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So I have 2014 Focus ST with 1-2 grinding or when starting off in 2nd. I brought it up to the dealership and after playing their games of the reproducing problem, I finally got them to initiate the replacement process. Later on that day I got a call from the tech who asked me if the has ever been lowered which it has not been. He informed me Ford claims suspensions modifications will cause warranty denial due to, and here I just have to throw out words: Half shaft angle, CV, excessive vibration on transmission throwing off final drive ratio causing damage to transmission. Maybe someone a little more technical could elaborate on this.

So if you have suspension modifications the dealers may try to refuse transmission warranty claims.

I'm sure were all aware of the risk of modding but I figured I would share anyways.
 

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Can you funk a CV half shaft hard enough to cause transmission damage? Yes.

Does what your dealer tech said make any sense? Possible , but not really unless you did some shady stuff to the suspension

A CV Joint (CV = Constant Velocity) is a is a way to transfer rotational energy (ie the turning force) through a drive shaft that changes it's angle. In our ST's case the front axle has two half shafts, each one connect to a hub and front wheel. The wheels/hubs move up and down with the suspension, so the half shafts are not always completely straight and can flex. A CV Joint at each end let them make this movement with out breaking. See example of a half-shaft below:
cv.jpg

The CV Joints and the overall 'Half Shaft' is normally engineered to a certain angle range with limits, and these correspond to the suspension's intended length of travel under normal load.

The issue that can be encountered when the suspension is raised or lowered too far, is the the CVs are stressed more. The bearings can be damaged, and the operation can cause vibrations that can eventually affect the transmission.
 
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Can you funk a CV half shaft hard enough to cause transmission damage? Yes.

Does what your dealer tech said make any sense? Possible , but not really unless you did some shady stuff to the suspension

A CV Joint (CV = Constant Velocity) is a is a way to transfer rotational energy (ie the turning force) through a drive shaft that changes it's angle. In our ST's case the front axle has two half shafts, each one connect to a hub and front wheel. The wheels/hubs move up and down with the suspension, so the half shafts are not always completely straight and can flex. A CV Joint at each end let them make this movement with out breaking. See example of a half-shaft below:
View attachment 289657

The CV Joints and the overall 'Half Shaft' is normally engineered to a certain angle range with limits, and these correspond to the suspension's intended length of travel under normal load.

The issue that can be encountered when the suspension is raised or lowered too far, is the the CVs are stressed more. The bearings can be damaged, and the operation can cause vibrations that can eventually affect the transmission.
Spoken like a Ford Tech. We have a traitor in our midsts!!!

Lol just kidding. Yes, what you wrote is correct and makes sense.
 
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