Rolling back on slope - car in D5

Thread Tools
 
Search this Thread
 
Old 04-22-2004, 05:52 PM
  #1  
1st Gear
Thread Starter
 
momigi's Avatar
 
Join Date: Apr 2004
Location: CA
Age: 57
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
Rolling back on slope - car in D5

Last weekend I was parking my car on a steep upward sloping street at a friends place (the grade/slope was about 15-20 % - my guess). Car was in D5 and moving forward. When car reached in a desired position along the curb, I pressed break to stop it. Then I released the break, car is still in D5, and it started rolling back on the slope as though it was in neutral.

I was surprised as I always thought that automatic car is not supposed to do that. Next day I tried to replicate the problem on some other streets (relatively mild slope) but it did not happen. I was curious so I went back to my friends place and checked again - yes car did it again.

So car rolls back (not skidding), wheels move as if it is in neutral on steep slopes while in D-5.

Am I missing something? Is this normal ?
Or is this some sort of transmission failure? (transmission otherwise works fine).

It is a 2000 TL with 40,000 miles. I bought it a year ago in a private sale.
Old 04-22-2004, 05:54 PM
  #2  
Senior Moderator
 
fsttyms1's Avatar
 
Join Date: Aug 2002
Location: Appleton WI
Age: 49
Posts: 81,383
Received 3,063 Likes on 2,119 Posts
that is normal, every car will do that if the slope is greater than the force of the engines idle.
oh and before you park on a hill you should apply the parking brake, take your foot off the brake (if the parking brake holds) then shift to park
Old 04-22-2004, 10:07 PM
  #3  
Pro
 
Join Date: Jun 2003
Location: Castro Valley, CA
Age: 43
Posts: 598
Likes: 0
Received 0 Likes on 0 Posts
Had a 97 BMW 528i that didn't roll back even on the hills of San Francisco. Don't know how the Germans did it but it was definitely nice.
Old 04-22-2004, 11:50 PM
  #4  
Racer
 
optiq's Avatar
 
Join Date: Sep 2002
Location: kissimmee, fl
Age: 43
Posts: 488
Likes: 0
Received 0 Likes on 0 Posts
does rolling back hurt the tranny or anything because mine does that all the time if its steep enough. i feel like i should be engaging the clutch or something
Old 04-23-2004, 12:22 AM
  #5  
Instructor
 
yoda's Avatar
 
Join Date: Oct 2003
Location: San Francisco, CA
Age: 54
Posts: 126
Likes: 0
Received 0 Likes on 0 Posts
SOme cares have "hill holders"...bmw's I know do as a lot of the lux german cars do..i'm kind of surprised the TL doesn't...but then again, it doesn't have a lot of other "simple" things that it should..but that's for another thread! :toothless
Old 04-23-2004, 01:25 AM
  #6  
Burning Brakes
 
Vicman17's Avatar
 
Join Date: Jun 2003
Location: NNE of 716
Posts: 1,010
Likes: 0
Received 0 Likes on 0 Posts
This was done on purpose as I understand, to help in fuel economy. Even while in gear, it somewhat applies a form of a clutch until the torque converter gets up to speed and moves the car forward.

You'll also find another strange thing- while stopped at level pavement (if your A/C is on) and foot slightly on the brake, you'll find your car start to unexpectedly surge forward. This would surprise mainly AT only drivers since they have their foot rested on the brake while stopped. On the same principle, if the A/C compressor is on, the tranny tries to compensate for the slight power drag and move the idle up slightly. But a car with this much power, your foot should be firmly on the brakes anyway.
Old 04-23-2004, 06:25 AM
  #7  
Purchased: April 28, 2001
 
edgalang's Avatar
 
Join Date: May 2001
Location: Berkeley, CA
Posts: 3,009
Likes: 0
Received 2 Likes on 2 Posts
Originally Posted by momigi
Last weekend I was parking my car on a steep upward sloping street at a friends place (the grade/slope was about 15-20 % - my guess). Car was in D5 and moving forward. When car reached in a desired position along the curb, I pressed break to stop it. Then I released the break, car is still in D5, and it started rolling back on the slope as though it was in neutral.
...
Am I missing something? Is this normal ?
Or is this some sort of transmission failure? (transmission otherwise works fine).
...

This happens to me ALL THE TIME when I'm in San Francisco. When I first noticed it, I immediately wanted to test out how far & fast it'll allow me to roll back.

My GF thought I was nuts since I purposely drove up a HUGE hill (lumbard I think), waited till I was the only 1 on the block, released the brakes so I can roll back, then all of a sudden BAM! Engine shuts off and I lost my power brake! Mind you I was still rolling down when I popped it in neutral & started the engine, but by then I've already rolled down quite a bit.

I doubt it was distance, since I can roll down the hill pretty far without stalling, but it's the RATE of decent that you should worry about. Once you go too fast backwards in D5, the engine will shut down AND you'll be going even faster since you just lost power. So...if someone is not strong enough to stop the car without power brakes, then they'll definitely be OWNED in a matter of seconds.

Now...some of you guys are probably thinking...WTF would you EVER want to roll back in D5?! Well...try parallel parking uphill!
Old 04-23-2004, 09:20 AM
  #8  
Senior Moderator
 
fsttyms1's Avatar
 
Join Date: Aug 2002
Location: Appleton WI
Age: 49
Posts: 81,383
Received 3,063 Likes on 2,119 Posts
Originally Posted by edgalang
This happens to me ALL THE TIME when I'm in San Francisco. When I first noticed it, I immediately wanted to test out how far & fast it'll allow me to roll back.

My GF thought I was nuts since I purposely drove up a HUGE hill (lumbard I think), waited till I was the only 1 on the block, released the brakes so I can roll back, then all of a sudden BAM! Engine shuts off and I lost my power brake! Mind you I was still rolling down when I popped it in neutral & started the engine, but by then I've already rolled down quite a bit.

I doubt it was distance, since I can roll down the hill pretty far without stalling, but it's the RATE of decent that you should worry about. Once you go too fast backwards in D5, the engine will shut down AND you'll be going even faster since you just lost power. So...if someone is not strong enough to stop the car without power brakes, then they'll definitely be OWNED in a matter of seconds.

Now...some of you guys are probably thinking...WTF would you EVER want to roll back in D5?! Well...try parallel parking uphill!
hahahahaha sounds like something i would try (if we had hills big enough around here
Old 04-24-2004, 03:01 AM
  #9  
Three Wheelin'
 
chewi's Avatar
 
Join Date: Apr 2004
Location: Vancouver BC
Age: 42
Posts: 1,672
Likes: 0
Received 1 Like on 1 Post
Originally Posted by fsttyms1
that is normal, every car will do that if the slope is greater than the force of the engines idle.
oh and before you park on a hill you should apply the parking brake, take your foot off the brake (if the parking brake holds) then shift to park
Correct...
i do this all the time..
i never just slam into park without the food brake...
Old 04-24-2004, 07:09 AM
  #10  
Three Wheelin'
 
chewi's Avatar
 
Join Date: Apr 2004
Location: Vancouver BC
Age: 42
Posts: 1,672
Likes: 0
Received 1 Like on 1 Post
oops foot brake
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Yumcha
Automotive News
9
02-25-2020 09:57 AM
james357
Car Parts for Sale
19
02-13-2016 02:37 PM
lland
Car Parts for Sale
6
10-04-2015 04:47 PM
spoiler900
5G TLX Photograph Gallery
11
09-11-2015 09:39 PM



Quick Reply: Rolling back on slope - car in D5



All times are GMT -5. The time now is 01:58 PM.