Automatic Transmission Quirks

I have noticed a few transmission quirks on the truck as compared to other vehicles I've owned with same trans and engine (3rd gen 4runner and another 1st gen Taco) and wanted to get some feedback on what might be happening, if I should be worried, or maybe I'm paranoid? Would love some opinions.... @gearcruncher :


Transmission flare going from coasting in OD to coming on the gas. Seems to overshoot by a couple hundred rpms and then come back down. In the video, I start at a coast, push the accelerator a bit to maintain speed, and you'll see a blip of the tach and then it comes down. Later I push the accelerator hard to get the torque converted to unlock (I assume that is what happens when the rev jumps up and then finally shifts down into third).

https://vimeo.com/731152680

I also have a scan gauge. I've noticed in 1-3, the transmission temps tend to be 170-190ish. However, just cruising on a relatively level highway, I notice my temps in the 210-225 range consistently going around 65-75mph. My 3rd gen T4R tends to sit around 185 under the same conditions. I plan to add a cooler inline to address this. Any thoughts if this is normal?

Background:
Since buying this truck, I've noticed the trans acting strangely as compared to my previous 1st gen Taco or my 3rd gen 4Runner (both 5vz, Autos). When I bought it, I noticed an issue where the truck is in OD and the turn signal on, the truck would lock/unlock the torque convert in sync with the turn signal light. The trailer harness was backfeeding the brake lights which caused the truck to think I was applying the brake. The previous owner said he used the truck for towing sometimes and install the harness, which unknown how long that issue was present. Perhaps this is a contributing factor? I have since fixed this issue. The truck also seems to shift very firmly between gears, and a Drive to Reverse shift can cause a slamming sort of feeling when it engages, but not 100% of the time.

I have already inspected/tried:

• Trans filter change about 2000 miles ago. The issue was noted before this. No clogs or unusual amounts of metal/material found on the magnets. Old Fluid was dark red.
• New trans fluid after the filter change, currently the level is in operational range, still a good color (checked with engine running).
• Driveline was inspected to find the shift roughness, all u-joints and slip joints feel firm, even greased them for good measure.
• I checked out this thread already but didn't see much about flares in there: https://www.tacomaworld.com/threads...sions-write-up-your-4-speed-automatic.325531/

 

You're welcome.
https://spikerengineering.com/product/scangauge-mount-01-15-tacoma

 

OP, snap a pic of your trans kick down cable at the throttle body. If someone messed with that also it could explain the abrupt hard shifts. But the video seems weird. Both the noise of the vehicle engine/trans and behavior of the tach; something isn't quite right.

 

Disclaimer: not an expert, just a dude on the internet. As i understand it, the air/fuel ratio data influences shift points significantly. So if it's shifting hard, check to be sure your air/fuel ratios are behaving as they should. IE no exhaust leaks, sticking egr or throttle body, no dead spots on tps, vaccum leaks, etc. My iac was sticking intermittently and causing a similar issue with unusual trans shift behavior.

 

LMAO, Thanks! This has been on the mod list for a while. I only have one gauge so I tend to swap it between vehicles for long trips. I do intend to eventually mount it.

Mine is an 2003, so I don't think it has a kick down cable. I believe it's the "electronic" throttle body, it has a throttle cable but no other cables going to it. Please correct me if I'm wrong.

Okay, I'll have to check it out, I'll let you know if I find anything.

 

I knew your throttle cable was different than mine. My 01 having a cable and your 03 being electronic. I *thought* you still had a trans kickdown cable but I could be wrong.

Generic photo from google of 03 shows what looks just like the kickdown cable on my 01.

 

Edited for future clarity:

The picture you sent is what mine looks like, but that cable in the photo is definitely the throttle cable. Therefore I do not have a kickdown cable.

Below is a picture of what the throttle cable & kickdown cable setup looks like for identification. I don't have both the cables, since mine is electronic. I only have a throttle cable attached to the throttle body. I believe the transmission pressure is regulated electronically. (source: ):


Kickdown cable setup example

 

Bumping thread. I've checked the things above and don't have any leads. Any other ideas? @gearcruncher

 

I believe the trans cable needs to have the metal bit flush with the rubber thingy like this:

 

I think it calls for it to protrude a very small amount like 1 or 2mm. Barely visible. The image in the picture looks correct to me.

