Front suspension renew and adjustment

[gundee]

3 hours ago, BDJeff said:

This is becoming a real saga, sorry!  In the previous episode, you can see the two struts looked very similar but I was comparing the old one to the new one while it was still in the strut housing.  I finally took the new strut out of the housing and compared them side by side on the bench!  And look!  They're different, further investigation shows I got a different shock than what was listed on the box.  It's just long enough to make a difference.  Is this a rear strut?  It's a BZ3038 where the box shows it as a BZ3015.

 

Just found it, looks like what I have is for a 280Z front.

If the shock was wrong it would not fit in the front housing. Not the issue. I sent you a PM. Try that.

[Terrapin Z]

BZ3038 are listed as fitting the 79-83 280ZX front.

All the strut companies list 3 types for the Z cars Koni, KYB and (now obsolete) Tokico's  https://www.thezstore.com/page/TZS/CTGY/classic20b

240 to early 260 - BZ3015 / BZ3016

late 260 to 280 - BZ3012 / BZ3013

and ZX fronts only.  - BZ3038

It would seem to me something is different in the valving or gas charge or length, etc.  

Reading through my instructions I can find no mention of any accessories that came with the cartridges. There is mention of a spacer needing to be added if the gland nut does not torque down properly.

Not sure if this helps you with the issues at hand. Personally I would find the correct application strut. 

Just my observation and opinion.  

[BDJeff]

21 hours ago, Zed Head said:

BZ3038 is the base shock, the others are renumbered based on the gland nut or the space underneath.  They're the same shock just different part numbers based on the accessories.  I have some of the basic Tokicos in the garage with both labels.  I can peel one off and 3038 is underneath.

Your problem would be with how long the shock is when compressed.  No, the problem is when the strut is fully extended, dropping the position and so angle of the lower control arm.  The strut is not settling under the weight of the car. Yes, this is correct, it's riding on the top stop Have you run them through the travel?   Maybe they're binding up.  You should be able to fully compress the shock by hand.

The strut is not binding,  I can push it a little way in easily.  But almost no way to compress it fully by hand, way too much spring/pressure.  I can straight arm it and put almost all my not-so-minimal weight on it and it's difficult to make it to the bottom. 

No accessories with the strut.  Only the collar nut and top nut.  Collar nut screws down tight, strut tight in tube, no spacer needed.

I'm liking TerrapinZ's suggestion about the different valving or gas charging in the same strut body.  If this strut is for a 280 Z, that is a much heavier car and so would probably have a different/higher gas charge which would also explain my difficulty with pushing it in (smoothly). 

I can't be certain but I'm pretty sure the spring/strut assembly is at the top of it's travel when installed.  That would explain the bottom inboard angle of the tires because, at full extension it is longer than the original configuration, the new strut is 15 mm longer (see pictures above) and so would make the lower control arm position a bit lower and so angle in the wheel.  I could probably prove this by putting a lot of weight somehow in the front and get the strut assembly off of the upper stop and to more of a midrange position.

I'm still going to call ZCarDepot tomorrow and see what they say about the P/N's

gundee, thanks for the PM, I'll check it out.

 

[Zed Head]

The gas in the strut is not for lifting.  Not sure what you mean by "spring/pressure", there's no spring inside the shock.  The gas charge should be the same across platforms, it's just there for sealing and/or foam reduction.

Might be that you got a defective over-pressurized strut/shock.  Tokico, the company, has been in limbo for many years, wouldn't be a surprise if there were counterfeits or bad stock out there.  Get some reasonably priced KYB's and you'll probably be very happy, with no problems.

Here's an old thread about the part numbers.  Good luck.

https://www.zcar.com/forum/10-70-83-tech-discussion-forum/277489-strut-interchangeability-now-can-told.html

[Zed Head]

What was in gundee's secret PM?   

[Zed Head]

https://www.monroe.com.au/trade-corner/tech-info/gas-charging/gas-charged-shocks-struts-replacement-cartridges.html

[BDJeff]

Good link, thanks.  Yes, I understood there are no springs in a strut, I was trying to make a comparison by using the word "spring".  Poor wording. 

I took the old sway bar off last night, there was a recommendation above to try that.  I'm installing a larger one anyway so no extra effort.  I should have it back together tonight (not installing the new bar yet) so we'll see if it had anything to do with it.

[BDJeff]

Sorry for the delay, back at it now.  I had taken off the sway bar and it had zero effect.  The wheels were still angled inward at the bottom.  So I replaced the new Tokico struts with the original struts I removed at the beginning of this saga.  And found a very strange effect.

When I back out of the garage, over the slight drop at the door, the wheels are angled outward.  When I drive around the block and pull in forward and park in the same position, the wheels are angled inward at the bottom (the original problem).  So I drove into the garage, then backed out and stop in the same spot again.  The wheels were again angled out at the bottom.  I seem to have a binding problem that reacts to the last driving direction.  And yes, I tightened the big lower control arm bolt when the car was fully weighted on the shop floor.

First picture is parking after reversing, second picture is parking after moving forward.  I'm thinking about loosing the lower control arm bolt and driving up and down the driveway a couple of times, just to see what happens.

[BDJeff]

And now I don't think it's the control arm bushings.  I loosened up the big nuts on the control arms and did the back up, drive forward thing again.  Backing up the wheels angled out at the bottom, going forward they moved back to angled in at the bottom.  So I backed up the length of the garage and the wheels angled out again so I tightened up the bolts with the wheels angled out.  So now with the bushings tight, I backed down the driveway (wheels were angled out a the end), then drove back to the shop and the wheels angled in. 

So I have the same action whether the bushings are tight or not.

What's going on here?  Forward in, backward out?  This actually means the ride height is changing because the control arms are swinging up and down (?) as the wheels actually move thru an arc.

[grannyknot]

So if you jacked the front wheels off the ground and grabbed the tire at the top and bottom you should be able to move the wheel in and out like it's doing while on the ground? Sounds like the rubber isolator at the top of the strut is worn and moving around or the ball joint is severely worn. This is bizarre.

[w3wilkes]

Sounds like the car is pigeon toed so that going forward tends to push the tires inward where going backwards tends to pull them apart.

[LeonV]

What's the state of your compression rod bushings and all associated fasteners (at body and control arm)?