Tag Archives: DIY

DIY Installation: Rear Differential Bushing

4 Mar

You’re only as strong as your weakest link. To that end, there are many small changes you can make that will literally transform how your car performs.

One issue that plagues the Z and G is rear wheel hop. Some try to “cure” it with an aftermarket differential, only to find the problem magnified. The solution are some rather simple looking, but ultra effective bushing replacements. The Z and G have a rather conventional differential (aka the pumpkin, because of its shape…even though on these cars, it looks more like a squash) mounting system with 2 “ears” at the front and a single, large rear bushing. The front set of bushings are mounted into the pumpkin casing itself. The rear bushing, however is mounted in the subframe. All these bushings are liquid filled rubber, encased in an aluminum shell. OEM’s use this style because its reasonably stiff and strong, but able to dampen out noise and road imperfections. The whole rear differential assembly weighs about 90 lbs, so those bushings are under tremendous strain as the car squats, launches and turns. What many owners find is the rear bushing eventually starts to weep its liquid out, eliminating its effectiveness. The tell tale signs are a black stain on the rear subframe. The subject car here didn’t have that issue, but that does not make the result any less awesome. On this car, the front bushings had previously been replaced with the solid SPL units several years ago. The rear most bushing never was done due to time constraints at the time. But that’s what is being tackled here.

Step one involves using some PB Blast and getting under the car and soaking the bushings. This will cut through any surface rust that may have developed, and give the factory bushings some slickness to help in its removal. Step 1.2 starts with unbolting the mid pipe, and loosening the rear swaybar brackets. This lets the bar spin upside down, granting you more room to work. The pumpkin comes out without the bracket removal but you will appreciate the room when reinstalling it. Next, remove the 4 bolts that connect the rear driveshaft yoke to the pinion flange. Next up, unbolt the output shafts from the axles. The axles will dangle in place which is fine. Next step is drain the differential fluid via the side drain bolt. From there, unbolt the speed sensors at either side. Be careful! your speedometer and ABS use these, so unbolt em and tuck them up top. If you can reach it, use a pair of needlenose pliers and remove the breather hose at the top of the pumpkin. Next, you’ve got the 2 14mm bolts at the front of the pumpkin, and the rear nut that is “in” the bushing in the rear subframe. A tranny jack and a friend are very helpful here. 90 lbs is a lot and this isn’t something you want to drop!

Rear pumpkin with axles disconnected:



Next up is the big rear cylindrical bushing. Some people stop the whole subframe and use the opportunity to also replace the bushings that mount the whole rear cradle to the chassis. For this job, we are leaving the subframe in place. There are several methods to remove the large factory bushing. What we chose to do is use is a traditional removal tool to push the bushing out. Others choose to drill through the factory rubber, then saw several slits through the casing to collapse the bushing. Both methods work, just depends on your preference and tool collection.

Removal Kit:


The removal kit works like a plunger. You have a “pushing end” and a receiver. A bolt rides through the center and is secured with a nut at the other end. As you tighten the assembly, the stock bushing is pushed through its residence until it “falls” into the receptacle. Going slowly is key as is generous amounts of PB Blast. You must ensure torque is applied evenly to avoid doing any damage.

Stock bushing removed with the help of a bushing removal tool:




With the factory bushing removed its time to install the new one. We chose the SPL solid aluminum bushing to match the ones previously installed at the front. This is a solid chunk of billet goodness, and provides the strongest possible mount with maximum stiffness. Whiteline and Energy make urethane versions as well. If you go the solid route, a word of advise. A day before you tackle the install, put the factory bushings in the freezer. This will contract then ever so slightly, but will allow them to slide more easily into place. Leave them in the freezer till its time to install them.

To install the new bushing we used a simple mallet and tapped it in place. It’s actually quite easy.

New bushing installed:


From there it’s a reversal of the previous pumpkin removal procedure. Make sure you get the pumpkin all the way squared up to the subframe otherwise you will never get those 2 front mounting bolts back in place. We found that by installing the rear bushing nut and tightening first, it “pulled” the pumpkin more into place allowing the front bolts to more easily thread in.


Bolt the driveshaft up, then output shafts and you’re done! Torque specs can be found in this diagram:


The results? Awesome! You will LOVE this mod. Even though the front bushings have been installed for several years the rear is the most transformative. The car bites down much harder now from a dig as well as in the turns. We noticed a slight increase in noise due to the fully solid mounts but its so faint it’s not even worth mentioning. Launch the car and that “hop-hop-hop-hook” sensation you used to feel is now just a squat and hook. Your axles will thank you……

With the affordability of these bushings, it’s on that list of “must have mods” for this car.


