tuner-automotive Posted October 15, 2007 Share Posted October 15, 2007 I have a 96 outback MT that I just purchased. 180k miles. new oil New tranny oil New air filter. Makes a wierd rattle sound, which I thought was a heat shield but isnt, when I down shidt or let off the gas and let the engine slow the vehicle. Sound is coming from underneath the car . Sounds like its coming from under the middle console, between the seats. Car drives like a champ and doesnt have any clutch slippage or tranny driveability issues. Any ides? Quote Link to comment Share on other sites More sharing options...
uniberp Posted October 15, 2007 Share Posted October 15, 2007 I have a 96 outback MT that I just purchased.180k miles. new oil New tranny oil New air filter. Makes a wierd rattle sound, which I thought was a heat shield but isnt, when I down shidt or let off the gas and let the engine slow the vehicle. Sound is coming from underneath the car . Sounds like its coming from under the middle console, between the seats. Car drives like a champ and doesnt have any clutch slippage or tranny driveability issues. Any ides? The heat shields can be tricky, and can expand and rattle when warm. It could be an internal cat rattle, but the mechanic told my GF that about her Forester adn it turned out to be a heat sheild. The oneunder the center of the y-pipe is expecially tricky to tighetn. I recommend a narrow (.25) hoseclamp. The narrowness allows some spring to be imparted and handle heating and cooling. You can also cut down a wider hose clamp to a narrow profile for a few inches to accomplish the same thing, Quote Link to comment Share on other sites More sharing options...
tuner-automotive Posted October 15, 2007 Author Share Posted October 15, 2007 Thanx. Im kinda leaning on the Heat shields as it olny happens when I down shift from any gear. Doesnt matter if ist warm or cold. Had a passenger w/me yesterday and they thought the rattle was coming from under there bum , LOL. Quote Link to comment Share on other sites More sharing options...
tuner-automotive Posted October 16, 2007 Author Share Posted October 16, 2007 Well it wasnt the heat shields . Inspected , tapped and tightned them all. Could my Viscous Coupler be causing this . The growl or rattle is coming from right in the middle of the car under the center console between the frt seats. This is getting annoying, LOL. Quote Link to comment Share on other sites More sharing options...
xrturbo Posted October 16, 2007 Share Posted October 16, 2007 The viscous coupling shouldn't cause a noise like that. It is probably your front diff the way you described it. Quote Link to comment Share on other sites More sharing options...
tuner-automotive Posted October 16, 2007 Author Share Posted October 16, 2007 Yeah after much reading and education I dont suspect the VC . I dont have any torque bind what so ever. Just a rattle/growl when letting off the gas at above 2k rpms , or downshifting . What type of inspection can I do to check if its the front diff.? Quote Link to comment Share on other sites More sharing options...
WAWalker Posted October 16, 2007 Share Posted October 16, 2007 In front of the rear wheels there are mounting plates for the rear diff. crossmember. These plates sometimes get bent to the point that they will touch the cross member. Makes a terrible noise when you let off the gas. Quote Link to comment Share on other sites More sharing options...
avk Posted October 16, 2007 Share Posted October 16, 2007 Just in case, take a quick look at the flexible joint between the 2d converter and the exhaust pipe. That's what I spent a good part of the past weekend to fix. It wasn't rattling though. Quote Link to comment Share on other sites More sharing options...
tuner-automotive Posted October 16, 2007 Author Share Posted October 16, 2007 Thanx for the info. Yeah it doesnt rattle when accelerating or idle. Just when I let off the gas or down shift . Its weird. Driveline seemed solid and no play. Center heat shield that goes over the driveline was intact and solid. All flex points on the exhaust are good. Ill check those mounting plates tonight when I get home. Quote Link to comment Share on other sites More sharing options...
johnceggleston Posted October 16, 2007 Share Posted October 16, 2007 is it clutch related, when you let off of the gas and it makes the noise, does it go away if you push in the clutch pedal.? Thanx for the info.Yeah it doesnt rattle when accelerating or idle. Just when I let off the gas or down shift . Its weird. Driveline seemed solid and no play. Center heat shield that goes over the driveline was intact and solid. All flex points on the exhaust are good. Ill check those mounting plates tonight when I get home. Quote Link to comment Share on other sites More sharing options...
tuner-automotive Posted October 16, 2007 Author Share Posted October 16, 2007 Yes , it does but I dont suspect the throwout bearing as the sound is no where near the clutch area. Also it doesnt do it when I accelerate. Only on engine deceleration. Yes I have a manual tranny. Quote Link to comment Share on other sites More sharing options...
