Community Member Credit: CS_AR

Over the past couple of months, I have received several requests to post information on the sub-frame spacer modification. It has taken a couple of months to try several different products and approaches to finally settle on a method that I feel comfortable sharing.

All total I must have spent $400 on an assortment of poly bushings, washers, ceramic magnets, and spacers to finally reach an approach where the modification can be repeated in the $90 to $100 per vehicle range. Since I paid $90 for the original set of spacers that I’m replacing with a hopefully better product, I think it will be worth it. I want this modification to last for several years.

This modification uses a combination of parts from the following vehicles:

1) Nissan 300ZX Aluminum Sub-frame Spacers
2) Nissan Titan Truck PRG Delrin Suspension Spacers
3) Subaru WRX – Perrin 4268 Sub-frame Bushings

Installation Vehicles

1998 Maxima GLE – Recently converted to SE suspension. Note initially this modification was made to the stock GLE sub-frame. Later the 98 GLE was converted to use the triangular sub-frame braces from a 97 SE. Pictures of how the bushings look in both the stock GLE and upgraded SE type suspension are provided.

The suspension uses H&R Lowering springs with Koni STR-T orange struts. New Lower Control Arms (LCA) with end links, poly bushings, inner/outer tie rod ends have been installed. The mod was installed on a vehicle with basically a new front suspension. This car already had a very tight suspension before the modification was made. It just tightened it up a bit more.

1999 Maxima SE – This is the 2nd installation where I used this modification.
This vehicle’s suspension was replaced approximately 3 years ago with H&R lowering springs, KYB AGX struts, new Lower Control Arms (LCA) with end links, poly bushings, inner/outer tie rod ends have been installed. This is the 2nd time that subframe spacers have been used on this vehicle. The original mod was installed on a vehicle with basically a new front suspension. The 2nd (enhanced) modification was made after the 1st modification’s parts worked loose and fell out after approximately 2 years of use. Note this car also had a very tight suspension before the modification. This modification just tightened it up a bit more.

Post Installation Pictures

Front 300ZX Aluminum Subframe Spacer with PRG Delrin Titan/Armada spacer and flat washer.

Rear 300ZX Aluminum Subframe Spacer with Perrin 4268 Subaru WRX Bushing

SE Type Suspension

Non-SE Type Suspension

The Problem

Space between the sub-frame mount post and the body results in a loose sloppy feel when driving over rough places in the road and lowers the amount of feedback from the rack to the driver.

Also, when the sub-frame upper post rubs against the body it can make a creaking noise.

Roughly 3 years ago, I purchased a set of plastic spacers to tighten subframe movement. Unfortunately, the upper spacers were not thick enough to completely stop the movement. Since the upper spacers are C-shaped, the upper rears spacers eventually worked loose and fell out on the street somewhere.

The old spacers helped after the initial installation. Since I could see the gap that remained between sub-frame post and the body would eventually allow the upper C-shaped collar to fall out. So I had to use Gorilla Tape as a temporary measure to wrap the area until I could come up with a tighter solution.

Looking back, I could have stacked up additional washers on the bottom post to remove slack. By then, I had already lost one of the rear spacers. Unfortunately, I just did not have a solution at the time when I realized the old spacers were too loose. Since the spacers are no longer available and the seller was not responding to email when I attempted to buy another set, I decided to find a repeatable solution using a combination common parts from other platforms.

Old to New Parts Comparison

The old parts are in the upper row.

Comparing the Perrin rear lower bushing to the original lower spacer.

Here’s a picture of the new Perrin 4268 bushing that is used on a Subaru WRX compared to the old rear lower spacer. The Perrin bushing is definitely thicker and is capable of absorbing shock that may be transmitted to the rear part of the sub-frame.

Cost Summary

• Aluminum 300ZX subframe spacers $25 to $28 depending on color. Shipping free from eBay sellers.
• PRG Delrin Titan spacers (set of two) $20 + shipping
• Perrin 4268 WRX bushings ~$10 + shipping.
• Fastenal 33098 Washers $1 to $2 x 2 = $4 high
• Harbor Freight Step Drill Bit $16 (with a 20% off coupon) to $20
• Rough Estimate Total $90 to $100 depending on shipping costs.

Parts Sources

Perrin WRX Bushings Part Number 4268
Send an email to Thomas at the following email address: Sales@perrinperformance.com
Approximate cost is $5 each + Shipping.

There is a full set for the WRX that contains bushings that are not needed on the perrinperformance.com site. I was able to get Perrin agree to sell only part 4268 to Maxima owners.

300ZX Aluminum Subframe Spacers

Multiple eBay sellers – Prices vary based by color. Just search for 300ZX aluminum sub-frame spacers and go for the best deal.

Red – http://www.ebay.com/itm/Aluminum-Sub…RYbvZO&vxp=mtr

Silver (I bought silver because I didn’t want a color to get scratched off during installation.)

http://www.ebay.com/itm/Rev9-SILVER-…5Vbew2&vxp=mtr

Flat Washers

• Fastenal
• SKU 33098
• https://www.fastenal.com/products/details/33098
  Approximate Cost: ~$0.88 each.

I actually purchased and tried six different types of industrial washers before settling on the on this particular washer. This was the only washer that has the best fit around the inner subframe bushing stalk and matches the 1.250” ID (after bore) on the Delrin Titan spacer.

