Messed up my transmission: A warning to everybody!

If your truck has the lurch after coming to a stop I would definitely read this.

I’m not an expert and could totally be wrong but I think I figured out what is happening. Sorry this will be a long post.

I bought my 2005 double cab 4x4 (currently 240,000 miles) several years ago. The first time I towed with it it threw p2757 code for torque converter lockup. Only when towing. Did the easy stuff, full fluid swap and all the additives, put in a new solenoid and the in transmission wiring harness. Didn’t fix it. Took it to a transmission shop and they couldn’t get it to duplicate. Basically said don’t tow in overdrive and watch for temps. After several years of heavy towing I’ve been fine. No high temps and no light as long as I keep o/d off. But the code has started to come on during regular driving in the hills. I always thought maybe I have a worn out valve body and need one of those line booster kits to up the pressure……

I thought unrelated, but my truck would also do the lurch after a quick stop. Now I believe they are related. Mine would only lurch when I did a moderately hard/fast stop. Like if I had to stop for a light last second. Then bam it was like I was rear ended. I’ve read on here people say grease your driveline but I don’t think that’s it anymore.

So the other day I was doing about 40 and last second went “oh ya I have to swing in there” I did a fast brake. Nothing crazy, no wheels screeching, just a fast slow down and turn into a parking lot. I came down to maybe 3-5 mph. It was a little up hill into the parking lot so after slowing down I gave it a little gas. Just a little. The engine revved up to about 2,500 as if I was in neutral. I had just enough time to look down and go “what the?”….BAAMMM!!!! It slammed in to gear and roasted my back tires. I basically did a 2,500 rpm drop into gear.

ok…..that was weird. After stopping I got back in my truck, pulled out on the road……second gear was gone. Just gone. I could drop it into first, speed way up and skip into third. But no second. Crap. It also threw the code for “shift solenoid D”. Later that day it actually came back and now drives fine but I’m done. New transmission time.

Now for my theory. After this happened I drove around doing hard stops to see what I could learn (transmissions already toast, why not) whenever I did a really hard brake the engine rpm would go really low. Like sub 500. Then kinda rev back up then the lurch. If I did a normal stop the rpm’s would not get as low, and no lurch. I think when I do a quick stop the transmission can’t get into first gear quick enough. Since it’s still in second by the time I come to a stop or nearly a stop, the rpm’s drop so low that it looses line pressure. This was probably amplified by my already low line pressure from a worn out valve body. When it looses line pressure it essentially falls out of gear. At the same time the engine revs up a little and then the line pressure spikes. And instead of a smooth shift into gear it slams back into gear causing the lurch. I think further poof of this is that I lost second gear. Not first. So when I came to nearly a complete stop I was in second gear. And that’s the gear that got toasted when I revved the engine up an it smacked back into gear. Again, not an expert, just my theory.

So if your truck does the lurch. Watch out for this situation! Edit: my truck has the A750

 

Ok part 2. Need some advice. A while ago I bought a transmission off Craigslist. Guy said it had 120,000, ran fine but truck was totaled. I figured good idea to have a spare. I was planning on putting it in next week. However the guy I got it from…..little bit of a sketchy vibe if you know what I mean. It’s all together and looks fine but…..
I looked at new transmissions and I just don’t have that money right now. Looks like they are 2,500-3,500. ( I can do the work in my dads shop and have changed out transmissions before) I was wondering if anyone had experience with having one rebuilt. I live in Auburn CA so a local place would be preferred, but I’m open to options. And how much? I have the spare sitting there so I can drop it off. The truck actually drives fine right now (and I can borrow a car short term if needed) if it’s in the $1,000-1,500 ballpark I can work a little extra and have that in about a month. Anyone have experience doing this?

 

Sorry, don't live in CA, but you need to call the transmission shops in your area. You'll have a more accurate picture of what it will cost for rebuilding your transmission along with warranty. If your dad has a vehicle mechanic shop, he should have heard who has a good reputation with rebuilding transmissions in your area.

 

That’s the plan. Looked up several and are going to start calling. Just wondering if anyone has first hand experience doing this. And my dads “shop” is just his personal garage with tons of tools. Not a commercial shop or anything.

 

The lurch you originally felt likely is just a dry slip joint on the driveshaft. The transmission failing like it did probably is the result of towing and valve body wear.the a750 is known for valve body erosion but other than that is a pretty solid trans. The 120k unit should be fine. Just check the harness (they love to corrode) install a larger transmission cooler to help keep the temps down on the new one as well.
Generally OD is fine to tow with UNLESS the transmission keeps hunting for gears. It’s when the converter is out of lockup that it builds a ton of heat. Heat kills the fluid which in turn starts wearing the transmission

 

For the cost of a reman the other option is a new reman from Toyota. The core charge is high. But cost vs a other company reman is usually similar.

 

https://parts.toyota.com/p/Toyota_2...matic-Transmission/69297212/350100C03084.html

 

The core charge is meant to be high. There are many reusable parts in most transmissions. They would exceed the 1k in parts value I'd bet, or the core charge would be less.

 

Oh for sure. It just scares people

 

Noticed Toyota is no longer supplying some 1st gen remanufactured transmissions, and would buy one before they stop offering mine. But I don't have a clue with how long the seals would last (not dry up) in one that's safely stored in a garage. Any ideas??

 

Iv been having this same issue. At red lights the rpm’s stay high and I have to take my foot off the brake and brake again. Or you can hear it still winding up like something is still spinning. I’m at 191k

 

I get this lurch sometimes as well. Should I lube the zerk fittings along the driveshaft? And if so, when I have done this in the past, some fittings just will not accept the grease. Maybe dirt or something? How would I deal with that if it comes up? Thanks.

