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Whiteline Rear Diff Positive Power Kit Inserts

MODEL # WHIKDT903

$55.70


42 Reviews
4.9 out of 5 Stars
5 Stars
(38)
4 Stars
(4)
3 Stars
(0)
2 Stars
(0)
1 Stars
(0)
Customer Photos and Videos
Whiteline Rear Diff Positive Power Kit Inserts ( Part Number: KDT903)
Whiteline Rear Diff Positive Power Kit Inserts ( Part Number: KDT903)
Whiteline Rear Diff Positive Power Kit Inserts ( Part Number: KDT903)
Whiteline Rear Diff Positive Power Kit Inserts ( Part Number: KDT903)
Whiteline Rear Diff Positive Power Kit Inserts ( Part Number: KDT903)
Whiteline Rear Diff Positive Power Kit Inserts ( Part Number: KDT903)
Whiteline Rear Diff Positive Power Kit Inserts ( Part Number: KDT903)
Whiteline Rear Diff Positive Power Kit Inserts ( Part Number: KDT903)
Whiteline Rear Diff Positive Power Kit Inserts ( Part Number: KDT903)
Whiteline Rear Diff Positive Power Kit Inserts ( Part Number: KDT903)
Whiteline Rear Diff Positive Power Kit Inserts ( Part Number: KDT903)
Whiteline Rear Diff Positive Power Kit Inserts ( Part Number: KDT903)
Whiteline Rear Diff Positive Power Kit Inserts ( Part Number: KDT903)
Whiteline Rear Diff Positive Power Kit Inserts ( Part Number: KDT903)
0 of 1 people found the following review helpful
WOW 2 years ago
5out of 5stars

Can't believe what an improvement these made on the overall driveabililty of my 11 WRX hatch. Shifts are significantly smoother (especially 1st to 2nd) and the power delivery is immediate when you get on it, it just hauls a**! Also significantly reduced the rubber-band effect when letting off the gas at low speeds. I really wish I would've bought these sooner. I had these installed within an hour tops. Shipping was super quick (only took 3 days). Will continue to order from RSD!
  
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1 of 1 people found the following review helpful
Used with Pos Trac Inserts 3 years ago
5out of 5stars

I should have greased these up more, you should too. Paired with the Pos Trac inserts, I could feel the rear wheels work. On a 14 wrx, stock suspension, you know its AWD but it tends to feel like FWD or like you are floating in between 4 wheels when pushing it in corners. With the bushings, you know where you are located and can feel the rear wheels actively gripping and providing power.
  
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0 of 1 people found the following review helpful
Rear Diff Bushing Inserts 3 years ago
5out of 5stars

I just installed these inserts.. top two went in just fine, the bottom two around the rear diff a pain. The nut on the driver side by the exhaust had been stripped to someone already messing with it before me. I didn't really notice a difference until I got on open road and gave it the beans.... WOW what a HUGE difference under load... for the money and mostly simple install.. def worth it. I will be buying the whiteline rear suspension inserts next with the steering rack bushings too..
  
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2 of 3 people found the following review helpful
Must Do Upgrade 3 years ago
5out of 5stars

I installed this product and immediately noticed the difference. The car has less give (if you will) when applying the throttle and it feels much more responsive, as if the slop in the rear diff was eliminated altogether. This is a must do upgrade to any WRX/STi!
  
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slop no more!! 4 years ago
5out of 5stars

So like everyone was always talking about how the rear diff had so much play when launching this kit right here doesn't "completely" eliminates the problem (bc they're just inserts), but however this kit makes your Subie feel more planted and solid! especially when leaving from a dead stop and through cornering! If I knew how big of a driving difference this kit was I would have done this as a MUST for first mod! And of course Whiteline produces a top quality kit. Check IG#subiegoon for a pic!
  
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1 of 1 people found the following review helpful
Rear Diff Positive Power Kit 4 years ago
5out of 5stars

Eliminates that clunkiness in your drivetrain, more positive feel under acceleration. If you are going to install these inserts it would be a good idea to purchase the positive shift crossmember transmission bushings and a front and rear shifter bushing set. I also have the positive traction insert kit, the combination of all those things give the car a more controllable feel. You can feel everything going on with the car it's very tight no wobble. Ride comfort isn't lost with these products either. It is totally worth purchasing, and the install isn't difficult at all.
  
