Suspension knock/bang on 07 hawk eye sti
 

ive got quite a serious knocking on the rear of my car more so on the passenger. I was told it might be the top mounts so I changed them and it’s didnt fix it.

But it did make it not as loud for a while till I loaded it up for a trip and it just came back. Can anybody give me any pointers as what it could be.

Ive taken it to my machnic and he can’t find anything wrong with it. thanks

It could be the shock absorbers, they are prone to failure and knocking on the Post 05 widetrack blobs and into the hawkeyes. They changed the design and mounted them upside down and they gather road crud up them and the seals go. Quite common place to replace the lot with coilovers as I think they are £700 quid each from Subaru. My in laws RB320's failed on him and so did my Bro in laws WR1's with the same issue a knocking coming from the rear.

Everyone's go at some point. The Unit on an STI is an inverted one. The damper is OK, it's the bush that sits in the lower leg and allows the shock body to slide in and out. the damper body and oil, etc, is attached to the top mount and is sprung weight and only the bottom leg, which is effectively hollow, and the damper piston are unsprung. Your crazy long, stupid and irritating bump stops live inside the lower leg....

As said, it's an expensive fix as the bushing, if worn, is part of the lower leg.

First step is to get the whole strut off, remove spring, undo the bottom bolt and strip the leg off then clean and fully re-grease the bushing, upper damper body and reassemble and see if that improves it. Often it does.

Failing that, either new units or go to coil overs- a simple BC Racing set will cost the same for 4 legs as your legs do each from Subaru....

If you go that way, as I did 5 years ago, then a tip. I got 5 years and 40,000miles out of mine. The damping sent at the end but no complaints. They do suffer a bit with corrosion, so a can of ACF-50 sprayed liberally on and maybe some socks for the springs to keep the weather off them and crud from the seals may be good. I'm doing that with my replacements.

I only suffered with seizure of one back leg adjuster due corrosion after about 3 /1/2 years in the end, and managed to free it up and re lube ok.

While mine awaits the new shocks, I've stripped the suspension down to check all by bushes and stuff and have sent the rear Whiteline ARB off for powder coating and got new Drop Links. Whiteline's Anti-corrosion is not a patch on BC Racing's efforts! I live on an Island so a lot of corrosive elements to endure. My BC Racing coil over setup passed the test!