510 Steering tracking

[Sinfull]

Hi everyone,

 

So for some time now I have been trying to remedy a tracking issue with the steering in my 69 510 4 door.  When I say some time im talking the 2 years that ive owned the car :)

I'll do my best to describe what is going on....when driving down a smooth surface freeway it drives smoothly with very minor movement from left to right in your lane, however when the road camber changes from right to left and vise versa it pulls sharply to that side. You'd expect this to occur but its quite nerve wrecking when its night and you don't see the change in the road.
Get onto county style roads and you have to be on your game to drive this thing, you cannot relax or truly enjoy the occasion that driving these cars brings.  As with any road you have the "worn" area of the lane where car tires always run, If you drift over say to the left to far its like the tires go over the high spot in the lane and the car suddenly pulls hard to the left, If had instances where the car has suddenly darted to the right - I'm in New Zealand so that's into oncoming traffic. really had my butt tweaking a few times.
If you try and catch it you can find yourself sawing at the steering wheel. let the car do what it needs and just gently guide it and hope for the best and you can relax a little more.

When you do steer it she is like a go cart and turns in the desired direction instantly and quickly.(caster issue here maybe)

October last year I did a 2500km (1500ish mile) round trip for our yearly National Datsun Meet and by the end of it I wanted to get rid of the damn thing as I just didn't enjoy driving it and scared the shit out of me so many times. I felt it was a danger to drive.

I hope that makes cense but I've done a heap of searching for an answer to sort it myself and try to avoid posting another my steering sucks post but here we are.
 

So my current setup is as follows.

 

Engine - SR20DE

G/Box - 5 speed
Diff - S15 Helical LSD R200
Axles - Custom CV
Wheels - 15x7 +20(i'm trying to think back on the offset so take it with a grain of salt)

Tires - 195/45R15

Suspension - Front - King springs 1 coil "trimmed" off unknown weight...….Rear - Cobra Springs 1.5 coils trimmed off unknown weight.
Ride height - Front 500mm both sides...….Rear 510mm both side - this is taken from bottom of rim lip up to base of fender
New shorter shocks all round - Munroe brand nothing fancy
Shortened front struts via cut and weld - potentially they are r30 skyline struts I'll post a picture up of the number on the strut and we can see if anyone can confirm it.

Datsport Adjustable rear camber/caster setup - Moved approx. 10mm inward to try allow for 8" rims that were on the car - issue was there before doing this.

Maddat sway bar - unsure thinness but definitely larger then stock

bump steer spaces - cant remember the thickness, pretty sure its 25mm approx. 1"

I can also tell you the following work has been done -
New inner and outer tie-rods.
drag link has been refurbished and all play removed from knuckles.
steering box has been removed and inspected and adjusted - all come back looking good.
Steering idler arm bushes replaced and re-sleeved to match shaft that it attached to.
LCA inner bushes replaced with Standard Nissan rubber bush.
ball joints replaced.

wheel bearings checked and adjusted

It has adjustable TC rods - Datsport branded - both appear unworn.

Wheel alignment carried out on machine.

That's the basic stuff I know while I write this at work at 1am. Glorious night shift :(

Anyway I really hope some help in resolving this is out there.  Any question please ask and I'll get answers up ASAP.

Thanks heaps
Mat

 

I'll get some videos of driving and vehicle stance when I can.

[Sinfull]

https://youtu.be/8gSoiyHjllU

 

https://youtu.be/6-SyjGkltzs

 

It's not a lot to look at but the keen eye might pick up the movement in the road and my steering wheel moment.

[Sinfull]

 The rear appears to be sitting up higher then the front but my measurements tell me it's only 10mm higher.

[datzenmike]

Sounds like alignment. Excessive toe in or out will cause it to hunt for a direction. My 620 truck came to me severely toe in and on a tight turn into a driveway the wheel would almost spin out of my hand into the turn and on the highway in the rain if you hit a small puddle on one side it would pull you over into that lane. It was scary.  I looked at the front tires from across the street and they had so much toe in they were pointing at me! One wheel fighting the other was ok on level pavement but the tires were worn on the insides.

 

Use the steering wheel to line one front tires edges with the rear behind it. It's harder than you think. Get help and stretch a piece of string front to back to help. Now go to the opposite side and look. The front tire should just noticeably be pointing inward. Outward would be very wrong. I don't know what the 510 alignment specs are but on my 710 the difference between measuring from left to right across the front of the tires is shorter by 4-6mm than measuring L to R across the rears of the front tires. Narrower at the front means they are toed in.

