Poly/Delrin Front Suspension Bushing FYI/PSA

[R13]

Several years ago now, I replaced the rubber bushings in the front suspension brackets with Delrin inserts and aluminum sleeves:

http://www.nsxprime.com/forum/showt...ont-!!/page2?p=1397426&viewfull=1#post1397426

This was due to the left-front camber bolt being seized in the OEM bushing such that it wasn't coming out without taking the bushing with it. Even at 212,000 miles (at the time) the OEM rubber bushings were fine...but it was impossible to align the car on account of the seized bolt.

The car is tracked fairly heavily so I didn't mind the extra "feel" at first. However, over time the incessant creaking/squeaking from the delrin wore on me and I finally decided to go back to OE-style bushings just to shut the car up so I didn't have to explain the noises and could take long trips in some peace.

I was able to source a pair of Brackets (e.g. 50310-SL0-A01 OEM) from "AHParts" on E-Bay (also at www.ahparts.com) for ~1/3rd - 1/4th dealer cost (and checking with the dealer, there were only one pair left in the 'States). I will say they were easy to work with, answered questions about the mileage on the car from which they were removed, and shipped promptly.

When I took the delriin-fitted brackets off, the bushings were significantly worn (sleeves sliding around in the bushing somewhat freely), so this also explained some of the slop that I'd felt developing. Service live was probably ~20-25,000 miles and maybe 10-15 track days/weekends.


So, in summary:

• Delrin bushings are wear items and should probably be replaced every-other season or so depending on the number of events you run (if tracking)
• They make a lot of noise
• If you wanted to/had to replace one of these bushings, I would go with a softer polyurethane with a shouldered bushing (that sticks out of the outer sleeve in the bracket and prevents it moving fore/aft).

 

[bngl3rt]

So I just had a suspension shop tell me that these bushings could not be removed from the subframe and that the only way to get new OEM ones in there was to replace the entire subframe (rear, in this case, as my rear ones are squeaking. $3000 in parts)

Sounds like that's BS, then? I can replace the OEM rubber ones with new OEM rubber ones, or get a polyurethane one?

 

[R13]

To go backwards (back to OE rubber) you DO have to replace the bracket. The OE bushings are molded/bonded in. And you might luck out like I did and find one or a pair from a wreck for a lot less, but yeah, dealer list would be $$$$.$$

If yours are making noise, I'd check to see if they're torn. if the bushings are still intact, I'm not sure I'd blame that for the squeaking. The flex from the rubber is what prevents that.

Also any Poly bushings will be custom, I don't think there are any available retail.

 

[illwillem]

I tore the same bushing at Big Willow last year, R-comps and sustained loads, oem bushing only had 56k on it, too. I couldn't figure out why the car was handling so vague in the front and I think it was you R13 who suggested i take a look at the upright bushings. when I did I found this.


After searching and even coontemplating making my own out of flexane- I had them replaced by TiDave, they are removable and serviceable and so far have not made a peep. They're certainly not a cheap option due to all the machining that must be done to the OE part, I was able to offset the bushing to gain additional camber. These are WAY overkill for a non track car but the option is out there.


Old vs New:

 

[R13]

Yeah, that looks like a well-thought-through design (not surprising if TiDave was involved). The good news is that I now have essentially a spare set of the upright brackets, so if I wanted to go that route, I could do so with no down-time. The fact that they are serviceable is significant.

I'll end up running a pseudo-R tire (Toyo R888) this season, so we'll see if the rubber puts up with it or no. More camber would be nice, but I don't think I could justify the expense for that alone.

 

[chussey]

To go backwards (back to OE rubber) you DO have to replace the bracket. The OE bushings are molded/bonded in.

The rubber is not bonded to the bracket, it's bonded to the metal outer sleeve of the bushing, which can be pressed in or out. You can reinsert the oem bushings if need be.