Jerking In-between Gears

Hey guys, I have a 4x4 Automatic TRD Sport SR5 Tacoma with 180k miles on it. I am having an issue with jerking when the truck shifts to a lower gear. Say I am cruising down a road and I start to slow down and the gear shifts down then I speed up and that is when I get my jerking. I took the truck to a transmission shop and they inspected the transmission and found nothing wrong with it other than it was a tad low on transmission fluid but no damage. I thought for sure they would have found something. I am not for sure what this could be, sometimes when I stop at a red light or stop sign its does it after the stop when I start to accelerate. Any help on this issue would be great!

 

Sorry you’re having trouble with your jerking. Hope you get it fixed...

 

Ummmmm.....as a random thought.

At 180,000 miles has the tranny ever been serviced? If not, I'd start with a fluid and filter change. Go through the process to check the fluid level. Make sure it is filled to full.

I'm not big on a "fluid flush", just a fluid and filter change can do wonders.

 

this thread is going to get off, i mean go off the rails real quick

 

Probably be easier if you’re at a stoplight or something

 

All depends on what is on display in the Start UP screen.

 

Check the transmission mount

 

Kinda sounds like torque converter lock unlock issues....but....I dunno

I bet @gearcruncher might have some ideas, 'cuz he's awesome

 

Not awesome yet , Lets see if we can figure this out LOL
If the truck went to a transmission shop , usually the first thing the technician does with a completely computer controlled transmission is throw it on the scanner checking for codes and then take it for a road test from cold to hot .
Were you charged for a computer scan ? were there any codes ? How intermittent is the issue ?
Did they have the transmission pan off ?
Those guys know what they are doing if its a reputable shop and I will agree with the trans shop that its not transmission related .

MY first thought is a fuel injector control issue . The fuel injectors shut off when you remove your foot from the gas pedal in an effort to save you fuel .
But if this is also happening at a stand still , that should rule out the injectors unless your fuel pump is getting lazy
Your issue is happening as you request more fuel because you are placing a load on the engine. They call this an engine hiccup
How long has this been happening ?
How many miles do you have on the truck ?
When was the last engine tune up ?
Does the jerking happen when cold and hot ? Sounds more like a problem with primary and secondary ignition at this point .

I would suggest a stall test in your driveway next .

 

This has been happening for a good year now, I have been shrugging it off until about 3 months ago when I took it to the shop. The transmission shop did hook it up and ran scans they also drove it and they found nothing wrong. They suggested that I replace the front wheel bearings which I did and that fixed the "humming" noise I was hearing. The truck is pushing almost 185 thousand miles. I expect some issues with an older truck getting up in years and mileage. The truck has never had an engine tune-up, but I have a vacation from work right after new Year I am thinking about taking it to the shop and letting them inspect everything and tune the engine. The jerking happens no matter the temperature outside. I am thinking on the lines of what you said it could be a lazy fuel pump or the injectors, it almost feels like engine lag when I tap the gas and it does not accelerate right then and then all of a sudden it jerks, and then it is accelerating pretty good. The issue happens every day when I drive it mostly at stop signs or red lights, but it really hates when I slow down for a turning car then accelerate.

 

OK , i would seriously consider an engine tune up for your truck as a start followed by investigating your fuel pressure and scoping your primary and secondary ignition under engine load
As mentioned above , I can pretty much bet you are able to re-produce the issue in your driveway without moving the truck .
If your truck has a tachometer , pay close attention to the engine rpms when you feel the engine stumble . You will see that the stumble always occurs near the same engine rpm
Not that its nesessary , but have you ever performed a stall test ?

 

I have never performed a stall test, yeah I say an inspection of everything and an engine tune-up would most likely solve the issue. When I drive to work today I will see the rpm at which the jerk occurs. Thanks for your help, I'll keep this thread updated when I take it to the shop and they perform their inspections.

 

Any updates to close this thread out??

 

I had a very similar issue years ago on a different vehicle. Slight lurch at part throttle. Ended up being the TPS ( throttle position sensor). YMMV

 

Hey guys, sorry it been a while I've been busy. There was nothing wrong with the transmission, I took it to the Toyota dealership for a rear leaf spring recall. They took off my drive shift (I guess) and put new leaf springs on, then when they were all done they accidentally put my drive shaft on backwards. (I have never seen that). I took it to my transmission place and he flipped it around and then I went and rebalanced my wheels. All is good now!

Edit: Also forgot to include that my transmission place also replaced the carrier bearing.

 

What the hell, well it would have been helpful if you had mentioned that the problem started after that repair work. When mysterious problems crop up, it's always helpful to look at what was recently touched. On the other hand, I always like it when Gearcruncher gets dragged into the conversation, LOL. I almost thought he was a counterfeit though, because he has changed his avatar! Then he started talking, and yeah that's him

 

@gearcruncher

Please educate me.

What is the "stall test"?
Purpose?
How To?
What does it show?

 

Golly , you guyz making me type lol .

Purpose of a stall test .
to identify a possible engine misfire or torque converter shudder
So you are driving down the highway and your truck starts bucking and farting with the torque converter locked up .
Everybody diagnoses this as a torque converter shudder but is it ? Your engine is under load when the shuddering occurs
When you feel the shudder at highway speed , record the engine rpm where you feel the shudder .
When you are in your driveway you can duplicate an engine misfire .

How ?
warm your truck up so both your engine and transmission are warm
Place the shifter in drive and hold the brakes as hard as you can .
The idea here is to bring the revolutions of the engine up to where you felt the shuddering while you were travelling down the highway
Hit the gas pedal and hold the brakes . This places the engine under a good size load .
As you are increasing engine revolutions , the truck starts misfiring at the same rpm you felt during your highway run .
Allow the transmission to cool after your diagnostic
In the case above , The torque converter doesnt lock up in first gear under engine load so we can rule out the torque converter locking clutch circuit as the cause of the shuddering and concentrate on the engine controls instead .