jrt2nd Posted November 30, 2010 Share Posted November 30, 2010 Hey all, I'm new to posting on the forum, but have been a reader for a while and found there to be an amazing amount of info here. I just bought a 05 impreza RS, auto tranny, at a really good price knowing that there was a need to have a bit of work done. It seem that the middle diff was going to need to be rebuilt. It was a gamble, and in this case it was a bad one. I put these new michelin snow tire on it that everyone is raving and of course the binding in the middle diff got worse, but it also developed a howl especially on deceleration. I took it to a very reputable tranny guy tat i have used before, and he told me the front diff needed a new ring and pinion as well as a complete rebuild on the tranny, So after a complete rebuild of front diff and tranny, and a fluid change on the rear diff, I still have a howl. The mechanic couldn't figure it out. Could it be those tires? any ideas? Link to comment Share on other sites More sharing options...
lmdew Posted November 30, 2010 Share Posted November 30, 2010 The wheel bearings can cause the howl. It's pretty common. If the backs are going, it seems to be more noticable at highway speeds. If the front's are going the noise will change some when you corner. I take it the trans and front diff gear ratios are the same! Link to comment Share on other sites More sharing options...
1982gl4 Posted November 30, 2010 Share Posted November 30, 2010 +1 on wheel bearings we change them all the time at the shop I work at. Link to comment Share on other sites More sharing options...
nipper Posted November 30, 2010 Share Posted November 30, 2010 All transmission shops are EVIL! I do not care if your father, or Priest (uses it to suppliment his income), or beloved Grandmother turn people evil. As soon as they have the first cup of coffee they start to go towards the dark side. The AWD unit on the tranny could have been replaced all by itself. I have my doubts on the pinion ring. A used tranny would have worked just as well, as that could not have been cheap. If they can not diagnose a wheel bearing noise that is even worse. Wheel bearing. You do know that all four tires must match, be properly inflated, and have equal wear to keep from blowing up the AWD unit. Link to comment Share on other sites More sharing options...
jrt2nd Posted November 30, 2010 Author Share Posted November 30, 2010 The tires are a brand new matched set of michelin X-ice Xi2's. I have read about the wheel bearing issue on this forum, and I dont think its that, because it changes from acceleration to deceleration and from cold to warm operating temp. But I could be wrong. Any other thoughts? Link to comment Share on other sites More sharing options...
Fairtax4me Posted November 30, 2010 Share Posted November 30, 2010 So after a complete rebuild of front diff and tranny, and a fluid change on the rear diff, I still have a howl. OUCH! Tire noise tends to be constant and varies with speed rather than throttle. Have you checked the rear differential fluid? How many miles on this car? Another source of strange noises in the middle of the car and is affected by throttle input is the driveshaft carrier bearing. That tends to cause a wobble/shudder under heavy acceleration, mostly at low speed, and can cause a whining or howling sound at higher speeds similar to a bad wheel bearing. Link to comment Share on other sites More sharing options...
MilesFox Posted November 30, 2010 Share Posted November 30, 2010 possible scenarios: transmission was replaced before, and has the wrong final gear ratio compared to the rear diff. rear diff has been replaced and is wrong gear vs the trans front diff is failing, lack of fluid or wrong fluid Link to comment Share on other sites More sharing options...
jrt2nd Posted December 1, 2010 Author Share Posted December 1, 2010 Interesting thoughts guys. The car has 84k on it. the front diff was rebuilt at the same tie as the tranny, and the rear diff fluid was changed at the same time. milesfox, you're idea of a possible earlier tranny or diff change is very interesting. I will have that checked out. a new development; I'm still getting the lurching or what some call a shudder, in tight turning. Its still binding up. In other words the same reason that the tranny was rebuild and supposed to fix. Another reason why I think Milesfox may be on to something, because it took several hundred miles for it to start binding up again. Also the parking pall won't engage when its put in park. ( I know, some rebuild huh!) I've been told that it is operated electronically. does anyone know if this is true? Link to comment Share on other sites More sharing options...
jrt2nd Posted December 1, 2010 Author Share Posted December 1, 2010 All transmission shops are EVIL! I do not care if your father, or Priest (uses it to suppliment his income), or beloved Grandmother turn people evil. As soon as they have the first cup of coffee they start to go towards the dark side. Interesting and amusing editorial there, nipper Link to comment Share on other sites More sharing options...
Fairtax4me Posted December 1, 2010 Share Posted December 1, 2010 84k seems way too young to have needed a rebuild. However, given the proper amount of abuse or incorrect maintenance, it's entirely possible. Unfortunately. I agree that swapping in a used transmission would have been the better option. Check on the bellhousing for the transmission part number and post it up here. It's on the drivers side near the starter. (I think. That's where it is on the manual at least) It's going to be something along these lines: TZ1A4Z**** The last 4 digits will be a combination of letters and numbers that vary depending on year and final drive ratio (diff ratio). Hopefully we can figure out what trans is supposed to be in there, and if you have the right one. Checking the rear diff ratio is fairly simple if you can count. The front is a bit more involved. Link to comment Share on other sites More sharing options...
lmdew Posted December 1, 2010 Share Posted December 1, 2010 Put the FWD Fuse in the holder to put it in FWD mode. Does the problem go away? I thought you had a 5 sp until you asked about the parking pawl. Link to comment Share on other sites More sharing options...
