Transaxle oil testing results

[orange4boy]

What size is the transaxle drain plug? Just to make sure I have that socket. I will try to drain the thing to look for chunks and possibly to get it tested.

[bwilson4web]

Originally Posted by orange4boy

What size is the transaxle drain plug? Just to make sure I have that socket. I will try to drain the thing to look for chunks and possibly to get it tested.

This may help:

2003 Prius - Cold Weather and Transaxle

Ask the seller for the codes. I can look them up.

If the car moves at all, see if there is speed proportional hum that does not go away if you roll in "N." That is the signature of a failed MG2, the most frequent problem.

The gears are nearly indestructible. What I'd recommend is opening the 'filler' hole and sticking a finger in to get a sample. If it smells burnt ... not good but not fatal. The real test is rolling the car in "N" and hearing the 'hum.'

Can the car move on it's own? If not sure, turn it on and off three times and see if the error lights go out. Then put it in gear and see if it moves.

Bob Wilson

[orange4boy]

The car is mobile. I think it was driven to the garage. I will see if i can do a coasting test. How fast do you need to be going to hear the hum? I'm wondering if this can be done in the parking lot.

Is there any point in checking the battery voltage. The seller claims it's fine as far as he knows. He works for the co-op that is selling it. I trust that his info is good because for that price they are just trying to cut their losses and he has no personal interest in the sale other than getting it out of his hair.

Your site is a wealth of info and fascinating. Nice work.

I think we will buy it. At $1500, we could part it out and not loose our shirts if it goes sideways.

[bwilson4web]

What happens is if MG2 burns out some windings, they become a permanent, short. So as the car moves, MG2 steals energy from the rotor and being a dead short, it causes a speed dependent 'hum.' I've never heard it but a couple of transaxle failures have confirmed it as the 'kiss of death.' Needless to say, the heat builds up in the transaxle and things only go down hill.

At $1,500, it sounds like a fair price for a 'fixer upper' and if you have a nice place to work on it, a lot of fun. You may be able to figure out how to remove the transaxle w/o taking out the engine but that is going to be one heavy piece of metal. Work SAFE!

Art's Automotive mentioned having trouble getting the 'shims' to rebuild the transaxle properly. It may be better now but there is no guarantee.

We had one person in California report swapping in two salvage transaxles and having them both go bad (check the "Prius Technical Stuff" message archives.) But that was just one report.

My thinking is try 'cheap' and you might get lucky. If not, you can always get a new one from Toyota and put it in yourself.

One caution, don't ignore the 12 VDC battery. In that old of a car, they do wear out. Just be prepared. Also, you may want to try and put a 'forced charge' on the traction battery before removing the transaxle.

A forced charge is holding the brake (or leaving it in "park") and flooring the accelerator. The engine turns MG1 and puts a charge on the traction battery until it is fully charged ... then the engine shuts off by itself. This just leaves your traction battery in a nice, fully charged state. Since MG2 is not turning, it should work just fine.

Do get the Toyota manuals, often available on Ebay. Volume 2 is critical, Volume 1 has more diagnostic info.

Bob Wilson

[orange4boy]

We took a look at it and put down a deposit today. We might tow it home tomorrow if we can find a tow bar. I think your idea of permanent tow bar mounts is a good one. We can always rescue it with the van and avoid towing charges. Luckily it's just below the max tow capacity of the Previa.

I couldn't get it running but possibly because the lead acid was dead. The screen had a grey PS icon, grey battery icon and a red car icon on it. I hope the main battery revives. It was sitting for about a month. He said the only code it threw was the P3120. It was driven to the dealer for a diagnosis but when they were done with it, it wouldn't start again. He was pretty peeved at the dealer. I hope it will start if I clear the codes so I can charge the traction batt.

Thanks for your help so far. I'm sure I'll be bugging you again soon. I'll start a revival thread for it somewhere here or at Prius Chat.

Thread hijack complete, sir.

[bwilson4web]

Originally Posted by orange4boy

We took a look at it and put down a deposit today. We might tow it home tomorrow if we can find a tow bar. I think your idea of permanent tow bar mounts is a good one. We can always rescue it with the van and avoid towing charges. Luckily it's just below the max tow capacity of the Previa.

In the trunk on the right-hand side is a space that holds the 'tow eyelet.' It screws into the front and using two drivers, a rope, and keeping the speeds low, you can get it home.

Over in "Prius Technical Stuff," one of the members rigged some heavy gauge, angle-iron and a ball-hitch that bolted together for 'slow speed', limited distance towing. Check the message archives for the photos.

The 'recommended' towing practice is to put it on a flat trailer and tow the trailer. The problem with the front wheel dolly is the angle is too steep at the rear and grinding the tail pipe.

My setup is for 'dingy' towing but that is another story.

Originally Posted by orange4boy

I couldn't get it running but possibly because the lead acid was dead. The screen had a grey PS icon, grey battery icon and a red car icon on it. I hope the main battery revives. It was sitting for about a month. He said the only code it threw was the P3120. It was driven to the dealer for a diagnosis but when they were done with it, it wouldn't start again. He was pretty peeved at the dealer. I hope it will start if I clear the codes so I can charge the traction batt.

Thanks for your help so far. I'm sure I'll be bugging you again soon. I'll start a revival thread for it somewhere here or at Prius Chat.

I would recommend trying the Yahoo Group, "Prius Technical Stuff." IMHO, those are the Prius 'brain trust.' PriusChat is good but sometimes a little ... noisy. Something about a text based interface that seems to 'cull the heard' if you know what I mean. <grins>

BTW, be friends to EcoModder and share your progress here. One of the things I admire are the large ratio of fact-based, experimenters. Sharing your rebuild project progress helps folks understand the Prius is different but not that different.

Bob Wilson