Hard Acceleration question
Thread Starter
Junior Member
Joined: May 2016
Posts: 33
Likes: 2
740il
Hard Acceleration question
Hey guys,
Just hit 1600 km on the new G63. Took it out on the highway for a quick rip. Have been trying to break it in slowly. Given Covid/working from home, haven't driven the car much the past year. Really the first time on the highway under hard acceleration. Notice its pulling hard to the right. Its my first G wagon, not sure if that is normal or if it has something to do with the differentials? I also had the summer wheel/tires put on yesterday...
Any thoughts guys?
Just hit 1600 km on the new G63. Took it out on the highway for a quick rip. Have been trying to break it in slowly. Given Covid/working from home, haven't driven the car much the past year. Really the first time on the highway under hard acceleration. Notice its pulling hard to the right. Its my first G wagon, not sure if that is normal or if it has something to do with the differentials? I also had the summer wheel/tires put on yesterday...
Any thoughts guys?
Super Member
Joined: Aug 2020
Posts: 783
Likes: 266
G63, G65
Hey guys,
Just hit 1600 km on the new G63. Took it out on the highway for a quick rip. Have been trying to break it in slowly. Given Covid/working from home, haven't driven the car much the past year. Really the first time on the highway under hard acceleration. Notice its pulling hard to the right. Its my first G wagon, not sure if that is normal or if it has something to do with the differentials? I also had the summer wheel/tires put on yesterday...
Any thoughts guys?
Just hit 1600 km on the new G63. Took it out on the highway for a quick rip. Have been trying to break it in slowly. Given Covid/working from home, haven't driven the car much the past year. Really the first time on the highway under hard acceleration. Notice its pulling hard to the right. Its my first G wagon, not sure if that is normal or if it has something to do with the differentials? I also had the summer wheel/tires put on yesterday...
Any thoughts guys?
MBWorld Fanatic!
Joined: Oct 2019
Posts: 5,156
Likes: 1,770
From: Colorado
G550
Hey guys,
Just hit 1600 km on the new G63. Took it out on the highway for a quick rip. Have been trying to break it in slowly. Given Covid/working from home, haven't driven the car much the past year. Really the first time on the highway under hard acceleration. Notice its pulling hard to the right. Its my first G wagon, not sure if that is normal or if it has something to do with the differentials? I also had the summer wheel/tires put on yesterday...
Any thoughts guys?
Just hit 1600 km on the new G63. Took it out on the highway for a quick rip. Have been trying to break it in slowly. Given Covid/working from home, haven't driven the car much the past year. Really the first time on the highway under hard acceleration. Notice its pulling hard to the right. Its my first G wagon, not sure if that is normal or if it has something to do with the differentials? I also had the summer wheel/tires put on yesterday...
Any thoughts guys?
This would be the ESP system - the deactivation switch is on the drivers side of the center console, the botton with the car and curly tire marks.
Last edited by streborx; Apr 10, 2021 at 09:52 AM.
Thread Starter
Junior Member
Joined: May 2016
Posts: 33
Likes: 2
740il
Welcome to G Wagon torque steer. I've never driven a G that didn't have at least a little torque steer under hard acceleration. Some are worse than others (particularly if they are lifted). I was quite surprised when I first got in a 2020 and still had some torque steer when mashing the gas. The worst offender was a 2013 I lifted and it had a 700HP tune. When you mashed the gas you had to hold on for dear life and counter steer just to try and keep it on the road. The new ones aren't quite as bad, but it's still there.
It may in fact just be a function of design and normal, however, I cant seem to find any posts of these newer G63s doing this. It wasnt a slight yaw to the right, it was like a hard dart towards the ditch. Yet driving down the road under low/nil acceleration 100km/hr car is arrow straight. Just during acceleration does it dart right. I have never experienced this hard pulling in any vehicle. This 2020 G63 is totally OEM, running factory 22" Pirelli summers. Summer wheel/tires just got reinstalled Thursday. Do you think this could have anything to do with the summer wheels that were just reinstalled?
