Welcome to the North American Subaru Impreza Owners Club Monday July 14, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Subaru Models > Legacy Forum

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 01-13-2012, 03:24 PM   #1
MDRSK
Scooby Newbie
 
Member#: 226510
Join Date: Oct 2009
Chapter/Region: MAIC
Location: Maryland
Vehicle:
2001 Legacy GT
Black

Default Differential Thud?

Trouble with trying to use the search function for something is you have to know how to describe it in a way that others would have described it...

Here is something close to what I am experiencing: http://forums.nasioc.com/forums/showthread.php?t=116310

Only difference is that it is not when I remove foot from the clutch (although that does happen sometimes), but it happens simply from taking the foot of the gas pedal quickly, i.e. deceleration. These thuds which seem to be coming from the differential do not happen all the time but happen fairly regularly. Any ideas?

I will be taking the car to the dealer on Monday for an oil change. I am the original owner of a 2001 Legacy and it is just at 198K miles. So I do not think it is my driving style as I have been driving manual transmission cars for the past 30 years and this car exclusively for the past 10+.

Just started happening since summer... Coinicidentally around the same time I started teaching my son how to drive a manual. I do not think he did anything too terribly wrong other than reving too high on inclines to avoid stalling.

Any assistance is greatly appreciated.
* Registered users of the site do not see these ads.
MDRSK is offline   Reply With Quote
Old 01-13-2012, 11:46 PM   #2
Frogsthatmoo
Scooby Specialist
 
Member#: 153374
Join Date: Jul 2007
Chapter/Region: South East
Location: Ocala, FL
Vehicle:
2001 Outback Wagon
White

Default

This one

ANNDDDDD


This one here

Read both of those. See if any of that helps a little.
Frogsthatmoo is offline   Reply With Quote
Old 01-14-2012, 06:35 AM   #3
MDRSK
Scooby Newbie
 
Member#: 226510
Join Date: Oct 2009
Chapter/Region: MAIC
Location: Maryland
Vehicle:
2001 Legacy GT
Black

Default

Thanks, Frogs. Most of the scenarios are not exactly the same, although JLaw3000's description is pretty close. But I get the connection you picked up on. I actually was thinking motor mounts initially, but when my son indicated that he felt the thud in the rear and suggested the rear differential I started directing my attention in that area.

I did not realize that there were rubber mounts for the rear diff and will check them out (or more likely as the dealer to check them out). I am happy that my Legacy GT has the rear diff LSD, but wonder if the thump may be more pronounced than if I had a regular open diff?

Anyway, your analysis makes the most sense to me and with almost 200K miles that seems like a likely reason. Any idea how much dealer will charge to swap out the mounts? Thanks again.
MDRSK is offline   Reply With Quote
Old 01-14-2012, 11:43 AM   #4
Frogsthatmoo
Scooby Specialist
 
Member#: 153374
Join Date: Jul 2007
Chapter/Region: South East
Location: Ocala, FL
Vehicle:
2001 Outback Wagon
White

Default

You're welcome. I figured it was worth looking at the mounts before breaking open a diff. Also, I doubt the LSD has any part in the noise.

A dealer would probably be in the range of a couple hundred bucks. The mounts themselves are really cheap, but labor may be like 2 hours. If you have a local indie mechanic that you know of, I'm sure they'd be more than willing to put the car in the air and check out some of the mounts. Or you could even try having the dealer do it for free.
Frogsthatmoo is offline   Reply With Quote
Old 01-14-2012, 07:35 PM   #5
Cervantes
Scooby Newbie
 
Member#: 219252
Join Date: Aug 2009
Chapter/Region: International
Location: Okinawa, Japan
Vehicle:
2000 Impreza STi
Black

Default

I'm about to replace a rear diff mount and my motor mounts. The issue I'm having is a thud in the rear when I get off the gas pedal. I had it looked at and the mechanic said it was the right rear diff mount. I'm thinking we have a similar issue.
Cervantes is offline   Reply With Quote
Old 01-15-2012, 05:54 AM   #6
MDRSK
Scooby Newbie
 
