The very first time I installed urethane bushings I was very happy with the result. That was back in '98 and the car had a stock suspension and wheels. Over the course of time I’ve suscessfully converted the car to 5-lug with modified ITR knuckles, TL 12" ft brakes, and rear ITR brake and trailing arms, and installed Koni yellows and Eibach sportlines and an ITR 22mm rear sway with 16" prelude SH wheels.
While the Toyos on the car (205/45VR16) wore pretty evenly since I do my own alignments and practically all the camber,caster and toe on ft and rear is adjustable, I’ve always wondered about the urethane bushings since I’ve never regreased them. Since I had another car to drive I decided to one day take it all apart. Didn’t surprise me but the urethane stuff was totally shot. Not only did all the grease vanish but so much dirt was in there that as the bushing was becoming offset the other side was being filled in with dirt. Whenever I put the car on the lift and moved the wheels and tires I never felt any play. Even trying to push on the bushings with a pry bar showed no movement but they were completely gone after I disassembled them.
I gave a lot of thought as to what can be done to address the issue. This time I wanted to get rid of all the rubber bushings. The only stuff left is the rear upper arm, rear toe arm and rear trailing arms. I know that there has been a lot of debate about the ES trailing arm bushings. While a lot of guys had mentioned about the binding issues I did made a lot of inspections. The OEM bushing has air voids on the ft and rear of this bushing. The top and bottom provide the support. This creates a issue with the fore-aft movement. I believe Acura designed this to allow the suspension to give rearward upon a drastic surface condition change as in a bump or pot hole. This bushing also gets a slight twist on a lowered car to further help wear it out quicker. Not to mention that it lowered cars are usually driven harder than stock cars. Before I installed another set of bushings I did take the car onto my alignment machine where I was able to lift the vehicle in the air with the car still on its suspension. This gave me an idea about the position of the trailing arm bushings. Since the vehicle is lowered and the upper arm is spaced out further, the trailing arm bushing was pushed inward since the main shaft was located with the bolts and the trailing arm was positioned further out. Of course I can’t bring in the trailing arm since the lower arm isn’t adjustable and the option of raising the vehicle isn’t there. The ITR trailing arms were purchased new when I did the 5 lug conversion. The trailing arm bushings on them only lasted 4 years and 70k miles. Whenever I worked at Acura none of the cars trailing arms were ever so short lived. I though about the OEM replacement bushings but I thought about giving the ES bushings a try. Fortunately, I still had my DA trailing arms and I did purchase the larger bushings. I installed them one day and removed the rear ITR trailing arms and swapped out the hubs so the remaining 5 lug setup stayed.
The remaining upper and lower arms I installed a new full ES master kit but this time I strategically analyzed the ideal location for the zerk (greaseable) fittings. I really didn’t want to take apart my suspension for greasing them and I thought that this would be the best method. On the control arms there resides compression and elongation forces. Compression forces are the ideal location for these fittings, IMO, since the fitting won’t be disturbed. If I installed the fitting on the elongation area it would be the source of weakness and potentially break. I did also have the intention to make sure that the fitting wouldn’t be facing towards the bottom to avoid the possibility of damage from debris from the road. Fortunately, I was able to kill 2 birds with one stone. All the jerk fittings on the front lower arms were installed on the top side. The ones on the ft upper arm pivots ended up on the under side and the rear lower arms also ended up on the top with the exception of the shock mounts which were installed on the center. I was even able to install zerk fittings on the ES trailing arm bushings. The OEM shaft was buffed clean and reinstalled onto the ES trailing arm bushings. The shaft has full 360 deg rotation and side to side movement to allow the toe to compensate now.Tilt on these bushing were still to be determined.
