Automatic trans slipping/no overdrive

New to the forum! I don't have the history of my truck but have had the head replaced a few years ago and other than that have not had major issues. The recent history of my vehicle is complicated and I may not be the best story teller, but here it goes... Had my 2WD 2002 Automatic diagnosed with a transmission failure. This was at a tire and lube shop. Funny thing is my car started driving odd after a simple oil change and battery replacement from them- bogging down/not changing gears over 40mph or so. But it didn't happen on the way home, it was after a week or two. I live a small town with 30mph speed limit and don't leave often enough to detect issues that might be revealed at higher speeds, such as the current transmission issue. I returned to this shop because I had a CEL on that I wanted a second opinion of. A previous shop said it was a faulty Cat but wouldn't cause any issues if left as is. I thought this might be causing some issues. The oil change location diagnosed the bad Cat and also said I needed a new transmission. I was suspect because they didn't drive it off the lot and they said with the age of my vehicle with over 200k mi, I might want a new car. Do I really need a new car? These vehicles can last much longer though, right? I love my little old Tacoma and can't imagine losing it.

Took my truck back home and to a local mechanic who discovered a very well established rodent nest occupying the air filter cavity (wasn't checked at time of oil change I guess). He thought air filter, trans filter, fuel filter replacement and 1qt trans fluid replaced (had never been changed as far as I know) would help fix slipping gear. It has not changed. This is as far as the local shop is willing to dive into the issue. I will have to tow it out of town to a Trans shop or a Toyo dealer and either way I am worried of being taken advantage of as a female car owner. I am learning the language of auto repair and transmission issues from the great threads within this forum!! I feel very well informed but also very much up a creek with no paddle.

So far I have gathered from the great members of this forum that there are several avenues to trouble shoot before going full transmission overhaul. How do I communicate to the next service technician to check all possible issues? Do you think all of these should be examined? : sticking shift solenoid, dirty 02 sensor, spark plugs, MAF sensor, torque converter, electrical issues from rodent damage (wiring, PCM, ECU)?

Whew!!

 

Verify that the small ground cable off the negative battery post is there and attached to the inner fender.

When the battery was replaced the PCM was reset and she is going through her learning process, does this explain all of the new symptoms, no.

 

I will take a look at the battery. Thanks.

 

On mine there's kick down cable from the throttle body to transmission...

and that is how mine shifts ......if that cable is moved or in a bind in anyway..
then mine has all kinds of delayed shifting problems....

even when I moved it a couple inches from the exhaust headers....the tranny threw a fit...

I had to insulate jacket that cable and moved it back close to the headers.....ugh..

You have to be super careful with that cable...because it can stick or bind right where it goes into tranny.......I've had a couple oh..sheet moments trying to gently unstick that....sweating bullets...

 

Good work leaning in and doing your own research, as well as describing what work you've had done and the issues at hand. You should add what engine (2.4, 2.7, or 3.4) and lug count (5 or 6 lug) to your post so others here can properly give you advice, as it may differ.

I would first suggest looking through some of the regional sub forums and try to find some recommendations for a local (ish) shop you to that other members can vouch for. The biggest hurdle I hear in your story, is that you're getting advice from more than one source, which is good, but it also sounds like they are conflicting.

It's hard to say if 200k warrants a new vehicle for you or not... Those issues don't add up to a new truck for me, but I can fix all those issues myself and I have a rust free frame, which isn't the case for everyone. One thing going for you though, is that it doesn't sound like you routinely drive long distances and wouldn't be far from home if something went wrong, and left you on the side of the road.

I would try to address the transmission and catalytic converter issues independently- as they really should not affect one another.

I don't know about all the variations of the auto transmissions, but 1qt of fluid is not enough to drop the pan to change out the filter. I also wouldn't replace the filter until a few drain and fill cycles have been done- you'd want to get rid of as much of the existing fluid from the system as possible before putting a new filter in.

 

As these trannys get into real old age....that Over drive off solenoid can stick as it gets real old...

So I recommend never touching that OD off button......so it doesnt stick in the off position....thereby loosing your top gear...

on mine that solenoid is discontinued.....and over $400 for a salvage one...

mines a commuter....so thats not a burden to me..


You might state where your close to and engine size......may be some of these guys are close to you..........and almost all us distrust professional mechanics
biggest group of idiots and/or thieves....

Unfortunately, because of that kickdown cable....its super easy for a mechanic to savatage it and hit you with a bogus repair bill.....or even worse.....offer you $500 to take your piece of junk off your hands....doing you a big FAVOR....
a bunch of them are always looking for an easy MARK......sad but true..


The trannies in the simple RWD's can and have last well past the 300K mark....
in fact...its pretty common...mines just coming up on 200K....works fine...
especially since I never engage the OverDrive off.....

 

OP you mentioned a CE lite
what was the OBD2 code?

