722.9 vs 722.6 transmission (w166 vs w163)
Thread Starter
Super Member
Joined: Sep 2018
Posts: 706
Likes: 114
From: Los Angeles, CA
'22 GLE 350 | '15 ML250 | '87 560SL | '19 GLC 300 | '12 C250 (sold) | '02 ML500 | '98 C230
722.9 vs 722.6 transmission (w166 vs w163)
Hi fellas --
Wanted to throw this out there to the group. Is there a general consensus that that old, bulletproof 722.6 transmission from the w163's was a smoother transmission? (For those who have had both trucks).
Here's the backstory -- I had an 02 500 with 325k miles on the clock, original owner, original engine, tranny, driveshaft and differentials. When i sadly parted with her when I bought the ML250, the most noticeable difference was how the new truck (with 50k miles) shifted compared to old one.
The 500 was so silky smooth in upshifts, and extreme, overtaking downshifts via the kick down pedal, that I was very surprised that the new tranny was no where near as smooth. 5-3 clunks sometimes, you feel the 1-2 and 2-3 shift if you're at lower rpm shift points, leading me to believe there was an issue with the new tranny.
The truck is still under warranty (was cpo), and had her in for the 60k miles service on Friday. I told them to road test it, drive it hard, and pull the codes from the transmission with sds, and drain and refill the tranny fluid. All came back normal, and no shavings in the fluid (did not see for myself though).
I want to drive another w166 and see if it drives the same (this is the only one I've driven) but was curious with the group here if anyone had a similar experience. Before the warranty is up this summer, I'm trying to build a case to replace the transmission if this is not the norm, but am starting to set myself up for "they don't make them like they used to".
Makes me regret selling the 02 sometimes 😔
Wanted to throw this out there to the group. Is there a general consensus that that old, bulletproof 722.6 transmission from the w163's was a smoother transmission? (For those who have had both trucks).
Here's the backstory -- I had an 02 500 with 325k miles on the clock, original owner, original engine, tranny, driveshaft and differentials. When i sadly parted with her when I bought the ML250, the most noticeable difference was how the new truck (with 50k miles) shifted compared to old one.
The 500 was so silky smooth in upshifts, and extreme, overtaking downshifts via the kick down pedal, that I was very surprised that the new tranny was no where near as smooth. 5-3 clunks sometimes, you feel the 1-2 and 2-3 shift if you're at lower rpm shift points, leading me to believe there was an issue with the new tranny.
The truck is still under warranty (was cpo), and had her in for the 60k miles service on Friday. I told them to road test it, drive it hard, and pull the codes from the transmission with sds, and drain and refill the tranny fluid. All came back normal, and no shavings in the fluid (did not see for myself though).
I want to drive another w166 and see if it drives the same (this is the only one I've driven) but was curious with the group here if anyone had a similar experience. Before the warranty is up this summer, I'm trying to build a case to replace the transmission if this is not the norm, but am starting to set myself up for "they don't make them like they used to".
Makes me regret selling the 02 sometimes 😔
Out Of Control!!
Joined: Sep 2018
Posts: 14,668
Likes: 4,569
From: unbegrenzt
2017 GLE350 4MATIC
I have the 722.9 transmission. It is smooth, and it is not perfect.
Driven mildly, the complaint I have is downshift clunks, primarily 3-->2 or 2-->1, when coming to a stop with the foot off the accelerator and off the brake, gear selector in "D" in Comfort mode.
Driven more aggressively, overtaking downshifts seem not well managed, particularly in D/Comfort mode. It seems the transmission does a 2 gear downshift, and the result is jerky. This to me is programming/software, and not related to mechanical hardware. In Sport mode, downshifts happen with less accelerator pedal velocity and displacement, which to me is a more drivable program.
Based on experience and what I have read, I don't perceive a reliability or longevity concern with the 722.9. Driveability however, based on the comments above, is less than class leading. It could be that today we are accustomed to transmissions with more gear ratios. For example, a retired 205,000 mile Toyota 4Runner with a 5 speed seems very un-driveable by today's standards. The 4Runner transmission performs normally, just not comparable to today's 7, 8 and 9 speed units.
The Aisin TR-80SD in my 2010 Touareg, and the ZF 8HP50 unit in my wife's G01 BMW X3 are far better transmissions. I have driven a few C300 and GLC300 loaner vehicles with the 9G-Tronic, and these seem pretty good.
Driven mildly, the complaint I have is downshift clunks, primarily 3-->2 or 2-->1, when coming to a stop with the foot off the accelerator and off the brake, gear selector in "D" in Comfort mode.
Driven more aggressively, overtaking downshifts seem not well managed, particularly in D/Comfort mode. It seems the transmission does a 2 gear downshift, and the result is jerky. This to me is programming/software, and not related to mechanical hardware. In Sport mode, downshifts happen with less accelerator pedal velocity and displacement, which to me is a more drivable program.
Based on experience and what I have read, I don't perceive a reliability or longevity concern with the 722.9. Driveability however, based on the comments above, is less than class leading. It could be that today we are accustomed to transmissions with more gear ratios. For example, a retired 205,000 mile Toyota 4Runner with a 5 speed seems very un-driveable by today's standards. The 4Runner transmission performs normally, just not comparable to today's 7, 8 and 9 speed units.
The Aisin TR-80SD in my 2010 Touareg, and the ZF 8HP50 unit in my wife's G01 BMW X3 are far better transmissions. I have driven a few C300 and GLC300 loaner vehicles with the 9G-Tronic, and these seem pretty good.
Thread Starter
Super Member
Joined: Sep 2018
Posts: 706
Likes: 114
From: Los Angeles, CA
'22 GLE 350 | '15 ML250 | '87 560SL | '19 GLC 300 | '12 C250 (sold) | '02 ML500 | '98 C230
I have the 722.9 transmission. It is smooth, and it is not perfect.
