steering too hard/stiff

[Zoldman]

All,

 

I've been trying to track down my hard steering problem in my V8 260Z, and would like some input if anyone can help. The car's overall steering is just very "stiff", like the wheels don't want to turn. It has been this way ever since I got it last year.

 

Items that have been replaced include ball joints, tie rod ends, struts, springs, all bushings. The steering effort has not changed one way or another with the replacment of these items. When the front end is jacked up, the rack and wheels turn smoothly with no noticeable problems or sloppiness. By the way, I also have a '72 240Z, and it's steering is much lighter by comparison.

 

I guess I need some advice as to all the things that can cause a high steering effort and what to try next. I did my searching and have checked and replaced the items that I thought were suspect, which I was doing as part of my suspension rehab anyway, but no change. The stiffness is not just apparent at low speeds, either. I can feel a difference in the 260 steers at all speeds in comparison to the 240. It does track straight and does not exhibit any dartiness or wandering, and the front tires seem to be wearing evenly.

 

Here is a list of things I have thought of:

 

1) Tire size. I know width is an issue, but both cars have 205's. Is diameter an issue? The hard steering 260 does have a 25.5" tire, as opposed to the 240, which has a 24" tire. I have checked inflation pressures.

 

2) Steering wheel size. A smaller wheel, mine is a 13" Grant, should contribute to this problem. Is this wheel just too small. The stock one on the 240 is almost 16" by comparison.

 

3) Steering geometry. How do toe, camber, and caster figure in? The car is lowered about an inch; the LCA's are level with the ground. This is an area where I am admittedly weak..........toe is 1/8" in, but do not know what camber and caster are.

 

4) The rack. As I said earlier, it seems to operate smoothly, but I am no expert here. Is there a difference in the steering racks (ratio or fit) between the 240 and the "early" 260? Most of the early 260 parts are actually 240 stuff, I have found. Is there a way I can check the rack that will actually tell me something, other than my "seems smooth" nonscientific method?

 

Sorry for the long post, but I have been tring to figure this out for myself, and although I have learned a bunch while rehabbing this car, I have not managed to learn everything...............and this thing in particular.

 

Thanks

 

Bill

[cyrus]

Bring a note book because class is in session. Steering wheel to small? Lets find out for sure.

 

The leverage you have is related to the distant from the center which you are pulling. Lets see:

 

Steering stock

d= 16

rad=8

 

Steering Grant

d= 13

rad=6.5

 

So if all other things are equal you are pulling 8/6.5 or 1.23 or 23 percent harder on the grant. That is huge! Lastly you did not mention wheels offset but the grant has to go.

[Zoldman]

Cyrus,

 

Wheels are the 15 X 6 Datsun "Swastika" units from 280 ZX. Offset is supposed to be +12mm.

 

Ok, the Grant has got to go...............any other ideas?

 

Thanks

 

Bill

[Pop N Wood]

Don't dispute the numbers on the smaller wheel, but on smooth pavement and 205 tires you should be able to turn the wheel lock to lock with only the palm of one hand.

 

Replacing the rubber steering coupler with a solid urethane one made my 240 feel like it had power steering. I replaced the steering rack bushings with urethane at the same time. Getting rid of the slop in the front end does help.

 

Might want to check whether one of the previous owners put in the shorter steering knuckles to "quicken" the steering. How many turns lock to lock?

 

http://www.zcarparts.com/store/merchant.mvc?Screen=PROD&Product_Code=23-4181

 

Also I would make sure nothing is binding under load. Check the U joint at the base of the steering column and make sure it is solid.

[innerware]

For now just swap the wheel from your 240 with that of your 260. Since the earlier steers fine if that is the problem then problem solved. What is the wheel on the 240? Stock? Most wheels are like 13-14" dia. Mine is a 14" and is fine. Would one inch make that much difference?

[Zoldman]

Good idea,

 

I am going to swap steering wheels and see what happens. As to how much difference it could make, see the answer Cyrus posted, it looks like it will make a big change. Stock wheel is close to 16".

 

Bill

[buZy]

Did you take apart the rack?? It's very easy to do. Make sure the actual rack and pinion gears are well greased, inspected and then re-set up properly for wear. Please correct me if I am wrong, but think I remember you can adjust the preload gear lash to get just the right wear action and smoothness. I did this to fix the rough feel in the steering with the car on jacks. As far as steering wheel sizes go mine is a 13 inch outside diameter. Too small my tastes, but still the steering action is free and smooth. So it tells me something else is going on here? I hope this helps.

[Forrest]

Although it seems your question is already answered, I just wanted to add that I have the short knuckles, 225/50/16 tires, and 13" wheel on my 77 and the 13" wheel made a much more noticable difference than the other 2 modifications.

 

Personally, though, I like it.

[blueovalz]

One thing that I'd check on is the rack. Under the rack gear is a large set screw that preloads (for lack of a better term) the rack gear. It could be that the previous owner, in an attempt to eliminate the play caused by worn bronze bushings at each end of the rack tube, tightened this set screw (it's about 1" in diameter) and thus made the steering very hard. But, typically when this is done, the steering effort increases slightly as the rack nears full lock on both sides. You may want to loosen it by 1/4 to 1/2 turn and see if this makes any difference.

[ZR8ED]

Uh I hate to sound obvious, but your 260 does have a V8 in it. does it happen to be a scarab position or a jtr position? Its a big difference, let alone the difference from your L6 240.

 

205's should not make the only difference. I run 235's with sticky rubber, and the car is only difficult in the parking lot. Driving with "the palm of your hand" ain't gonna happen when backing up in my 280z.

 

If you don't find short steering knuckles or a damaged rack, you may have to just suck it up and build some bigger arm muscles.. hehe

[Zoldman]

Thanks to everyone who posted. I swapped out the steering wheel for the stock unit, and adjusted the preload on the rack. It is quite a bit better now, but ain't no way its "palm of the hand" easy.

 

I'm swapping out the 305 that's in it now for an LT1 so when I get the old motor out, I'm gonna pull the rack and take it apart. My guess is it needs a going through.

 

By the way, the motor is in the JTR position, the steering arms are stock size, and yes, I probably need to build up my arm muscles........

 

Thanks again

 

Bill