Thread Starter
Junior Member
Joined: May 2016
Posts: 33
Likes: 2
740il
There was a similar post a couple weeks ago -- pulling to one side during acceleration. I suggested inspecting the sensors that feed the traction control system. These sensors measure individual wheel rotation and the system applies braking if one wheel is spinning faster than others. This is suposed to prevent the vehicle from yawing when a wheel loses traction, but a defective sensor could result in pulling as you describe during acceleration. I think this system can be disabled -- if this possible, see if the pulling remains.
This would be the ESP system - the deactivation switch is on the drivers side of the center console, the botton with the car and curly tire marks.
This would be the ESP system - the deactivation switch is on the drivers side of the center console, the botton with the car and curly tire marks.
MBWorld Fanatic!
Joined: Oct 2019
Posts: 5,156
Likes: 1,770
From: Colorado
G550
Thanks for the reply. The roads are free from gravel and moister at this point. Factory 22" Summer set was just reinstalled. Just passed the break in point and started to open up the throttle -- this is when it started to pull hard to the right. Truck is arrow straight on the road, its just on acceleration. Given the roads were clear, do you think its a traction thing re: sensors? It almost felt like the outside wheel had more power and was pushing the car to the right.
Trending Topics
Thread Starter
Junior Member
Joined: May 2016
Posts: 33
Likes: 2
740il
UPDATE ___ I took the car out on the freeway. Tried normal, ESP Sport, and ESP OFF, same thing. Irrespective of the speed, once the car is done accelerating and coasting at low revs its arrow straight. But 2k-6k RPM it pulls hard into the right lane.
Conclusion, seems to be only during accelerating the car wants to pull right.
Conclusion, seems to be only during accelerating the car wants to pull right.
MB World Stories
The Best of Mercedes & AMG
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)
Verdad Gallardo
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
MBWorld Fanatic!
Joined: Oct 2019
Posts: 5,156
Likes: 1,770
From: Colorado
G550
UPDATE ___ I took the car out on the freeway. Tried normal, ESP Sport, and ESP OFF, same thing. Irrespective of the speed, once the car is done accelerating and coasting at low revs its arrow straight. But 2k-6k RPM it pulls hard into the right lane.
Conclusion, seems to be only during accelerating the car wants to pull right.
Conclusion, seems to be only during accelerating the car wants to pull right.
Thread Starter
Junior Member
Joined: May 2016
Posts: 33
Likes: 2
740il
Does it feel like the left wheel is pushing you to the right (unbalanced torque distribution) or does it feel like the right wheel is dragging you to the right (possible braking action)? Can you tell if it's the front axle (pulling) or the rear axle (pushing)? Have you also tried disabling the lane keeping assist?
MBWorld Fanatic!
Joined: Oct 2019
Posts: 5,156
Likes: 1,770
From: Colorado
G550
Well no matter what the cause, the effect, IMO, is not normal, and pulling as you describe is a safety issue. On gravel, ice or water, it could cause loss of control. Take your dealership's service manager for a drive and demo this behavior.
MBWorld Fanatic!
Joined: Nov 2002
Posts: 1,028
Likes: 133
From: Massachusetts
2018 GLE350, 2014 G550, 2000 SL500, 1980 TR8, 1995 E320 Cabriolet
The old G chassis used trailing/leading control arms front and back. The new G is independent up front, but I believe it sill uses trailing arms in the rear. Torque steer (e.g., under acceleration) occurs because the 90 degree direction change of torque from the driveshaft through the differential to the axle causes the axle to want to twist. This force is resisted by the trailing arm bushings, the Panhard rod, and the springs, but especially the trailing arm to chassis bushings. These bushing must be compliant enough to allow for normal suspension movement, but rigid enough to keep the axle in alignment. Axle twist under acceleration causes the thrust angle to change from 0 degrees (straight ahead) to a value the pushes the vehicle to the side.
