rubberman Posted November 21, 2008 Share Posted November 21, 2008 I recently added an IPT VB to my 5EAT, everything has been fine. Trans shifts nice and firm, no diff/trans gear noise or any symptoms. Front/Rear Diffs & trans fluids replaced with quality synthetics some time ago and are at correct levels. On my way to work this morning (~25 degrees F; after driving about 10 miles, so everything was warmed up) I got on the gas pretty hard after turning right at a stop sign. The car started immediately moving of course, breaking the front wheels loose while accelerating. When the trans shifted into 2nd, I heard a pronounced clunk (loud) coming from the rear of the car. The sunroof cover partially opened (maybe 2 inches) during the trans shift & clunk. I've never heard this clunk sound before. It is repeatable, I tried the same near WOT coming out of another turn from a near stop (~10mph) and got the clunk sound again. I have about 51k miles on the car, Rallitek trans mount, stock springs/struts, Perrin RSB/endlinks/HD SB mounts. I don't think that anything is rolling around in the spare tire well or in the tray above it so I can only assume some type of rear diff noise? I have been running Cobb OTS stage 2 map since about Feb 08 and the car has NOT been brake launched, only WOT throttle a few times from a stop but mostly only while rolling/after a sharp turn. I'm probably a bit sensitive to drivetrain/shift noises anyway, but this sound being somewhat new was what alarmed me. Anyone else with a 5EAT experience anything similar? Link to comment Share on other sites More sharing options...
Habitual Line Stepper Posted November 21, 2008 Share Posted November 21, 2008 I also have the VB, i've experienced a clunk, but not to the magnitude your talking about. And not during a turn, my clunk happens when i'm upshifting on a hill. Check tranny fluid and reset the TCU. "I for one do not doubt you, dude. Your car is fast and an internet legend." -Gire Link to comment Share on other sites More sharing options...
rubberman Posted November 21, 2008 Author Share Posted November 21, 2008 The clunk actually occurred after the car had straightened out. I know that the trans fluid is ok, I just re-checked the level a few days ago. I'm not aware of a way to reset the TCU other than the dealer / Subaru Select Monitor tool unless you know of another method? Link to comment Share on other sites More sharing options...
Habitual Line Stepper Posted November 21, 2008 Share Posted November 21, 2008 The clunk actually occurred after the car had straightened out. I know that the trans fluid is ok, I just re-checked the level a few days ago. I'm not aware of a way to reset the TCU other than the dealer / Subaru Select Monitor tool unless you know of another method? How many miles has that VB been in? This may be one of the weird things it does during a break in. I recently popped that damned overboost CEL, and reset my ecu to get rid of the CEL. After that my tranny started doing weird things, this cell has hit me a couple times before and i can tell you that after 200-300 miles of driving after the reset the tranny goes back to normal. Now i have an 07 and i dont know what the CANBUS system does or what it is, but it seems that i can reset the TCU with my AP. So if your still within the breakin period i'd say its just weirdness and should go away or lessen. "I for one do not doubt you, dude. Your car is fast and an internet legend." -Gire Link to comment Share on other sites More sharing options...
Beanboy Posted November 21, 2008 Share Posted November 21, 2008 Rear diff can bang on hard shifts, common with Imprezas. Assume the issue can carry over to newer Legacy. Harder shifts, little power boost thanks to cold weather, and perhaps temp and age might have made rear diff bushings not up to the task. Just a guess... -B http://www.standardshift.com Link to comment Share on other sites More sharing options...
rubberman Posted November 21, 2008 Author Share Posted November 21, 2008 How many miles has that VB been in? This may be one of the weird things it does during a break in. I recently popped that damned overboost CEL, and reset my ecu to get rid of the CEL. After that my tranny started doing weird things, this cell has hit me a couple times before and i can tell you that after 200-300 miles of driving after the reset the tranny goes back to normal. Now i have an 07 and i dont know what the CANBUS system does or what it is, but it seems that i can reset the TCU with my AP. So if your still within the breakin period i'd say its just weirdness and should go away or lessen. I've had the VB in for about 350-400 miles now. Thinking back, I really haven't gotten on the gas that hard (maybe 75% throttle) since the VB install, this morning was probably 95% throttle. It may very well be the TCU is still adjusting. I don't get the impression that my AP will reset the TCU on my 05 LGT. I even purchased another aftermarket scan tool to check some CEL codes from a VB sensor issue during the 1st install attempt and while it can clear CEL trans codes, I don't know that it can actually reset the TCU. Would surely be nice if someone ever cracks the TCU and gets some solid knowledge about the parameters. Link to comment Share on other sites More sharing options...