Driven mildly, the complaint I have is downshift clunks, primarily 3-->2 or 2-->1, when coming to a stop with the foot off the accelerator and off the brake, gear selector in "D" in Comfort mode.
Driven more aggressively, overtaking downshifts seem not well managed, particularly in D/Comfort mode. It seems the transmission does a 2 gear downshift, and the result is jerky. This to me is programming/software, and not related to mechanical hardware. In Sport mode, downshifts happen with less accelerator pedal velocity and displacement, which to me is a more drivable program.
Based on experience and what I have read, I don't perceive a reliability or longevity concern with the 722.9. Driveability however, based on the comments above, is less than class leading. It could be that today we are accustomed to transmissions with more gear ratios. For example, a retired 205,000 mile Toyota 4Runner with a 5 speed seems very un-driveable by today's standards. The 4Runner transmission performs normally, just not comparable to today's 7, 8 and 9 speed units.
The Aisin TR-80SD in my 2010 Touareg, and the ZF 8HP50 unit in my wife's G01 BMW X3 are far better transmissions. I have driven a few C300 and GLC300 loaner vehicles with the 9G-Tronic, and these seem pretty good.
Driven mildly, the complaint I have is downshift clunks, primarily 3-->2 or 2-->1, when coming to a stop with the foot off the accelerator and off the brake, gear selector in "D" in Comfort mode.
Driven more aggressively, overtaking downshifts seem not well managed, particularly in D/Comfort mode. It seems the transmission does a 2 gear downshift, and the result is jerky. This to me is programming/software, and not related to mechanical hardware. In Sport mode, downshifts happen with less accelerator pedal velocity and displacement, which to me is a more drivable program.
Based on experience and what I have read, I don't perceive a reliability or longevity concern with the 722.9. Driveability however, based on the comments above, is less than class leading. It could be that today we are accustomed to transmissions with more gear ratios. For example, a retired 205,000 mile Toyota 4Runner with a 5 speed seems very un-driveable by today's standards. The 4Runner transmission performs normally, just not comparable to today's 7, 8 and 9 speed units.
The Aisin TR-80SD in my 2010 Touareg, and the ZF 8HP50 unit in my wife's G01 BMW X3 are far better transmissions. I have driven a few C300 and GLC300 loaner vehicles with the 9G-Tronic, and these seem pretty good.
Junior Member
Joined: Apr 2018
Posts: 27
Likes: 10
From: Potomac MD
2015 ML350
2015 ML350, bought 1/2018 with 15K miles, currently at 35K. No extended factory warranty as I did not purchase at MB dealer.
The transmission is one thing that really surprises me about this car - I didn't test drive it long enough to experience the clunks and jerks and hard shifts that it has at times, 1-2, 2-3, 3-2. While under the factory warranty I had it at the dealer and they supposedly ran all the tests on the transmission and said no problem found. Most of the time it is smooth and a delight to drive, but get it in stop and go rush hour traffic and it can be unpleasant. I find that I'm pretty good at feathering just right on the gas and brakes so that the harsh shifts are minimized, and it is fortunate that I am not in heavy traffic that much. Am somewhat relieved that others have experienced similar. Do worry about the longevity of the transmission and wonder if a fluid change might make any difference.
The transmission is one thing that really surprises me about this car - I didn't test drive it long enough to experience the clunks and jerks and hard shifts that it has at times, 1-2, 2-3, 3-2. While under the factory warranty I had it at the dealer and they supposedly ran all the tests on the transmission and said no problem found. Most of the time it is smooth and a delight to drive, but get it in stop and go rush hour traffic and it can be unpleasant. I find that I'm pretty good at feathering just right on the gas and brakes so that the harsh shifts are minimized, and it is fortunate that I am not in heavy traffic that much. Am somewhat relieved that others have experienced similar. Do worry about the longevity of the transmission and wonder if a fluid change might make any difference.
Thread Starter
Super Member
Joined: Sep 2018
Posts: 706
Likes: 114
From: Los Angeles, CA
'22 GLE 350 | '15 ML250 | '87 560SL | '19 GLC 300 | '12 C250 (sold) | '02 ML500 | '98 C230
2015 ML350, bought 1/2018 with 15K miles, currently at 35K. No extended factory warranty as I did not purchase at MB dealer.
The transmission is one thing that really surprises me about this car - I didn't test drive it long enough to experience the clunks and jerks and hard shifts that it has at times, 1-2, 2-3, 3-2. While under the factory warranty I had it at the dealer and they supposedly ran all the tests on the transmission and said no problem found. Most of the time it is smooth and a delight to drive, but get it in stop and go rush hour traffic and it can be unpleasant. I find that I'm pretty good at feathering just right on the gas and brakes so that the harsh shifts are minimized, and it is fortunate that I am not in heavy traffic that much. Am somewhat relieved that others have experienced similar. Do worry about the longevity of the transmission and wonder if a fluid change might make any difference.
The transmission is one thing that really surprises me about this car - I didn't test drive it long enough to experience the clunks and jerks and hard shifts that it has at times, 1-2, 2-3, 3-2. While under the factory warranty I had it at the dealer and they supposedly ran all the tests on the transmission and said no problem found. Most of the time it is smooth and a delight to drive, but get it in stop and go rush hour traffic and it can be unpleasant. I find that I'm pretty good at feathering just right on the gas and brakes so that the harsh shifts are minimized, and it is fortunate that I am not in heavy traffic that much. Am somewhat relieved that others have experienced similar. Do worry about the longevity of the transmission and wonder if a fluid change might make any difference.
