Herbmiester 938 Report post Posted February 19, 2015 (edited) So I decided to replace the rear trailing arm bushes in my E36 as part of a general refresh of the old girl. After much reading and discussion I went with some poly bushes from Speedfactor in Tauranga. I went to a Garage in Upper Hutt that has a good reputation and has apparently done this before. The mechanic said "are the bushes you want to install voided?" The are solid Poly bushes so the answer was no. He said that would be a WOF issue as bush's had to be replaced like for like and the poly bushes may cause the rear subframe mounting points to crack due to the limited amount of movement that poly bushes provide. This was news to me and considering the fronts already have poly bushes instead of the standard rubber ones and just got a warrant I am confused. Opinions? Edited February 19, 2015 by Herbmiester Quote Share this post Link to post Share on other sites
mops 4 Report post Posted February 19, 2015 Interesting. I have poly bushes all round in my e30, and had them for years, and this never came up. Having said that, I would not recommend poly bushes for a road/street car. You loose alot of comfort and gains are questionable really. Probably the only good thing you can say about them is that you 'feel' the road better but this actaully means less comfort. Quote Share this post Link to post Share on other sites
Herbmiester 938 Report post Posted February 19, 2015 Yeah I know the ups and downs but as I only use this car to shoot over the rimutakas and through Whitemans Valley I was happy to sacrifice some comfort. I run 45 series tires so they give back a little comfort. Quote Share this post Link to post Share on other sites
Allanw 1072 Report post Posted February 20, 2015 Our E39 is polybushed right through the front - no harshness and certainly doesn't feel any harder than the standard bushes were (and they were poked). Best thing about polybushes, is the are easy to get in and out - no press, so can usually be done on the car. Often cheaper the new OEM type too If they going to worry about BS like that, they'd need to worry about lower profile tyres, aftermarket rims, cheap-ass tyres and worn (but not leaking or rooted) shocks too. They don't though. Quote Share this post Link to post Share on other sites
gjm 3258 Report post Posted February 20, 2015 You can now get urethane bushes of same hardness as OEM/original fitment. The idea is that the comfort is the same, but the bushes will last longer. Quote Share this post Link to post Share on other sites
CamB 48 Report post Posted February 20, 2015 Opinions? He should read the VIRM more closely (bottom of page): http://vehicleinspection.nzta.govt.nz/virms/in-service-wof-and-cof/general/steering-and-suspension/steering-and-suspension-systems Urethane suspension bushes: LVV certification is never required: in-service requirements for condition and performance must be met. Quote Share this post Link to post Share on other sites
kiwi328i 118 Report post Posted February 20, 2015 I think you just got a whole load of opinions about poly bushes. I am guessing you were actually asking about our opinions on you getting pinged for having poly bushes? I have had plenty of cars with poly bushes, none of them have been pinged. I got this from googleland, and I would tend to agree from my own experience, but I could be wrong... "Says the LVVTA: “A vehicle is not required to be certified to the Low Volume Vehicle Code where a suspension modification is the sole modification, and the following criteria is met, provided that the safe performance of the vehicle is not compromised.”... ...(d) Aftermarket suspension bushes may be substituted for the originals, provided they are made from an appropriate material such as polyurethane, and there has been no cutting or machining of the suspension arms to fit them; I guess they may have you on 'sole modification', but I think whilst he may have an opinion about using poly in certain areas for whatever reason, he is just dead wrong about it being a WOF issue. I am calling BS on this one. Quote Share this post Link to post Share on other sites
MLM 57 Report post Posted February 21, 2015 I think two documents or sets of requirement are being confused. The first is from the virm CamB posted which aligns with the wof guys comments point 13 H reasons for fail. h) is a replacement urethane suspension bush that is not voided or shaped to allow for similar movement to an OE bush The second is the lvv cert limit which is stated above I read this as poly bushes of a design which limits intended suspension movement as designed by the car manufacturer are not allowed for wof but in it self is not enough to warrant a cert. Rock......hardplace Quote Share this post Link to post Share on other sites
MLM 57 Report post Posted February 21, 2015 (edited) Can confirm they are not voided. I have just swapped mine for poly and have the original here. WOF this morning at vtnz no problem. Based on that there should be no grounds to fail wof regardless of which rule is quoted Edited February 21, 2015 by MLM Quote Share this post Link to post Share on other sites
