What's the general take when we replace suspension parts? Is it really necessary to preload the Rx and imitate ride height when we swap out suspension parts like control arms and etc? Most shops would not bother doing this, what's the impact on this on your new suspensions? Wearing out faster? Or would ride quality become poop?

 

The physics behind preloading is determining the natural position of flexible links and then affixing them there. While moving the parts would flex on both sides of the normal/unstressed/natural position. This gives balanced flex back of moveable parts. This results in longest life and no bias towards return to "normal". Extreme travel may exceed the limit on one end, resulting in premature failure.

If a shop does not follow this, they are essentially trying to maximize on the labor charged [labor charges are pre-established based on the job and not the actual time taken]. So a short cut benefits the shop. I would say the shop should not be in business. I know I am being harsh as I expect the shop to follow published specs when torquing fasteners. Since most don't, I prefer doing the work myself.

Realistically most folks expect things to be in perfect shape when the purchase the vehicle and as time lapses [near end of ownership] they treat the vehicle as a disposable item. That is the reason why multiple owner vehicle is usually the worst kept.

Since you asked for the 'general take', I am sure my expectations will be biased.

Salim

 

I agree with you and feel the same way, that's also the reason I try to do things myself too. But some items are just not possible without the right tools. I know for a fact that most, if not all of the mechanics in the metro area of NY do not pre-load the car before they torque down the fasteners; nor are the torque values anywhere close to the factory specs.

I just recently went to a shop to replace my rear control arms, the upper bolt is near impossible to get to without a lift of some sorts to give clearance/access from underneath the car. Assuming they didn't pre-load, aside from early failure of the bushings- are there any other negative impacts on the suspension/car ride itself?