[gm325xi]

i have a 2006 325xi auto trans with 55000 miles and ive noticed as im slowing down from speed of 50mph the car will shift hard from 2nd gear to 1st. it feels as if the car wants to lurch forward. Any idea as to whats causing this?? thanks.

[VTECaddict]

The car should not be shifting down to 1st at 50mph...

[Affify11]

Originally Posted by VTECaddict

The car should not be shifting down to 1st at 50mph...

LOL exactly what i was thinking!

[ndog14]

Originally Posted by VTECaddict

The car should not be shifting down to 1st at 50mph...

Maybe 3rd to 2nd?

OP, need more info. What are you doing? Paddle shifting?

[username604]

your story doesn't add up
most of the time, the car doesn't even use first gear
you'll notice that downshifts take place around 1000rpm and so they should be pretty smooth

if you want a diagnosis via the interwebs, we're gonna need more details!

[EQUANT]

Had similar issue when slowing down at a stop, step changing 2-1 with a big bump, sometimes.
Had the steptronic adaptations reset at the dealer, issue never returned since.

[Bimmer84]

Probably because you are shifting from 2nd to 1st at 50mph... I'm not a mechanic though.

[Turb0Surge]

like everyone else says... 1st should not come at 50mph.

[ndog14]

It's funny, your name is gm325xi and your car has a GM transmission. LOL.

Joking aside, how do you know your in 2nd gear at 50? Are you in M mode being a pretender? If you are, why the fuck are you shifting to 1st at 50mph in M mode? Are you trying to break your car?

[gm325xi]

I apologize, i worded the situation wrong...when im slowing down from 50mph to a complete stop it will jum when it down shifts from 2 to 1.

[ndog14]

Originally Posted by gm325xi

I apologize, i worded the situation wrong...when im slowing down from 50mph to a complete stop it will jum when it down shifts from 2 to 1.

What are you doing? Down shifting in M mode? How do you know it is 2nd to 1st? What exact speed does it happen? Exactly at 50mph? Then it isn't 2nd to 1st.

[Cali_Creez]

You Dont Shift To First Gear While In Motion!!!

[EQUANT]

@Cali - why? The car's an automatic, it will not allow shifts that will potentially break it.

@gm325xi - if you feel the bump at very low speeds, nearing complete stop, then read my other post here and go get your tranny adaptations reset!

[VMRWheels]

If it's from 2nd to 1st.. I'm pretty sure it's any MPH and not 50mph specifically. However, do these cars even shift into 1st when slowing down? I'd assume it'd just go into neutral instead of hopping onto 1st. Then when you stop or you're at a slow enough pace then accelerate, it'll hop into gear. If it's in manual mode, totally different situation. haha.

[gm325xi]

ok just to clear thigs up, i dont shift the car into 1st at 50 mph im not a moron. when i am decelerating while the car is in DRIVE, not M, the car will jump when comping to a complete stop. At high speeds the car does NOT go into 1st gear! its in either 5th or 6th,im not sure which being that its in DRIVE.

[gm325xi]

Originally Posted by ndog14

What are you doing? Down shifting in M mode? How do you know it is 2nd to 1st? What exact speed does it happen? Exactly at 50mph? Then it isn't 2nd to 1st.

NO the car is in D. And it happens at really any speed i just put 50 as a reference. And I THINK its 2nd to 1st, it could be 3rd to 2nd, im not 100% sure, i just know the car jumps when coming to a full stop.

[gm325xi]

Originally Posted by Cali FlyBoyZ

You Dont Shift To First Gear While In Motion!!!

do u think im a moron, who on earth would do that....

[ndog14]

Originally Posted by gm325xi

do u think im a moron, who on earth would do that....

Is that first part unintended sarcasm?


Ok, so this jump is when you're about to come to a complete stop, not at 50mph. Now this jump, is it high enough to dunk a basketball? JK, you mean it is a slight jerking motion. That is common of the GM slushboxes.

[gm325xi]

Originally Posted by ndog14

Is that first part unintended sarcasm?


Ok, so this jump is when you're about to come to a complete stop, not at 50mph. Now this jump, is it high enough to dunk a basketball? JK, you mean it is a slight jerking motion. That is common of the GM slushboxes.

Yes it was lol, and the jerk is sudden, as if someone lightly rear ended me.

[MrZ]

5er ZF transmission is know to do crazy things on 2-1 downshifts, but it's more violent than what you are describing. Some have solved it with a software upgrade, for some transmission fluid change was enough and some had transmissions replaced. Since it's a different tranny, I doubt you have the same issue.

I would start by getting a mechanic to check the AT fluid level, maybe it's low. And changing the AT oil is probably a good idea (many debates about it, but it's up to you).

Try downshifting with steptronic, does it also happen? Sport mode?

[ndog14]

Try "resetting" the transmission. Put the car in accessories mode (?), hold the gas to the floor for 30sec, and 'Poof'! I think that is how it goes.

Yeah, transmission fluid change.

[gm325xi]

Originally Posted by ndog14

Try "resetting" the transmission. Put the car in accessories mode (?), hold the gas to the floor for 30sec, and 'Poof'! I think that is how it goes.

Yeah, transmission fluid change.

Im going to start with a trans flush,and see if that works if that doesnt then i will do what equant has suggested and have the dealer reset the adaptations reset. Ill let u know wha works.