Rely18 Posted September 13, 2005 Share Posted September 13, 2005 anyone else hear a thump coming from the rear of the vehicle every once in a while when accelerating from a stop? i have nothing in the trunk but it sounds like a basketball rolling around. maybe i'm missing something? Link to comment Share on other sites More sharing options...
jj808 Posted September 13, 2005 Share Posted September 13, 2005 I heard the same thing when i would shift in the higher gears @ higher RPMS and i was lead to believe that it is the spare tire shifting. Remove it or tighten it down and see what happens. I chose to modify my driving to eliminate the thump instead of removing the tire. Link to comment Share on other sites More sharing options...
rfd425 Posted September 13, 2005 Share Posted September 13, 2005 I wonder how many of these thumps and rattles are attributable to "factory add-ons"...http://legacygt.com/forums/showthread.php?t=18231 Link to comment Share on other sites More sharing options...
Rely18 Posted September 13, 2005 Author Share Posted September 13, 2005 i was thinking that but the sound is more of a bump than a rattle so it makes me think it is something bigger shifting around, not something discrete that could have been placed there by an inconsiderate worker. i'll check the spare... thanks Link to comment Share on other sites More sharing options...
eles1 Posted September 13, 2005 Share Posted September 13, 2005 I wonder how many of these thumps and rattles are attributable to "factory add-ons"...http://legacygt.com/forums/showthread.php?t=18231 That's the first time I saw that thread Link to comment Share on other sites More sharing options...
Brady Posted September 13, 2005 Share Posted September 13, 2005 Oh man, I can't believe no one has caught this yet. It's your differential. It's quite common on Subarus, and as jj808 mentioned, you can make it go away by modifying your driving. Essentially, you need to shift more smoothly. You can also make it happen under sudden acceleration in lower gears or usually during any upshift if done abrupty. Basically, the differential shifts under your car (the rear diff) and you hear the thump when it stops turning. It took me a long time to get used to that in my RS. Was very common in the WRXes too. Link to comment Share on other sites More sharing options...
BoxerGT2.5 Posted September 13, 2005 Share Posted September 13, 2005 Take the bitch out of the trunk. OBAMA......One Big Ass Mistake America! Link to comment Share on other sites More sharing options...
fop377 Posted September 13, 2005 Share Posted September 13, 2005 I had the same thing in my 05 wrx and it drove me crazy!! Also going over speed bumps I will hear a thump but I found out what was causing it.The panel that covers the spare tire was making that noise every time I would go over a speed bump. All I did was put some strips of foam and that fixed the problem. But some Fu kers stole the car from me!~!!1!! And now I have no car or THUMP!!!! BASTARDS Link to comment Share on other sites More sharing options...
canis Posted September 13, 2005 Share Posted September 13, 2005 Dood, you forgot to buckle in your trunk monkey! Poor little fella... Link to comment Share on other sites More sharing options...
BDII Posted September 13, 2005 Share Posted September 13, 2005 Oh man, I can't believe no one has caught this yet. It's your differential. It's quite common on Subarus, and as jj808 mentioned, you can make it go away by modifying your driving. Essentially, you need to shift more smoothly. You can also make it happen under sudden acceleration in lower gears or usually during any upshift if done abrupty. Basically, the differential shifts under your car (the rear diff) and you hear the thump when it stops turning. It took me a long time to get used to that in my RS. Was very common in the WRXes too. I thought I was hearing things..... Need forum help? Private Message legGTLT Link to comment Share on other sites More sharing options...
Guest *Jedimaster* Posted September 13, 2005 Share Posted September 13, 2005 Take the bitch out of the trunk. I'd rather listen to a thump than a nag. Link to comment Share on other sites More sharing options...
mmm def Posted September 13, 2005 Share Posted September 13, 2005 Yeah slow it down a little when shifting like that, your diff will thank you. I'll get it if I nail a 2-3 shift getting on the highway, not good for the car. Link to comment Share on other sites More sharing options...
TSiWRX Posted September 13, 2005 Share Posted September 13, 2005 http://legacygt.com/forums/showpost.php?p=263770&postcount=8 ^ search. <-- I love Winky, my "periwinkle" (ABP) LGT! - Allen / Usual Suspect "DumboRAT" / One of the Three Stooges '16 Outback, '16 WRX, 7th Subaru Family Link to comment Share on other sites More sharing options...
Yukonart Posted September 13, 2005 Share Posted September 13, 2005 Oh man, I can't believe no one has caught this yet. It's your differential. It's quite common on Subarus, and as jj808 mentioned, you can make it go away by modifying your driving. Essentially, you need to shift more smoothly. You can also make it happen under sudden acceleration in lower gears or usually during any upshift if done abrupty. Basically, the differential shifts under your car (the rear diff) and you hear the thump when it stops turning. It took me a long time to get used to that in my RS. Was very common in the WRXes too. Exactly . . . it was even MORE prominent in stock STis. I used to hear that all the time when I was pushing the car and shifting. Urethane bushings for the diff do wonders. (Just cause a tad more ambient road noise in the back) Link to comment Share on other sites More sharing options...
Rely18 Posted September 13, 2005 Author Share Posted September 13, 2005 well i'll take this into consideration but if you read the original post, the noise is not happening during hard driving or hard shifting. it happens every once in a while during normal starts from a stop sign or light. if you think this diff shift can happen under normal acceleration from a stop, let me know... and yes, i did a search and saw that post TSi... but since it didn't apply to my situation, i thought i'd start my own. Link to comment Share on other sites More sharing options...
BoxerGT2.5 Posted September 13, 2005 Share Posted September 13, 2005 I'd rather listen to a thump than a nag. There are better ways to shut them up than rattle them retarded in the trunk. But I like your thinking. OBAMA......One Big Ass Mistake America! Link to comment Share on other sites More sharing options...
Brady Posted September 14, 2005 Share Posted September 14, 2005 well i'll take this into consideration but if you read the original post, the noise is not happening during hard driving or hard shifting. it happens every once in a while during normal starts from a stop sign or light. if you think this diff shift can happen under normal acceleration from a stop, let me know... and yes, i did a search and saw that post TSi... but since it didn't apply to my situation, i thought i'd start my own. Same thing applies. You're applying more torque than usual in a more abrupt manner (by releasing the clutch) and you're hearing the diff thump against the car so to speak because of the torque. It's mostly normal, but as noted, you can probably alleviate the problem by altering your driving. Frankly, unless it's particularly loud when you hear it, you probably needn't worry about it. Edit: and the technique suggested in that linked FAQ is total bullshit. If anything, if your revs are up, that would amplify the problem. The only reason that would work is because you've allowed the RPMs to drop while you're waiting for the "happy medium" or whatever they call it. Rev match and release the clutch smoothly and roll back into throttle and you'll still be fine. Hell, just clutch out smoothly and roll back into throttle, and you're good. It's all about being smooth. Link to comment Share on other sites More sharing options...
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