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'10 3.6R Outback Limited, 2zr swapped Toyota Yaris track toy, '05 AWD Pontiac Vibe
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Discussion Starter #1
I just finished replacing my driveshaft (propeller shaft) on my 2010 OB 3.6R. I have 272k km on it and when I bought it at 254k km I noticed some symptoms of a bad shaft. My two main symptoms were a vibration under the middle of the car during moderate to hard acceleration and a vibration under the front of the car between 100 and 105 km/h. The later never actually vibrated the steering wheel so I knew it was likely a drive line issue (I have oem axles all around).

The vibration at 100km/h recently started a few thousand km's ago and wasn't present when I bought the car. I figured the drive shaft was getting worse so I went under the car and checked it out. The only thing I noticed that was wrong was some small amount of play in the U joint at the rear differential when I put a pry bar to it. I ordered a used one from Car-part.com and had it shipped to my US address. It only had 53k miles on it and was $85 + $45 shipped USD. When I got home from my trek across the border this morning I inspected the joints and bearing. Everything checked out smooth with no play but the front u joint was notchy in the middle of its range of motion. I was pretty pissed since I was thinking I was sent a bad shaft and figured the seller should have checked it first.

After some research online I found out that some notchyness is very common in various manufacturers cars, some people reporting noticing it after 30k miles. Another poster on another subie forum mentioned that he always used used drive shafts and they always were slightly notchy and he never had issues. So I ended up installing it and sure enough, all my symptoms were completely gone. The old shaft had a really bad worn out rear U joint, there actually was very little play in it but it was almost seized on 2 out of the four bearings. The front joint was completely fine however. The middle bearing was bad, it spun too freely and made a quiet grinding noise. More importantly is the middle joint was bad and had play in it, this allowed the two shaft halves to have some play between each other. I am not sure what type of joint the middle joint is but it is the one that also allows the shaft to change lengths.

The install is relatively straight forward, I left the exhaust in place which was fine, I just had to be careful removing and installing the shaft. I only had to remove the exhaust heat shield. The only issue I ran into was the two bolt for the carrier bearing. The holes in the bearing bracket are too close together to easily reinstall the bolt onto the body of the car. I don't see any solution for this other than using a pry bar and struggling with it for a bit. The bolts ended up going in at a slight angle but oddly enough they were not cross threaded. It seems the actual part the bold threads into may have bent slightly. Either way it all worked out fine.

In summary, don't be alarmed if a used shaft has a notchy U joint. As long as the joints are tight and have no play then you should be good to go. Also, without removing the driveshaft it may appear that your current shaft is perfectly fine even though it could have bad joints. In my case my rear seized joint and the play in the middle joint is likely what caused my symptoms. This new (used) shaft should easily last another handful of years.
 
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