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1 of 1 people found the following review helpful
Excellent product 4 years ago
5out of 5stars

So I installed all at once. (recommend doing all these at once) Whiteline Rear Diff Positive Power Kit Inserts Whiteline Gearbox Positive Shift Kit Beatrush Shifter Link Bushings Kartboy Rear Shifter Bushing Perrin Subframe Lockdown Bushings Hard for me to differentiate which product did what, But MAN, I can tell the difference, With a 2011 Fully built WRX (EJ257 block, 380HP) and no suspension upgrades, These products were amazing. PROS - Rear end is muuuch tighter/sticks to the road during turns and taking off from stop - Acceleration is improved greatly, and feels like you have more power - Feels like power is going into the ground more - Very little drive line shock - Shifting is solid - went from feeling like a semi truck, to a Indy Super Race car CONS The rear shiftier bushing, was hard to line up with the existing holes (turn a little by little on each side)
  
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1 of 1 people found the following review helpful
Does a great job rounding out my other drivetrain mods 5 years ago
5out of 5stars

Other related mods: solid engine mounts, beatrush trans mount and pitch stop, STS and shifter bushings, and whiteline positive shift kit. When getting on the throttle whether it be after a up shift or throttle tip in the power deliver seems more instantaneous than before even with other drivetrain mods done. As others have mentioned there's less "lag" with the delivery of power. Cheap, easy, and well worth the price if you ask me. I've been putting this one off and did this, whiteline positive shift kit, and coilovers on at the same time. This improved power deliver and throttle response on the upshift whereas the positive shift kit improved downshifts (in my case that is). The inserts are a bit of a tight fit but will slide in just fine. They're pretty stout inserts and was very happy with the quality of the inserts. Noticeable difference even with other mods done and would do it again if I had to.
  
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1 of 1 people found the following review helpful
Nice, easy, and good price  5 years ago
5out of 5stars

Not something necessary on everyday driving, however if you do not want to worry about a lag or bounce when putting the power down (especially on harder launches) I would highly recommend this product and the price is just right. Install was very easy. I just jacked the rear end up and used hand tools with no issue. The one thing I would recommend is lubing the bushings up thoroughly because they literally fit the exact void in the stock bushings and the lube with help ease this.
  
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1 of 1 people found the following review helpful
Simply amazing 5 years ago
5out of 5stars

This will take you 30-45 minutes to install with lifting the car. I installed this yesterday along with the Perrin subframe lock down kit since they are both in the same area. Let me just say... wow, this is one of my favorite mods to date. It totally gives the rear end of my hatch the oomph it needed under acceleration. There is no slop, the car just goes, and by goes, I mean it GOES. Throttle down you get an even faster in your seat push and it feels solid. The rear end has less side to side slop on hard turns thanks to the perrin kit but it also helps the sub frame stay stiff which compliments these inserts so well. I would definitely recommend this along with the sub frame lock down. Easy mod that requires minimal tools and gives you a big difference in your driving experience and gives you a true feel of the torque of the 2.5.
  
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2 of 2 people found the following review helpful
Great upgrade 5 years ago
5out of 5stars

Excellent Quality. I installed this on a 2008 Subaru Impreza 2.5i MT. Improved shifting and removed a lot of driveline slop.
  
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1 of 1 people found the following review helpful
Better power transfer 5 years ago
5out of 5stars

Much better power transfer to the rear dif; feels more direct; much easier to drive from stop; better overall driveability; shouldve done this a long time ago..
  
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0 of 1 people found the following review helpful
WHITELINE KDT903 REAR POWERKIT 5 years ago
5out of 5stars

after I got these on I feel the rear better acceleration , oh I got a 2011 impreza N/A 2.5 BETTER FEEL GOING UP HILLS . NO HESITATION !!! MY ONLY OTHER SUSPENSION UPGRADE IS A S.P.T FRONT STRUT TOWER BRACE , OTHER UPGRADES I WANT TO TRY TO DO ARE WHITELINES KDT 902 subframe traction kit inserts & whitelines front & rear swaybar bushings thanks rallisport for great parts & great service
  
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1 of 1 people found the following review helpful
Amazing. All i can say.  5 years ago
5out of 5stars

I have a decent amount of work done to my car and i just put these in and these really blew me away. Shifting just feels planted and smoother. When you drop throttle quickly, you don't get that feeling like your getting kicked in the back, since the diff is not torquing around back there. Iv recommended this to all my friends. Id be a terrible person if i didn't.
  