rubberman Posted November 21, 2008 Author Share Posted November 21, 2008 Rear diff can bang on hard shifts, common with Imprezas. Assume the issue can carry over to newer Legacy. Harder shifts, little power boost thanks to cold weather, and perhaps temp and age might have made rear diff bushings not up to the task. Just a guess... Sounds exactly like what I heard. Almost as if the driveshaft / rear diff wound up a bit and then transferred power to the rear pretty hard. Doesn't the Subie AWD system transfer more power to the rear wheels during hard acceleration? Following that logic, it would make sense that once the front tires start spinning, the AWD will attempt to recognize heavy accel and try to transfer quite a bit of torque to the rear resulting in the load-up of the rear diff and subsequent clunk. I can say that it seemed like when the clunk occurred, the rear seemed to really squat and and hook up (don't think it was spinning) causing the sunroof shade to open slightly. Thanks for the info guys. Link to comment Share on other sites More sharing options...
scoobydoobie Posted November 21, 2008 Share Posted November 21, 2008 I sometimes experience the exact same thing, but only on the 2-3 shift. My thread here: http://www.legacygt.com/forums/showthread.php?t=81399 You can definitely hear it and feel it every now and again. Hopefully after my 30K mi service and the tranny gets flushed, the transmission will be a bit happier. My shifts in "D" seem sloppier and to take longer than before. I never have launched the car nor tracked it since I've had it, but who knows how the previous owner drove it for 19K miles. Link to comment Share on other sites More sharing options...
atc5 Posted November 21, 2008 Share Posted November 21, 2008 I get the clunk all the time now when I turn and jam on it such as turning after a stop sign and trying to kick out the rear end. No big deal as I figure it's a bushing or maybe even the rear sway bumping something or another. My hope is that no long term damage is being done Link to comment Share on other sites More sharing options...
SeeeeeYa Posted November 21, 2008 Share Posted November 21, 2008 Gentlemen: http://legacygt.com/forums/showthread.php?t=48567 Link to comment Share on other sites More sharing options...
Habitual Line Stepper Posted November 21, 2008 Share Posted November 21, 2008 Gentlemen: http://legacygt.com/forums/showthread.php?t=48567 Interesting, thanks i'll review the thread and see if i have any of the symptoms. "I for one do not doubt you, dude. Your car is fast and an internet legend." -Gire Link to comment Share on other sites More sharing options...
rubberman Posted November 22, 2008 Author Share Posted November 22, 2008 Gentlemen: http://legacygt.com/forums/showthread.php?t=48567 Excellent info, but boy was it ever a novel to read - 41 pages and still ongoing. Sounds like: 1. I haven't trashed something, and 2. might be a while before we have the bushings/parts to fix the issue. I'm subscribing to the other thread. Link to comment Share on other sites More sharing options...
fishbone Posted November 24, 2008 Share Posted November 24, 2008 May I advise you people to not give the car hell until it's been fully warmed up? I'm not insinuating that's what happened here, just mentioning it. If I were to get in the car on a cold morning and whip her, I'd expect stuff to clunk, act funny, or break. rubberman, I'm interested to find out your impressions on the VB behavior versus stock shifting. Link to comment Share on other sites More sharing options...
