I installed a NM Engineering 25mm rear sway bar with the end link kit about a month ago. Recently started to get some knocking sounds from the driver side rear. Strut looked fine. Some threads here suggested checking the sway bar links. They look solid but I noticed the driver side wheel riding a bit lower than the passenger side.

NM Engineering's site has instructions on installation (https://cdn.shopify.com/s/files/1/02...328847.pdf?254) but nothing that outline how or when to adjust the overall length of the link when not using stock springs. I've got H&R lowering springs on now. So, presumably the links should be shorter and equal. But how short? Is there something to measure against? How do I ensure a proper preload?

 

Rule of thumb.

For basic street use.
Arm level to ground. While suspension on ground.
NO preload on the bar.
Remove right side, adjust left until bar is level. The adjust right to fill in the length distance only.

In theory, if the bar was forged perfectly and springs and frame are perfect the links should be equal, but nothings perfect, so one link might end up a different length.

 

OEM ride height, stock links. Actually, stock links will be just fine for any reasonable ride height. They are designed to prevent contact through full suspension travel. The NM links are a terrible design for any daily driver. That type of rod end will always be noisy.

That being said, adjustment should only be performed to eliminate sway bar pre-load. You should be VERY cautious to adjust shorter or longer than stock, since you could cause interference at some point in the suspension travel. To adjust for zero sway bar pre-load, make sure the car is parked 1000% level. First, adjust one of the links to OEM length and install. Then, adjust the second link to OEM length, check length against mounting points, and adjust until bolts align to mounting holes. Ideally, the link would have a center adjustment, similar to the adjustable camber arms, so you don't have to remove the mounting bolts for adjustment. That would be strike two against the NM links.

 

Not on the best coast!! No snow, now, no rain!!!

 

If there's a knocking sound, confirm you did not install the bar upside down. I know, I did it once!!
Disconnect the links, and see if the car is riding level. If it is level, then you do need to adjust links to neutral..