Activate More Grip – 350Z Whiteline Differential Bushing Install
The dreaded black goo of a blown rear differential bushing is very common among Nissan 350Z and Infiniti G35 owners. The problem is Nissan thought it was a good idea to fill a rubber bushing with gel, however over time the rubber tends to crack and the gel leaks out leaving you with a saggy feeling in the rear. The fix is the 350z Whiteline differential bushing kit, product sku KDT911. The Whiteline bushings are made from a premium polyurethane material and are extremely durable and long lasting. For racing or track applications you could alternatively use a solid aluminum bushing kit by SPL but the price point is about $40-50 more and since this is a street car we went with the Whiteline kit.
Tools You Will Need (all sockets are 1/2″ drive)
- 10mm Hex drive socket
- 10mm Socket
- 12mm wrench
- 14mm Socket and wrench
- 2x 17mm (regular + deep) Sockets and wrench
- 3″ Socket extension
- 1/2″ Drive breaker bar
- 1/2″ Drive socket wrench
- Spray lubricant
- Jacks + jack stands
- Creeper or work mat
- 3lb Hand held sledge hammer
- Rotary saw with an 8″ metal cutting blade 14/18tpi
- Corded electric drill and drill bits
- 5″ or 6″ C-Clamp
- 1-3/4″ Diameter section of steel pipe
- 3-3/4″~ 4″ Diameter heavy duty section of steel pipe
- Cable ties and zip ties
Jack the rear section of your car up in the air allowing for sufficient space for you to crawl and slide underneath at least half the length of the car. Place your jack stands in a safe spot on the pinch welds near the rear and be sure to be safe and put blocks under your front wheels to make sure the car doesn’t roll on you. It’s best to work on a flat stable surface.
Start by unbolting the rear exhaust, our car runs a GReddy Evo 2 catback exhaust system and uses 2 14mm bolts and gasket for each flange. You should be able to pull the exhaust hangars out of the rubber bushings with some spray lubricant and a bit of force. Remove the rear exhaust and set it aside in a safe spot or take some time to polish it up. Get back under the car and unbolt the 10mm bolts from the rear splash guard on each side, the splash guard covers the rear sway bar bolts. Once the rear bolt is removed from the splash guard you can bend it to unbolt the sway bar 14mm mounting bolts. Take a moment to also unbolt the rear sway bar 14mm end link bolts and place them aside for later. The sway bar should be free at this point, with a little finesse you can maneuver it out and store it. If you have trouble getting it free, proceed in loosening the next section of exhaust a bit.
You should be able to unbolt the next section of exhaust at or near the rear cross brace and pull it free from its rubber bushing to store with your other exhaust pieces. Be sure to keep all your bolts in a plastic zip lock bag for later. Now that nothing is in the way you can unbolt the 17mm bolts from the carbon fiber drive shaft. Use the breaker bar and a 17mm wrench on the other side to steady it. Make sure the car is in neutral so you can rotate the drive shaft with your hands. Once all four bolts are removed you can drop the drive shaft down or support it with some cable ties. Use zip ties to thread through the eyes of the bolt holes to remember the proper bolt pattern, one on the differential side and one on the opposite drive shaft side. You can also use the zip tie method when you unbolt the axles.
Next you will need to move to the axles and double check to make sure the e-brake off. Use a good amount of spray lubricant and a breaker bar with a 14mm socket and a 14mm wrench on the opposite side to crack each bolt off. Once all 6 bolts are removed you can use the cable ties to hang the axle from the suspension supports. Repeat the process for the opposite axle and then unbolt the 12mm speed sensors from the back of the diff cover. There is a speed sensor on each side, pull the bolt out and the sensor will slip out of the backing plate. You can then set aside the sensor over the sub-frame brace to get it out of the way so that it doesn’t get damaged.
It is a good time to drain the differential fluid out so grab your 10mm hex drive socket and your oil drain pan and open it up to let the fluid out. Be warned the fluid can be very stinky so we recommend not hanging around while it drains. Once the fluid is completely drained out put the drain plug back in and proceed forward.
