Ach! I don't have a scanner, but one of the Moderators should. We are all waiting w/"baited" breath(joke) for your data and thats no joke. Boomer

 

Thanks to jelledge who stepped up on my offer to post my alignment. I have faxed it to him and I am sure he will take care of it when he has the time.

 

Thanks, ezchief.

 

I will get the alignment stuff posted tonight when I get home.

 

Alignment Specs for ezchief's car



Before and After Readings for ezchief's car




Just for comparison here are the specs and readings
for my car that was horribly out of spec for toe.

 

Go to 350frenzy. com, someone, and look for Tere's Database under the Warranty issues thread and look at my before and after readings and compare them with ezchief's. His readings were taken at 13-14,000 miles?, and mine were taken at 1600 miles after I changed tires, found the beginnings of feathering, and got an alignment the next day. I would welcome any and all comments.

 

ezchief's caster is at the low end of the spectrum (7.2 LF and 7.6 RF) compared to jelledge at 8.18 LF and 7.81 RF and mine at 8.4 LF and 8.1 RF.

Question is how did exchief get those low caster numbers?

 

Good question. I don't have an answer. Nissan's specs for the acceptable range on Caster is 7.4 to 8.9 degrees. Mine are:

8.7LF and 8.5RF, the opposite end as ezchief's and jelledge's are more toward the middle. Yours are between mine and jellidge's What does this mean? Is such a wide range on the same car model acceptable? I feel uncomfortable that mine are so close to the top of the range for Caster. Should I be worried? Or should ezchief being slightly under the spec range at 7.2LF and 7.6 RF?

What are the mileages on the cars other than mine?

Boomer 1600 miles;
spn350z ;
jelledge ; and
ezchief 14,000+ miles.

Puzzling. Can anyone enlighten me/us? Boomer

 

My backordered RE-040s appeared two weeks ago after waiting three weeks.

 

Given the caster/camber of the Z's front end (both not adjustable), a toe-out condition will pretty much guarantee wear on the inside tread blocks. By increasing the front toe-in (the direction the Hunter folks are going), the load on the front inside tread blocks is reduced, and the tires would have more even wear. It seems a number of Zs (mine included) were delivered with near or above max toe-out. So far, with about 500 miles since my alignment (free at the dealership), it looks like the feathering has either stopped or is progressing at a significantly lesser rate (too soon to tell which for sure).

And yes, braking does load up the front end (which I believe would add toe-out), consequently putting more load on the front inside tread. I've always used downshifting (for about 40 years) for routine slowing down, so the technique does not transfer as much load to the front -- this may have reduced the amount of front inside tread wear I got.

If you use routine driving techniques like mine, it's my guess that around a 0.02 L/R (total 0.04) works OK. If you do a lot of hard braking, maybe a 0.05 L/R (total 0.10) would be a little better, but your Z may not do hard corners as well. I think it's a trade-off, and tuning your suspension to how you drive and the type of performance you want is the best bet.

Don't forget, that when you align the Z, always, always do all 4 at the same time. The back end is probably more crucial than the front end in the overall scheme of things.

Caveat: I'm for sure not an engineer, so these are just my anecdotal thoughts on the issue. I'll be interested to see what the Hunter folks come up with.

 

Given your anaylsis, mine seems to be set up more for touring than cornering, 0.00 LF and RF? Or am I reading it wrong?

 

LOL... Yeah Boomer -- going in a straight line and never hitting the brakes would work for your alignment by the way I look at it. I'd think you might want a bit more toe-in, based on the direction Hunter is going. But that's just my wild azz guess.

 

I think you're right, from the way the steering feels. The turnin is less sharp than I had hoped for. Maybe when Hunter's recs come in, I'll take it to OKC and have Tire Rack's installer set the toein for a little more corner carving. If I get 25,000 miles on my All Seasons with that setting, response will be much better on something besides a straight road. I think my service writer was trying to get the best setting for tire wear for me.

Now that I have more knowledge about alignment, thanks to you and others, I feel more confident in asking for a more aggressive one w/o worrying about excessive tire wear.

 

I have 2700 on mine (bought it about 1 1/2 months ago) and noticed early on that the tires seemed to wearing on the outside. The service manager agreed and they found the car was out of alignment. The wear seems better now, but I will watch this closely. Nissan has a problem and they need to correct it. Cars are still coming from the factory incorrectly aligned!!!

 

After 1200 miles my Michelin Pilot sports are "feathering" on the inside tread block.

