Kartboy Rear Diff Crossmember Bushings Standard Set

Part #: KAR KB-003-DIFF
( 11 reviews )


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Brand: Kartboy
Bushing Location: Outrigger
Installation Hardware Included: No, reuses OEM
Material: Urethane
Mfgr. Warranty: Limited Lifetime Warranty
Return Policy:

RallySport Guarantee - 30 Days

Items that are covered under the RallySport Guarantee offer a 30 day no questions asked return policy.

RallySport Guarantee items may be returned within 30 days of the original invoice date and must include all the original parts and contents for a refund.

The RallySport Guarantee does not apply to products that have been modified, damaged, misused or abused. All returns require an RMA (Return Merchandise Authorization) Number, and freight charges are strictly non-refundable. For more information regarding our freight refund policy, please refer to our return policy page found HERE.
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Subaru Impreza
WRX STI 2004, 2005, 2006, 2007WRX STI Limited 2007WRX 2002, 2003, 2004, 2005, 2006, 2007WRX TR 2006, 2007WRX Limited 2006, 2007Base 1993, 1994, 1995L 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001LS 1993, 1994LX 1995, 1996Outback 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004Brighton 1996, 1997RS 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005TS 2002, 2003, 2004Outback Sport 2005, 2006, 20072.5i 2006, 2007
Subaru Legacy
Brighton 2000GT 2000, 2001, 2002, 2003, 2004, 2005, 2006GT Limited 2000, 2001, 2002, 2005, 2007, 2008, 2009L 2000, 2001, 2002, 2003, 2004L SE 2003L 35th Anniversary 2004i 2005Limited 2005GT spec.B 2006, 2007, 2008, 20092.5i 2006, 2008, 20092.5i Limited 2007, 2008, 20092.5i Special Edition 2007, 2008
Subaru Forester
Base 1998, 1999, 2000, 2001, 2002L 1998, 1999, 2000, 2001, 2002S 1998, 1999, 2000, 2001, 2002X 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011XS 2003, 2004, 2005XT 2004, 2005, 2009XS L.L. Bean Edition 2005XT Premium 2005, 2010, 2011, 2012, 2013X L.L. Bean Edition 2006, 2007, 2008XT Limited 2006, 2007, 2008, 2009, 2010Sports 2.5 X 2008Sports 2.5 XT 2008X Limited 2009, 2010, 2011X Premium 2009, 2010, 2011X Touring 2011XT Touring 2011, 2012, 2013
Subaru Outback
Limited 2000, 2001, 2002, 2003, 2004, 2005Base 2000, 2001, 2002, 2003, 2004, 2008i 2005XT 2005, 2006XT Limited 2005, 2007, 2008, 20092.5i 2006, 2007, 2008, 20092.5i Limited 2006, 2007, 2008, 20092.5i Basic 20072.5i L.L. Bean Edition 20082.5i Limited L.L. Bean Edition 2008
Subaru Baja
Base 2003Sport 2003, 2004, 2005, 2006Turbo 2004, 2005, 2006

If you are experiencing rear clunk of your 2002-2007 WRX/STI, you may want to consider a set of Kartboy rear diff crossmember bushings! You will notice improvements on acceleration, deceleration, and these are made out of hard urethane that will reduce deflection and absorb more shock.

These Kartboy bushings are hand made in the U.S.A., and are guaranteed.

This product has no user uploaded media. You can upload your photo or video of your install by posting a review.

REVIEWS ( 11 )


Verified Purchase
thanks for nothing
whiskey.bent 6 months ago
just to start things off i wish i could give these a 0 star review. well first off wheres the installation instructions,oh on a crappy forum, thanks. second i know these are universal but guess what? my 05 sti look nothing like a legacy, so you just caused me a ton of confusion. third do these go to the diff support bracket at the rear, the front of the rear diff? where? i love crawling under my car and trying to compare my drivetrain to a legacy(pictures provided). all in all, just buy the perrin lockdown kit. instructions and only the parts you need. ill never buy kart boy again.
Verified Purchase
Good product
odie880 9 months ago
i don't drive my car hard enough to notice a difference but they are better than the oem ones
Verified Purchase
Gordo_sti 3 years ago
Any time doing something towards the rear diff or swapping drive shaft, why not change these. Better safe than sorry.
Verified Purchase
I think it stupid
talltom0414508 4 years ago
These are just insterts I wish I was the complete bushing cause you still use the same bushings just add these. The installed was easy but was hard to know which one to use where. I didn't notice much improvement
Verified Purchase
Kartboy again comes threw.
UncleSchnitty 4 years ago
This helped eliminate alot of the clunk I felt shifting threw the first few gears. This is one product I highly, HIGHLY recommend when making enhancements on your drivetrain but remember its only one part but its definitely a must have! The only downside is there are a few different installation instructions online best thing to do is mix and match and find the one that gives you the best result.


  • AnswerQ: just to be clear  Tim P. 7 months ago

    These go between the cross member and the frame above the differential carrier right? Not the outriggers under the back seats. Above the cross member would require 4 bushings or 2 kits right? These look similar to the oem but the oem has a metal sleeve around their's.

    • A: Correct, this will attach to the outrigger/crossmember mounts between the subframe. For better information Kartboy has an installation guide on their website. This is used in conjunction with the OEM bushing to help fill voids.

      Nick S. 7 months ago

  • AnswerQ: Fitment question   driftingrotaryz18719 1 year ago

    Fitment question, is this suppose to eliminate the metal plate that's found above my rear diff crossmember on my GC?

    • A: No these will not remove anything these are simply inserts to help prevent diff clunking.

      Spencer H. 1 year ago

  • AnswerQ: Legacy GT fitment problems  Charlie Tango 2 years ago

    I have an 07 Legacy spec.B on which I tried to fit this part (KB-003-DIFF) onto; however, I could not find a correct place anywhere on my car to install it. I called my tuning shop, they weren't any help. I called Whiteline (because I didn't have time to email Kartboy and wait for a response), they didn't have the right information. Is anybody sure this part actually fits on my car, and if so, where? Thanks.

    • A: Pull the plate where the ARB is on each side for one set. Then in front of the tow arm in the front will be the same thing. pull the plate and place a bushing in there. You will use 4 of the bushings that are the same thickness.

      Kirill C. 2 years ago

  • AnswerQ: Are these the same as the Rear Diff Lock Bushings?  laplacexformofs12794 2 years ago

    I have heard the Rear Differential Lock Bushings called about 20 different things, and there are around 3 different companies that make bushings that look very similar. Are these the Lock Bushings? Thanks!

    • A: These bushings go in the same location as Whiteline's Rear Diff Support Lock Bushings.

      Zach G. 2 years ago

  • AnswerQ: install only this?  dman703 4 years ago

    Hi I am wondering if it would be beneficial to install these but not the differential mount bushings (turn in race). I am looking to install either one, which is easier to install, quieter, and will give better performance?

    • A: I think that these would be easier to install, and quieter as well, but I also think you would see much greater performance with the rear diff bushings, as that will have more of an affect on the rear diff movement than these would. Thanks, Rick

      Rick C. 4 years ago