DIY: From Rust to Redemption

13 Sep

None of us have trailer queens, but we all want our cars looking their best at all times. One area that always has gotten under my skin is the brake rotor hat. While some rotors come with a protective coating on the hat, many more do not. In this installment we will cover this easy DIY anyone can do at home.

Rotors are made of iron. When iron meets water and air, rust results. Just look at your brake disk after washing your car, or after a rainy night. You’ll see a faint amount of rust forming in no time. Now, on the disk face it’s not a big deal because as the pad sweeps the rotor, it acts like a razor on your face, and cleans the surface. But the hat never comes in contact with the pad, so the rust forms, stays, and continues to form over time. Even brand new rotors will experience this. After this installment, you’ll put an end to it for good.

What you’ll need:

320 grit sandpaper, brake cleaner, clean rags, high temp paint in your choice of color, plastic shopping bag (like from a supermarket or store), masking tape.

Start off by loosening the lugs while the car is on the ground or ramps. Next, begin jacking up your car via the factory suggested jack points. Don’t forget to set your ebrake and have the car in gear or park. Also use a chock behind one of the rear tires to prevent it rolling backwards. A small block of wood works well for this too. Finish taking the lugs off and remove each tire.

These rotors have only been on the car a couple weeks but you already see rust forming.


Using the sandpaper, scuff the rusted area well, removing the rust. If its heavily caked on you may want to consider removing the disk completed and setting it in one of the commercially available rust removers such as Evapo Rust or Krud Kutter. For very bad areas, a rust inhibiting primer can also be used prior to paint.

Use brake cleaner on the sanded area to remove any of the debris and leave a clean area for painting. Wipe it down with a clean rag.

Next use your masking tape to isolate the hub section from the rest of the disk. Don’t worry about being too perfect here. Once the disk hits the rotor face any light paint will be wiper straight off. Also be sure to mask off the lug studs as well. You don’t want paint on these as it can make installing the lugs a real pain.


Take the plastic bag and wrap it around the caliper to protect it from the paint.

Next up, shake the paint well. I used VHT Flat Black Engine Enamel. For higher temperature threshold you can use VHT or similar header paint. Each comes in a wide range of colors to suit your tastes.

Use even coats and go lightly, overlapping your prior stroke each time. Allow about 15 minutes between coats. There will be one small section under the disk while the rest is exposed. After about 30 minutes, just remove the necessary about of tape, move the disk the appropriate amount by hand, apply tape to the new section and finish up that disk. If its warm out and not humid, it will be dry to the touch in about an hour or 2. Remove the tape and plastic bag once the paint has dried, and you’ll be all done. Repeat on each disk as needed.


Here are the finished results:


Good luck!

Tech Tip: How to Install Buddy Club Seat Rails

25 Aug

Mixing and matching parts can sometimes leave you with more questions than answers. Especially when the forums are filled with the ubiquitous “it should work” and “my friend’s cousin’s uncle has it”. Often times you’re left to take an educated guess, or just try it and hope for the best.

In this installment, we’ll talk about installing Buddy Club’s Super Low Down Seat Rail with a Momo Start 2012 Race Seat. These are a combination base/slider and side mount assembly offered for a variety of cars. While originally intended for the Buddy Club seats, they will also fit a wide range of aftermarket buckets that accept side mounting.

Now, many companies make seat bases. The problem is, they often take what I call the sandwhich approach. Seat base on the bottom, followed by a universal slider stacked on top, followed by the seat stacked on top of that. If it’s a side mount seat, you also then need to factor in the side mount bracket also comes into the mix. This means more stuff to buy, more cost, and, with everything stacked one of top of the other, you often find the seat sits higher than even a factory seat does! This is not only unappealing to the eye, it’s uncomfortable to sit in, and, if you’re doing track days with a helmet, you may find you no longer fit in the car once you’re strapped in.

The Buddy Club setup does away with the cluttered sandwhich approach, and does this with a bit of a different twist. The slider and base are incoporated into one cohesive unit – like a factory seat would have. There is an inside and outside base/slider half. The side mounts tabs (included) then attach in place, 2 per side. A handle connects the 2 slider/base halves, and all hardware is included.

This particular setup is being mounted to a Momo Start 2012 seat. It’s an FIA approved one piece fiberglass shell that is not only comfortable, HANS compatible, and very lightweight (19.6 lbs), very strong, and very afforable (just $450 per seat). Other seats from a variety of manufacturers will also work. Given the installation on these Momo seats, I’d say the seat needs to be no wider than 20.7 inches from outside to outside on the seats (these Momo’s are 20.6 inches when measured from outer end to end). Front to back mounting is more forgiving as the side mount tabs are slotted.

