Doesnt changing tires from OEM spec endanger the transmission?
05-16-10, 09:45 AM
#1
Pole Position
Thread Starter
Doesnt changing tires from OEM spec endanger the transmission?
I know a ton of you guys modify your tire specs and more, but isnt this a root cause of transmission problems?
The transmission and gear shafts are designed with particular wheel sizes. Once you start to deviate from the tire size it was designed for, you start to introduce variation to the transmission(ie transmission of torque, speed of shafts, etc)...especially in the AWD transmissions.
I used to work for a heavy duty transmission manufacturer and included the size of wheel as part of the entire design.
These trannies are electronially controlled but are not designed to self diagnose the size of wheel it is driving power to.
What am I missing? I have been wondering why the poor scores in consumer surveys for this car...especially for the AWD...and this is the only root cause I can come up with.
Thoughts?
The transmission and gear shafts are designed with particular wheel sizes. Once you start to deviate from the tire size it was designed for, you start to introduce variation to the transmission(ie transmission of torque, speed of shafts, etc)...especially in the AWD transmissions.
I used to work for a heavy duty transmission manufacturer and included the size of wheel as part of the entire design.
These trannies are electronially controlled but are not designed to self diagnose the size of wheel it is driving power to.
What am I missing? I have been wondering why the poor scores in consumer surveys for this car...especially for the AWD...and this is the only root cause I can come up with.
Thoughts?
to the tranny
05-16-10, 04:13 PM
#7
Pole Position
Thread Starter
Building with safety factors is standard to provide reliability within a certain predetermined designed range...but when you are using tires with diameters different for which it was designed (which affects the transfer ratios from the transmission to the tires), the tranny will suffer from premature stress (thus the vibrations, I assume some of you are feeling)...leading to early failure.
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05-16-10, 04:32 PM
#8
I really do not want to debate this issue, but I am curious now to know why Manufacturers offer accessories for all their model ranges?
AMG offer wheels for all MB models
F-Sport offer wheels for lexus models
You canorder or retrofit different diamter wheels from 17 inch to 20 inch on any BMW model straight from the dealer or manufacturer
etc etc
AMG offer wheels for all MB models
F-Sport offer wheels for lexus models
You canorder or retrofit different diamter wheels from 17 inch to 20 inch on any BMW model straight from the dealer or manufacturer
etc etc
05-16-10, 05:24 PM
#9
I'm with Designo on this. It's clearly non-sensical to think that the transmission is designed for a "specific" wheel size when Lexus themselves sell the same car with either 17", 18" or 19" F-Sport wheels. I would agree that if you deviate substantially from this range there would be a problem, but if you stay close your should be fine.
Given the largest Lexus OEM wheel for the GS is a 19" wheel, I would say 20" should be fine. I would certainly have concerns about 22" wheels.
For me the bigger concern is if the fitment is not perfect or if you are using spacers, this can cause strain which may cause damage over time. I know my cousin destroyed his S-class with aftermarket wheels and has sworn off them since. This said if you go with a 20" wheel that has an OEM fitment and doesn't need spacers - you are golden.
Given the largest Lexus OEM wheel for the GS is a 19" wheel, I would say 20" should be fine. I would certainly have concerns about 22" wheels.
For me the bigger concern is if the fitment is not perfect or if you are using spacers, this can cause strain which may cause damage over time. I know my cousin destroyed his S-class with aftermarket wheels and has sworn off them since. This said if you go with a 20" wheel that has an OEM fitment and doesn't need spacers - you are golden.
05-16-10, 06:46 PM
#10
Pole Position
Thread Starter
The 17's-19's should operate within spec....otherwise they would not offer them.
Agreed, it is when I see those 22's is when I wonder if it could have an impact.
Agreed, it is when I see those 22's is when I wonder if it could have an impact.
05-16-10, 06:58 PM
#11
[QUOTE=MelYW;5491399]I know a ton of you guys modify your tire specs and more, but isnt this a root cause of transmission problems?
I know that lifted trucks have problems with their rear end when they go over a certain size tire and that's why they re-gear so the tranny won't burn up. With 20's the overall diameter is about the same as stock. I never hear of a transmission go out due to aftermarket wheels. If that was the case someone would have proved it and the market for rims would shot out the window.
I know that lifted trucks have problems with their rear end when they go over a certain size tire and that's why they re-gear so the tranny won't burn up. With 20's the overall diameter is about the same as stock. I never hear of a transmission go out due to aftermarket wheels. If that was the case someone would have proved it and the market for rims would shot out the window.
05-16-10, 07:15 PM
#12
[QUOTE=Bambigular;5492463]
Super chargers and turbo's does a lot of dmg to the engine tranny ETC ECT. Do it on you're own risk. On our doors its says don't exceed more then 900 pounds on weight in the car, if you do its on you.Also lets keep a main factor in mind that our car's are new if you tried doing this on a older car with a lot of mile's you would definatly feel it much more.
I know a ton of you guys modify your tire specs and more, but isnt this a root cause of transmission problems?
I know that lifted trucks have problems with their rear end when they go over a certain size tire and that's why they re-gear so the tranny won't burn up. With 20's the overall diameter is about the same as stock. I never hear of a transmission go out due to aftermarket wheels. If that was the case someone would have proved it and the market for rims would shot out the window.
I know that lifted trucks have problems with their rear end when they go over a certain size tire and that's why they re-gear so the tranny won't burn up. With 20's the overall diameter is about the same as stock. I never hear of a transmission go out due to aftermarket wheels. If that was the case someone would have proved it and the market for rims would shot out the window.
05-17-10, 06:09 AM
#13
Lexus Test Driver
from what ive heard around is that you have like a 2 size up leeway, ie you have stock 17 you can go up to 19 with no problems, having bigger wheels does play some havoc on your tranny also on your odometer they say you are actually are going faster than it shows not too certain about that but thats what ive heard in talks about bigger wheels on cars and such
