Righto, I'm getting what feels like a wiggle coming from the rear, yes that sounds funny I know, but seriously guys.......

 

Now, the best way to describe this is that only at speeds over 40 or so whenever I go over those painted lines that you usually get on approach to a junction, you know the ones? ripples, cracks or even cats eyes if I hit them right, I'm getting a weird steer from the rear feeling, kind of wobbles about and I find myself gripping the wheel to fight it ffs.

 

So I'm thinking is this could be a problem with the hicas, the hicas light doesn't come on, only apart from when you switch the ignition on and goes off when engine starts, which is normal, which also means that the steering fluid is ok. so the hicas theory is out.

 

So could this be a worn bush, or something?

 

Also don't know if this is related but I'm getting a feint diff noise occasionally, not all the time.

 

Any ideas?

Rear wobble can be caused by worn hicas arms or shock/springs, jack the rear end up & check if you have any play in rear wheels as you shouldnt have any play at all.

Righto, I'm getting what feels like a wiggle coming from the rear, yes that sounds funny I know, but seriously guys.......

 

Now, the best way to describe this is that only at speeds over 40 or so whenever I go over those painted lines that you usually get on approach to a junction, you know the ones? ripples, cracks or even cats eyes if I hit them right, I'm getting a weird steer from the rear feeling, kind of wobbles about and I find myself gripping the wheel to fight it ffs.

 

So I'm thinking is this could be a problem with the hicas, the hicas light doesn't come on, only apart from when you switch the ignition on and goes off when engine starts, which is normal, which also means that the steering fluid is ok. so the hicas theory is out.

 

So could this be a worn bush, or something?

 

Also don't know if this is related but I'm getting a feint diff noise occasionally, not all the time.

 

Any ideas?

 

Doggy Hicas or worn rear steering arms wouldn't cause this. Worn or deffective Hicas is usually felt in highspeed corners and can be confused with poor dampers as the car can shift dirrection at the slightest of bumps. The rear wheels feel loose. More noticeable when going through succesive left right combinations/or rear stepouts favouring on side more than the other.

 

This sounds more like Tramlining and is caused by several things.

 

The most common is having too large a footprint on your front tyres. The ideal tyre width combinations are.

 

225 front and 245 rears is ideal or 255/265 rears a good compromise if you like a slight understeer feel to compensate for the twitchy rear end on the Z

 

235 front and 265 or 275 rears ideal 285/295 make her understeer slightly

 

245 front and 295 ideal larger makes it understeer slightly.

 

The oppersit happens if you have too wide a front for the rear. The car will oversteer. It gets hold of every undulation in the road and pulls the car as though it is getting the wheels stuck into tram lines (hence its name)

 

You also get it when tyres are baddly worn or, as in ready to be replaced or worn irregular do to incorrect alinement or damaged setup. Cheep tyres can cause it even when new. Even if they are the correct size and correct tyre combination.

 

Most Zeds I've driven haddle like sh1te, but new bushes (this being a common problem dur to the age of the Z) and correctly set up on good rubber they are a real drivers car.

 

What tyres ie make and sizes have you got?

Worn outer HICAS bushes or worn shocks. Jack the back end of the car and check the wheels for lateral play - this would be the outer bushes. If not then its time for new rear shocks... Of course it could be both as these cars are 15+ years old now...

I'll go with Andy on this but, I found to check the outer ball joints effectivly I had to take the hicas arm off, then I found the ball joints were well and truely fubar.

 

Do yourself a favour and get all the back end replaced with new bush's and hicas joints before you stick it in a ditch

Worn outer HICAS bushes or worn shocks. Jack the back end of the car and check the wheels for lateral play - this would be the outer bushes. If not then its time for new rear shocks... Of course it could be both as these cars are 15+ years old now...

 

I'd go along with this , but he describs his problems as only showing when crossing chevrons and white line markings. Which is why I said the first bit.

In addition to the above, check your wheel nuts http://www.300zx.co.uk/forums/showthread.php?t=86583http://www.300zx.co.uk/forums/showthread.php?t=86583

 

and the final cure for me was a pair of rear shocks which fixed it completely.

There's a bumpy bit on the M42 that sends the back end of my zed crazy, having done everything but the hicas ball joints and rods, it must be them.

There's a bumpy bit on the M42 that sends the back end of my zed crazy, having done everything but the hicas ball joints and rods, it must be them.

