Knocking sound, universal joint?

[Hatchet]

EA81 wgn 4wd

 

I've got this knocking sound coming from the rear. I can only hear it at low speed like 5 mph. Could it be the universal joint? If so where would I find a new one? At an autoparts store like Napa or would I have to go to a dealer?

[hooziewhatsit]

to check the u-joint, just crawl under the car and start feeling for a loose joint in the driveline.

 

Also, check the axle nuts on each of the rear wheels. They can make nasty knocking noises if they're loose.

[Subarian]

If you can sit in the rear seat while someone else drives, it makes it a lot easier to locate the noise. If it's coming from either side, it could be the wheel bearing or loose axle nuts. If it's coming from the center, I'd suspect the U joint.

 

BTW, where in Utah are you?

[pattiandruss]

Yes, it could certainly be a ujoint. Try to rotate the shaft in both directions, and also shake it sideways. Mine has sideways movement, and it causes quite a little rattle under the right conditions. I figure that an old Sub doesn't have enough power to break anything, so I'm just running it until it gets worse. Russell

[Guest shadow]

I just diagnosed the same problem on one of my RXs. I was POSITIVE it was a loose rear axle or the rear u-joint, but it turned out being the ujoint right behind the trans has some side play. Just shows how hard it can be to tell where a noise is coming from when setting in the driver's seat.

 

Rockford has a joint for our application, 430-10. I did this on my other RX not long ago and it has been going strong.

 

Reference: http://www.ultimatesubaru.org/forum/showthread.php?t=28208

[Hatchet]

Thanks for the replies! I'll do as advised tomorrow. I've been ignoring it for awhile but I think I better figure out what it is before I get a hundred miles out in the desert from any town and break down. I just did a major tune up including installing new front springs, mounts and struts. I figure I might as well get this noise fixed also. I need another 18,000 miles to hit 300,000 and I need something to get me out in the middle of the desert and back for another year.

 

 

 

Subarian, I guess you would call it central Utah. It is about two hours south of Orem. I get to off road in some pretty rough stuff in any direction just minutes from town. Red rock country, but not as close to Moab as I would like. I moved from Provo last spring, I was sick of that place, the traffic, and the stupid drivers. The only thing I like about that area was Van Wangenens pawn shop.

 

You might have seen my Soob. An 83 red wgn with black Por15 on the rust over rear wheels. I never saw another one like it in Utah county... Or the rest of the state for several years now.

[[HTi]Johnson]

... I figure that an old Sub doesn't have enough power to break anything, so I'm just running it until it gets worse. Russell

 

That's what the prior owner of my wagon thought. The U joint went and busted the rear output shaft housing on the tranny all to hell.

[Guest shadow]

I ordered the 430-10 joints for my 2nd RX and they came today. To my surprise they will NOT fit the driveshaft on my RX, even though the shaft on my other RX used the 430-10 joints. I suspect the shaft on that RX may have been replaced with a shaft from a normal 5 speed d/r non-turbo car, as I found out today are compatible, just with the smaller joints.

 

I am going to measure the joint tomorrow and order a bigger joint from Rockford if I find they have an application that fits. These joints are not staked in like they are on the smaller u-joints, but they look factory, there does not appear to be any evidence of grinding out older stakes or anything of the sort. The entire yoke assemblies are much heavier built. I will report back with the proper size joint for this "heavy duty" RX shaft when I measure it.

 

It could also be that a driveline shop built this shaft with new yokes that accepted replaceable joints, but i doubt it since the heavy duty joints that are in there are internally clipped just like the rockford replacements are.