I've had the Z aligned 4 times. Ever since the first alignment my toe alignment has always been toe-in. The toe is set to 0.05 degrees per wheel at the alignment. After about a thousand miles or so the feathering progresses and I take it in for an alignment and toe-in becomes 0.10 degrees per wheel.

So even with toe-in and different/new tires, the "feathering" continues. Castor is 8.8 and 8.5 degrees. Camber is -1.0 and 1.5 degrees.


Enforcer

 

It's hard to tell from only a few data points and all the other variables (weights, wheels, tires) but it supports a "theory".

I've been reluctant on this idea. Friday I took my Z in to the dealer to put it on the lift and carefully investigate the suspension. If this guess is correct, I found a potential cause.

It is my wild azz guess that this problem is caused by the large castor alignment. On a wheel that is not constrained in toe movement, castor causes wheel flutter. Like a shoping cart castor that flutters side to side when you push ithe cart. The wheel flutter could only occur if a part in the Z suspension flexes.

Camber should change where this unusual tire wear occurs. Excessive toe would cause a true feathering across the tread block as depicted on many websites, not circumferentially around the tire like I have. So tire composition, camber and toe aren't the primary cause but are contributors.

Always the front end seems very tight to me on the lift. I cannot exert enough force by hand to cause the flexing. However a friend of mine has a TT RX-7 and claims this "feathering" issue occured on the 7 until Mazda changed out some rubber encased joints and went to metal on metal.

So if this is true, the Z has what appears to be a rubber encased joint where the bottom trailing link attaches to the chassis. Here is the picture. It is my guess that this component is rubber encased and will flex under load which could allow the wheel flutter initiated by the high castor alignment.


Enforcer

 

Now that's a very interesting analysis! Great detective work, and it makes sense given the RX comparison. I also liked your grogery cart analogy. Now all we have to do is get Nissan to evaluate your theory and respond.

 

Thanks for everyones opinions on our reaccuring problem.

I have not looked at the board for about a week so my post is about 10 posts back. We live in Virginia and the Lemon Law states the problem must be discovered within the first 18 mo of ownership. The VA laws are pretty strict and actually favor the consumer. We are going to have an independent shop review our tires for a second opinion. If the independent shop in agreement with our calculations that the second set of tires won't last more than a few thousand miles, we will then notify Nissan of our intent to file a Lemon Law claim. Nissan has 15 days to respond to our certified letter and an attempt to another fix. If nothing is resolved then our attorney will proceed.

The one thing that everyone must realize is that if you align your car beyond Nissan's factory specs they can deny any warranty claim on your tires. Why should we be the ones to come up with our own fix as our warranty and mileage time clicks by. If it was an easy repair Nissan NA would have fixed it by now.

Don't really know what to do because we really love our car and if it is bought back by Nissan, will a newer Z have the same problems?!

 

I still would like to know more of ezchief's caster....changed anything?

I have over 12K miles and over 3k miles on my second set of tires. The tires are starting to show same old problem with wear. The inside treads are "baby butt smooth", while the outside treads show some small pits. Someone posted a closeup of the tire wear a while back.

The difference in wear is about 1/64 inch between inside tread and center to outer.

Is the 350Z the Edsel of the new millennium?
No wait the Edsel didn't have these many problems!

 

Let's wait for Hunter's analysis before we take such a leap. Its becoming more and more obvious that this problem is difficult to diagnose. Enforcer's view on the caster may be corroborated by Hunter and Nissan. What I want to know is why the caster values move toward the bottom of the spec range as the miles pile up. Enforcer may be correct and we may have a suspension joint that is not strong enough to take the repeated rigors of hard driving like the car was designed to do. I think someone at Nissan is taking a very hard look at our problem and we will have some action soon.

BTW, I have 2400 miles on my new tires(not OE), and have no signs of feathering at all. The feathering showed up at 1600 miles w/OE tires and the toe setting way out of spec. You have 3 times as many miles as I have and that may be a major factor. I think Nissan will need to look at blocks of mileage for a solution to the problems. I have always wondered about wear on suspension parts as out of spec alignment, not caught early, had an impact, along with OE tires with a very soft tread. Enforcer may have hit the button on suspension part wear and high mileage cars may need that part replaced and the car re-aligned.

I don't know how many know, but Nissan has issued a new TSB on cars with a severe right hand pull and if it falls within certain parameters, a suspension part will be replaced. The feathering could be treated in much the same way. I am not an engineer, so I am just GUESSING and every reader of this post needs to remember that fact.

Boomer