Hey guys, I have a couple of problems with my rear susp. First is too much negative camber, and the second is really bad axle tramp (or wheel hop).the photo below shows my rear cradle bush mount, and it also shows the rear upper control arm adjusting mechanism to alter camber.Page RA-6 of the workshop manual shows which way to turn this, and it also says you can get 5' of adjustment. I assume this means 0.5 degrees??? Assuming mine is at the 'zero' position, how much of a camber change can I expect to get?Where do aftermarket offset bushes go? do they replace this existing offset bush to give even more camber adjustment?I assume lowering of a zed also puts the toe out of whack, as well as the camber?Arrow "B" points to what I assume is the rear subframe cradle bush. I am thinking of getting the rear subframe cradle bushes from UAS to replace my orig rubber items - link below: http://www.uniqueautosports.com.au/pricelists/Pricelist_300zxsuspension.htmArrow "A" in my attached pic points to a space between the top of the cradle bush, and the actual chassis. This gap isn't very big here in the pic, but the gap on the front between the bush and the chassis is about 10mm.Now I assume subframe spacers/helper bushes go where Arrow "A" is pointing, to remove this gap. I intend to buy these to try and reduce my axle tramp.Has anyone replaced their orig. rubber bushes with nylon (or simply stiffer) ones, and installed cradle helper bushes??? Has this improved the situation much.I also understand that most people think that rear shocks play a big part, and I dont know if mine are buggered or not, but it doesn't feel "boucy" at the rear.Incidentally, what models had adjustable shock absorbers?? Its in the workshop manual, page RA-24.thanks Ben[image]http://www.giant.net.au/users/wight/images/DSCN1863modified.JPG[/image]
You have mentioned >> about changing the bush's & that's fine.:YD But to get more adjustment than standard, you will need after market upper rear control arms, which can also be purchased at UAS or any of the other recommended supply business's mentioned on this forum.}) I also had bad rear camber on my Zed, but when I changed to the above after market arms, this improved my tyre wear beyond belief, once fitted & adjusted by Pedders Suspension.:YD :-Z I hope that this helps in your war against wear of tyres & axle tramp. Cheers Kerry
Are my assumptions correct? Thanks KEZA, I am not sure if I need to go to adjustable upper rear arms, as I dont know how much adjustment the stock setup offers. I think I will probably have to do the arms, or maybe just offset bushes.Does anyone actually know how much adjustment there is??? is it 0.5deg?? (is that what 5' means)?? Is this minutes, ie, 60' in 1deg??Can anyone confrim my other assumptions regarding the cradle bushes and cradle spacers? In particular, do these go where I assumed? Are they known for reducing axle tramp?thanks guys
I think you have about .9 deg. max.> Your on the right track with the cradle bushes, but like everything in a Zed, nothing is easy. You may get a satisfactory result first time, but NOT definite. If you scan through SEARCH, you will find a lot of info about this problem of wheel hop. There are so many bushes/spacers/links in the rear end, any one of them can be contributing to the problem. (Pay particular attention to the 4 bushes locating the differential). Every bush has been replaced with Urethane on my car, plus adjustable U/Control arms, new coilover shocks & springs, and this has minimised the problem, but not eliminated it.Good luck:YD
thanks Chili, I will go to my local wheel aligner and measure how much its out, and see what difference the factory adjustment makes.I may go the the adjustable upper control arms if I need more, as I can imagine the offset bushes might be a pain.Incidentally, where do these aftermarket offset bushes go? I assume the rear upper/rear outer bush is replaced? as the inner bush is already offset isn't it bacuase the anchorage is adjustable.I will check out the diff mounting bushes, never even saw them the other day when the wheels were off.thanks Ben
Urethane vs Rubber......>> ...There is a general misunderstanding about urethane, I have noticed, on this forum. Polyurethane is not the be all and end all, in bush replacement some people seem to think it is. There are some pros for rubber as well as urethane, as well as some against. One thing which has to be kept in mind, is that manufacturers, spend millions developing suspensions, and they still use rubber, why? Obviously its not the cost, (an important property of car manufacture), as urethane bushes are way cheaper to produce than rubber bushes. Use Urethane if you want..Stiffer, more responsive suspension. Use rubber if you want slightly softer ride, fractionally less feel to the steering, less road noise amplified through the suspension, and having to replace the bushes less often. (urethane, as it work hardens, shrinks, eventually coming loose in its mount, causing poor handling, and rattles. So use urethane for performance, but be prepared to change bushes more often, and use rubber for less performance, more street and comfort orientated. Actually, I defy an average person to tell the difference between a urethane or a rubber bushed suspension.GT (I worked with all grades of polyurethane for 6 years in the foundry business, and often made my own bushes, for various vehicles, not Zed, but one thing I can tell you, the price charged for urethane bushes works on the old consumer theory, "if its expensive, it must be good" as I could have made about 20 sets, for the retail price of one set)=)
Well one thing I was considering was to use urethane cradle helper bushes/spacers, whilst retaining the stock rubber cradle bushes.The only problem being if my current rubber bushes are stuffed, it may still wheel hop as bad as before.I cant seem to find any replacement rubber cradle bushes available (haven't contacted local Nissan dealer yet) but imagine they will be pricey compared to aftermarket urethane ones.
Rubber vs Urethane Thanks for the educated opinion on that, I have wondered about this. But I also wonder why a few rubber washers that could probably be made out of some old tyre carcass with a hole saw, still cost so much. http://www.whiteline.com.au/images/thumbnail/tn_W93047.jpg
Spot on GT. I talk customers out of Urethane bushes for control arms all the time as often there is nothing wrong with the ones in their car. Also the factory Nylon and Rubber combo bush I think are better than Urethane. However cradle bushes and more so radius rod bushes do tear and leak Silicon and good to replace with Urethane. When replacing cradle bushes you can machine or linnish the rear ones shorter to slightly raise roll centre but mainly improve squat angle. Replacing the stock upper rear control arms with adjustable Rose jointed type is a good idea. There is no noticeable increase in vibration, they reduce bind and gives adjustment. Note if adjusting these more than a little you should also get adjustable leading traction arms or you will get bind.