 

One of my tacomas has 322k with original auto trans, my other has 318k ......about 7 years ago the trans started slipping and i drove it that way for a couple weeks , my buddy runs an advanced auto and said do the Lucas trans stop slip. So i bought a hand pump from harbor frieght 5.99 and measured what i sucked through the dip stick tube then added the Lucas to replenish. Totally solved the problem , I swear by that stuff , Lucas has some great products.

That truck is still rollin down the road slip free

 

I appreciate so much all the feedback regarding this issue. You have given me some gems to look into. I don't know how to respond in line to each reply yet. A slow learner here. HA

@ O'Silver the kickdown cable is something I will look into for sure. From the stress you experienced in adjusting yours, I know to take xtra care and caution.
I am on South Coast of Oregon on HWY 101. Thankful I have AAA for hauling the vehicle to neighboring towns.

@ControlCar One of the codes was P0420 and I'm blanking on the other code!

 

@Bob12321 How great the Lucas potion worked for you! I was wondering if, as in my vehicle, the transmission fluid is too high, how much would I have to remove to make room for the additive? Do I remove tran fluid a little bit at a time and check in between drains?

@Andy01DblCabTacoma Thank you for the insight! I checked transmission fluid levels after seeing your post and darn it, it is overfilled. The auto mechanic said I should be able to drive around town and be okay for a while but if the fluid is high, will this compound the stress already placed on the transmission?

 

So hopefully if the shop added fluid they didnt overfill. You should check the fluid level on level ground with a hot transmission.

Just use as measuring cup to pump the old fluid into. Then replace what you take out. The lucas bottle will have a measure of fluid on side of bottle. I would pump out half a quart.

Lucas stop slip is very thick use the measuring indicator on the side of the bottle to get close to the 1/2 quart you took out. Just pour it down the dip stick tube checking you level frequently to not go over the full line.

 

Someone didn't happen to accidentally add oil to the transmission during that last change and then try to hide their screw up did they?

 

Just remember this is a patch for the slipping transmission, ive been lucky beyond belief on this 96 tacoma . What worked for me may not work for you, theres alot of variables. And like you said you drive in town which is good , my 96 is my work truck I drive it on city streets to work I have been at hiway speeds and have not had any problems , but I also baby this truck because of the once slipping transmission. I have 3 tacomas and if i need to do an outta town trip I always use the others.

And i keep a very strick maintenance on all my trucks and drain transmission fluid when the time comes. I always add some Lucas to my new change on my old tacomas. And I always use toyota transmission fluid, which is very expensive

Good luck

 

Before you put anything else in the transmission, I would get a handle on what's currently in there. I am not a fan of additives going into anything- they are a last ditch move once you're out of all other options.

I would really start getting the fluid changed out. Normally I would suggest successive drain and fills over a few thousand miles, but given milage it takes to do that, I'd go with the removing the return line and catching the old fluid as it comes out, then replacing that amount (but not overfilling). It's a quicker way to replace as much of the transmission fluid as possible without artificially forcing fluid through the transmission. General idea: drain 4 qts from the return line while the truck is running, turn the truck off, add 4 qts, repeat, until the fluid is pink. I think Timmy the toolman on youtube has a video detailing this process- Even if you have a shop do this work, you should probably watch the video to learn what the process is.

I say artificially forcing, because there are techniques that pump/force fluid through the system- if you are having a shop perform this work, specifically ask what process they plan on going with, and do not let them go with something that'll force fluid through.

The other thing to note- is many of us use Valvoline MaxLife Full Synthetic for ATF. I have personally done three drain and fills on my truck using MaxLife over the course of the last two years (I work from home, drive around 20 miles a week) without an issue mixing new and old fluid. I have 150k on my truck, for reference.

 

tht P0420 wouldnt be related to tranny issue

 

sometimes ECM throws a Transmission code for solenoid(s) thou

 

Correct. BUT I wouldn't touch anything except for an exhaust leak until I knew the state of the transmission. The A\F sensors aren't that expensive, but a catalytic converter is.

Square away transmission
check for exhaust leaks
change front and rear o2 sensors with Denso parts
replace the cats

 

Ouch. Hope not.

Andy thank you. BTW, You are the second to have recommended Timmy's videos - a good sign. Embarrassed I never paid attention to the transmission fluid. Two years with 3 drain-and-fills is a good reference to keep in mind.

 

Towed the rig out of town up to a recommended home mechanic willing to dive in and investigate. We ran into one another at THE one and only fuel station and got to explain everything about the truck to him. Is that totally annoying for a mechanic? Lol! He will start with draining transmission fluid and check for stuck solenoid. Sounds good to me. I really appreciate him keeping me informed. Oh, but, I didn't ask if he's using pressure to drain fluid! So, fingers crossed here in agonizing anticipation. Haha

 

Timmy's videos are great, even if you're not going to do the work yourself- he does a great job of explaining the work and concepts at play. He used to be a frequent contributor to this forum, until a dispute with another member and the mods, but his information and videos are still invaluable.