 

Or your Tyres

 

What is it with people on this board. you all do everything without first doing the fundimentals.

 

Tyres

Tyre presures

Tyre quality

Tyre type's (how many of you know what tyre types you actually got on)

 

it could be bushes track rod ends steering rack or even a twisted monocock,

But first thing to check are your tyres.

 

You don't cook a dinner by serving it up first.

 

PS. By checking your tyre first your see how they are waring and therefore know what is broken or out of line etc. Then you check to seee if its mechanical ware or damage.

 

It's just the same are engine fault finding Check plugs first then you can see if its running properley, burning oil, sreaming off etc.

 

Also when they set race cars up they start by putting the best rubber on and then see how it wares, not start fiddling with the geometry first because your tyres are you only proper reference point. :headvswal :headvswal :headvswal

I didnt say I hadn't addressed the tyres already... ;)

But cheers for the suggestions.

I have to admit, from your list I havent checked for a twisted monocoque! :rofl:

 

Hopefully we have all created a nice list of things for insanezed to check. :)

I didnt say I hadn't addressed the tyres already... ;)

But cheers for the suggestions.

I have to admit, from your list I havent checked for a twisted monocoque! :rofl:

 

Hopefully we have all created a nice list of things for insanezed to check. :)

 

Then whats the ware like on your rear tyres and what does it tell you.

Ok, firstly this only occurs if I go over a bump or something, other than that its a sure footed handler.

 

Tyres are Bridgestone with 265 rears and 245 fronts, wearing evenly, I get no understeer at all, and oversteer is basically how much do you want when you want it, so to me this is perfect as I like to drive the zed, my car can usually be seen with the rear end out on most bends and roundabouts in the Sunderland area lol.

 

Suspension are not standard, they are Tein, struts and springs, not coilovers. not adjustable in any way, however I do get a lot of 'afterbounce' which does sound like suspension might be away, just been out to have a bounce on the front and they pretty solid, but the rear is very bouncy, so this might just be the bogey.

 

Thats now new suspension to add to the shopping list. yeah!

 

However today I will jack up the back end and check for lateral play to be sure.

 

Thanks once again guys, you are like a fountain of knowledge.

Ok, firstly this only occurs if I go over a bump or something, other than that its a sure footed handler.

 

Tyres are Bridgestone with 265 rears and 245 fronts, wearing evenly, I get no understeer at all, and oversteer is basically how much do you want when you want it, so to me this is perfect as I like to drive the zed, my car can usually be seen with the rear end out on most bends and roundabouts in the Sunderland area lol.

 

Suspension are not standard, they are Tein, struts and springs, not coilovers. not adjustable in any way, however I do get a lot of 'afterbounce' which does sound like suspension might be away, just been out to have a bounce on the front and they pretty solid, but the rear is very bouncy, so this might just be the bogey.

 

Thats now new suspension to add to the shopping list. yeah!

 

However today I will jack up the back end and check for lateral play to be sure.

 

Thanks once again guys, you are like a fountain of knowledge.

 

The front tyres are the cause they are two wide. I been there and got the Tshirt. Honestly if you drop your fron tyre size to to 225's or 235's you'll be amazed at the transformation.

 

If rear shocks have to soft a damping setting it will cause bounce and give you an unsettled feel so either ajust or replace. You tram linning is tyre size though

 

I'm had my Z 7 years in April and done over a 100,000 Miles and tried more set ups and tyres than proberbly most people on this board. I've race karts and motorbikes and been around friends that have race cars for years. One of my best friends is Dave Perry (dpmotorsport owner and one time Porscher challenge champion) Tyres and Tyre choice is the most important handling device on any car. It is what keeps you on the road. I've tried most performance road tyres on my Zed as 4500 to 5500 miles seems to be the tyre life limit. Some tyres like the Dunlop 3000 sports where that scarey that I replaced them after 3 days.

 

What Bridgestones you got on. I have found that the S03's or the Potenza will still cause this even at 235 because of the compound. S02's (classed as Porsche only fitment) where the original tyre that the Z was designed on and 225 or 235 S02's make overall sability like you carn't believe.

 

S02's are best all round tyre forthe Z giving verygood dry handling and the best road tyre wet handling poss. Mitcheline Pilots are dam good and Yokahomas are the best dry tyre, but scarey wet.

