Front Alignment Questions

jadcock · Oct 25th, 2003, 06:01 PM

I noticed today that there's some "feathering" on the front tires on the outer edges -- enough that I consider more than usual. I haven't had the truck aligned since I bought it a year ago, and I just adjusted my ride height to level in the front, so I figure an alignment couldn't hurt anything at all. I have some general q's for those who have done it before:

1) My lower ball joints have splits in the boots, and I'd like to replace those. I don't have any special tools (like a puller). The Haynes manual indicates that a puller should be used...is this true? I'd probably replace both ball joints on both sides while I'm in there...any advice on that? Seems to me that I would just need to support the lower control arm with a jack and everything above that (knuckle, upper wishbone, etc.) would have no tension on it, true? I love working on the truck, but I'm always leery of front suspension work. I'm trying to decide whether to try to replace these myself or have it done, because I know they'll strongly suggest replacement during the alignment, and I want to get some new parts under there anyway.

2) AC (4x4parts.com) sells genuine Nissan ball joints. I've never seen a performance supplier advertising genuine OE parts. Are Nissan ball joints that much better than 3rd party pieces (like Moog or others)? I'd probably go through Joe (Heath's favorite supplier) instead of AC if the genuine Nissan parts come recommended by you guys.

3) I see two different alignments advertised in my local rags. There are coupons for a standard 2-wheel alignment in the $20-30 range. There's also a "thrust alignment" advertised (doesn't specify # of wheels aligned) for $50. What is the difference between a standard and a "thrust" alignment?

Thanks guys,

aaronford · Oct 25th, 2003, 10:00 PM

Well, your joints are diferent than mine. I suspect Nissan will try to sell you the whole arm like me. I bought the Advance brand and they are fine so far. I know you will need a pickle fork to seperate the ball joint from the spindle mount, but I am not sure if your ball joints bolt in or get pressed in like mine.

The feathering is normal, it is due to the geometry of the tire while turning. As long as the feathering isn't bad, you normally rotate the tires to control it. A badly worn or damaged front end will feather tires quickly, but I don't think that this is the case here.

The difference in a thrust angle and a 2 wheel align is fairly simple. A 2 wheel alignment compares the right and left tires only. A thrust angle alignment also brings in the rear wheels into account. As the rear wheels are not really adjustable, they look at the thrust vector created by the rear tires. What it boils down to is a 2 wheel will make the front tires roll okay, but this may or may not be the direction the rear tires are pushing. The vehicle may crab sideways while driving. A thrust angle solves this.

There may be someone else who can explain this a little better...

jadcock · Oct 26th, 2003, 08:13 AM

Thanks Aaron,

I think the feathering got a lot worse in the past week, because I've never noticed it before, but it's very apparent now. Coincidentally, I had just adjusted my ride height, but I agree that that shouldn't appreciably affect the feathering.

So with the thrust alignment, even though the rear tires' alignment isn't adjustable (or even variable in this case, save for bending or breaking something), if there is a problem or misalignment in the back, they can align the front tires in accordance with any error in the back?

Fortunately (for me), all the ball joints on the 4x4 models are bolt in -- I don't have to worry about drilling any rivets out or pressing a joint out of the arm. The Haynes manual does suggest to use a separator to separate the top of the knuckle and the upper ball joint; I guess they'll be hard to separate simply from years of being mated together. The UBJs look pretty easy to do...the LBJs look quite a bit more of a pain. Unfortunately, it's one of my lowers that has a split boot. I think I can tackle the uppers easily, but maybe I'll have the shop change the lowers with the alignment if it looks too complicated for my comfort level.

**morepower2** · Oct 28th, 2003, 02:30 AM

Quote:

Originally posted by jadcock
I noticed today that there's some "feathering" on the front tires on the outer edges -- enough that I consider more than usual. I haven't had the truck aligned since I bought it a year ago, and I just adjusted my ride height to level in the front, so I figure an alignment couldn't hurt anything at all. I have some general q's for those who have done it before:

1) My lower ball joints have splits in the boots, and I'd like to replace those. I don't have any special tools (like a puller). The Haynes manual indicates that a puller should be used...is this true? I'd probably replace both ball joints on both sides while I'm in there...any advice on that? Seems to me that I would just need to support the lower control arm with a jack and everything above that (knuckle, upper wishbone, etc.) would have no tension on it, true? I love working on the truck, but I'm always leery of front suspension work. I'm trying to decide whether to try to replace these myself or have it done, because I know they'll strongly suggest replacement during the alignment, and I want to get some new parts under there anyway.

2) AC (4x4parts.com) sells genuine Nissan ball joints. I've never seen a performance supplier advertising genuine OE parts. Are Nissan ball joints that much better than 3rd party pieces (like Moog or others)? I'd probably go through Joe (Heath's favorite supplier) instead of AC if the genuine Nissan parts come recommended by you guys.

3) I see two different alignments advertised in my local rags. There are coupons for a standard 2-wheel alignment in the $20-30 range. There's also a "thrust alignment" advertised (doesn't specify # of wheels aligned) for $50. What is the difference between a standard and a "thrust" alignment?

Thanks guys,

It Is pretty easy, have someone pry down lightly on the LCA while you hit the side of the knuckle (after having removed the nut!) with a big ball peen hammer. The tapered shaft of the ball joint should break loose from the knucke with a few good hits. Unbolt the ball joint and put in the new one.

You can adjust the camber and caster with shims under the LCA mounting points. The thrust angle is the caster. I set mine for about 3/4 degree negative and a couple of degrees positve caster with just a tad (about 1/16 toe-in).