 

 

IRS are weird as in they can very much affect the steering from the rear. Lowering can bugger the camber and the toe in/out. So are the rear wheels tilting noticeably inwards at the top? 

[BrandonS]

I see you have adjustable TC rods.  What do you have your caster set at?  Adding more caster will help the car track straighter.  

[fiveoneO]

Way back when I had a 69 2 door that I was fighting tracking issues with. I replaced every steering component, had a couple different steering boxes in it, installed adjustable TC rods, played around with alignment settings and nothing really worked. I was running a 15x7 +0 wheel with a pretty sticky directional 195 50 15 tire. I changed wheels to the snowflake 280zx wheel which is 15x6 +12 with the same sticky directional tire and it made a huge difference. After that I bought some less aggressive non directional tires and it fixed all my issues.

 

I think 510s are very picky about wheel offsets and aggressive tires. That car also had 280z front struts which changed the track width. You said your car has skyline struts which I'm sure changes your track width. I'd play around with some different wheels and see if there are any changes.   

[Draker]

Sounds like you need an alignment. When was the last time it was professionally aligned? Post your results.

 

[datzenmike]

1 hour ago, fiveoneO said:

Way back when I had a 69 2 door that I was fighting tracking issues with. I replaced every steering component, had a couple different steering boxes in it, installed adjustable TC rods, played around with alignment settings and nothing really worked. I was running a 15x7 +0 wheel with a pretty sticky directional 195 50 15 tire. I changed wheels to the snowflake 280zx wheel which is 15x6 +12 with the same sticky directional tire and it made a huge difference. After that I bought some less aggressive non directional tires and it fixed all my issues.

 

I think 510s are very picky about wheel offsets and aggressive tires. That car also had 280z front struts which changed the track width. You said your car has skyline struts which I'm sure changes your track width. I'd play around with some different wheels and see if there are any changes.   

 

The zero offset rim was towards a positive scrub radius compared to the +12 zx rim which moves towards a negative scrub radius. Generally you want a slight negative scrub radius so  +12 offset was a move in the correct direction. What's correct on that 510? Was it enough? not enough? No idea, but I suspect the poor handling was a result of being too positive in the scrub radius to begin with.

[Sinfull]

14 hours ago, Draker said:

Sounds like you need an alignment. When was the last time it was professionally aligned? Post your results.

 

 About 6months ago but have just had one 2 days go. I havnt had a chance to really drive the car properly. 

This is the 3rd company to do the alignment and the only ones who have spoken about adjusting the caster and the effects it has. Will no more them is week when I get on it and drive it. I'll post up the WAY sheet shortly.

[john510]

I had some issues like yours.After replacing some steering components and getting an alignment,same problem.Alignment shop thought it might be the directional tires.It was ! All that headache and time because of directional tires.Go figure.It doesn't make sense to me.

[Draker]

4 hours ago, john510 said:

I had some issues like yours.After replacing some steering components and getting an alignment,same problem.Alignment shop thought it might be the directional tires.It was ! All that headache and time because of directional tires.Go figure.It doesn't make sense to me.

directional tires, even rotating the correct way?

[john510]

26 minutes ago, Draker said:

directional tires, even rotating the correct way?

Yes 

[Sinfull]

Took the car for a good drive into Auckland city. A good hours worth of driving consisting of motorway smooth driving and country roads. Things are looking very positive. Car felt a lot more settled on straight roads and through corners. I could actually relax a bit while I drove.

WA guy said he would like to wind a little more caster into the front to see how things go so I will be in touch with him. Although now I do notice the steering is heavier at slow speeds as expected so throwing more caster at it might cause the heavy steering to become worse and really just announcing. Can't have ya cake and eat it too I guess.

I'll get my Wheel alignment spec sheet up shortly too.

[Draker]

1 hour ago, Sinfull said:

Took the car for a good drive into Auckland city. A good hours worth of driving consisting of motorway smooth driving and country roads. Things are looking very positive. Car felt a lot more settled on straight roads and through corners. I could actually relax a bit while I drove.

WA guy said he would like to wind a little more caster into the front to see how things go so I will be in touch with him. Although now I do notice the steering is heavier at slow speeds as expected so throwing more caster at it might cause the heavy steering to become worse and really just announcing. Can't have ya cake and eat it too I guess.

I'll get my Wheel alignment spec sheet up shortly too.

 

Good to hear things are improving!