 

Interesting. I'd love to check the field service manual on this detail

 

OP, check this thread. Post #27 is by gearcruncher. I covered the kickdown cable tightness/protrusion on page 1.

https://www.tacomaworld.com/threads...ned-grades-at-normal-speed-tyia.768943/page-2

 

Thanks, y'all. I don't have a kickdown cable, but I can see how the previous posts could be misunderstood. I've edited my previous posts to be more clear.

Still looking for suggestions!

 

Hmm, unless I missed it I don’t think we’ve seen your throttle body yet. Additionally, since your 2003 has the electronic throttle body/drive by WIRE, I’m thinking you may be confused and the cable you’re seeing IS the kickdown cable. I could be wrong but this is what my gut is telling me. Not trying to make it more confusing. Can you post up a picture of your throttle body OP?

*edit: if you setup your phone to record under the hood while you go press the gas pedal (hood open & engine OFF) you’ll see if that cable is for your throttle or not.

 

Here is my throttle body. Hopefully that settles the debate

 

My 03 Prerunner drives exactly like that as well, seems kinda normal. I think they’re just clunky. Cold shifting is weird getting out of second gear until it warms up. I think the couple hundred RPM drop is it going in OD. At about 65 MPH with cruise control on when going up a hill the downshifts are jerky, I think it’s just crappy old programming on an old transmission if we’re being honest. Mine runs like a top, no slipping, fresh Valvoline synthetic trans fluid, new rear end fluid, nothing has made a difference really, just improved MPG’s.

 

How's the trans oil looking?

 

Watched the video . You really had to hit the gas heavy to get the converter to unlock , then the transmission dropped from 4th to 3rd
When the converter unlocks , you will see approximately 300 rpm increase
When the transmission downshifts from 4th to third gear , you will see 1000 rpm increase in engine speed
A shift flare is a transmission slip usually fealt when the transmission upshifts from 2nd to 3rd or 3rd to 4th
In your video , I see the transmission hesitating to unlock the converter clutch .
With this being said , we cant feel what you are feeling over a keyboard . If I could test drive the truck , I could identify if there is an issue much easier .
I can see the load you are placing on the transmission , but I cant feel whats happening in the drivers seat .

Cold temps - Transmission will have delayed upshifts , no 4th gear and no converter lock up until engine and transmission are at operating temperature


I do agree that the scan gauge needs a mount hehe . I was interested to see the mileage but I think the scan gauge covers up the odometer in your video .
What do you have on the truck for mileage ?

Next go to the ATSG website and positively identify your transmission and post back . I beleive there were 3 different models of transmission for that year but I beleive you have the A340E series .... No transmission throttle cable
https://atsgmembers.com/transtype/

A transmission cooler is a great idea . Your temps are on the warm side and a cooler will help but there may be more going on .
Was the previous owner towing without a cooler ?
https://www.tacomaworld.com/threads...l-toyotas-write-up-with-many-pictures.526283/

Last engine tune up ?
As mentioned above , I am wondering if you have an engine problem that makes it feel like a transmission issue ?
Any codes pop up with that scan gauge ?

 

Thanks so much for your input. Here are the answers to your questions:

What do you have on the truck for mileage ? About 143k miles
Next go to the ATSG website and positively identify your transmission and post back. - Data plate on transmission says Aisin 30-40LE, vehicle information sticker indicates A340F.
Was the previous owner towing without a cooler ? Yes, no signs of any additional cooler being installed. Since purchasing from him I changed the trans fluid and replaced the trans filter, and removed the faulty trailer light harness. I don't know how much he towed but he didn't make long hauls with it.
Last engine tune up ? Regular oil changes, spark plugs approx 15k miles ago. The timing belt, water pump, tensioner about 3k miles ago.
As mentioned above , I am wondering if you have an engine problem that makes it feel like a transmission issue? I suspect there is an exhaust leak at the manifold, I do hear a small ticking noise under load in the 2500-4000 rpm range.
Any codes pop up with that scan gauge ? No codes or CEL.

 

Thanks for your input! It's entirely possible I'm being paranoid.... that's what happens when you irrationally love your vehicle lol

Looks good, proper fill and good color.