Member#: 226510
Join Date: Oct 2009
Chapter/Region: MAIC
Location: Maryland
Vehicle:
2001 Legacy GT
Black

Default

Yes, that is exactly the issue. Maybe it is because I have the JDM tail lights and my car thinks it is a Blitzen too
MDRSK is offline   Reply With Quote
Old 01-16-2012, 04:54 PM   #7
MDRSK
Scooby Newbie
 
Member#: 226510
Join Date: Oct 2009
Chapter/Region: MAIC
Location: Maryland
Vehicle:
2001 Legacy GT
Black

Default

OK. Dropped off the car at the dealer today. Confirmed the differential mounts needed to be replaced. Trouble is they are quoting me 5.0 hours of labor. I said no way so I just ordered the parts (both sides + bolts for $60). Now I have to find a place that can install them once the parts come in. Anyone have an idea if this is possible DIY?
MDRSK is offline   Reply With Quote
Old 01-16-2012, 05:16 PM   #8
GTP231
Scooby Newbie
 
Member#: 144366
Join Date: Mar 2007
Chapter/Region: MAIC
Location: Smyrna DE
Vehicle:
2001 Legacy GT-L
10 2.5i Prem L Imp

Default

Quote:
Originally Posted by MDRSK View Post
OK. Dropped off the car at the dealer today. Confirmed the differential mounts needed to be replaced. Trouble is they are quoting me 5.0 hours of labor. I said no way so I just ordered the parts (both sides + bolts for $60). Now I have to find a place that can install them once the parts come in. Anyone have an idea if this is possible DIY?
If you're eastern shore I can give you a hand.
Something tells me this is my thud I've never really tried to hard to diag
GTP231 is offline   Reply With Quote
Old 01-16-2012, 08:55 PM   #9
Frogsthatmoo
Scooby Specialist
 
Member#: 153374
Join Date: Jul 2007
Chapter/Region: South East
Location: Ocala, FL
Vehicle:
2001 Outback Wagon
White

Default

It seems to be a very common problem among our cars. There are a lot of threads for our generation over on Outback.org. There's a couple how to's that I've seen floating around. It's mostly a DIY but maybe with a helping hand, some jack stands, and a big big wrench.

Do you a little searching around for replacing diff mounts on Subarus so you can get a feel for the work involved and then decide whether or not you want to tackle it.
Frogsthatmoo is offline   Reply With Quote
Old 01-16-2012, 10:15 PM   #10
MDRSK
Scooby Newbie
 
Member#: 226510
Join Date: Oct 2009
Chapter/Region: MAIC
Location: Maryland
Vehicle:
2001 Legacy GT
Black

Default

Thanks, GTP and again to Frogs. I will do some researching and will ask a local shop how much they would charge. BTW, I will also try to cancel my order from the dealer as subaruparts.com has those parts for sale for about $31 vice $60.

I am not on Eastern shore, btw. I am way down south in St. Mary's county.
MDRSK is offline   Reply With Quote
Old 01-16-2012, 10:32 PM   #11
MDRSK
Scooby Newbie
 
Member#: 226510
Join Date: Oct 2009
Chapter/Region: MAIC
Location: Maryland
Vehicle:
2001 Legacy GT
Black

Default

Looks like a pretty involved job requiring dropping the rear.

http://www.subaruoutback.org/forums/...acement-2.html

http://www.rs25.com/forums/f8/t98598...hing-help.html

Seems like a hooptie method would be to inject some window weld into the bushings as a temporary fix.
MDRSK is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Rear differential ratios jkershaw Subaru Conversions 20 01-17-2012 06:11 AM
Installed Ver. 5 struts with 5Zigens springs, now have a weird thud? garface Brakes, Steering & Suspension 19 10-11-2001 09:16 PM
Loud thud when shifting under hard acceleration PhilG Normally Aspirated Powertrain 7 03-11-2001 04:26 PM
I changed my clutch and tranny and motor mounts now i have a drivetrain thud bill harvey Normally Aspirated Powertrain 5 03-03-2001 01:57 PM
Thud! meebs General Forum Archive 1 12-16-2000 09:16 AM


All times are GMT -4. The time now is 08:49 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.