700R4 3 & 4 Shift

[HH]

Got the 6.2 diesel ZJ running last Fall, but the transmission, 700R4, will not shift into 3rd or 4th gear. I now have time to look at it, and want to have it drivable. The trans is new/rebuilt, new torque converter, clutches, etc. Reset the tv cable. Trans is the one that came with the 6.2 engine. Running synthetic transmission oil.

What can I look into that would cause it to not shift into 3rd gear and 4th gear? I have not been able to reach the person who rebuilt it. Any ideas??

[john8662]

Sounds like the governor hanging.

I'd pull the governor housing on the tail and see that it's in good shape. It's possible it's lost the teeth on the gear, etc.

Maybe the wrong governor in there as well.

J

[Robyn]

Does it make the 1-2 shift and if so at what speed with light throttle??

If its making the 1-2 shift OK then the Governor is probably ok and the issue is in the valve body or other internals

1-2 is accomplished by applying the 2-4 band. the 2-3 shift releases the band and applies the 3-4 clutch. The 3-4 shift applies the 2-4 band in conjunction with the 3-4 clutch.


It can be one of may issues. Seals in the 3-4 clutch fouled up, valve body issues or ????

These trannies have a lot of little things that can cause issue so without doing pressure tests and then likely rip into it ????????///


Missy

[HH]

Does it make the 1-2 shift and if so at what speed with light throttle??

Missy

Yes makes the 1-2 OK and at light throttle.

[Robyn]

OOOOOOOOOOOOOOK

Get ahold of a tranny manual for the 700R as well as a pressure test gauge with a LONGGGGGGGGGGGGGGGG hose that you can hook up to the tranny and then get up into the cabin.

Check the book as to the locations of the various pressure taps on the tranny case.

There is one for line pressure and I believe a couple others.

You need to connect to the 3rd gear oil pressure tap.

Run the truck up through the 1-2 shift and then push it on up. Once shift speed is reached there should be pressure at the tap (gauge)

You can also connect to the LINE pressure tap and then do a drive and watch whats happening.

The 2-3 shift valve may be installed wrong or ????

The fact that the thing shifts from 1 to 2 says that the governor is working and that its mechanical components at least are working.

If the tranny will not shift into 3rd it will go no farther even if you can get the speed up high enough.


Shift valve
oil seals in servos or on other components.

Just a bunch of stuff that can cause the problem.

Do some pressure tests and let us know.

A good tranny book 700R specific will give you very detailed diagnostic info.

These books are available at most tranny parts supply houses and are not real spendy, but worth their weight in GOLD.

Keep us posted


Robyn

[HH]

Thanks for the help. Talked to my tranny rebuilder. He recommended I get the fluid hot and see what happens. So it works! Apparently he uses a water based cleaner and when a trans sits for a while some things can hang up.

Seems to work good, except it seems to down shift too easily. Any ideas. I assume that I need to adjust the TV cable again.

Nice to make some progress on this project. Have one rattle to figure out probably the exhaust. Think I can start driving it. Need to calibrate the speedo and check the tach once I know the speedo is good.

[Robyn]

To properly adjust the TV cable, do this.

Press the little release button (Located at the bracket near the rear of the engine) slide the cable mechanism towards the firewall as far as it will go.

With this done, press the throttle pedal all the way hard to the floor.

The adjustment is now correct.

To test things, drive on a flat level surface and with a very light throttle, just as soon as the 1-2 shift happens, mash the pedal, the tranny should drop back to first gear.

If this happens, TV is properly set.

Robyn

[HH]

Trans appears to work well. Thanks for the help.

Now the list of things left to do:
Calibrate Speedo & tach
Find rattle
Clean up wiring
Install some sound deadner
Regear to 3.07
install WVO set up
Find AC parts for the 6.2

At least now I can drive it.

[Robyn]

Glad to hear that things are OK.

Good luck with the project.

Missy