Hello,

This is my first post. I recently bought a 96' Disco 4.0L automatic for short money as a project and I'm excited to get into it but want to make sure I don't do anything stupid. The engine runs great (sounds perfect, doesn't overheat, good oil pressure). However, it wont move when put in gear. It makes an extremely slight rpm drop when put into any gear other than N, but only revs when pressing the accelerator. There is a clicking sound that matches the rev and I found a broken "kick down" cable. My thought was that it may be the torque converter or flex plate. A friend thinks it could be the tranny pump...any insight would be extremely appreciated. I was planning on dropping the tranny somtime this week so I can come up with a plan for the project. Thanks

 

Is the transfer case shifter in gear?
It must be in any of the hi or lo ranges for the truck to move.
These transmissions are all but indestructible...

 

I had a d1 with a burned up transmission. (Actually at that time my friend owned it) It was probably the pump. Fluid was black though, could have been anything. It wouldn't move in any gear. It had certainly been abused, when stuck in the mud, though. Lots of revving and attempting to rock it back and forth. Another friend repaced the tranny and some months later I ended up getting it for a VERY good deal.

 

I've tried putting it in both high and low with no luck. The trans fluid reads extremely high on the stick but doesn't look too bad. My thought was that if the kickdown cable broke, the transmission would be stuck in a higher gear than it should be. Seeing as I live on an island with dramatic relief, the torque converter may be put under extreme strain and could possibly fail. Does this logic sound valid or should I just drop the tranny and see for myself what's going on?

 

Also would want to look and see if when engaged in drive and revved up above idle - is any drive shaft spinning - which would indicate a blown diff. Could try putting CDL in lock mode, which makes power divide front to back, rather than to what is path of least resisance.

Do you have a copy of the RAVE (shop manual)? The ZF tranny has a diagonstic proceedure (uses a pressure gauge), plus detailed info on how to adjust kickdown cable, internal repairs, etc. May want to review that before picking up a wrench. May also help to drain and refill to proper level, would let you see large chunks coming out.

 

It won't be the kick down cable, go smell your ATF and see if it smells burned and how high over the level is your fluid?

 

Being over full wont have any effect with this issue.
But if it is full of water and thats why its over full will.
I highly doubt the pump is bad, but you can check easily enough, remove one of the trans cooler lines, stick it into a jug, start the truck, does fluid come out?

 

First off, thanks for the dialogue. I appreciate the help. I just spent some time with the Disco and the transmission fluid smells normal. However, its reading about 6 inches above the full mark on the dip stick. The drive-shafts do not spin when revved above idle in gear, high or low, locked or not. I do have a hard copy of the shop manual and have been researching it quite thoroughly. I've not checked the pressure on the transmission yet or checked to see if the pump circulates fluid through the cooling lines. I did spend a good amount of time under the vehicle with it running and could really isolate where the knocking sound was coming from. Its definitely from the front part of the bell housing. I shone a light into the observation hole on the bottom of the bell housing and saw spinning. I will continue working on a diagnosis in the morning...

 

I removed the cooling line from the transmission and started the engine. No significant amount of fluid shot out. The manual shows a fairly simple set of steps for removal and replacement of the oil "sump pump" in the automatic gearbox section. I also found a chapter that describes replacing the "pump" in the same section. The second process involves dropping the transmission and the first does not. Can someone please help clarify this for me. Also in either case, what other parts could be damaged as a result of the pumps failure?