TV is not adjusted correctly. To properly adjust have someone sit in the car and hold the petal to the floor, press the detent button and move the cable housing (not the cable itself) all the way back toward the rear of the engine. It should slide back inside the detent bracket. This is your maximum adjustment. To get a softer earlier shift press the detent button and move the cable housing forward one click at a time, then road test. With the car in Drive idle up slowly till the trans just shifts into second, then floor it, the trans should immediately shift back down, if it doesn't you have to move the cable back toward the max adjustment. Do this one click at a time and road test each time. If the TV cable is not adjusted properly you will toast your tranny. One other check would be to see if the lockup torque converter is locking and unlocking. To do this cruise at around 55, tap the brake and listen for the RPM's to increase, release the brake and the RPM's should drop. This indicates the lockup is operating properly.

I wouldn't rule out the governor, but it sounds like the TV is not adjusted properly. The govenor can be accessed without pulling the trans. Pop off the cover and slide the govenor out of its bore. Check the weights for proper range of motion. With a 3/32" punch press out the retainer pin for the gear and slide it off. The gear itself may be worn so check it for worn teeth. With the punch go behind one of the weights and slide the valve out of the govenor check all the lands for burrs with your fingernail. The three lands on the govenor should be checked also. If you find the teeth on the gear worn you should be able to find a new gear pretty easily, as this is a common problem with these trannys.

I hope you have had this tranny beefed up because it will never withstand the kind of power you are making. Once built up I've heard of them withstanding 700 hp and 700 ft/lbs of torque.

Hope this helps.

A hui hou

 

[onefast95vette]

Very much, thanks!

I'm going to pass this on to my crew chief, and I greatly appreciate the info. I have another 700 in my garage and I'll try swapping out the governors, we hadn't thought of that. Yes, it has a rediculous B&M shift kit, I'm not worried about blowing it up, but thank you for the concern. Another q, though...the detente cable shouldn't have any effect except at speed, right? Or am I just that stupid? (I'm just the driver, and learning) Also, my friend Al said we can put a spring in the detente cable to make it shift. Ideas?

Dan

 

[onefast95vette]

And what the hell is a throttle valve cable? Is that the same as the detente cable? I've had the valve body off twice, ok three times and I'm pretty sure I have the check balls back properly, so I'm good to go there.

I just reread your msg, and yes it is, we've already done that. I've also reseated the shifter cable, that's all good. I still think it's the governor.

 

[Hrtbeat1]

TV cable

The TV cable goes from the Throttle body to the transmission. The 4L60E doesnt use one. On the 700R4 it is on the passenger side behind the fill check tube hole, just infront of the servo bore. You've had the valve body off so you should have seen where it hooks up. Its the lever mechanisim opposite the shifter selector. There should be a couple of springs and a lever that acuates a valve in the valve body. I'm kinda confused about what you are calling the detente cable (I hope its the same thing.) As far as putting a spring in the cable to make it shift I don't know, Where would you put the spring? and whats it going to do?

As far as the rest of the tranny, I don't think a shift kit alone will help save it from the kind of power you are talking about. There are other things inside that would have to be done. Sun shell, hardened sprag, replacing the bronze thrust washer with a torrington bearing, probabally more clutches and steels, improvements to the pump, and a 13 vane wouldn't hurt.

 

[onefast95vette]

ummmm ok

I have absolutely no idea what you just said.

I'm an owner/driver. I pay for the car, i do a good burnout, I stage, and when the third yellow light comes on I dump the accellerator, then I keep it on the track for 1/4 mile.

 

[Hrtbeat1]

Shifting

So its not up shifting?

I respect the fact that you are the driver and pay the bills. Just trying to help.

 

[onefast95vette]

Appreciated

Yes, it won't shift up. I came off the H-3 at 4800 rpm at 36 mph, yesterday. It has great response, if i go into it, it'll blow like a mf! but it won't shift at low speed.

 

[onefast95vette]

i still think it's the governor

 

[Hrtbeat1]

Have you tried replacing you're B&M shift kit with the stock one?

Sounds like some of the valves inside the valve body may be sticking. When you took the vavle body off did you do a good cleaning to all of them? Couldn't hurt.

 

[onefast95vette]

valve body

Trust me, I've already done that repeatedly. The valve body is ok. I only wonder about a spring that I can put in the detente cable. Ever heard of that?

 

[Hrtbeat1]

Check out the post by Moe Jr about an 84 700R4 FYI it should come up in related liknk at the bottom of the page. Follow one of the links in the post (not the one for netgearheads.com) its got some good pictures of the throttle valve. Where it connects ect. His problem was different from yours but it will give you an idea what your looking at.

 

[Hrtbeat1]

Cant say I have. I would wonder where the spring is going to go? and how its going to help.


It sounds like a pressure problem. Not enough pressure at low RPM's. Pressure is controlled by the pump. So maybe your boost valve (inside the pump) is suspect.

 

[onefast95vette]

Dude! I think I know your car!

You have the white '90, right? I have the white '95! I've seen you race at the track, that is one sweet beast! I just saw on your thing that your in Hawaii

 

[onefast95vette]

sorry

Didn't mean to go bananas, it's just that the spring thing has me confused. You'd have to talk to my crew chief, I'm just the driver. If you're really in Hawaii, give me a call, 561-1652. There's a race & car show this weekend, I'm hoping to have my car ready for it.

 

[Hrtbeat1]

Wasn't me

Sorry man my Vette is mainland. I am there quite often (10 of the last 16 months.) I am currently mainland. I will be back sometime in Aug.

Sorry brah

 

[VetNutJim]

The TV piston is hanging up inside the transmission.
There IS a speing you can get to put behind it and stop it from hanging.
The spring will essentially return the valve to the non-actuated position.

This is what is causing the excessively high shift points.

You can disconnect the TV cable at the throttle body and yank on it aggressively and try to unstick the valve.

If this doesn't work, it's drop the pan and valve body time.

Give this thread info to your 'crew chief'. He will know what it means.