 

The rest are some way behind.

 

Remember fatest doesn't mean better.

Sounds like the problem I had with my HICAS ball joints being worn.

The back end squirmed all over under full throttle and over the slightest bump it would kick from side to side.

The joints are a pain to change though as the hub usually has to come off to get them out.

Ok Mark I'll try on a set of 235's and see what the difference is, worth a try as I happen to have a set here.

 

Chris, sounds the same, I'll check that too when its jacked up, wouldn't I get lateral play in the wheels due to this also?

Ok Mark I'll try on a set of 235's and see what the difference is, worth a try as I happen to have a set here.

 

Chris, sounds the same, I'll check that too when its jacked up, wouldn't I get lateral play in the wheels due to this also?

 

99% it's the HICAS ball joints ;)

Mine failed the MOT with play in the wheels so I'm sure it will be noticeable.

If you've got wear then speak to Mike Feaney @ MJP in traders section he usually has the bits in stock and knows what you'll need. Faster and cheaper than Nissan.

The parts that wear are the ball joint and sometimes the end of the HICAS arms so might be worth doing both as it's quite a job to swap the joint anyway and you know it will all be back to factory spec.

I think the arms and joints cost about £130 for both sides but could be wrong. Joints alone would be much less I think.

Tyres, £140 each, hicas balljoints £70ish each. I know which I'd go for first... Seriously seriously doubt its the front tyres - its the back end thats moving! Then again, maybe its cos your clock is set wrong....

Righto, I'm getting what feels like a wiggle coming from the rear, yes that sounds funny I know, but seriously guys.......

 

Now, the best way to describe this is that only at speeds over 40 or so whenever I go over those painted lines that you usually get on approach to a junction, you know the ones? ripples, cracks or even cats eyes if I hit them right, I'm getting a weird steer from the rear feeling, kind of wobbles about and I find myself gripping the wheel to fight it ffs.

 

So I'm thinking is this could be a problem with the hicas, the hicas light doesn't come on, only apart from when you switch the ignition on and goes off when engine starts, which is normal, which also means that the steering fluid is ok. so the hicas theory is out.

 

So could this be a worn bush, or something?

 

Also don't know if this is related but I'm getting a feint diff noise occasionally, not all the time.

 

Any ideas?

 

The big Letters is the question. The rest is exploring what he thinks it could be.

 

Tyres, £140 each, hicas balljoints £70ish each. I know which I'd go for first... Seriously seriously doubt its the front tyres - its the back end thats moving! Then again, maybe its cos your clock is set wrong....

 

Could be.

 

That would be why he's accelorating hard and turning when he's approaching junctions obviously.

ok ,I'm a bit hungover here, as you are on a sunday morning, but can someone please explain about the clock? What clock?

In addition, now that I've been paying close attention to whats going on at the rear, I've noticed a light knocking sound also, suspiciously like the knock of a worn ball joint, So I'm thinking Chris knows his onions on this one, I think a call to MJP is on the cards.

 

Thanks.

Markzx, although you are spot on with the tramlining bit I do think you are off target with this one.

 

I had the same thing with mine, slowing down towards a roundabout and hit a bump, next thing I'm off the road and heading for a lamp post, it was my hicas joints. Imagine if your track rod ends were hanging out, your front wheels would wobble all over the shop and steer the car when they wanted, well its the same at the back but cos they are trailing then the arse steps out.

 

I waited too long to change mine and ended up haveing to put a new rear subframe in as I had smashed the back up against a curb.

The clock bit was a joke ;)

 

Rear hicas balljoints it is....

lol, ok right, like I said I didn't know my arse from my elbow this morning, thanks for clearing that up, rear hicas balljoints now added to the shopping list.

 

Thanks all.

I had this when I first bought my zed. I had lots of people saying it could be the HICAS etc but it turned out to be the shox. They were fubar. I bought mine from the z centre (about £75 for both for OEM parts) and once they were fitted hey presto. I'm guessing this is the answer Buddy. Hope that helps

£75 for both? That sounds like the price for NA ones to me!

The shocks can cause a very similar vauge wandering sensation at the rear but if it's a really bad side to side kick I'm sure it's the HICAS ball joints.

You should be able to check which it is if there's play in the wheels or if the suspension has gone a bit soggy with the usual shock tests?