Transmission stuck in drive no matter where the shift lever is positioned (1 Viewer)

[BBlaze]

Ok so my first post here is a doosey. Long time shade tree mechanic with several engine rebuilds (stripped to the block, rebuilt) under my belt so I am brave enough to probably get into trouble sometimes. Have a new to me 2000 LC100 with the A340F family transmission. Was throwing code P1760 which is the SLT solenoid in the transmission. Spent the weekend dropping the pan AND the valve body, replacing the solenoid and putting everything back together. I'm 99% certain, because I double checked them, that I reconnected each solenoid electrical connector and reseated the shifter lever onto the quarter circle gear teeth.

Pan back on and all back together with fresh fluid, fired it up and it seems to be stuck in a forward gear (started that way) regardless of moving through the gears with the shift lever. There is no park now, it's just in drive. It will start fine but you can tell it starts in gear. The only thing I can think of is that I didn't fully get the shift lever mechanism mounted on the valve body (pictured below) fully seated back into the gearing mounted inside the transmission. I know I checked this, but I could have bumped it. That said, maybe I forgot a connector somewhere and I'm just old and forgetful. The picture is from before I removed the valve body. I didn't snap after I reinstalled it as I was ready to have it back together and covered in ATF, but I wish I would have.

So, for you experts out there who have been inside your transmission, any thoughts or ideas? Am I overlooking something simple? Hope to hear I did before dropping the pan again only to find out that what I think it is is not the issue.

Much appreciate the help. As I learn these vehicles (first one for me, had 3 4runners in the past) I hope to pass on what I learn to others.

 

[2001LC]

Have you tried having someone shift, while you watch mechanical shift arm very closely. If that works as it should, including seeing the stud at neutral lock off switch turn. I'd pull pan again, and re-due.

 

[BBlaze]

Thanks 2001LC. I did part of that myself last night to confirm the mechanical shift arm still moved as it is supposed to, but I didn't watch for the neutral lock off switch. Thank you for the suggestion. I will try that, then if all is working, will pull the pan again. At least, after taking my time the first go round, it will be much faster this time, and the FIPG likely won't have turned to concrete yet!

 

[2001LC]

I've been meaning to buy me and FIPG tool. To replace my handmade one (bent knife). Un-sealing is a PITA.

 

[BBlaze]

Nice homemade one - I like it. I have a few different things laying around that I used, but reverted to a longer pry bar in the end as it just wouldn't budge. Bent the lip of the pan a little but it straightened out fine with a little work around the bench vise (just for straight line bracing). There's not much room around most of the pan so yeah, not the most fun thing, but patience certainly pays off. And some old clothes you don't care to get ATF all over. That valve body is like a weeping wound. It dripped all night and into the next day. Think it might still be dripping if the pan were off already.

 

[flintknapper]

Easiest way to get the pan off an A343F trans *with FIPG* is to start on the drivers side rear corner of the pan. Use a 'stout' painters scraper. That corner of the pan is the ONLY place that allows enough room to place the scraper and use a small hammer to tap it along. You will go parallel with the long side of the pan *back to front*. This will cut the old FIPG and the wedging effect provides a place for you to get a small pry bar/tool under that side of the pan for further removal once you've gone the entire length.

Traditionally, folks go around the perimeter of the pan with a 'cutting tool' of some sort...and that is how I did my first one. But its tedious work and unnecessary IMO. MUCH easier to loosen one side....then pry it off, no damage to pan or mounting surface of the trans.

 

[flintknapper]

Can you elaborate on the initial issue with your trans? What prompted the repair *solenoid* replacement to begin with?

Did you have shifting issues and subsequently found the DTC P1760? That solenoid responds to the Primary Regulator Valve which modulates line pressure....is the reason I ask. Did you have erratic shifting or a CEL show up?