This gives good bite in the turns and prevents feathering. Also your center link and idler arm bushings are proably shot, these suck and wear out pretty fast.

Use geniune nissan replacments. I used Spencer Low bronze idler arm bushings to rebuild my idler arm. Also you might want to do the energy bushing thing while you have the front suspension apart.

Mike

jadcock · Oct 28th, 2003, 07:08 AM

Thanks for your thoughts Mike. I'm planning to replace all the ball joints with either Moog or TRW parts (which may be made by Perfect Circle). They have a lifetime warranty (which I don't think I get with Nissan parts) and after I do it once, I think it'll be easier to tackle the job again if I have to because I'll be more comfortable, having been in there already. Board members over at nissan4wheelers.com seem to like the Perfect Circle brand (available at Autozone) and they're pretty hardcore wheelers over there so I tend to have confidence in a general consensus about a product (good or bad).

I believe I'm going to leave my bushings as rubber for now. I'm not a fan at all of Polygraphite or Polyurethane bushings because of a bad experience I had with them before. I don't like them in torsional applications because of their resistance to spin, especially if installed incorrectly. Greaseable bushings might solve this, but I still prefer rubber in this case (control arms). I like Poly bushings in compressional applications (like stabilizar bar endlinks or bumpstops) because of their superior performance to rubber in those situations. Besides, my budget is of the essence right now. I don't plan to unbolt the UCA from the frame at all -- just replace the ball joints and go have it aligned.

By the way -- I tweaked on my t-bars once again and the ride height is just about level now (front to back) and the off-road ride from the front suspension really is much better than it once was. I owe you thanks for steering me in the right direction there. I still plan to buy the AC foam stops, but the ball joints will go on first. The rear axle tends to give a choppy ride, but I'm not sure how to fix that, since there doesn't seem to be anything that I can modify back there (just the spring pack I guess). I'm not worried about that though...the truck is really starting to behave like I'd like it off-road and I enjoy driving it more everytime I go 'wheeling.

**morepower2** · Oct 28th, 2003, 06:11 PM

Quote:

Originally posted by jadcock
Thanks for your thoughts Mike. I'm planning to replace all the ball joints with either Moog or TRW parts (which may be made by Perfect Circle). They have a lifetime warranty (which I don't think I get with Nissan parts) and after I do it once, I think it'll be easier to tackle the job again if I have to because I'll be more comfortable, having been in there already. Board members over at nissan4wheelers.com seem to like the Perfect Circle brand (available at Autozone) and they're pretty hardcore wheelers over there so I tend to have confidence in a general consensus about a product (good or bad).

I believe I'm going to leave my bushings as rubber for now. I'm not a fan at all of Polygraphite or Polyurethane bushings because of a bad experience I had with them before. I don't like them in torsional applications because of their resistance to spin, especially if installed incorrectly. Greaseable bushings might solve this, but I still prefer rubber in this case (control arms). I like Poly bushings in compressional applications (like stabilizar bar endlinks or bumpstops) because of their superior performance to rubber in those situations. Besides, my budget is of the essence right now. I don't plan to unbolt the UCA from the frame at all -- just replace the ball joints and go have it aligned.

By the way -- I tweaked on my t-bars once again and the ride height is just about level now (front to back) and the off-road ride from the front suspension really is much better than it once was. I owe you thanks for steering me in the right direction there. I still plan to buy the AC foam stops, but the ball joints will go on first. The rear axle tends to give a choppy ride, but I'm not sure how to fix that, since there doesn't seem to be anything that I can modify back there (just the spring pack I guess). I'm not worried about that though...the truck is really starting to behave like I'd like it off-road and I enjoy driving it more everytime I go 'wheeling.

Spencer Low Racing sells softer rear leaf springs for a more supple ride off road (not for carrying big cargo!) These might help. In my experiance Energy bushings are better for sticksion than stock rubber bushings and actualy make the ride smoother over bumps (if not a little more noise transfer).

In any case you might want to try the rear lower arm TC bushings, those are compression load and my offroad buddies say they make the biggest difference. They are also the easiest to install.

Hopefuly these simple mods will completly solve your harsh ride issues. Check the idler arm and center link joints, if your ball joints are worn, chances are these will be really worn and will make setting toe imposible.

Mike

jadcock · Oct 29th, 2003, 06:18 AM

Thanks Mike, I'll check all that. My steering has some play in it...probably 5 degrees of "dead travel" on center (at the steering wheel). The steering itself is pretty firm and linear, but there's some vagueness on center. I figure this was just play in the box. It might also be the joints and the idler arm bushings. Do you recommend the idler arm brace, if I go in and overhaul the idler arm with new bushings?

**morepower2** · Oct 29th, 2003, 03:31 PM

Quote:

Originally posted by jadcock
Thanks Mike, I'll check all that. My steering has some play in it...probably 5 degrees of "dead travel" on center (at the steering wheel). The steering itself is pretty firm and linear, but there's some vagueness on center. I figure this was just play in the box. It might also be the joints and the idler arm bushings. Do you recommend the idler arm brace, if I go in and overhaul the idler arm with new bushings?

The idler arm brace looks like cheap insurance and most people argee that the idler arm is the first thing that breaks when you start getting serious.

The dead spot is a lot due to the lame geometry of the stock Nissan steering. If you have someone rock the steering wheel while you watch, you'll see that the first 1/8 turn or so of the wheel just rocks the center link around, then finaly it moves the tir rods. (at the same time look for play in the idler arm and center link joints, you'll proably flip out when you see how worn they are)

Spencer Low's steering linkage fixes this. I am not sure about Calmini's.

Mike