PO299 and PO734 codes, tranny limp mode

I just pulled the tranny out and replaced both aluminum cylinders that went bad. One was broke so the clutch pack came apart. I found and accounted for all the chunks and it looked like the filter did it's job. I cleaned, flushed, and resealed the entire unit. Put everything back together and I'm not making boost now.

I'm not nervous about the assembling of the tranny, I've been doing these for quite a few years. Can these two codes be intertwined? Is the lack of boost causing the tranny code as well, or am I just wishing it would be that easy?

I have been having trouble finding a thread with a few pictures on how to test the N75 valve. I'm thinking I could have caused the problem by "disturbing" everything when I removed the tranny. I'm starting to run out of ideas.

I can reset the codes and the limp mode goes away. The tranny starts shifting smooth again but with no boost.

I'm running out of hair!!

Your two codes may or may not be related. The boost problem may well be a charge hose loose or with a hole. That should be easy. The trans code is most probably internal. When you clear code, it returns as soon as slippage occurs and tcu determines incorrect speed. When you had it apart you didn't mention using a master zf kit. Valve body cleaned and checked ? Tc replaced? After a major failure such as you had with drum D exploding, there are many possibilities.

I used a master zf kit, the valve body was cleaned and checked, and tc replaced. I'm just going to pull it out and go through again. There's only one way to be sure.

Zf factory original master kit or aftermarket? Friction, steels, rubber? Upgraded factory drum D? Was the tc new or done by a reliable source such as Eriksson? Pump replaced? From your description, it sounds like a pressure problem. Condition of main pressure piston bore and spring?

Forgot to ask if you replaced the pump with a ZF original. The people who do these transmissions successfully on a regular basis use all Factory ZF stuff. You might call Nate at Ericsson industries for suggestions. They may have vb or other mods they use as they are and have been doing ZF for 30+ years and presently do all the transmissions for LandRover. They are not cagey and will help you I'm sure.

I will give them a call. I used all factory zf parts. In WA I can call a place named Transtar, they are the zf dealer. Nice to deal with and pricing that isn't too painful. The motor and tranny are almost out, the big game made me take a pause, should be out tomorrow. I will be able to look at everything closer then. I will update then.

So I got it all back together. Tranny is working fine, I found an o-ring that I had sliced when putting it together. I am still having what fells like no boost. It just threw an Emission Workshop code. I brought home my NexusIQ from work hoping it would do the trick but no luck. I let a friend borrow my other reader so I am dead in the water until I get it back from him. I have vacuum at idle to the turbo but do I need to unhook the line to see if it will increase the power? Would that be an easy of telling if it is something vacuum or valve related?

Can you hear the turbo? Glad you found your pressure leak, its really easy to toast an oring when assembling the pistons. Try unplugging the maf and see if it makes a difference. If you hear the turbo look to see if the actuator rod to the vanes moves. Make sure the bellcrank that controls the vanes in the turbo isn't seized as that would prevent the rod from the vacuum actuator from moving. Also, the charge hose coming from the turbo has a habit of either blowing a hole or having a hole rubbed in it from the ground cable. That cable should be rerouted so as to not be close to the hose while you are checking it. If you were able to get the ZF straightened out, this stuff should be easy for you. However, its recommended to get a vcds for anyone that owns one of these vehicles.

I can't hear the turbo spool up at all. The transmission is spot on, now I just to have some power in front of it! I can see the actuator rod move, I pulled the vacuum line off and could watch it extend out. I replace the hose off the turbo to the crossover pipe, I found a spot rubbed through on the metal flange inside the turbo housing. I will try unplugging the maf tomorrow night and see if that makes a difference.

Unplugging the MAF didn't net any results for me. I replaced all the o-rings on all the intercooler piping and pulled all the hoses to make visually look at them and make sure they were all good. It just feels like a have a "lazy" turbo. It wants to build pressure very slowly then comes on hard at the end. I'm thinking about pulling the turbo and taking it somewhere to have it checked out. On the outside everything looks to be functioning properly but something could be off on the inside. I think thats my next move.

Turbo failures on these cars are not common, but do happen. Fora turbo check and or repair, Eriksson is the most trustworthy I know. They are a Garrett dist as well as ZF.