How I fixed my transmission morning sickness 01 QX4

[ddz0403]

First of all let me say that I had never worked on a transmission before. There were 3 reasons I undertook this task. First, Aamco quoted $1200 just to pull the transmission to look at it. Second, the transmission worked just fine when it was warm. Third, I didn't have to take the transmission out to do this.
I do not claim that this procedure will work for you, just that it did for me. If you screw up your transmission by using this procedure I can only wish you a quick recovery. Read on if you accept this warning.
My friend had a transmission that wouldn't shift out of first until it warmed up. I noticed this when I drove it to my house. When I first looked at her problem weeks before she had a check engine code P0733 which is 2nd to 3rd shift which was probably set when cold. I downloaded the transmission service manual and found there was a in vehicle procedure to repair these symptoms with specific parts that were likely culprits, the shift solenoids A and B and the shift valves A and B. I followed the procedure to drain the fluid, remove the pan, and test the solenoids with battery voltage. I didn't hear any clicking from the solenoids, including the overrun clutch, but did hear the click from the line pressure solenoid. So out comes the control valve assembly. I removed the bolts noted in picture SAT353B on page AT-273 and additionally the bolts holding the plate underneath the fluid temp sensor. Fortunately the last bolt I removed was one near the middle of the assembly because as I loosened it I got another 2 quarts of fluid out of the transmission. Make sure you have a drain pan to catch this extra fluid. As the assembly came out there were 3 springs that dropped out from the accumulators and later I had to figure out how to get them back in as I put the assembly in.
The next step was to separate the upper and lower bodies. I took a picture of both sides before proceeding so I knew easily which holes to reinsert the bolts removed. I removed the solenoid assembly first and later found I did need to also remove the torque converter clutch solenoid as well. I removed all the other bolts and laid them out on a towel in the same relative position they came from. I pulled the lower body off the upper and set the two halves down. I then could see in the upper body the 9 steel balls referred to in the manual, removed them and drained the rest of the fluid. I first inspected the lower body after lifting off the separator plate and saw no problem with the filters (there is 1 extra one there not noted in the manual) or the orifice check valve. I set the lower plate aside and did no more to it. All the work was done on the valves in the upper body.
I initially checked in place the shift valves for operation by using a small flat blade screwdriver to move the inner end of each valve and found they were both sticking. Eventually I checked every other valve that was spring loaded and found all but the 4-2 valves and 1 other valve with a heavy spring on it were sticking. I started with the shift valves removal first. I removed the holding plate, then the springs, and then had to figure out how to get the valves out. I used a combination of my small flat blade screwdriver and a bent large paper clip (as detailed in the service manual) to get them out a little at a time. Sometimes I had to use the screwdriver to push the paper clip. After removal I wrapped a long length of 400 grit sandpaper around an appropriate sized drill bit (both length and diameter) and twisted it in 1 direction into the aluminum body and cleaned up the inside of the holes a bit. There was enough ATF fluid there to wet the sand so I didn't feel like I was scratching the aluminum. I also did a quick buff of the steel valve by twisting it in a wrap around of the sandpaper. I continued with this process for a few minutes, stopping to check for, as the service manual states somewhere, "the valve should fall out of it's own weight". I was careful to make a lot of checks along the way to make sure I didn't go too far with it. The first time through I didn't mess with any other valves. I put everything back together and in testing I couldn't even shift out of first gear. So everything came back out and I did the same procedure to almost all the other valves, removing pins and plugs and such. I checked each valve that was spring loaded after reassembly with my little screwdriver to make sure it moved freely back and forth.
In the solenoid testing the manual states that you can apply battery voltage and hear the solenoids click. Even with the solenoid assembly removed I could only occasionally hear a click, just once, from the 3 valves in the cluster but could always hear it form the line pressure solenoid. I thought it pretty unlikely that all 3 solenoids were bad but found a new replacement (part # 31490-41x13) online from Cobra Transmissions for $140 to my door. The dealer wanted $450 and other online sources were around $320. When I received the new assembly I tested it and, to my dismay, I still got no clicks. The guy at Cobra said that the only test he knew of was checking with an ohmmeter. I did install the new assembly because I didn't want to take this apart a 3rd time. So, the comment here for you is to just get a new solenoid assembly and put it in. The only parts I bought for this job were the solenoids and a new filter, gasket and about 7 quarts of transmission fluid.
The only trick I learned for reassembly into the transmission is how to get the accumulator springs in. The springs sit on a plate on the top of the control valve assembly and there really is no way to balance them there while pushing the assembly into place. I used a ruler to help me. I held the ruler up near the accumulators and put in each successive spring as I moved the ruler along. With the ruler holding all springs up I pushed the control valve assembly up and pulled the ruler out, letting the springs fall where they landed. I installed 1 bolt near the center of the assembly screwing it in by hand only a couple of turns and took a break. I rocked the assembly gently side to side and just assumed the springs centered. I then installed all the rest of the bolts loosely, then tightened them all and put the rest of the hardware back on.
As I drove it initially it seemed like I hadn't accomplished anything because at first it wouldn't shift out of first again. About 100 yards down the road I Dropped the shift lever into 1st and then 2nd and it shifted. When it was supposed to shift to 3rd, at first it seemed to shift back to 1st (or neutral) and I stopped in the road. I started again in drive and eventually it did shift to 3rd and then 4th. I drove around the block and it worked perfectly. After about 6 hours I drove it again and with the engine showing cold it worked perfectly. This morning when it was dead cold it again worked perfectly, no more morning sickness! Not really knowing anything about the innards of the beast I can only assume that my initial startup problems were associated with the many channels inside the control valve not being immediately filled with fluid, just a guess.
In conclusion, if you only have morning sickness and your transmission does work when warm, this procedure will only cost you a few bucks but a bunch of time. All the pictures you need are in the service manual and the only tools you need are a 10mm socket (I needed a 1/4" drive socket to get out the front middle bolts from the pan), a 10mm wrench for a couple of nuts, a flat blade screwdriver for removing a couple of harness clips, a 19mm socket for the drain plug, and some 400 grit sandpaper and various sizes of drill bits (some longer than others). The largest drill bit I used was 3/8". The other thing you will need is a LOT of patience, take lots of breaks but I wouldn't recommend beer breaks with this job. You need to keep your wits about you with this one. Good luck if you undertake it.
Post your results back to this thread please, whether you are successful or not.

