[chetJ]

Hi Guys,

I searched the 'tranny lag' posts extensively, but could not really find an answer to the question I have in mind. Most of the people in those posts were experiencing a tranny lag in low speeds going from 1st to the 2nd gear. I do not have that issue.

The issue I have is (I was not able to find any posts about this-perhaps because of my search criteria- but I do remember reading a post somewhere in which Harper talks about this)-

What I am experiencing is that when I start up the 4R and put it into either R or D, the truck will make a perceptible 'leap' -almost like it is badly wanting to get going. Is this normal? I do not really mind it doing that as long as it is not going to cause any long term damage to the truck.

Any input is much appreciated!
CJ

[westwind77]

Does this happen when you shift (either from P ->D or R-->D) then immediately hit the gas? If so, it seems to be 'normal' and 'common' with these. If you shift, then wait a second then hit the gas she takes off like normal...but if you are in a hurry/rush and shift and quickly hit the gas you will feel and delay/hesitation...then zoom (yes, I said zoom) the 4R will jump and take off (faster than you would expect). I get this a couple times a month, but only when I 'rush' things.

Oh, and yes, I did have the 'tranny lag' and had it re-flashed. It was miserable before that fix and now 100% better. I don't think I could have or would have kept the 4R if they never fixed that lag. It was like someone dropping the tranny in N, scary and annoying.

[chetJ]

Westwind77- The next time I drive, I will most certainly try both- immediately hitting the gas as well as waiting a second before doing so to see when it happens. I your post you say that it happens to you may be a couple of times a month- for me it happens quite regularly. Again, like I said I don't really care that it does (every vehicle has its quirk), but I would hate it if it were damaging the tranny/ something else on a long term basis.

Eng1 and Harper- could you guys weigh in as well?

[1engineer]

Originally Posted by chetJ

Hi Guys,

I searched the 'tranny lag' posts extensively, but could not really find an answer to the question I have in mind. Most of the people in those posts were experiencing a tranny lag in low speeds going from 1st to the 2nd gear. I do not have that issue.

The issue I have is (I was not able to find any posts about this-perhaps because of my search criteria- but I do remember reading a post somewhere in which Harper talks about this)-

What I am experiencing is that when I start up the 4R and put it into either R or D, the truck will make a perceptible 'leap' -almost like it is badly wanting to get going. Is this normal? I do not really mind it doing that as long as it is not going to cause any long term damage to the truck.

Any input is much appreciated!
CJ

First, yes, mine does it too and here is why I think it happens (my observation):

When the 4Runner is started it has a period of time during warmup that it is in a "high idle" position. This is a programmed function designed to allow components to "warm up" to operating conditions and allow fluids to circulate accordingly and certain parts warm up to operating parameters. The catalytic converter is one such component. You will notice it idles immediately after start up at 1200-1300 rpm. After a short time the idle speed drops to 700-800 rpm. When I jump in and start it and immediately shift into reverse or drive when it is in it's high idle condition I too will get a "jump." If I wait until idle rpms are down to their norm it will not do that - UNLESS I do not have the brake firmly depressed.

To conclude I see this condition can happen two ways: Shifting when in high idle warmup mode or shifting without depressing the brake firmly. Hope this helps.

[chetJ]

Hi 1Eng- thanks a lot for your input. It does help, first because I see that I am not the only one with this issue, and second because it helps to understand why it may be happening. So based on your post- is it OK to assume that there is no damage being done here to anything in the truck as a result of this 'leap'?

[1engineer]

Originally Posted by chetJ

Hi 1Eng- thanks a lot for your input. It does help, first because I see that I am not the only one with this issue, and second because it helps to understand why it may be happening. So based on your post- is it OK to assume that there is no damage being done here to anything in the truck as a result of this 'leap'?

I wouldn't think twice about it. I know I don't. It is best though to wait a minute or two from a cold start to let everything warm up and idle speeds to go down. I sometimes forget or am in a hurry so I don't always wait either. Remember your vehicle is shifting into "R" or "D" at 700-800 RPM. If it shifts at a higher rpm you will get a "jump."

[nw_4Runner]

Same thing here - and since I don't want to warm the rig up in the garage, typical morning is for the 4R to leap out of garage, and then warm up in the driveway. Coffee has been spilled, but nothing more damaging than that.

[chetJ]

1Eng and NW_4Runner-This definitely helps. I will stop worrying about it and follow the advice of waiting just a minute or so for the truck to warm up. Thanks again!

[jamesq]

Originally Posted by 1engineer

I wouldn't think twice about it. I know I don't. It is best though to wait a minute or two from a cold start to let everything warm up and idle speeds to go down. I sometimes forget or am in a hurry so I don't always wait either. Remember your vehicle is shifting into "R" or "D" at 700-800 RPM. If it shifts at a higher rpm you will get a "jump."

I have exactly the same experience with my 12 4R SR5 4x4. When I drove mazda6, tribute and altima before, they did not jump when cold start in morning with rpm difference. What these car doing is just dropping rpm without jump, pretty smooth. I talked to one service guy of TOYOTA dealer, he explains to me the jump is due to solid transaxle design something.. what I really worry about is the crack sound when engaging from P to D, it is really annoying.

[ant-ny]

Chet,
I have it and have had it on other vehicles. I always have attributed it to what 1engineer said: When you first start up the car, the rpm's run high. therefore, when you take your foot off the brake, (no gas, just let it go), it does "jump" a little. 1engineer explained it much better than I could (that's why he is an engineer, and I am not!), but I don't think you have anything to worry about. My previous vehicle (Chev trailblazer) did it as well, and much worse.

[chetJ]

Jamesq- I have never heard the sound that you talk about. This could be a problem- you should definitely check in with your dealer about the sound.

[ant-ny]

james,
this may be a stupid question, and I don't mean it as an insult to your intelligence. Could the "crack" simply be the sound of the automatic locks locking when going from park to drive? Mine is pretty loud, but I do not have anything coming from the gear shifter area.

[jamesq]

Originally Posted by ant-ny

james,
this may be a stupid question, and I don't mean it as an insult to your intelligence. Could the "crack" simply be the sound of the automatic locks locking when going from park to drive? Mine is pretty loud, but I do not have anything coming from the gear shifter area.

I think my expression may be not clear, I have the same issue with this thread:Rough shift out of park to Reverse

[ant-ny]

if we are thinking of the same thing, mine has it too. As 1engineer said, it is much more noticeable when the engine is cold or I did not set the parking brake on a hill. Same thing happened on my Chev, and currently happens on my wife's Pontiac and the Ford's I drive at work. I would not be too worried about it, but no harm in having the dealer look at it next time it is due for service.

[chetJ]

Ant-Ny-thank you for your input. So, it looks like it is a very common problem with many brands of vehicles then!