 

My daughters 2004 V8 4Runner had somewhat of a similar item happen. After a hard stop, it went into limp mode and pulled code P2714. I took it to the transmission shop and the codes were cleared and the thing drove just fine. We are watching it now but nothing unusual has happened since then. It has 200,000 miles on it. They told us not even to replace a fluid for 500 miles just to see what happens.

 

This doesn't apply to the cause of the OP, but for some of the other guys that have a lurch, when I had my 1st gen I had this issue and it turned out to be a dirty throttle body. There was enough build up that it wouldn't close all the way coming to a stop and idle high causing what felt like a surge/lurch. Something to check out.

 

That's actually not as bad as I thought. I can get as low as $2600 locally, with $1000 core. $1600 OTD on OEM reman is really not that bad for a new trans.

 

I grease up my whole driveline every oil change so in my case I don’t believe it’s a dry slip joint. I’ll bite on maybe a dirty throttle body. Maybe mine caused a too low of idle and that combined with a heavy stop caused a too low of rpm situation and fall out of gear.

I don’t think my trans had a sudden change that caused the failure. I think it’s been primed for this for a long time. I just haven’t had a sudden stop followed by an application of gas.

I would gladly pay 1,600 for a reman but when I look at the Toyota website they add the core charge at checkout, so still almost 3,000. Wish I had the money for that but don’t right now. I’m going to call a couple shops and see what they have to say.

 

Ah, I was reading it as $2,600 at checkout, including the core. Then you get the $1k back on the backside, bringing it to $1,600.

I have multiple dealerships near me. Price is variable. Some are charging full MSRP, others giving 15% off.

 

That price does not included

 

Isn't it $2600 PLUS $1000 core, and then you get you $1000 back when you turn it in?

 

Well that was quick. Called JRs transmission in Auburn. Nice guy who took 10 minutes to answer all my questions. Basically said a rebuild on our a750s would be about 3,000. Said on these 5/6 speeds the valve bodies are much more complicated and he has to use a local guy for them. Valve body alone is like 1,000. Asked about just looking through it and he said as you tear it apart you ruin seals and basically have to rebuild it. I also brought up whether to just put on a new torque converter and he said no, he has more problems with aftermarket ones than the originals. He said open the pan, check for debris, new filter, flush all the fluid out of my lines and run it. I always get a good feeling when a shop talks you OUT of spending money. Trans swap starts tomorrow!

 

I live in Auburn too, I usually do my own wrenching, but if i do have to pay someone, it’s always Strictly Toyonda’s, up behind Placer High school. Good people, excellent work.

 

This was going to be my suggestion, as I read through your thread. If I'm given a choice between a shop rebuild or a used one that was working properly when put out of service, I'm going the used OEM one. Ton's of examples these transmissions can go a ton of miles with no problems. I don't trust a shop to rebuild and come close to the build quality and service life they did from the factory. Same goes for our engines. I'll take a good running 200k mile one over a rebuild.

 

SUCCESS!!! New (to me) transmission in and it runs awesome. I can tell a big difference. It’s shifts much faster and I would say crisper. My old one would almost be a little lazy on down shifting. This one is smoother. No codes or any real trouble. Also did a hard stop and did not get the lurch. So that’s exciting. I think it was definitely the trans.

New trans is suppose to have 120,000 on it. My truck has 240,000 but I’m not sure if my old transmission was original. The torque converter was bright baby blue and didn’t have that hi quality Toyota look to it. And it had paint pen writing on the top of the trans that looked like junkyard scribbles. Oh well it’s out now.

There are great videos on changing a trans and I just followed that. The only thing I had to come up with was how to do the top two bolts on the bell housing. In the video I watched he lowered the back of the trans to access those bolts. My exhaust wouldn’t let it go low enough. But rather than break the exhaust loose I just un bolted a couple exhaust brackets from the frame and that allowed it to drop. Then I could get the top two bolts. Also deep creep penetrating oil is a life saver. I found it also works awesome on old rubber hoses that don’t want to come off. A drip of that stuff and they come loose and twist off!

Thanks everyone for the help/advice.

 

Hey Guys great resource here . My 06AC 4x did the same as norcalyotaman. Saw some good videos on y tube. Most reference a bipass to drain all AT fluids. My truck doesn’t seem to have that. I see the hoses all the way to the radiator and cooler then back to the transmission. Top hose goes to cooler. Bottom line goes to the radiator. I think if I can figure the direction of the fluid I can pull one of the hoses after the cooler. I’ll post pictures from my laptop in a few minutes.

 

Hey @shifty` Im newer here. I have seen you hit up in a bunch of posts. you seem to be a person of immense knowledge. Any help or direction would be truly appreciated.

 

Not following - what are you looking to do?

'05-'06 have a sealed transmission. Are you looking to drain, fill, flush, or what?

 

I think maybe post 24 might be of interest

 

I might be dumb, maybe it's the meds or the fact I may be dying right now, but I'm not following. Is it just a question of what direction the fluid is going? Or did he take his lines off and can't figure out which goes to which? That's kinda where I'm lost here.

It's also my understanding these circled connections are where the trans passes fluid through the radiator for cooling; when these seals go out, this is how folks end up with pink milkshake and dead transmissions from not changing out their radiator. I'm not sure what the red-marked line is, though, unless OP has the extra trans cooler w/tow pkg in front, smaller finned in front of the radiator/condensor, and that's bypassing up to that cooler:

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That I don't know, just wasn't sure you saw the original post. Good luck and I wish you a good recovery!