MilesFox Posted December 1, 2010 Share Posted December 1, 2010 a new development; I'm still getting the lurching or what some call a shudder, in tight turning./quote] some of this would be normal, from my experience. Every automatic awd soob i have driven will make a little bit of noise while tight turning. not anythign binding, but just enough to tell the awd mechanism is working. my 94 legacy wagon(093,000 mi), and my girl's dad's 98 forester(165,000 mi) both do it. There is a thing called the "DUTY C" solenoid that controls how much transfer force there is to the rear wheels, and its designed to let tension off the 4wd while turning to prevent binding, since the trans wants to be in full time 4wd when there is no difference in rotation across the diffs. Link to comment Share on other sites More sharing options...
jrt2nd Posted December 2, 2010 Author Share Posted December 2, 2010 84k seems way too young to have needed a rebuild. However, given the proper amount of abuse or incorrect maintenance, it's entirely possible. Unfortunately. I bought it from a late teens young man. 'nough said? Link to comment Share on other sites More sharing options...
jrt2nd Posted December 2, 2010 Author Share Posted December 2, 2010 There is a thing called the "DUTY C" solenoid that controls how much transfer force there is to the rear wheels, and its designed to let tension off the 4wd while turning to prevent binding, since the trans wants to be in full time 4wd when there is no difference in rotation across the diffs. The solenoid was supposed to be replaced as well as a new clutch pack Link to comment Share on other sites More sharing options...
lmdew Posted December 2, 2010 Share Posted December 2, 2010 Did you try the FWD Fuse? If you get the FWD indicator on the dash and the problem goes away the C-duty is working. Link to comment Share on other sites More sharing options...
jrt2nd Posted December 3, 2010 Author Share Posted December 3, 2010 Did you try the FWD Fuse? If you get the FWD indicator on the dash and the problem goes away the C-duty is working. My fiance' has the vehicle right now, but I will try the fuse as soon as I can. Link to comment Share on other sites More sharing options...
lmdew Posted December 3, 2010 Share Posted December 3, 2010 I'm home this weekend if you want me to take a quick drive. NW side of town. Larry Link to comment Share on other sites More sharing options...
jrt2nd Posted December 3, 2010 Author Share Posted December 3, 2010 I'm home this weekend if you want me to take a quick drive. NW side of town. Larry Shows you how observant I am. I didnt even notice you were in the springs. I'm not sure when the fiance' is getting back with the car. btw, I'm out in the black forest. Link to comment Share on other sites More sharing options...
nipper Posted December 3, 2010 Share Posted December 3, 2010 yes it sounds like a mismatched diff. It is easy to tell on a lift. Start the on the lift raised only high enough to get the tires off the ground. Mark the other 2 wheels with chaulk in matching spots. Since these are open diffs have 2 people san use 2x4's to stop the ine side from spinning. On the side with the marks the tires should stay in synch. Since Autos transfer a minimum of 10% of power to the rear, they will spin. Link to comment Share on other sites More sharing options...
jrt2nd Posted December 4, 2010 Author Share Posted December 4, 2010 Wow nipper! Great idea! One question. Could I do that test by just jacking up one side of the car? Link to comment Share on other sites More sharing options...
1-3-2-4 Posted December 4, 2010 Share Posted December 4, 2010 That's pretty dangerous.. Link to comment Share on other sites More sharing options...
jrt2nd Posted December 4, 2010 Author Share Posted December 4, 2010 How is that any different from stopping the wheels on one side from turning with a 2x4? Link to comment Share on other sites More sharing options...
1-3-2-4 Posted December 4, 2010 Share Posted December 4, 2010 Link to comment Share on other sites More sharing options...
jrt2nd Posted December 4, 2010 Author Share Posted December 4, 2010 Thanks so much, that was a helpful answer;) Link to comment Share on other sites More sharing options...
Fairtax4me Posted December 4, 2010 Share Posted December 4, 2010 (edited) That will work, however, due to things like brake drag, drivetrain friction, etc, the wheels might not all spin at the same rate, even if you block two of them. Blocking wheels isn't all that bad if you have open diffs. You still get some torque transfer, but at idle speed you can hold a wheel still with your hand pretty easy. Not likely to roll off a set of jack stands unless you get carried away and gun the throttle. The better way to block wheels is with wheel chocks though. (read as: chock one side, jack up other side on sturdy jack stands.) Edited December 4, 2010 by Fairtax4me Link to comment Share on other sites More sharing options...
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