I just put on my new drums (still need new shoes) I made sure everything, king nut and all are tightened down extra good, but there's a knock sound that I can feel in the pedal when I brake harder than lightly. It happens once per wheel rotation and I think it's coming from the wheel that stripped the old drum. What's going on back there?

Stripped the old drum????

 

Well you need new shoes and brake hardware to start off with.

 

It can be a tired spring, a shoe with a flat spot in it, a bad wheel bearing etc etc etc

 

nipper

Stripped the old drum????

 

 

The Drum has a set of splines that the axle goes through; similar to the front hub. The splines will strip out if someone consistently drives in 4wd on dry pavement.

 

I just put on my new drums (still need new shoes) I made sure everything, king nut and all are tightened down extra good, but there's a knock sound that I can feel in the pedal when I brake harder than lightly. It happens once per wheel rotation and I think it's coming from the wheel that stripped the old drum. What's going on back there?

 

Make sure the Castle nut did not loosen up.

 

Did you properly adjust the brake shoes after replacing the drum?

 

Now that you have a good drum, perhaps other problems are coming out of the woodwork. Check the U-joints of the drive line to see if they are wearing out.

The Drum has a set of splines that the axle goes through; similar to the front hub. The splines will strip out if someone consistently drives in 4wd on dry pavement.

 

 

 

.

 

Is it possible the splines werent that great a shape to begin with?

 

 

nipper

Is it possible the splines werent that great a shape to begin with?

 

nipper

 

The damage to the drum was probably caused by the previous owner. The splines will take a fair amount of abuse before they let go.

 

When I was working at a local Subaru shop, I saw 1 or 2 cases of this a year and when we would ask the customer if they played around in 4wd on dry pavement; the usual answer was yes.

I'm pretty sure the splines grooves getting stripped was my doing because of how I didn't tighten the lugnuts and castle nut before and the wheel got all wobbly. The spindle splines on the left rear wheel (the troublesome one) are somewhat more worn down than the right side, but the new drum fits very snugly on it with no wobbling. I did not adjust my brake shoes or anything, I just put the new drums on. Don't know how to "adjust" them but my shoes are unevenly worn and I need to get new ones anyway, it's on my list of things to do.

 

What's strange is that it sounds and feels like something is lightly hitting something else every wheel rotation when braking, like something is "stuck" on the drum or shoe. My car's not going anywhere til I take care of the ignition thing so I will pull off all the wheels in a while and check for foreign objects.

Okay, you really need to adjust the shoes on the side with the new drum. Subaru did not start using automatic adjusting drum brakes until the Gen3s came out, so the shoes are currently set for the old drum. You might as well adjust the opposite side while you are at it. At worse this will make your Subaru safer to drive but it may even resolve the noise issue. There are several posts about how to adjust them so just do a search.

similar problem with me if i slam on them or brake to hard it makes a loud clunk like something banging around in the trunk but up front and no there isnt anything in my trunk havnt really looked into it thought just hoped it would go away lol