 

[BBlaze]

Great question, and I should have included that. So, to start it's my wife's DD, so I don't drive it often and she's not attuned to small drivability changes/differences. She told me about the CEL before leaving for work, so didn't drive it once it appeared. I ran a scan and it only reported P1760. After searching here and elsewhere (very little info anywhere on this, seems rare for the A340F and variants to have this problem) I found one report that shifting between any of the gears will be a little more rough and abrupt, and in test driving it that's exactly what I experienced. It would still shift through the gears fine, but each shift was more immediate and noticeable whereas normal shifts are, to me, barely perceptible. I've only had the truck for 2 months (our first LC). The few other reports of the issue got the recommendation to replace the transmission, which is not my style, so decided to dig in and replace the solenoid to see if it solved the issue.

Notably, when testing after the replacement and finding what appears to be the shift linkage no longer being connected inside the transmission, the computer still reports the P1760 issue. I'm guessing it may be frayed wiring going from the ECU to the transmission, but it could certainly be something else. I'm interested in any thoughts anyone has on other causes since I don't think the replacement (OEM part) will fix the CEL or harder shifting issue.

 

[flintknapper]

Great question, and I should have included that. So, to start it's my wife's DD, so I don't drive it often and she's not attuned to small drivability changes/differences. She told me about the CEL before leaving for work, so didn't drive it once it appeared. I ran a scan and it only reported P1760. After searching here and elsewhere (very little info anywhere on this, seems rare for the A340F and variants to have this problem) I found one report that shifting between any of the gears will be a little more rough and abrupt, and in test driving it that's exactly what I experienced. It would still shift through the gears fine, but each shift was more immediate and noticeable whereas normal shifts are, to me, barely perceptible. I've only had the truck for 2 months (our first LC). The few other reports of the issue got the recommendation to replace the transmission, which is not my style, so decided to dig in and replace the solenoid to see if it solved the issue.

Notably, when testing after the replacement and finding what appears to be the shift linkage no longer being connected inside the transmission, the computer still reports the P1760 issue. I'm guessing it may be frayed wiring going from the ECU to the transmission, but it could certainly be something else. I'm interested in any thoughts anyone has on other causes since I don't think the replacement (OEM part) will fix the CEL or harder shifting issue.

Thanks for the added info, it is helpful.

I agree that checking the harness and connections would be a good place to start checking things off.

When replacing the valve body were you careful to get all the bolts back in their proper places? A few of them are longer IIRC.

Also did you actually 'torque' them to spec? If the valve body gets 'tweaked' in the least...it can cause binding of the valves.

I expect the issue will end up being something simple/overlooked....but can result in a lot of work chasing down.

 

[BBlaze]

Hi flintknapper - yeah the differing length bolts had me initially hesitating, but after finding the proper section of the FSM and the specific bolts to remove, I dove in. Interestingly, I'm 95% certain this is not the first time the valve body has been removed as the FSM shows 2 bolt lengths (.91 inches and 1.26 inches) but I found three. I believe the person who previously removed it got the bolts mixed with others (or lost some) and replaced with what he had on hand. That led me to follow as closely as I could the lengths listed in the FSM, but I did have 3 that were 1.4 inches, so finding a home for them was trial and error (where they wouldn't bottom out). It took me about an hour to sort through it when reinstalling, but I believe I did as good as or better than how I found it.

As far as proper torque, I don't have a torque wrench that goes as light as is called for (65 in-lbs I believe) so I carefully did it by feel. That said, your comment is really insightful and when I go back in today I will get a proper torque wrench (have three, all do the same) and re-torque them to spec.

One other thing that's a possible mistake on my part, that maybe you all can guide me on. When I removed the valve body, what I believe is the "check ball" feel out as well as two of the 5 springs. The check ball I'm 90% sure goes where I replaced it as the ball surface fits into a depression in the valve body and the transmission has a slot for it to fit into. The springs however were a best guess on my part where they needed to go and how. There was only one spot on the front driver's side where a spring could have been inserted behind the throttle body, and there were two springs, one small, and one large. I caught a brief glimpse of them when they fell out initially and felt they could have been concentric - one inside the other - so that's how I placed them when reinstalling the valve body. I could have this totally wrong, but that's the only thing I could logically come up with and nothing on it was mentioned in the FSM (at least that I found). Any isight here would be greatly appreciated.

So, I will drop the pan this afternoon, check the mechanical gear lever and all electrical connections, re-torque the bolts and, if guided here, put the springs and check ball back in their proper homes. Thanks again for the insights. You guys are awesome!

