Gummed Valve Body?

[Bannon88]

I am in the process of putting a 97 Disco back together, and have run into a transmission problem.

140K on transmission.

I checked fluid and it was slightly discolored, but didn't smell burnt and after draining a few mL it wasn't full of particulate matter.

So I just drained the pan, about 6 quarts. Refilled and for two days everything was fine, however, today it will not go into R every time. It is also slow to go into D, and I noticed this morning it seems to be hydraulically locked in N when the engine is running. Shut the engine off and it will roll fine in N.

So I assume the valve bodies are gummed up or have so clutch material packed in them keeping them from functioning properly. Am I correct? If so what advice will you veterans of these ZF's give to to go on?

Thanks in advance.

 

[ptschram]

You may have flushed out all of the suspended friction material when you dumped the pan.

If you got lucky, you just disturbed things and replacing the filter and refilling might get it back.

What happened to you sounds scarily like what many folks say will happen if you flush and fill an older trans that hasn't been serviced regularly.

Dump the fluid, replace the filter, refill, it's worth a shot.

 

[Bannon88]

That was my original plan....

Replace about 6qts, run it for 100 miles, then replace the filter and add another 6qts.

I too have read all the stories about disturbing the fragile nature of a neglected transmission.

If that doesn't work, is it a big job to remove the control unit and clean the valves?

 

[ptschram]

If that doesn't work, is it a big job to remove the control unit and clean the valves?

You should know better than to ask ME if a job is a big job. They are almost all easy after you've been doing it daily for six years:smilelol:

 

[Bannon88]

Well, then boss....

Drop pan, remove filter, remove control unit, remove each valve individually and clean(is brake cleaner OK?), button it all back up with new filter and gasket.

It doesn't seem that bad, the removal of O2 sensors, exhaust, and crossmember seems far worse.

 

[ptschram]

That's pretty much it. Good luck with the kickdown cable.

 

[Bannon88]

That's pretty much it. Good luck with the kickdown cable.

Are you talking about the special spacing tool?

 

[sven]

If the clutches are worn, cleaning the valve body isnt gonna do anything. You typically clean the valve body as part of a rebuild.

Maybe a bottle of Lucas ATF might help?

 

[Bannon88]

I've got it all out now. I'll put it back together tonite and see what happens.

 

[MUSKYMAN]

That's pretty much it. Good luck with the kickdown cable.

whats the issue with the kick down cable? are talking about breaking the plastic insert that snaps into the case.

 

[Bannon88]

The only issue I had with the cable was that the barrel slipped out of the cam, and putting it back in with ATF covered hands was a real treat.

 

[MUSKYMAN]

The only issue I had with the cable was that the barrel slipped out of the cam, and putting it back in with ATF covered hands was a real treat.

I have never had a issue with the cable, I have seen a number that the plastic clip breaks but once your in there swapping the cable out is really pretty simple.

 

[Bannon88]

My issues run much deeper than the valve body.....

Put it all back together, with some Lucas ATF. Started up, ran it through the gears, still no engagement into R. However, N is no longer hydraulically locked. I will give it another shot tomorrow, then go to my old truck and begin to pull the trans and T-case.

Which leads me to my next question....

How difficult is it to pull both the trans and T-case as a single unit? Keep in my my donor Rover is sitting on 30" jack stands.

Again thanks to you guys who give my advice.

 

[MUSKYMAN]

there really isnt any reason to pull them as one unit, it just makes the job slower and more a pain in the ass.

 

[Bannon88]

Thanks.

I was just thinking that this "new" truck has a bad trans, and a questionable T-case. But my donor was pampered quite well, and therefore thought about doing the entire swap at one time. I thought it might be easier. I guess I was wrong.

 

[MUSKYMAN]

either unit alone really is not that bad weight wise...bolt them together and they get heavy.

the job isnt that bad if you take your time and dont force anything. the only thing that really takes alot of attention is making sure the torque convertor stays in postion in the trans pump as you install the trans.

If the TC comes outa the pump when you are installing the trans the result is you have to start over

 

[Bannon88]

Good to know....

This is probably how I'll be spending the next couple of days.

 

[ptschram]

Keep track of which bolt came from which hole on the transfer case...

 

[Tate]

either unit alone really is not that bad weight wise...bolt them together and they get heavy.

the job isnt that bad if you take your time and dont force anything. the only thing that really takes alot of attention is making sure the torque convertor stays in postion in the trans pump as you install the trans.

If the TC comes outa the pump when you are installing the trans the result is you have to start over

Take a thin piece of metal and drill a hole big enough to put one of the bolts through it. Place the metal piece with the hole aligned with one of the bolt holes in the transmission case. Stick the corresponding bolt to the housing hole through its hole and through the hole on the piece of metal. Bend the metal so that it is touching the torque converter. Keep the metal piece in place until you get the tranny into its place. Then pull the bolt out and slide the piece of metal out. This will keep the torque converter from sliding out of place. I hope I have explained this clearly enough if not let me know and I will try to do a better job.

 

[MUSKYMAN]

Take a thin piece of metal and drill a hole big enough to put one of the bolts through it. Place the metal piece with the hole aligned with one of the bolt holes in the transmission case. Stick the corresponding bolt to the housing hole through its hole and through the hole on the piece of metal. Bend the metal so that it is touching the torque converter. Keep the metal piece in place until you get the tranny into its place. Then pull the bolt out and slide the piece of metal out. This will keep the torque converter from sliding out of place. I hope I have explained this clearly enough if not let me know and I will try to do a better job.

that sounds really complicated, I have always just used a piece of thick wire up through the round inspection hole on the bottom of the trans bell housing. On the older trucks you can wire around one of the square blocks welded to the torque convertor. On the Gems engine you can wire right through one of the holes on the raised ring that bolts to the flex plate.