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Reduced bucking feeling. 5 years ago
5out of 5stars

Prior to installing this product, my car had the Gtworx/Bilstein sport cup kit, front/rear whiteline sways, Kartboy endlinks, STI left/right engine mounts, Kartboy pitch stop, and STI transmission mount. So my car (2012 WRX) was REALLY stiffened up. I think having all those upgraded items really made my car buck a lot more easily and I also felt a lot of increased vibration when engaging in 1st gear from a complete stop. After I installed this product (along with Kartboy rear sub-frame inserts), that bucking and vibration when getting into first was reduced a lot and the car now feels a lot more solid on take off. I highly recommend this upgrade if you have also upgraded your engine and transmission mounts. NOTE: when my mechanic installed the lower inserts on the cradle, he only installed 1 insert on the left side because the right side bushing was solid and he did not know what to do with the other insert. Later I found that BOTH lower inserts go on the LEFT side bushing (one in the front, and one in the rear).
  
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Great feel 5 years ago
5out of 5stars

Easy install and a noticeable difference, but not too stiff. As far as noise, I didn't notice anything different than stock.
  
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Bushings 5 years ago
5out of 5stars

Just do it. They are easy to install and work great!
  
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1 of 1 people found the following review helpful
Noticeable Improvement 6 years ago
5out of 5stars

I installed these my 2014 WRX Wagon. Easy install took about 30 minutes not including jacking up the car. It solved clunking noise that you might hear from your rear differential under hard acceleration and shifting between first and second gear. Also transfers power more efficiently.
  
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2014 WRX  6 years ago
5out of 5stars

Performance-wise 5 stars. After installing these bushings the performance increased the install was a little harder because I was using jacks and didn't have access to a lift.
  
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Great Mod for the Money 6 years ago
5out of 5stars

Easy install only took about ~25 minutes with a lift!
  
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Very Noticeable!  6 years ago
5out of 5stars

If you are looking to improve handling and overall feel then these inserts are the way to go. Though they seem like such a simple upgrade the difference is felt right away. Don't hesitate, you will not regret it.
  
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Whiteline rear diff, positive track, and steering bushings 6 years ago
5out of 5stars

So I purchases all of these and put then all in at the same time. Awesome difference! Car feels tight and predictable with great road feel. No longer slushy in the corners. Easy install and just what I was looking for. You won't be disappointed.
  
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Great upgrade!! 6 years ago
5out of 5stars

Nice cheap upgrade. Removes the thud with acceleration. Install tip: Lube the bushings really good with provided grease and insert the large flange first on the rear differential bushing near the rear sway bar, otherwise it'll be very hard to push it in.
  
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Amazing 6 years ago
5out of 5stars

Do it!!! I've spent more on pieces purely serving aesthetic function. At a fraction of the cost of the aforementioned and performamce enhancement as a result, what are you waiting for?
  
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Worthwhile modification 6 years ago
5out of 5stars

Noticed a slight improvement in tightening up the drive line. I have considerable suspension/drive line mods already, but this was worth it IMHO. The rears were a PAIN to install, actually had to shave little bits off of the rears to actually get them in, fit was super tight.
  
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5 minutes on a lift, done. 6 years ago
5out of 5stars

Trying to reduce the drivetrain sloppiness, I figured I would do these at the same time I did the Whiteline Rear Positive Traction kit. This portion took me all of 5 minutes once I got it up on the lift. Could easily be done while on jack stands as well. I would recommend this to anyone looking to stiffen up the rear differential.
  
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Come with extra set of insert 7 years ago
5out of 5stars

The kit come with one extra insert for longevity reason. Rear diff won't give you a moving sensation but exhaust note do increase a bit due to loss of damping through harder bushings
  
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Solid! Whiteline is awesome!  7 years ago
5out of 5stars

Very nice! Much more solid now with little to no noticeable increase in noise. What impressed me most was when I jacked the car up from the diff to put in the inserts and when I put the jack under it again to let the car down the diff does not squish up at all like it used to. Very impressed and easy install.
  
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1 of 1 people found the following review helpful
Great purchase. 7 years ago
5out of 5stars

Performance-wise 5 stars. After installing these bushings I'm getting significantly more noise specifically from the rear diff. It's like breathing through your teeth, amplified on throttle. Fortunately, I also think this is a totally separate issue my car was having in the first place. So another 5 stars for helping me find a potential problem before it got worse... lol. After installing any bushings, take advantage of the extra noise you get, and always take the next few weeks to carefully listen to your car. If any moving parts sound a bit odd, change your priorities up and get that fixed. :)
  
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Sum of the parts... 8 years ago
5out of 5stars

I would like to say this fixed all the clunks and chunks but no. This is a step to a larger problem that subaru left us. I will say I noticed a small difference during WOT and decelleration but don't expect all the clunks gone and you wont be disappointed. Pro tip for installing the bushings on the rear diff. DO NOT USE THE SUPPLIED GREASE! It will create a vacuum seal between the rubber and urethane making it nearly impossible to push it in. You only need the grease for where the urethane contacts metal to keep them from wear.
  
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