Virrdog Posted October 16, 2007 Share Posted October 16, 2007 New tranny mount might help out the problem. Check to make sure no exhaust piping is near the crossmember that can come in contact with it. Probably not, but I have a similar noise, but its from a 3" pipe fitting where a 2 something use to be. Quote Link to comment Share on other sites More sharing options...
Hondasucks Posted October 17, 2007 Share Posted October 17, 2007 my old 84 4x4 wagon did something similar when I had a bad tranny mount... Quote Link to comment Share on other sites More sharing options...
tuner-automotive Posted October 17, 2007 Author Share Posted October 17, 2007 WellI got under there yet again tonight and shook and shook the heck out of the driveline . Banged on the all of it with a rubber mallet and still...... Nothing came into contact or resembled the noise Im trying to track down! I even removed all the heat shields from the front cat back. Nothin helped! GRRRRRRR!!!!! The sound is only when I let the vehicle decelerate using the engines back pressure. Not on acceleration . Could a bad front diff cause such a ruckus noise ? And how much play should the tranny mount have ? Quote Link to comment Share on other sites More sharing options...
WAWalker Posted October 17, 2007 Share Posted October 17, 2007 Did you look at the body mounts for that differentail cross member? I have seen this many times. If the plates are not bent check for any mud or rocks stuck between the cross member and plate. Have seen a rock got stuck it there and do the same thing. Quote Link to comment Share on other sites More sharing options...
tuner-automotive Posted October 17, 2007 Author Share Posted October 17, 2007 Yes , I did look at those mounts. I didnt see anything out of the ordinary or alarming but then I dont really know what they should look like? I could move that crossmember just a hair when I wiggled the deiveline . Quote Link to comment Share on other sites More sharing options...
WAWalker Posted October 17, 2007 Share Posted October 17, 2007 Yes , I did look at those mounts.I didnt see anything out of the ordinary or alarming but then I dont really know what they should look like? I could move that crossmember just a hair when I wiggled the deiveline . They have two bolts holding them to the body, they come straight out and should be flat. One bolt going up through the plate, crossmember bushing, into the body. The corners of these plates should not be bent upwards at all. Quote Link to comment Share on other sites More sharing options...
tuner-automotive Posted October 17, 2007 Author Share Posted October 17, 2007 I did look at those plates. They looked intact and unbent. Nothing that caught my attention. I will inspect them closer. Im wondering if my rear tranny mount is possibly shot ??? When I grabbed the front of the driveline and pulled on it , there seem to be signifigant movement. Im doing Timing belt, water pump, seals and front driveaxles beginning of next week so when I have it up off the ground and imobile for a few days Im gonna try and recreate the sound with the wheels off the ground while I hang out below the car. Might aswell replace the mount since itll be up and it doesnt seem like its all that tough to do. Looks like 2 14mm nuts. Quote Link to comment Share on other sites More sharing options...
cookie Posted October 17, 2007 Share Posted October 17, 2007 This could sound kind of like my car. It made noise while backing off for a couple of years. I posted here and setright assured me that many old Subie manuals did that and kept on going. Well mine did for maybe 40,000 miles before the transfer case blew. There is a spacer in the rear of the case that keeps the rear bearing from allowing movement of the gear set back and forth. After some time the transfer gears wear a bit and create play. The gearset then moves backward under load and slams the spacer, and moves forward causing a slight mismesh and noise while backing off. This eventually work hardens the spacer and in my case it shattered. At that point spacer parts went through the rear bearing and into the gearset.This totally trashed gearset and rear bearing and actually locked the car up for a moment. This is really no surprise to Subaru as there is a fix for it. You just install a thicker rear bearing and remove the spacer. Now, $1700 poorer I know this. All I needed to do when I first heard the noise was pull off the tail and change to the thicker bearing, maybe $150. Quote Link to comment Share on other sites More sharing options...
tuner-automotive Posted October 17, 2007 Author Share Posted October 17, 2007 interesting. Anybody know what this bearing is called so when I call the dealership I can ask for the right part? Also, Im a formidable mechanic but havent done any work on subaru trannies and drivelines. Is this a easy to medium fix inthe garage? Quote Link to comment Share on other sites More sharing options...
cookie Posted October 17, 2007 Share Posted October 17, 2007 Call Rudy at San Carlos transmission 650-622-9210. He fixed mine and perhaps he can point you in the right direction. If you can get the car up on a lift and move a stethascope back and forth, if your noise is in the transfer case that may be the problem. Quote Link to comment Share on other sites More sharing options...
tuner-automotive Posted October 20, 2007 Author Share Posted October 20, 2007 Well I cant call long distance and Ive spent more time on my back hunting for this rattle/hum/growl all to no avail. I guess I have to take it to the stealership and see if they can diagnose it. Bummer cause thats gonna cost me. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.