93 Previa 2 TZFE / A46DE transmission problem

Hello all,
I believe my transmission is failing and going to die soon.I have been limping it along for the last 15,000 miles. This is my wife’s dailydriver. The good news is we have two other TVW’S an 86 and 89 to get us by. Some history, the van has had transmission issues since I obtained it. It is very sloppy/clunky when underway. The initial color condition of the fluid when I inspected it was like espresso. I know this is not good. I have done a complete flush and fill with new filter. This kept the van operating fairly well for some time. The fluid does continue to burn /discolor. The transmission now likes to switch in and out of overdrive while doing anything over 40mph. The condition is, drive/overdrive 1 second on, 1 second off and a not so fuzzy feeling about getting from point A to point B. When it’s driven with the overdrive turned off, it operates fairlywell, no slipping, still sloppy/clunky. I did pick up a replacement trans from the scrap yard a while back and was waiting for a failure before attempting the swap. I am a fairly skilled home mechanic and have done just about everything besides a complete engine swap or trans swap. Is there any threads that show the process of removing this trans and successfully swapping a replacement in?I have read the generic instructions and it all seems pretty straight forward.I understand that the engine and trans will have to be disconnected from there mounts in order to be lowered enough to access the upper trans housing fasteners.Does the SAD shaft have to be removed or can it stay in place? I hope I do not have to remove it, I have replaced the SAD bushings two times already and do not enjoy messing with this part of the Previa. Any tips or tricks that can be shared will be much appreciated as I will be doing this job solo, laying on theg round.

Thank you,
Blake

In the spirit of sharing info, I am replying to this threadwith an update. I was able to swap the transmissions without much difficulty.The SAD bushings do not have to be removed and I was able to get to the top most Bell Housing bolts without removing the engine mounts or lowering the transmission. I utilized all of my ratchet extensions, a ratchet swivel and I believe the socket was a 17mm? The bell housing has channels molded into it, using these as a guide I was able to engage my ratchet. The bad news is the salvage yard transmission was worse than the one I took out. I gambled and lost. I decided to open my wallet and buy a new/rebuilt transmission from mylocal parts store. 1500.00 plus tax with a new/rebuilt torque converter and 3year warranty and all avail updates. It should be at the store on 01/23/17. Iwill update my progress once I install the new one. I learned a few tips and tricks while working on this task. This was a lay on the ground driveway job.If anybody has any questions or needs some problem solving tips, let me know.One of my insights while working on these Toyota Van's is that, ratchet straps may be one of the best inventions and problem solving tools of all time. There not for just strapping things down, when used against manufactures recommendations, they lift, pull, align and help out the lone mechanic in a myriad of ways.

Best regards,

Blake

Hey! I am about to swap out my engine and transmission also! Where did you connect the straps to on the van? How did you lower the transmission? This would help me tremendously!

Hello,

I did not take any pictures and did not have any reason to remove the engine mounts, so I left that area alone. In the area above and around the transmission on the uni-body of the van you will see several holes.You can manipulate your strap hooks to fit into those holes. Also removing the driver seat access panel and running a strap up through this area opens up more rigging options. I utilized the straps to help raise up the replacement transmission orient it to the flex plate and to keep it from falling off the jack, I basically only used the jack to make small adjustments up and down. I had acheap 1 ton jack that was laying around and I removed the metal saddle pad (thepart that comes into contact with the vehicle) and used a carriage bolt, washer,lock washer, and nut to attach a small piece of ply wood to the jack. Obviously I installed it with the threads facing downwards and tightened it until it countersank into the plywood, so as not to dent or damage the drain pan. The size of the ply wood is approx. 10” x 8” and I placed the transmission on this utilizing the square drain pan area as the load bearing surface. When removing thetransmission, I utilized the vans service manual and followed the instructions, most automatic transmissions follow the same basic process. The ratchet straps are harder to utilize for removal and lowering. The best bet is to use the retrofitted jack and to strap the transmission to the plywood. Just be careful because this will create a top heavy situation and you don’t want the Trans to tip over and cause you injury or damage the dipstick tube, transmission send/return lines and sensors….etc.
In my experience removal was slightly easier than replacement. I had never done this before on any vehicle and glad that I attempted it, because it’s really not all that difficult, just time consuming. If you take it slow and steady you should have no problem. So far I have taken the bad one out, only to put a bad one back in and now taken that one out. My next move is to put a new/guaranteed one back in. Hopefully it will be delivered early next week and in by the weekend? I know there is a good write up on this forum regarding working in this area. See: http://www.toyotavantech.com/forum/s...engine-removal
Best regards,
Blake