A4 tranny behaviour
Thread Starter
Burning Brakes
Joined: Mar 2003
Posts: 915
Likes: 1
From: UK
A4 tranny behaviour
Guys, I've noticed that with my tranny in '3', if I accelerate with a moderate throttle input (ie. not enough to downshift) from about 35-40mph, the converter seems to slip (revs stay constant, but road speed increases). The rev counter is showing about 2,000rpm at this point. Is this normal??? I was under the impression that once the converter was over the stall rpm (1,600rpm stock) that the slippage would stop and there would be direct drive via mechanical clutches. I'm assuming I'm wrong (or, at least, I HOPE I am!)
Also, can someone please clarify exactly what function the clutch packs serve? I know the lock-up clutch is a mechanical clutch that locks the converter at 1:1 providing direct drive, but what purpose do the clutch packs (1-2, 3-4) serve?
Thanks for helping my understanding... as the 4L60E is a weak unit in stock trim, I'd like to understand the correct behaviour FULLY so I know what is right and what signifies a problem.
Thanks a lot :)
Also, can someone please clarify exactly what function the clutch packs serve? I know the lock-up clutch is a mechanical clutch that locks the converter at 1:1 providing direct drive, but what purpose do the clutch packs (1-2, 3-4) serve?
Thanks for helping my understanding... as the 4L60E is a weak unit in stock trim, I'd like to understand the correct behaviour FULLY so I know what is right and what signifies a problem.
Thanks a lot :)
Racer
Joined: Feb 2002
Posts: 301
Likes: 0
From: El Paso
Re: A4 tranny behaviour (i_york)
First of all, TTT for you.
I guess you meant the opposite, right?
Well, I have the opposite problem. My tranny doesn't slip (yet) on my 1,200-mile car, but the T/C locks up below 1,600 (as low as 1,200), and gassing up only lugs the engine. It takes a heavy foot to induce a downshift.
I didn't know a tranny always locked up above its stall speed. However, what's the deal with 1st and 2nd? Our tranny only locks up in 3rd and 4th.
JC
(revs stay constant, but road speed increases).
Well, I have the opposite problem. My tranny doesn't slip (yet) on my 1,200-mile car, but the T/C locks up below 1,600 (as low as 1,200), and gassing up only lugs the engine. It takes a heavy foot to induce a downshift.
I didn't know a tranny always locked up above its stall speed. However, what's the deal with 1st and 2nd? Our tranny only locks up in 3rd and 4th.
JC
Thread Starter
Burning Brakes
Joined: Mar 2003
Posts: 915
Likes: 1
From: UK
Re: A4 tranny behaviour (GRAY_VETTE)
First of all, TTT for you.
(revs stay constant, but road speed increases).
I guess you meant the opposite, right?
(revs stay constant, but road speed increases).
I guess you meant the opposite, right?
Actually, no... what I stated originally stands: at some points above the stall speed, the revs appear to stay constant while the car accelerates... maybe this is just the converter slipping on fluid and is normal, but I'd definitely like another A4 owner (or several!) to confirm this or tell me I might have a problem on my hands.
:cheers:
Racer
Joined: Feb 2002
Posts: 301
Likes: 0
From: El Paso
Re: A4 tranny behaviour (i_york)
Oh man, did you get the CVT option on your car? :lol: Seriously, you might have a problem, but state your rear end ratio for better diagnosis. 2K in 3rd means 55 mph in my car. In a 3.15, 2K rpm is 47.5 mph; much less of a 'problem', because it'd be slipping a lot less.
My 2.73 car by 40 mph steady is dead locked, however. The only way to make it slip is by a downshift. I wish it DID slip a little, like yours. So maybe I have the problem???
Good day buddy. I'll be monitoring the answers too.
JC
My 2.73 car by 40 mph steady is dead locked, however. The only way to make it slip is by a downshift. I wish it DID slip a little, like yours. So maybe I have the problem???
Good day buddy. I'll be monitoring the answers too.
JC
☠☣☢ Semper Ebrius ☢☣☠
Joined: Jun 2001
Posts: 83,301
Likes: 4
From: Virginia
Cruise-In IV-V-VI-VII Veteran
St. Jude's Donor '06
Re: A4 tranny behaviour (i_york)
Guys, I've noticed that with my tranny in '3', if I accelerate with a moderate throttle input (ie. not enough to downshift) from about 35-40mph, the converter seems to slip (revs stay constant, but road speed increases). The rev counter is showing about 2,000rpm at this point. Is this normal??? I was under the impression that once the converter was over the stall rpm (1,600rpm stock) that the slippage would stop and there would be direct drive via mechanical clutches. I'm assuming I'm wrong (or, at least, I HOPE I am!)
Racer
Joined: Feb 2002
Posts: 301
Likes: 0
From: El Paso
Re: A4 tranny behaviour (Scissors)
That sounds normal. The converter should only lock up above 40 MPH, and then only when giving light throttle. Once you start to get into it, the converter unlocks.
JC
Team Owner
Joined: Jun 2000
Posts: 37,636
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From: Just trying to make it through each day.
Cruise-In III Veteran
Cruise-In V Veteran
St. Jude Donor '03-'04
Re: A4 tranny behaviour (GRAY_VETTE)
Torque converter lock-up is based on speed and throttle angle. The TC will un-lock based on input from the throttle position sensor. You can adjust all of this via the PCM.
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Thread Starter
Burning Brakes
Joined: Mar 2003
Posts: 915
Likes: 1
From: UK
Re: A4 tranny behaviour (Buckmaster)
I've read a LOT about Torque Converters and I'm STILL trying to get my head around it all!
Is it normal for the stock converter (or aftermarket too, for that matter) to slip to the extend that the revs either stay constant while the car accelerates or the revs increase v.slowly... even PAST the rated stall speed of the converter?? :confused:
My converter locks-up fine at 40+mph in 3rd and OD and, without applying the brakes (which will unlock it automatically), takes quite a large throttle input to downshift and unlock.
Can someone also please explain what the clutch packs do?? I'm assuming they don't perform the same function as a clutch on a stick-shift, or the converter would be locked all the time by definition.
I'm sure I'll get all this eventually! :crazy:
:cheers:
Is it normal for the stock converter (or aftermarket too, for that matter) to slip to the extend that the revs either stay constant while the car accelerates or the revs increase v.slowly... even PAST the rated stall speed of the converter?? :confused:
My converter locks-up fine at 40+mph in 3rd and OD and, without applying the brakes (which will unlock it automatically), takes quite a large throttle input to downshift and unlock.
Can someone also please explain what the clutch packs do?? I'm assuming they don't perform the same function as a clutch on a stick-shift, or the converter would be locked all the time by definition.
I'm sure I'll get all this eventually! :crazy:
:cheers:
Team Owner
Joined: Jun 2000
Posts: 37,636
Likes: 0
From: Just trying to make it through each day.
Cruise-In III Veteran
Cruise-In V Veteran
St. Jude Donor '03-'04
Re: A4 tranny behaviour (i_york)
What year is your car? There have been TSB's for the auto tranny....but can't remember when. Or you could very well have a problem. Lock-up also is affected by tranny temps.
Thread Starter
Burning Brakes
Joined: Mar 2003
Posts: 915
Likes: 1
From: UK
Re: A4 tranny behaviour (Buckmaster)
What year is your car? There have been TSB's for the auto tranny....but can't remember when. Or you could very well have a problem. Lock-up also is affected by tranny temps.
All details in sig... car is a 99 with 27k miles. Tranny temps peak at around 215f in slow traffic and sit around 165f on the highway at 80mph.