 

[BBlaze]

I just found this writeup on TacomaWorld and it is fantastic.

TransGo Valve Body Shift Kit Install Writeup with Pictures

Believe I reinstalled the B-0 springs and drain check valve correctly, so likely just the shifter linkage didn't get seated properly. I'm hopeful that's what I find this afternoon. Will report back what I find so others can learn from my mistakes .

 

[2001LC]

Good luck today and take your time.

Also I found it best to let pan drain overnight, getting as much a 7 qts. Less mess that way.

BTW: When I've hard shifting, even some codes (CEL or not). I've often found someone recently did a drain and fill, an under or over filled. Very likely they used the wrong transmission fluid, like a T-IV or WS. First thing I do is a full 12 qt flush, with Mobil 1 full synthetic MV ATF (in 98-2002). Then see if condition improves, which usually does!

 

[flintknapper]

I just found this writeup on TacomaWorld and it is fantastic.

TransGo Valve Body Shift Kit Install Writeup with Pictures

Believe I reinstalled the B-0 springs and drain check valve correctly, so likely just the shifter linkage didn't get seated properly. I'm hopeful that's what I find this afternoon. Will report back what I find so others can learn from my mistakes .

Check ball and springs would be critical to have correctly placed....no doubt about that.

I wish I could help more. I have the repair manual for the A343F trans...but it has no info about the Valve Body with respect to where springs and check balls are to be situated.

 

[BBlaze]

Check ball and springs would be critical to have correctly placed....no doubt about that.

I wish I could help more. I have the repair manual for the A343F trans...but it has no info about the Valve Body with respect to where springs and check balls are to be situated.

Good luck today and take your time.

Also I found it best to let pan drain overnight, getting as much a 7 qts. Less mess that way.

BTW: When I've hard shifting, even some codes (CEL or not). I've often found someone recently did a drain and fill, an under or over filled. Very likely they used the wrong transmission fluid, like a T-IV or WS. First thing I do is a full 12 qt flush, with Mobil 1 full synthetic MV ATF (in 98-2002). Then see if condition improves, which usually does!

Thanks fellas. Will be taking my time and double check everything. I did let the pan drain overnight so hopefully that minimizes some of the fluid left in the pan. I'll get wet anyway, but I'm ok with that. Will definitely do a complete flush right when I'm done.

 

[BBlaze]

Well no luck. I did find I reinstalled the tube by the filter in the wrong location, but re-torqued all the bolts to 65in/lb and made sure all the solenoid connectors were seated firmly but it still is just stuck in a forward gear (seems like L2). I verified that the shifter does in fact rotate the shift gear on the inside of the housing properly, but the shifter has no effect on the transmission, it just stays in the same gear. I believe there is something I am missing on the valve body. I've watched several youtube vids removing and disassembling it (I didn't do that) and I think I did everything necessary. If anyone has any other ideas I'd appreciate it. Otherwise, I might have to give up and find somewhere to take it. Thanks for the help so far.

 

[SNLC]

Easiest way to get the pan off an A343F trans *with FIPG* is to start on the drivers side rear corner of the pan. Use a 'stout' painters scraper. That corner of the pan is the ONLY place that allows enough room to place the scraper and use a small hammer to tap it along. You will go parallel with the long side of the pan *back to front*. This will cut the old FIPG and the wedging effect provides a place for you to get a small pry bar/tool under that side of the pan for further removal once you've gone the entire length.

Traditionally, folks go around the perimeter of the pan with a 'cutting tool' of some sort...and that is how I did my first one. But its tedious work and unnecessary IMO. MUCH easier to loosen one side....then pry it off, no damage to pan or mounting surface of the trans.

View attachment 2717108

This actually works better than the SST which has a tendency to scar up the mating surfaces.

Cheers

 

[flintknapper]

This actually works better than the SST which has a tendency to scar up the mating surfaces.

Cheers

It didn't take me but just a couple of minutes to tap the scraper completely down the length of the drivers side pan. Then its a simple matter to pry the pan off. I've done it before....but even a first timer should have no problem. No scratches or gouges at all.

Then be sure to get your mating surfaces CLEAN before reinstalling the pan.