NOTE: The washer is listed as 1 – 1/8 ID but you can see it actually has a larger ID.

Washer Inner Diameter

Washer Outer Diameter

https://www.fastenal.com/products/details/33098

PRG Delrin Titan Spacers

Approximate Cost $20 for a set of two.

PRG Products Nissan Titan & Armada lower control arm Delrin spacer kit. The factory bushing design has a significant gap between the end of the bushing and the pivot mount. This gap allows the lower control arm to move forward and rearward under braking and acceleration. In some cases this movement leads to a clunk when the vehicle is driven over uneven road surfaces. The PRG Products Delrin Spacer Kit acts as a bushing between these two surfaces which helps to eliminate the gap. By eliminating the gap these spacers can reduce clunking and also make handling more precise.

Update: 2/27/2016 – PerformanceLifts.com has agreed to sell the spacers in sets of two to the Maxima Community for $20.

Until PerformanceLifts.com posts a part number for the Maxima set on their site, you can email Sales@PerformanceLifts.com and reference Maxima.org set (2) of the following part.

http://performancelifts.com/prg-niss…pacer-kit.html

Note the Inner Diameter must be bored out to 1.250″ to clear and fit around the old sub-frame bushing post. I use the Harbor Freight stepped drill bit listed below.

Harbor Freight

Warrior Titanium Nitride Coated High-Speed Steel Step Bit Set 2 Pc
Approximate Cost: $20 – I used a 20% off coupon that brought the price to $16 + Tax

Note: Other methods to bore out the Delrin Titan Spacer to 1.250” or 31mm will work fine.
Use the 1-¼ INCH bit to bore out the Delrin Titan Spacer
http://www.harborfreight.com/2-piece…lls-96275.html

Harbor Freight 24″ Tire Iron

This $5.99 Harbor Freight Tire Iron worked best for wedging in between the rear subframe mount area and the body to “open a gap” so the aluminum collar can be inserted. It came in handy when I needed to push the down on the subframe during installation.

http://www.harborfreight.com/24-inch…ron-93230.html

Installation Notes

Tools: 19mm socket for sub-frame mount bolts – for SE models there are two 14mm bolts that hold the additional support plate to the body.

Perrin Bushing Location – SE Suspension

Perrin Bushing Location – non-SE suspension

Rear Spacer

You will need to use a pry bar to push the sub-frame downward and away from the body so the sub-frame collar can slide over and into the sub-frame mount position. Remove both rear sub-frame 19mm bolts and loosen the fronts to provide ample clearance for sliding the aluminum collars into position. This was relatively easy the passenger side but required more effort on the driver side. Where you insert the pry bar depends on the size and length of the bar.

Here’s a picture of the location where I inserted the pry bar at the rear of the sub-frame to push it down so the C collars (front and rear) would slip around the old rubber mount. It is not necessary to cut the old rubber mount or to widen the opening of the C collar after the sub-frame has been pushed down and out of the way using a pry bar for installation. Using this approach allows the new C collars to fit tight around the old rubber post bushing so they will not fall out.

After you slide the new C collar into position, be sure to center the spacer so the most contact is made between the spacer and the upper part of the sub-frame mount post before tightening the 19mm nut on the sub-frame post stud bolt.

Front Spacer

Like the rear, a pry bar will need to be used to push the sub-frame down far enough for the aluminum collar to clear the sub-frame post. The 19mm bolt and square washer will need to be loosened and removed so the sub-frame post can be lowered enough to allow the collar to clear the upper mount post.

Note on the driver side, I could not get enough clearance for the collar to slide around the post. I used a rubber hammer and tapped the collar into position. Since the inner post is made from rubber, it won’t hurt it. Once the post has been cleared, the collar will be loose for adjustment and final tightening like you see in the picture below.

Note that the PRG Delrin Titan spacers will need to be bored out to an Inside Diameter of 1-1/4 inch.

Use care and wear eye protection when operating a drill and performing this operation to bore out the spacer. How you choose to secure the spacer while boring out the hold will depend on your skill level, and tools available. I used a small drill press vice to hold the spacer in place while I drilled out the ID. I could have used vice grips to clamp the spacer while holding it down. Be sure to stop periodically to clear away shreds of plastic remnants from the sides of the spacer that will appear as you start to bore out the ID.

Disclaimer

This mod should be only used for experimental AutoX track type vehicles that operate on smooth road surfaces where the driver needs maximum feedback from the suspension to make quick decisions while driving a slalom type competition course.

If you drive on rough unpaved roads, cobblestone streets, and traverse large potholes often, then depending on your tire/rim size, you may find the direct feel between the sub-frame and the body to be harsh, uncomfortable, and hard to handle.

For example, this modification on the 98 model with 17″ wheels and 235/45 tires has a completely different feel when compared to the 99 model with 18″ rims and low profile tires. A normal driver would find this modification on the 99 model, with an already stiff suspension, to be too harsh for anything other than smooth interstate driving.

So consider this modification at your own risk.

After 5,000+ miles of use on the 99 model SE, here are a couple of pictures to check on on how the bushings are holding up. So far so good.

Rear

Front

Over a year later and we’re in July of 2018. The spacers are still working.

Here’s a July 2019 update for the 99 model.

Left Front

Right Front

Left Rear

Right Rear