[CanuckQx4]

Wish I could picture and pull this off, very helpful, but Im a picture person

[ddz0403]

Wish I could picture and pull this off, very helpful, but Im a picture person

Every picture you need is in the service manual for the transmission. I printed out about 7 pages to help me while I was working on it. I really only needed 2 or 3.

[DAiNiUS]

My QX4 has recently gotten this morning sickness. It was fine one day, and then started acting up the next. At first I was letting the car warm up before driving if it has been sitting for many hours, but that's both inconvenient and does wonders on the already poor MPG numbers. Now I found a "trick" where if you accelerate in first and hold the revs at around 2750 rpm, it shifts more or less smoothly into second after about 3-4 seconds. Then as I drive along for a few minutes it warms up and shifts normally.

I would love to do this fix, but I don't have the time, place, nor the patience required for something like that. Given that this car is old, rusty, and worth $200 according to one dealership, I'll probably ride it out until it dies completely and move on to something else.

Does anyone else here have or has had this issue? If so, how did it start? Did you fix it? Did it die eventually due to this problem and if so how long did it take?

[atraudes]

I had that problem where the first two or three cold 1-2 shifts would flare. I wasn't as brave (stupid?) back then so I just paid a shop $3k to have it rebuilt. I was planning on keeping it for a while so I didn't sweat the cost too much (as much as you can not sweat dropping that much coin on anything).

Another option is to have a used transmission swapped in for half the cost, but you run the risk of it having the same or other problems. You could start with a fluid change and see if that helps. It's worth a shot, especially if it's overdue anyway, right?

Something to keep in mind is that like any car repair, the longer you put it off, the more expensive it'll be at the end. Gears and whathaveyou will wear out at an accelerated rate when it's not operating as designed. Naturally if you're planning on driving it to its final resting place it really doesn't matter...

[DAiNiUS]

It served me fine for the last 6+ years, but at this point it's nearly 18 years old, has 311k kms (~193k mi) on the odo, rusting at an ever-increasing rate, and has water leaking in the passenger side foot well. It's also worth very little on the market. I don't believe it's worth pouring more money into it. There's also the fact that after having driven such a slow car for a good while now, I long for something faster and more luxurious. If it were an easy fix I would probably do it, but now it's probably not worth it. The only question that lingers in my mind is how long it'll live with this issue.