Since ES doesn’t make a rear upper arm bushing set, I was able to source a set from Prothane. I installed then and installed zerk fittings on them as well. While the rear suspension was apart I was able to compare the rear toe arm bushings. The rear toe arm and the rear upper arm bushings are pretty similar. The upper arm bushing is 40mm wide while the toe arm in only 30mm wide. The rear upper arm on the outside uses a sleeve at the trailing arm. The rear upper arm uses a shaft on the inside to bolt to the body. The rear toe arm uses a sleeve on both ends. Currently, no one makes a rear toe arm bushing but I think that it might be soon coming to a change. I’m going to contact prothane for a custom set since it will only need a few modifications to the rear upper arm bushings in order for it to work. I do realize that a hand ful of companies do make a set of rod end style links for the upper and toe. First off the ratio of the upper and lower arm allows for the engineered camber change to happen during suspension movement. Lenghtening or shortening these links changes this camber change which can be hurt you more than help you if there was any indifference in lenghts from side to side as this may cause the imbalance in camber/toe when the suspension undergoes travel. The car already has a slotted hole for adjusting toe. For these reasons I’m out on using these links and only prefer to use the custom toe bushings I’m conducting some research on.
Back on to the progress. The vehicle is now put back together. I didn’t use the grease that was provided in the kit. I instead used 3M silicone paste. I bought enough of this stuff to load into a small grease gun since I can now grease all my bushings periodically (every oil change or 3000 miles). I prefer to use this grease since it has lower viscosity than that provided with the kit. The alignment specs are as follows
Ft spec
caster L: 2.5 deg R: 2.5 deg
camber L: -0.4 deg R: -0.4 deg
toe L: 0.03mm R: 0.03mm
RR spec
Camber L:-1.0 deg R:-1.0 deg
toe L:0.04mm R: 0.04mm
The vehicle handles better than it has ever. I just replaced the tires after the suspension since it was worn to 2/32. The ride is now a little more bouncier due to easier movement of the suspension so I did firm up the valving of the Konis. When the rear was being adjusted I removed the shims and bolts for the rear upper arms to see how mush deflection the rear upper arms would allow for. To my surprise I was able to get -3.5 deg on the right side and -3.2 on the left side so the ES bushings in my vehicle don’t seem to create bind as most people have mentioned. IMO, case solved. While everyone talked about the issue with the ES rear trailing arm bushings creating bind I would think that this would be enough evidence that the durometer of this bushings can “give” enough to provide the necessary camber change and the lateral and rotational movement allow for the toe change to remain in effect.
Seat on the pants impression. I’ve driven a lot of high powered FWD,RWD and AWD vehicles and each vehicle behaved differently, especially when driven hard, so they all have to be taken to each of their limits differently. As most know out of all cars FWD cars can be the most forgiving in driving to the limits. This also brings up another issue with FWDs. Most of them don’t handle as well as a RWD since their tendency to understeer. Out of all FWD hondas I’ve always had a liking to the handling of the DA. To me it seems much better planted than the DC2/4 or even the Ludes or Accords. Well after the bushing change the car now behaves as stable as a RWD car under acceleration. The rear seems to well planted that it seems to me that gravity doesn’t even matter. The car hugs the road so well that I can now take high speed highway overpass curves with a much higher level of confidence. The tires no longer squeal when driven to their limits. They now growl when taken to the limit which is at a lot higher speed on the same turns.
I wish I was able to use the G-tech pro to measure the improvement in the handling. The plastic ball to suction cup mount broke and I’m waiting for the new one to arrive from Tesla.
My last set of tires lasted 35,000 miles of hard driving. I ran Toyo Proxes FZ4 in a 205/45R16 and have been very happy. This time I switch to Toyos newest Proxes 4 also in the same size.
The suspension isn’t finished yet. I plan on running some HKS coilovers on it. The HKS Hipermax are an aluminum coilover that can be rebuilt from HKS USA. Out of all HKS coilovers I’ve come across I’ve never had a set require rebuilding but its good to know about the service being available. Currently the only set available is for a DC2 ITR. While the front will fit with the DC2 drop forks the rears will need function-7 lower for the ITR. I don’t ever plan on running a rubber suspension bushing on the vehicle. I also have plans on the 04 TL 4 piston brembos fitting on the front with 16" wheels. I plan on running 16" X 7"-42mm offset OZ Ultraleggerra wheels with the Toyos to complete the suspension. The 16" type-SH wheels unfortunately don’t clear the TL brembo setup on the 5-lug setup I’m currently. Lets hope the Ultraleggerras won’t have the same issue.
Once, the suspension is complete I’ll work on the GT30R install.
-Joe
Subscribed. :salute:
:manual:
