Auto trans popping into neutral

[Tonkaman]

My 2004 Tacoma has started to slip out of drive while under sudden acceleration. I can simply pull the shifter back one slot into drive and continue on. I seem to only have a problem when accelerating quickly, usually taking off from a light or passing someone.

What is supposed to keep the truck in any given gear? Is it something external to the trans or inside? What can I do to fix it?

 

[jeeper]

Possibly a bad trans mount allowing movement while heavy on the throttle?

 

[Tonkaman]

Good thinking, I'll check that out

 

[Tonkaman]

This problem has been getting worse over the past few months. Today I realized I've developed the habit of driving while pulling back on the shifter, keeping it in drive.

I think my transmission may be slipping also. It feels more like it slips out of gear and then back into gear though. I've only had it happen when accelerating kinda quickly from a stop. It's slips around 2500 RPM shifting from first to second. When it re-engages it hits pretty hard like instant hook up, which makes me skeptical that it's actually the trans slipping.

Any thoughts on what my problem may be?

 

[jeeper]

T-O-Y-O-T-A??

 

[SLC97SR5]

Under my 4Runner there is an adjustment slot for the transmission linkage. I'm not sure if the drive-by-wire models have the same adjustment but we do have the same trans.

You might try adjusting it in the direction that equates to you pulling back on the shifter.

Another vote for a weak mount.

 

[Tonkaman]

Thanks I'll take a look for that adjustment.

I forgot to mention I already replaced the transmission mount so that wasn't the issue

 

[UNSTUCK]

How about engine mounts? They are the ones that allow the trans to twist.

 

[Tonkaman]

How about engine mounts? They are the ones that allow the trans to twist.

I didn't think they would allow it to move enough. I guess I'll have to take a look at them

 

[jeeper]

for reals, I can lay under the truck and look while you give it throttle, that will let us see what moves.. just don't squish me

 

[Tonkaman]

for reals, I can lay under the truck and look while you give it throttle, that will let us see what moves.. just don't squish me

No guarantees... I thought about putting my gopro under the truck and watching it thru wifi on my phone. We should do both next time I'm over

 

[MikeGyver]

What is supposed to keep the truck in any given gear? Is it something external to the trans or inside? What can I do to fix it?

Detents in the rooster comb mechanism in the valve body. I've had one loosen up causing similar issues (GM 4L60E)

 

[Tonkaman]

Under my 4Runner there is an adjustment slot for the transmission linkage. I'm not sure if the drive-by-wire models have the same adjustment but we do have the same trans.

You might try adjusting it in the direction that equates to you pulling back on the shifter.

Another vote for a weak mount.

I took a look at the linkage and everything looked tight and in its normal place. Just to be sure I put the truck in 1st gear, pulled the linkage as tight as possible, and re tightened the nut. It seems to have worked! It's only been a few days but I haven't had it pop out of gear or feel like it's slipping! One downside is the shifter indicator is off by one gear but I'm used to it already. As I drive you can really see the trans and transfer case shifters move around with acceleration and bumps. I assume this movement was able to push the linkage just barely into neutral and then slip back into drive. Next is to figure out why it flexes so much