First step, is unpack all the parts and lay them out. Each Buddy Club box will contain 2 base/slider ‘halves’, 8 cap nuts, handle, and 2 shorter, and 2 longer side mount bracket tabs. The bracket tabs have multiple holes allowing you to custom tailor the seat height to your own tastes. So, if you need the front a bit higher than the back, you can do that easily.

href=”https://cornerbalance.files.wordpress.com/2012/08/photo8.jpg”> Buddy Club Super Low Seat Rail[/caption]

Next, using the supplied cap nuts, install the brackets to the pre-mounted studs on each rail half. Use the shorter bracket up front, the larger bracket out back. The Buddy Club logo goes on the outside of each seat, and the half with the extra tab (for the seatbelt) goes on the inside. The mounting tabs are slotted both where they mount to the seat and where they mount to the base/slider. This allows them to fit a variety of width seats. Since the Momo are rather wide for a bucket seat, the brackets were installed to allow maximum width between each rail/slider half. If you’re using a seat that is narrower, you’ll need to do this step a couple times so you get the spacing correct, so that the base not only mounts to the seat but lines up with the mounting holes in your car’s floor. Just set them hand tight, rinse, and repeat till you achieve the desired width. Using an open ended 12mm wrench, torque till they are snug.

Next step is mount each assembled rail half to the seat. In this case, the seats come with the necessary allen head bolts and washers. Accessing the threaded side mount holes is done after popping out the plastic insers the seats ship with as shown in the picture below. This is where you’ll have to decide what height you want the seats at. This setup shows the lowest possible setting that would clear the seat. Thread the hardware into the seat by hand first and be careful not to cross thread. Using a wratchet and allen head socket, snug them down. You can choose to finally torque them down here, or, if you want to adjust the front to back pitch, you can fully torque them down once they are installed in the car.

Next up, install the female seatbelt buckle and mount the inner slider/base half to the seat the same way you did the outside one. Make sure you use the same height for the inside bracket half as you did on the outside!

Once done it will look something like this

Next, take the whole seat and base assembly and slide it into the car. Line up the mounting holes on the base to the studs and/or mounting holes on your car’s floor, and retorque the bolts/nuts to spec per your factory service manual. Don’t forget to plug your seatbelt harness back in so you don’t get a light on the dash.

Now take the handle included in the Buddy Club box and slide it onto the tabs on each base/rail. A flashlight comes in handy when lining this up. The tabs are notched in such a way that once the handle is installed it sort of “clicks” into place. You’ll feel it for yourself when installing.

And viola, you’re done! The successful merging of 2 different brand parts. You can now slide the seat back and forth. If you didn’t torque the side mounts to the seats, now is the time to do that.

To order any of the components mentioned, just give us a shout at z1sales@z1auto.com

Transmission Member Bushing Install Guide for Subaru

27 Feb

A few weeks ago, we posted about the new urethane Transmission Member Bushings for Subaru’s. Thanks to one of our customers in the NorthEast, we now have a detailed writeup for a DIY install, as well as confirmation that these bushings fit a non turbo 2.5RS.

To order a set of the bushings for your car, contact us at z1sales@z1auto.com

Click here for the install guide: TransMemberbushing

Mount Me

25 Feb

Z1 Performance Urethane Transmission Mount 350Z/G35

Just got our new batch of urethane transmission mounts in stock for the 2003-2008 350Z/G35. Some of you might remember the post we did here a few months ago DIY Urethane Transmission Mount Installation

These are now in stock and ready to go. We’ve got 3 stiffnesses to choose from.

The 60A is approximately 50% stiffer than stock and geared towards street/auto-x and club type track day drivers.

The 75A is for you more sporting types – those who do some street/strip work, or who auto-x more frequently, and who want crisp, consistent shifts, without resorting to a solid mount. There is increased NVH vs the 60A, but shifting is significantly more precise.

The 90A is the stiffest, and is typically found on group n rally cars and full out track cars, as it is nearly solid – expect significant increase in NVH, but with the most shifter precision.

Spring is hopefully around the corner (though you would never know it with the weather we’ve had here in the Northeast), so we’re going to be offering a special of $120 shipped in the 48 states. If you’re looking for the ultimate combo, package it up with our Billet Motor Mount Set. Combo price is just $255.00 shipped in the 48 states (saves you over $40 bucks from the normal website price!)

Any questions, let us know!

Faking the Funk

5 Oct
Fake it till you make it?

Fake it till you make it?

Longtime customer and friend Twan from TSE posted this up a few days ago in a “back in the day” thread. This was Englishtown circa 2004