That being said, the torque steer you are observing, especially on a new G, seems very excessive. I would absolutely have the dealer check it out. I have read posts where they shim the trailing arm bushings to correct the axle toe for a 0 degree thrust angle.
FYI: https://www.benzworld.org/threads/de...o-you.3035768/
That being said, the torque steer you are observing, especially on a new G, seems very excessive. I would absolutely have the dealer check it out. I have read posts where they shim the trailing arm bushings to correct the axle toe for a 0 degree thrust angle.
FYI: https://www.benzworld.org/threads/de...o-you.3035768/
Last edited by Floobydust; Apr 13, 2021 at 03:42 PM.
Thread Starter
Junior Member
Joined: May 2016
Posts: 33
Likes: 2
740il
The old G chassis used trailing/leading control arms front and back. The new G is independent up front, but I believe it sill uses trailing arms in the rear. Torque steer (e.g., under acceleration) occurs because the 90 degree direction change of torque from the driveshaft through the differential to the axle causes the axle to want to twist. This force is resisted by the trailing arm bushings, the Panhard rod, and the springs, but especially the trailing arm to chassis bushings. These bushing must be compliant enough to allow for normal suspension movement, but rigid enough to keep the axle in alignment. Axle twist under acceleration causes the thrust angle to change from 0 degrees (straight ahead) to a value the pushes the vehicle to the side.
That being said, the torque steer you are observing, especially on a new G, seems very excessive. I would absolutely have the dealer check it out. I have read posts where they shim the trailing arm bushings to correct the axle toe for a 0 degree thrust angle.
FYI: https://www.benzworld.org/threads/de...o-you.3035768/
That being said, the torque steer you are observing, especially on a new G, seems very excessive. I would absolutely have the dealer check it out. I have read posts where they shim the trailing arm bushings to correct the axle toe for a 0 degree thrust angle.
FYI: https://www.benzworld.org/threads/de...o-you.3035768/
I special ordered the car. Babied it from new. Followed the break-in period. Finally got finished the break-in period then this issue. I was hoping to hear from the dealer this was normal for G wagons and not to worry....
MBWorld Fanatic!
Joined: Oct 2019
Posts: 5,156
Likes: 1,770
From: Colorado
G550
UPDATE: Took the dealership foreman for a test drive. Showed him what was happening. He said, "ohhh no that's not good!" They started working on it. At end of day, they called me and said they've inspected everything, cant find anything wrong. They've set up a ticket with Ontario Corporate. Called me the next day, said still cant find anything. Day 3, still nothing....
I special ordered the car. Babied it from new. Followed the break-in period. Finally got finished the break-in period then this issue. I was hoping to hear from the dealer this was normal for G wagons and not to worry....
I special ordered the car. Babied it from new. Followed the break-in period. Finally got finished the break-in period then this issue. I was hoping to hear from the dealer this was normal for G wagons and not to worry....
It's freakin' scary that cars are now being built with problems which can't be diagnosed, much less repaired. IMO, the dealer needs to be talking to the design engineers in Stuttgart.
Member
Joined: Apr 2020
Posts: 165
Likes: 39
From: NV, UT
2012 Land Rover LR4 5.0L V8 LUX HD
Seems like a severe problem for a brand new high-end vehicle. As a teen I dealt with torque steer in a few cars that would steer just like that video on acceleration. It would pull to one side but you could feel the steering wheel want to go off-center and easily correct it. I'm not sure of the cause, but I heard it was from being front wheel drive and one half-shaft being shorter than the other. The power would go to the shorter shaft and that side would be the direction of pull. So it wasn't a defect, it was a design issue. I'm curious what MBZ has to say after a thorough investigation.
MBWorld Fanatic!
Joined: Nov 2002
Posts: 1,028
Likes: 133
From: Massachusetts
2018 GLE350, 2014 G550, 2000 SL500, 1980 TR8, 1995 E320 Cabriolet
Interesting. The new G has independent front suspension, so the front differential has to be on one side of the engine or the other, so the shafts are of unequal length which may be leading to the age old FWD torque steer problem. As such, it may indeed be a design issue.