With everything out of the way you can begin unbolting the rear main 17mm bolt with a deep socket wrench and breaker bar. If disaster should happen to you like it did to us and the bolt turns into stripped mush don’t panic just get your trusty rotary saw and at least an 8″ metal cutting blade and get to work cutting through the back plate of the differential cover where the cover meets the sub-frame brace. We’re not going to lie, space is very limited to get under there with a large rotary saw and it isn’t exactly easy but try to avoid cutting into your sub-frame as best as possible and just aim for the diff plate cover.
Place your car jack underneath the base of the differential and unbolt the two front 17mm bolts. If your worried about the diff falling off the jack you can use a chain to tie it up as best as you can manage. Once the two front bolts are removed and the diff is loose be sure to look for the top hats for the two front bushings. These top hats often fall out and can roll away. Lower the diff half way to the ground slowly and disconnect the rubber breathing tube from the top of the diff plate cover using a pair of pliers to pull the pinch grip apart.
The differential is relatively heavy, we didn’t weight it but if we had to guess we would say 90lbs. Now that you have diff free take it to your workshop area and turn it upside down being careful to support the bottom with blocks in the load bearing areas. You can tap the easy out bushing with a large socket and your 3lb sledge hammer. Again it is a good idea to use your lubricant spray for the step. The difficult bushing requires a 1~3/4″ diameter pipe used as a driver to span the distance required to hammer out the aluminum sleeve. If your confused view the picture to get an idea of how to tap it out.
If your doing the Nismo diff plate cover install then now is the time to open up the diff. The backing plate is held on by 14mm bolts, loosen them all and use wedge and a hammer to tap the backing plate off. Be sure to also remove both hex drain and fill bolts for use on the new finned Nismo differential cover. The tricky part about the Nismo cover is getting the separately provided breather tube in the top hole as they do not ship it as an assembled unit. We used a bolt and our 3lb sledge hammer to tap it in going slowly around the circumfrence of the tube. Eventually you will get the breather tube in and be good to go to install the new plate on the back of the diff.
Using an RTV grey stuff liquid gasket run a bead all the way around the back surface of the Nismo differential plate cover. Try not to use too much or too little RTV and then place it on the back of the diff and bolt the original bolts back into the diff finger tight. Let the RTV set until it is dry and then torque the bolts to spec using your socket wrench. Press the new Whiteline differential front bushings into the two holes using the bushing grease, you can do it by hand as they slide in fairly easily. The thin bushing goes on top and the thick bushing goes on the bottom assuming your differential is facing right side up again. Push the aluminum tubes into the center with the provided grease.
Turn the diff on its side being careful to support it and fill 1.5 liters of gear oil in through the fill hole then close it back up. Your now set to re-install the diff on your car but first you have to tackle the rear sub-frame bushing and it isn’t exactly a simple task. If your bushing is completely blown the gel should be gone and you wont have to worry about making a mess. However if the bushing is still in tact you will need to open the top and bottom gel filled pouches and let it drain out. Otherwise your drill bit will be flinging black messy goo everywhere. Get your drill and start plugging holes through the lower section of rubber, make it suffer for failing on you.
Once enough rubber is removed from the rear bushing you can run a c-clamp through the middle hole and press the center portion of the bushing out into your 4″ wide steel backing tube. Just keep applying force and the rubber will break apart leaving behind the aluminum sleeve that is stuck like glue inside the cylinder. Get your rotary saw and make two lines on the bottom side to remove a section of the sleeve. Be very careful not to cut too far as you don’t want to cut into the sub-frame. Once you get far enough through the sleeve you should be able to tap the cut section out with a hammer and chisel and then remove the rest of the sleeve.
The new Whiteline differential bushing presses into the slot easily from the axle side of the sub-frame using a c-clamp and some bushing grease. Align the flat aluminum surface of the bushing flush with the sub-frame and your good to re-install the differential. Begin by placing the diff back on the jack and raising it halfway back up to connect the breather tube and then align the backing plate bolt that you threaded into the cover through the new Whiteline rear diff bushing. Using some force to lift the diff into place you can get the top hats above the two front bushings and bolt them into the sub-frame of the car.
The hardest part is over and you’ve done it, just reverse the process of what you did originally by bolting the axles and drive shaft back together in the correct order. Install your exhaust and your sway bar in the order you removed them and then its just a matter of cleaning up your tools and lowering your car. Take a moment to grab a cold one, relax, and pat yourself on the back. 350Z Whiteline Differential Bushing Install Complete.