Interesting issue here...

[justaZcarguy]

And first of all, let me apologize for a sorta repost here....

Been travelling around in the Z, it seems that when I accelerate I can feel the rear of the car want to move over to the right and upon deceleration, it seems to go to the left, almost as if it has a degree of rear-wheel steering...

I swear that when it's tracking down the road I can feel the rearend following the road grooves a bit.

Has anyone else experienced this?

My initial guess is that the control arms are possibly moving to and fro on worn bushings? Or possibly the Moustache bar bushings? It seems that my experience with moustace bar bushings has been more of a upward downward movement issue.

Anyone wanna chime in here?

And yes, I plan on parking it until I can determine what the heck it going on, as this cannot be safe. This is a first for me which is weird for all the Zed's Iv'e had...

Not that I claim to know it all, heck I barely know my first name on most days.:stupid:

Thanks for any and all input.

~Brian

[BuDavid]

I woud suspect the control arm bushings.. the moustache bar would affect the movement of the differential only.. and as far as I think, the differential movement will cause knocking or banging under the car inetially when accelarating or decelarating and then he halfshafts have U-joints which can't affect the position of the wheels..

maybe one of the control arms is moving back and forth depending on accelaration or braking or even hitting small stones on the road.. check the bushings, coz when rubber goes out metal to metal vibration damages more stuff!

[justaZcarguy]

Thanks BuDavid, I glanced under there yesterday, Other than a loose half-shaft and u-joints that were needing to be replaced on the d-line, that is all I could spot.

I could see that dreaded pin that is on the control arm that I know can be a bitch to remove, but I am not sure that is where you are referring to, I think that where you are talking about is closer to the point where the control arm connects to the middle of the suspension.

Anyone here want to give some advice as to how to go about it?

Thanks!

[TBK1]

put it up on jack stands (body and frame) and try to move the rear end side to side , see where the play is coming from.

[justaZcarguy]

You know, I did that last night.

I tried to get play back and forth and up and down and the play that you get when bearings are going out of a wheel.

I really found nothing that was obvious. That tells me that it's torque related and needs more "force" than I can provide, and that points a finger to bushings in my opinion. Now, just to find them.

Are there bushings located on that dreaded pin that is at the end of the control arm?

thanks again all...

[240znz]

Brian,

There are two sets of bushes on the rear suspension that could be the issue.

The outer bushes are pressed into place and the spindle pin runs through the centre. The small pin in the centre is there to stop the spindle pin from rotating when you tighten the nuts. Yes this is the dreaded pin. There are a few threads on spindle pin removal but do yourself a favour and pay a shop to do it for you. They are evil evil things.

The inner (diff end) bushes are easy to change out. Loosen the bolts that secure the pins in place before removing the arm. The treads are more than likely rusted a bit and a little difficult to remove afterwards. I had to use a rattle gun on one end and a soak the other for 24hrs with CRC to get it to budge with the rattle gun. I'll be running a tap through them later and apply grahite grease to stop this from happening again (well there's always hope).

If I were you, I would buy new rubber bushings, spindle pins, nylocks and cotter pins. You can choose to go with poly pushings now if you wish, all depends what you want to do.

I would also look at axle stands and dropping the entire rear end and rebuilding it as a whole. Check the shocks while you are at it and fit new if they are suspect. Changing the shocks can not be done without removing the spindle pin. Why do it twice.

Parts list for a full on rebuild is:

2 x spindle pins

2 x cotter pins for centre of spindle pins

4 x nylocks for spindle pins

2 x outer bushes

2 x inner bushes

2 x moustache bar bushes

set of rear sway bar links and bushes

2 x half shaft boots

1 x rubber diff mount

set of wheel bearings

2 x gas shocks (or strut inserts if you like to call them that)

Check for play in the half shaft universals and replace if worn. Make sure you get new ones with grease nipples.

If you do the lot then you have peace of mind that your arse is safe.

[justaZcarguy]

I appreciate that 240znz...

I will call a shop and check into that, I know that a friend of mine has a pin puller, but from past experience, I really have NO desire to try that again.

Thanks again for the help.

~Brian

[beandip]

Brian , come by and pick up my spindle pin puller . With it you will pull the pins in 5 min. per side , after you have the car on stands and the wheels off . I the inner control arm bushings are simple to change . Some times if these bushings are torqued down with the car up on stands .

When the car is lowered it puts a strain on the bushings and they will fail prematurely because of the added twist . I just finished doing mine , and I learned allot doing the job . Gary

[justaZcarguy]

I've been meaning to bring the car by but parked it due to this issue, i don't think it would fail but I know I want to address the d-line this weekend.

Thanks Gary!

[mlc240z]

Bean,

so the procedure would be the same as what i've heard (and done) for the fronts.

snug bolts up handtight when raised to seat bushings, then torque to specs when car is down and full weight applied?

[=Enigma=]

Changing the shocks can not be done without removing the spindle pin.

Say what? Am I missing something here. Did you mean to say that the outer bushings can't be replaced without removing the spindle pin?

You should be able to replace the shocks or "strut inserts" without removing the spindle pin by unbolting the strut assy from the tower, and swinging it down to finish the job. I'm pretty sure it will clear the wheel arch, but if not, you could always either unbolt the half-shaft from the outer flange on the early R180 diff equipped cars, or pop it out of the diff on the R200 to allow the strut assy to clear the wheel arch. I'd much rather do that than mess with the spindle pin.

[240znz]

I read that somewhere but I could be wrong.

I dropped the entire back end and in the process of rebuilding the lot. So I can't confirm if there is enough space to swing it down. You'd need to loosen the inner bush bolts I guess to get enough play before trying to swing it out in addition to removing the half shafts. Hell, I'd give it a try first.

I agree, I'd rather tackle it the way you suggested than pull the spindles again.