MBWorld Fanatic!
Joined: Oct 2019
Posts: 5,156
Likes: 1,770
From: Colorado
G550
Interesting. The new G has independent front suspension, so the front differential has to be on one side of the engine or the other, so the shafts are of unequal length which may be leading to the age old FWD torque steer problem. As such, it may indeed be a design issue.
I have an old Jeep Wrangler with a Dana 30 open differential in the front. When put into 4WD, there's a vacuum actuator that slides an engaging collar on the right side axle to lock the right wheel. These vacuum actuators are notoriously unreliable and generally fail within a couple years, When this happened to me, I replaced the actuator with an aftermarket cable system that requires a 2-step procedure -- putting the transfer case into 4WD and pulling on the cable. Interestingly, this provides another drive mode -- 3WD. If I put the transfer case into 4WD and don't engage the axle collar, all the front end torque is sent to the left side wheel. While the Jeep's puny 4L engine is a windup toy next to the G's 4L TT, I have never noticed that the vehicle wants to drive in circles because there's no torque being sent to the right side wheel.
My money (based on the OP's description of the pulling) is on some braking system malfunction. The dealer's service department -- expertly trained in A and B service intricacies -- is not likely to solve this defect on its own.
Thread Starter
Junior Member
Joined: May 2016
Posts: 33
Likes: 2
740il
I don't understand how torque can be unequally distributed as a consequence of different length axles on each side of the differential. Wouldn't this require one of the axles to continue to twist up like a licorice stick during acceleration? Unless, of course, the limited slip differential is misbehaving.
I have an old Jeep Wrangler with a Dana 30 open differential in the front. When put into 4WD, there's a vacuum actuator that slides an engaging collar on the right side axle to lock the right wheel. These vacuum actuators are notoriously unreliable and generally fail within a couple years, When this happened to me, I replaced the actuator with an aftermarket cable system that requires a 2-step procedure -- putting the transfer case into 4WD and pulling on the cable. Interestingly, this provides another drive mode -- 3WD. If I put the transfer case into 4WD and don't engage the axle collar, all the front end torque is sent to the left side wheel. While the Jeep's puny 4L engine is a windup toy next to the G's 4L TT, I have never noticed that the vehicle wants to drive in circles because there's no torque being sent to the right side wheel.
My money (based on the OP's description of the pulling) is on some braking system malfunction. The dealer's service department -- expertly trained in A and B service intricacies -- is not likely to solve this defect on its own.
I have an old Jeep Wrangler with a Dana 30 open differential in the front. When put into 4WD, there's a vacuum actuator that slides an engaging collar on the right side axle to lock the right wheel. These vacuum actuators are notoriously unreliable and generally fail within a couple years, When this happened to me, I replaced the actuator with an aftermarket cable system that requires a 2-step procedure -- putting the transfer case into 4WD and pulling on the cable. Interestingly, this provides another drive mode -- 3WD. If I put the transfer case into 4WD and don't engage the axle collar, all the front end torque is sent to the left side wheel. While the Jeep's puny 4L engine is a windup toy next to the G's 4L TT, I have never noticed that the vehicle wants to drive in circles because there's no torque being sent to the right side wheel.
My money (based on the OP's description of the pulling) is on some braking system malfunction. The dealer's service department -- expertly trained in A and B service intricacies -- is not likely to solve this defect on its own.
UPDATE: They swapped the wheels from right to left and now the car pulls left. They rebalanced and remounted the wheels/tires, still pulling left. Think its a tire defect. These summer Pirelli tiers have covered ~800km. Dealership is doubtful they will be able to warranty them... WTH am I missing here???
MBWorld Fanatic!
Joined: Nov 2002
Posts: 1,028
Likes: 133
From: Massachusetts
2018 GLE350, 2014 G550, 2000 SL500, 1980 TR8, 1995 E320 Cabriolet
I don't understand how torque can be unequally distributed as a consequence of different length axles on each side of the differential. Wouldn't this require one of the axles to continue to twist up like a licorice stick during acceleration? Unless, of course, the limited slip differential is misbehaving.
