Fix For The Notorious Lurch

[flyman767]

Thanks to obwanconobe, I just got back from the dealer today and had the fluid level checked on the tranny. The tech advised the operating temp of the fluid had to be between 115-130 degrees in order to get an accurate reading. This required an approx 2 hour wait...but the tech finally checked the fluid and low & behold....it was nearly a quart low. BTW, the tranny only holds 3 quarts. As soon as I got inside the vehicle and engaged the tranny to "D"...what a difference. The lurching has nearly subsided. Prior to the tranny servicing: vehicle would run approx 7-8 MPH(flat ground). Afterwords: same ground, same test..3-4 MPH. A significant reduction.

This brings up another concern: If this is the cause of all the other Tacoma's who've complained about the lurch...why are these vehicles coming off the line at Fremont a total of 1/3 under-serviced? Furthermore, there have been several reported cases of A/C refrigerant levels at Fremont also being under-serviced? Maybe this is isolated to just a few cases, but it certainly doesn't sound like it. Hopefully, and doubtful there is, any long term damage to the tranny or torque converter..but if I do have any issues down the road I'll be sure to have the documentation.

[TucsonTRD]

interesting. i wonder if a few others can get their fluids checked and maybe determine this is the problem.

a quick question about the idle speed test you did. you said the truck idled at 3-4 mph, and this is probably right after the dealership was done and the truck was running at temprature. when it was running at 7-8 mph, was that when the engine was cold, or after it got up to temp?

[tacomajeff]

can't we check the tranny fluid level ourselves? I have a new 07 and haven't gotten down there to see if there is an accessible dip stick. Is it something the dealer has to do?

[Sony]

There is no dip stick the tranny is sealed.

[noladude]

Originally Posted by tacomajeff

can't we check the tranny fluid level ourselves? I have a new 07 and haven't gotten down there to see if there is an accessible dip stick. Is it something the dealer has to do?

Can't check the fluids on auto trannys 05 and up. There is no dipstick...Supposedly the tranny is sealed and the fluid is good for 100 thousand miles.

[flyman767]

Idle test was quite simple: Both times I went to the same level flat parking ground. Engine and tranny were at normal operating temperature. Both times the A/C was off and the engine tach registered approx 500-600 RPM.

Originally Posted by TucsonTRD

interesting. i wonder if a few others can get their fluids checked and maybe determine this is the problem.

a quick question about the idle speed test you did. you said the truck idled at 3-4 mph, and this is probably right after the dealership was done and the truck was running at temprature. when it was running at 7-8 mph, was that when the engine was cold, or after it got up to temp?

[tacomajeff]

on my 07 tacoma i notice when I brake the truck lunges forward slightly and I have to press the brake harder when it happens. This is what we are talking about right?

[jeremy556]

Only 3 quarts in the pan, but 11.5 quarts in the system.

[dl1027]

Flyman,

If I understand this correctly the lurch is caused by low AT fluid making the torgue converter grab more? Sounds odd. You would think the opposite would occur.

[keezer36]

You can check your tranny fluid. It uses a overflow in lieu of a dipstick. Check out the link: http://haroldmiller.net/FSM/05+/data...a/02800210.pdf

[WilsonTheDog]

Interesting. Thanks for that link. I'll be doing that this weekend.

[keezer36]

Originally Posted by WilsonTheDog

Interesting. Thanks for that link. I'll be doing that this weekend.

I like that method for checking the temp without a tester. A bit more than just resetting your maintenance light huh?

[flyman767]

Agree..low fluid usually will cause the fluid flow returning from the turbine to the pump to oppose the direction of pump rotation, usually leading to a significant loss of efficiency(slippage). Just the opposite is happening here. I'm not sure of the current torque converter plumbing... if fluid is being diverted or bypassed into some type of 'safe mode' due to the low quantity, but soon after the fluid was serviced...the difference was very obvious.

Originally Posted by dl1027

Flyman,

If I understand this correctly the lurch is caused by low AT fluid making the torgue converter grab more? Sounds odd. You would think the opposite would occur.

[flyman767]

I meant to ask the Tech what the Total quantity for the tranny assembly?
Jeremy556 says it's 11.5 qts... keezer36 link states:1.37 (drain and refill) 5.6(entire assembly).
The manual states: Up to 3.0 us qts(drain and refill)?

Originally Posted by keezer36

You can check your tranny fluid. It uses a overflow in lieu of a dipstick. Check out the link: http://haroldmiller.net/FSM/05+/data...a/02800210.pdf

[el_smurfo]

Maybe they snuck in a lighter weight trans fluid? Regardless, tends to show that some dealerships are starting to find workarounds?