rubberman Posted November 24, 2008 Author Share Posted November 24, 2008 May I advise you people to not give the car hell until it's been fully warmed up? I'm not insinuating that's what happened here, just mentioning it. If I were to get in the car on a cold morning and whip her, I'd expect stuff to clunk, act funny, or break. rubberman, I'm interested to find out your impressions on the VB behavior versus stock shifting. I'm not sure I understand why you posted the statement regarding allowing the car to warm up? Perhaps that was intended for another thread? If not, I'll ask you to re-read my original post. My car was warmed up fully after 20 minutes of driving, so that was not related to my issue. While I understand your intent, I don't want someone to come across this thread and think that I am hammering the hell out of the car as soon as it leaves the garage in 20 degree temps and assume that I am the problem. Per the thread that Seeeeya linked, this is seemingly more of an issue with the rubber bushing material used in the rear suspension & diff mounting points. If 20-30 F degree weather is enough to degrade the performance of a material in a car used on multiple continents, then maybe the material wasn't the optimum choice? Age and mileage could also be at play here and it might just be time to replace these problem bushings. The VB does shift quicker/firmer during WOT, overall I like the upgrade. The trans feels much more "connected" when in sport or regular drive mode (like holding in one gear on a MT for better throttle response), so it makes it much nicer moving around in traffic or merging on a short on-ramp. I just feel like there's less gray area as to when the trans will shift. Link to comment Share on other sites More sharing options...
fishbone Posted November 24, 2008 Share Posted November 24, 2008 I posted the statement just as a general heads-up for anyone else that might be reading it, to make sure they get that possibility out of the way. Link to comment Share on other sites More sharing options...
ArcTec34 Posted July 14, 2009 Share Posted July 14, 2009 my tranny is "clunking" every once in a while as well, how do I reset the TCU learning? Link to comment Share on other sites More sharing options...
ArcTec34 Posted July 14, 2009 Share Posted July 14, 2009 hmm I guess I'll try to explain my "clunking" a little more. it only happens under like 1/4 throttle, from 2-3 gear shift, it just has a little "clunk". I have a 2006 5eat, with 20,000 miles. I just went stage 2 a few months ago, but I never really abuse my car. and under WOT and all other throttle levels, higher and lower, it shifts perfectly. Link to comment Share on other sites More sharing options...
jim1969 Posted July 14, 2009 Share Posted July 14, 2009 anyone have any clunking when coming to a stop? 4->3 gear. Link to comment Share on other sites More sharing options...
snow05gtRI Posted July 15, 2009 Share Posted July 15, 2009 are you shifting yourself from 4>3 or when you feel the car do it on its own? Link to comment Share on other sites More sharing options...
jim1969 Posted July 15, 2009 Share Posted July 15, 2009 when the car does it on it's own. Like coming to a stop sign or stop light. I know it's 4>3 because if you put it in sport mode, manually go up to 5th gear then come to a stop, it will automatically down shift for you. I happens exactly when the gear shift indicator goes from 4 to 3 on the dashboard. Link to comment Share on other sites More sharing options...
fishbone Posted July 15, 2009 Share Posted July 15, 2009 my tranny is "clunking" every once in a while as well, how do I reset the TCU learning? Only the dealer can do this with the Subaru Select tool. Resetting the ECU does nothing, disconnecting the battery does absolutely nothing either. Link to comment Share on other sites More sharing options...
snow05gtRI Posted July 15, 2009 Share Posted July 15, 2009 have you tried doing 4>3 on your own to see if you get the same result? what it seems like (to me) is unless you have the torque converter locked when you downshift, it is spinning freely and sometimes when it downshifts it grabs finally and the tranny isnt ready or something. i've also felt this happen in "Sport" mode but not manumatic. For me, manumatic doesnt seem to downshift on its own until i get to about 20mph and then it quickly goes 5>4>3....>2 Link to comment Share on other sites More sharing options...
fishbone Posted July 16, 2009 Share Posted July 16, 2009 +1 that's what the usual manumatic behavior should be. It downshifts really late in the rpms (as in, high gear, low rpms) to make the downshifts smooth and you should not feel any of them. ATF fluid changed recently? Link to comment Share on other sites More sharing options...
jim1969 Posted July 16, 2009 Share Posted July 16, 2009 It's worse in normal mode. Very slight in SportMode. I don't usually manually shift it. Fluid changed recently. Link to comment Share on other sites More sharing options...
fishbone Posted July 16, 2009 Share Posted July 16, 2009 What transmission fluid have you used? Was it flushed or just drained? Link to comment Share on other sites More sharing options...
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