oooo Posted June 13, 2009 Share Posted June 13, 2009 I have a 1995 lsi sedan that is lifted with outback struts and 27.5 inch all terrains on it. I swapped in a junkyard 96 legacy outback 4.44 transmission and a 98 forester 4.44 rear diff. The problem is anything above 30 or a steady cruising speed like 55 or 65 there is rattling/whaling sound from the rear(kind of sounds like a loud heat shield rattle when inside the car driving, we checked its not that) and rear driveline vibration. It gets really loud(like a deafening squealing, can't stand under or near car without ear protection) when raised on a lift and the drive line angle is increased and car sped up to 60 mph . When driving on the road it goes away if under throttle but is there all the time when not accelerating. I know Its not from the lift and larger tires. I drove the legacy around on the stock 4.11 auto with the lift and larger tires for like 3 or 4 years with no sounds or problems whatsoever. Thought it might be the driveshaft carrier bearing so swapped in a whole different driveshaft and it still did it. So it wasn't that. A mechanic said sometimes a specific bearing in the tranny gets messed up when in a rear end collision and if that happens it doesn't rotate smoothly and the vibration can get amplified going from transmission to rear diff. Has anybody heard of this? I think I might have found something else that could cause it. I read that the driveshaft flange at the front of the rear diff on a forester is different then the flange on the legacy rear diff. I dont know if its the design or the way it bolts up or what, just that they were different. Does anybody know if thats true? Everything still bolted up, but if its a different even just by a little bit maybe thats causing my problem. Also if anybody elso has had this problem or any suggestions for what else could cause it, Im open to suggestions. Sorry for such a long post Thanks in advance Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted June 15, 2009 Share Posted June 15, 2009 Is the transmission an automatic? If so, try inserting a fuse in the FWD fuse holder. See if the squealing goes away. If the rear diff bolted up to the driveline, I don't see any issue there. Quote Link to comment Share on other sites More sharing options...
mdjdc Posted June 15, 2009 Share Posted June 15, 2009 If you took the tranny out of a 96 outback that was a manual then you have a problem with the final drive. The 96 outback was a 2.2 motor and not the 2.5 driveline. That will most likely be the cause of your noise. If the 96 was an automatic, then I am not sure what the sound could be. Quote Link to comment Share on other sites More sharing options...
oooo Posted June 16, 2009 Author Share Posted June 16, 2009 (edited) sorry I didn't say this first. It was a auto trans legacy to start with and I swapped in the auto trans out of an outback. It still makes the sound when I put in the fwd fuse. I checked that first. But I think the drive line still spins even when its in fwd. Just no power going to the back right? Any Ideas, if you guys can't think of any its probably that bearing in the transmission, and i'll need to start looking for another replacment. I knew that trans and rear diff had to both be 4.44 matching before starting. Unless the junkyard messed up and gave me two 4.11 rear diffs in a row, because i've tried two different rear 4.44 diffs. I think I'm running out of things it could be. Edited June 16, 2009 by oooo Quote Link to comment Share on other sites More sharing options...
wtdash Posted June 16, 2009 Share Posted June 16, 2009 Can you try it w/OUT the driveshaft? Since the FWD fuse should do the same, it probably won't help, but may isolate the issue even more? good luck Quote Link to comment Share on other sites More sharing options...
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