YACT: auto shifts aren't smooth...

[iamme]

i have a 2002 2.5 Altima (auto). When I accelerate, sometimes the car "jumps" or "jerks" a little between shifts. Nothing too harsh, but something i notice. i'm not a car expert, so no flames please

two questions:
1. is there something minor i can do to remedy this?
2. is it something worth taking the car to the dealer for?

edit: btw, it's got about 20K miles, i always put in 89 grade gas, and i've always changed the oil every 3K miles.

 

[T3C]

thats not good

 

[spidey07]

sounds normal.

 

[OS]

harsh shifts are good, better performance and less wear on clutch packs.

If I could, I'd put a shift kit in every auto I drive. The car would jerk and chirp the tires whenever you shifted.


That's the thing with the auto publication world, they want smooth auto shifts but then bitch that autos are slower than sticks.

 

[iamme]

is it ok that the car does this, considering how new it is?

i'm not really anal about stuff like that, but i don't want it to turn into a bigger problem in the future....

 

[Lithium381]

is it something new or has it been like this the whole time? how hard are you accelerating? like a grandma or someone who thinks they're in a race-car?

 

[cavemanmoron]

Originally posted by: Lithium381
is it something new or has it been like this the whole time? how hard are you accelerating? like a grandma or someone who thinks they're in a race-car?

in rear wheel drive cars there is a vacum modulator;
if the vacum hose comes off the car will shift,harsher than "normal"

 

[Descartes]

It's most likely normal, especially if you're accelerating hard. Automatics generally downshift to put the RPMs around the peak power range (~4500k rpm on my car) to get enough power to accelerate. If it didn't do that, it would be like accelerating out of 5th gear.

 

[Ryan]

Buy this stuff called Lucas Transmission Fix - it helps out failing transmissions, but it's also great for all transmissions. If you have an automatic, it'll shift smoother, and if you have a manual, it makes shifting better

 

[Pepsi90919]

Originally posted by: cavemanmoron

Originally posted by: Lithium381
is it something new or has it been like this the whole time? how hard are you accelerating? like a grandma or someone who thinks they're in a race-car?

in rear wheel drive cars there is a vacum modulator;
if the vacum hose comes off the car will shift,harsher than "normal"

what does that have to do with rear wheel drive?

 

[toph99]

if it's a 2002 it should still be under warranty, take it to the dealer.

 

[Zenmervolt]

Firm shifts are nothing to be worried about. Also, often if you quickly change the throttle amount right when the auto decides to shift there can be a big lurch between gears since it set up the shift for the old throttle input and not the new.

Check the transmission fluid. If it smell burnt or if it looks dirty there might be problems. (You can have a mechanic check this.)

ZV

 

[Zenmervolt]

Originally posted by: rbloedow
Buy this stuff called Lucas Transmission Fix - it helps out failing transmissions, but it's also great for all transmissions. If you have an automatic, it'll shift smoother, and if you have a manual, it makes shifting better

No, no, no, no! That Lucas crap increases (substantially) the chances of frothing and aeration. Aside from maybe putting a molybdenum disulfide additive in your oil (really only beneficial if you're racing) or a little "water wetter" in your coolant (first making sure that it has no silicates) you should not be adding anything to your cars fluids that is not specified by the manufacturer.

And iamme, unless your manual says you need 89 gasoline, use 87. There is no performance benefit from higher octane if the engine was not designed for it.

ZV

 

[Soybomb]

Originally posted by: rbloedow
Buy this stuff called Lucas Transmission Fix - it helps out failing transmissions, but it's also great for all transmissions. If you have an automatic, it'll shift smoother, and if you have a manual, it makes shifting better

I love lucas trans fix but I would only use it in a transmission thats on its last legs.

 

[SuperTool]

It's normal for Nissan 4-speed auto. I have it in my maxima. Actually, I put a valve body upgrade on it to make it shift even harsher.
It's a good thing because it wears the clutches less and is faster.
If you want silky smooth autos, you should have gotten a camry
Anyways, you'll get used to it.

 

[SuperTool]

If you are really paranoid, put an aftermarket transmission cooler in series with your stock cooler. It's around 20 bucks. So if it reduces the chance of your tranny failing by just 1%, it pays for itself
Although I don't think that 4 banger is stressing that tranny too much. Maybe if you had a V6.

 

[cavemanmoron]

Originally posted by: Pepsi90919

Originally posted by: cavemanmoron

Originally posted by: Lithium381
is it something new or has it been like this the whole time? how hard are you accelerating? like a grandma or someone who thinks they're in a race-car?

in rear wheel drive cars there is a vacum modulator;
if the vacum hose comes off the car will shift,harsher than "normal"

what does that have to do with rear wheel drive?

In a Rear wheel drive car especially GM,the tranny has a vacum Modulator
If the vacum hose is unhooked,breaks,etc.


No or low vac to the modulator tells the trans that you are under power, and want the fastest, hardest-hitting shifts possible, at a higher speed. Unless it is a race-only deal, I would not do it unless you call ahead to your dentist to replace any fillings that rattle out.

 

[Thegonagle]

Originally posted by: Lithium381
is it something new or has it been like this the whole time? how hard are you accelerating? like a grandma or someone who thinks they're in a race-car?

This is the important question. Has it always shifted like this, or has there been a recent change?

If there's been a change, bring it to your dealer. If it's always shifted like this, it's almost certainly fine.

BTW, I don't think "vacuum modulators," or anything similar, exist anymore. Electronic controls have replaced such hideously old fashioned controls.

 

[OS]

Originally posted by: SuperTool
It's normal for Nissan 4-speed auto. I have it in my maxima. Actually, I put a valve body upgrade on it to make it shift even harsher.
It's a good thing because it wears the clutches less and is faster.
If you want silky smooth autos, you should have gotten a camry
Anyways, you'll get used to it.

Where/who and how much was your valve body job?

 

[SuperTool]

Originally posted by: OS

Originally posted by: SuperTool
It's normal for Nissan 4-speed auto. I have it in my maxima. Actually, I put a valve body upgrade on it to make it shift even harsher.
It's a good thing because it wears the clutches less and is faster.
If you want silky smooth autos, you should have gotten a camry
Anyways, you'll get used to it.

Where/who and how much was your valve body job?

You can find out on Maxima.org.
It's called Don's valve body upgrade. Someone on the board had it, then the guy swapped for manual transmission, and sold me the VB in exchange for my old one. I think it was 250 or something like that. Recently I swapped it back for regular one because I will be selling car soon, so I got most of the money back. The guy did the labor for me since he is a mechanic. Basically the regular procedure is you send your VB to Don in texas, he upgrades it and sends it back, but it takes a lot of time.