I have an old Jeep Wrangler with a Dana 30 open differential in the front. When put into 4WD, there's a vacuum actuator that slides an engaging collar on the right side axle to lock the right wheel. These vacuum actuators are notoriously unreliable and generally fail within a couple years, When this happened to me, I replaced the actuator with an aftermarket cable system that requires a 2-step procedure -- putting the transfer case into 4WD and pulling on the cable. Interestingly, this provides another drive mode -- 3WD. If I put the transfer case into 4WD and don't engage the axle collar, all the front end torque is sent to the left side wheel. While the Jeep's puny 4L engine is a windup toy next to the G's 4L TT, I have never noticed that the vehicle wants to drive in circles because there's no torque being sent to the right side wheel.
My money (based on the OP's description of the pulling) is on some braking system malfunction. The dealer's service department -- expertly trained in A and B service intricacies -- is not likely to solve this defect on its own.
I have an old Jeep Wrangler with a Dana 30 open differential in the front. When put into 4WD, there's a vacuum actuator that slides an engaging collar on the right side axle to lock the right wheel. These vacuum actuators are notoriously unreliable and generally fail within a couple years, When this happened to me, I replaced the actuator with an aftermarket cable system that requires a 2-step procedure -- putting the transfer case into 4WD and pulling on the cable. Interestingly, this provides another drive mode -- 3WD. If I put the transfer case into 4WD and don't engage the axle collar, all the front end torque is sent to the left side wheel. While the Jeep's puny 4L engine is a windup toy next to the G's 4L TT, I have never noticed that the vehicle wants to drive in circles because there's no torque being sent to the right side wheel.
My money (based on the OP's description of the pulling) is on some braking system malfunction. The dealer's service department -- expertly trained in A and B service intricacies -- is not likely to solve this defect on its own.
And I agree with the O.P., there is a tire problem. Maybe one of the treads is molded off side a bit.
MBWorld Fanatic!
Joined: Oct 2019
Posts: 5,156
Likes: 1,770
From: Colorado
G550
___
UPDATE: They swapped the wheels from right to left and now the car pulls left. They rebalanced and remounted the wheels/tires, still pulling left. Think its a tire defect. These summer Pirelli tiers have covered ~800km. Dealership is doubtful they will be able to warranty them... WTH am I missing here???
UPDATE: They swapped the wheels from right to left and now the car pulls left. They rebalanced and remounted the wheels/tires, still pulling left. Think its a tire defect. These summer Pirelli tiers have covered ~800km. Dealership is doubtful they will be able to warranty them... WTH am I missing here???
Tires are warranted separately by the tire manufacturer. The dealer should be able to provide you information about and assistance with filing a warranty defect claim. On the other hand, IMO, the OE Pirelli's are crap and they were the first change I made to my G550 (there are now some neighbor kids enjoying brand new tire swings). There's quite a bit of info in other forum posts about tires, and what others have bought. My replacement selection was fairly conservative, staying as close to OE size as possible (275/55R20), with Yokohama Geolandar A/Ts (mountain/snowflake rated - good year-round in Colorado). My tire dealer said the Pirellis would be shot in 12K, so there was little loss.
MBWorld Fanatic!
Joined: Oct 2019
Posts: 5,156
Likes: 1,770
From: Colorado
G550
There are many factors that cause torque steer, but one of the biggest factors is the differing CV/U-joint angles from side to side that are present on an independent suspension with unequal shaft lengths. The differing angles with respect to the king pins result is a differing torque vector for each wheel (break out your trigonometry book). This loads each side of the suspension differently so the caster/camber/toe changes that occur under acceleration are different. This is not a problem on a solid axle like your old Jeep because the CV/U-joint angles w.r.t. to the kingpin axis are equal side to side regardless of the axle lengths.
