1999 Toyota 4Runner Bucking when taking off.

Tiny
AKALAY
  • MEMBER
  • 1999 TOYOTA 4RUNNER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 146,000 MILES
I will try to be brief. 3 months ago, I was advised my trans return lines into the radiator had allowed anti-freeze into the trans. R&R radiator and flushed trans then drove to florida. No problems. About a month ago, after an hour drive on the NJ Turnpike, I arrived at a light and my trans was acting weird. When I took my foot off the brake pedal, the truck was not moving forward. Then when the gas pedal was hit, it bucked a bit and then it was fine. I get to a parking lot and try to back up and it hesitates and I have to hit the gas pedal harder to get it to move. During normal driving to and from work or any other time on short drives (even at high speed limits), it does not do it, it seems only after about an hour of 65mph++ driving. This has now occurred 4 different times. Took the car to the dealer and they couldnt duplicate. All Fluids are on target. Smelled the trans dip stick for burning, it seemed normal, color normal (slightly dark for being changed 3 months ago)

Any suggestions.

Thanks.
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Thursday, June 19th, 2008 AT 7:51 AM

6 Replies

Tiny
KHLOW2008
  • EXPERT
Hi akalay,

Looks like a pressure or fluid problem.

When the problem occured, after taking off, were the gear changes ok, or did slippage occurs during hard acceleration?
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Friday, June 20th, 2008 AT 11:53 AM
Tiny
AKALAY
  • MEMBER
KHLow2008,

thank you for your response. After the intial bucking the gear changes seemed fine at higher speeds but at the next light, the same bucking occured during take off with just feathering the gas pedal. The reverse not working took me by surprise. It felt like a manual with the clutch slipping but with the added hesitation.

But today, all is well, you would not know there is a problem. Only after a consistent 65+ speeds does the issue pop-up.

Thank you for your time on this matter.
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Friday, June 20th, 2008 AT 12:11 PM
Tiny
KHLOW2008
  • EXPERT
Hi akalay,

You are welcomed.

I would suggest changing the fluid again as the last flush done might not have cleared the system 100 %.

Any idea if the fluid used was of correct spec?
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Friday, June 20th, 2008 AT 12:18 PM
Tiny
AKALAY
  • MEMBER
The flush was done at a Toyota Dealership 3 months and 5,000 miles ago. I will find out if the dealer will reflush or I will attempt. I was advised that never to flush a trans when the vehicle reaches high mileage but I had no choice.

Also worth mentioning, when I come to an abrupt stop and the gears are dropping and trying to catch up, there is a big thump in the trans. Or if I take off before it catches up, there is a thump, but again it doesnt happen all the time.

Thank you.
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Friday, June 20th, 2008 AT 12:40 PM
Tiny
KHLOW2008
  • EXPERT
Hi akalay,

The contamination of the trans must have caused the control valves in the trans body to be sticking at times.

In this case I would suggest servicing the trans valve body.
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Friday, June 20th, 2008 AT 12:45 PM
Tiny
RAYNAY99
  • MEMBER
I am having IDENTICAL problems with my 4runner. Identical diagnoses back in Feb 07 led to the same exact repiar work as you state (engine flush etc.). Mid summer I was also on the NJ turnpike and experience IDENTICAL issues to what you are having. Unoticable driving around town. Only noticable after reaching higher speeds. Toyota cannot replicate nor any codes show up in diags. Of course, I go for a drive on the parkway 1 day after getting it back from Toyota and sure enough, it happens. It is getting worse.
I see the suggestions below. Can anyone tell me what the solutions was?

Thanks!
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Saturday, September 13th, 2008 AT 11:26 AM

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