[flatlander757]

Originally Posted by scotch740

Great write up! Belongs in the FAQ in case it hasn't been said enough.

Question about toe in.

When you say TOTAL toe and give the factory spec of +0.30 degrees +/- 0.06 degrees. Is that saying one wheel is straight and the other is +.30 degrees inwards? Or are both wheels angled 0.30 degrees inwards.

I'm relating this to larger tires and setting the toe with a tape measure. It appears larger tires hardly effect what you would measure.
For a 30" tire I got 0.157" of toe in. For a 35" I got 0.183". So a little less than 1/32" difference for a 5" tire size increase. Sound correct?

Total toe = left side toe + right side toe.

+0.15 toe in on the left side and +0.15 toe in on the right side would equal +0.30 total toe.

Reason I say total toe is that on an alignment machine, you can't adjust either side independently of the other, so total toe is the only true measurement that is accurate. The machine could say +0.30 on the left side and an even 0.00 on the right side, but the fact is going down the road, the wheels will center themselves to more like 0.15 and 0.15(short of a tire pull or other mis-alignment issue).

As far as differing tire sizes and the measurement being taken further away front vs rear of the front tires, yes 1/32 difference between them on a 30" tire will net more actual toe-in than 1/32 difference between the front and rear of 35" tires.

You can use pretty simple trigonometry to figure it out, but in all reality it's not a huge issue, I'd say as you get into bigger tire sizes, more like 1/16" difference when measuring the front and back of the front tires to set toe would net you closer to the same measurement.

Honestly, just make sure that the front tires are toed in a small amount and it will be okay. 1/32 to 1/16" of toe-in using a tape measure is pretty well accepted as the standard for TJs with 33"+ tires. Like said earlier, aim closer to the 1/32" with smaller stock size tires.

That's my view on it anyways

[dbshea]

what is a reputable place to get an alignment ? do you recommend anywhere specific?

[flatlander757]

Originally Posted by dbshea

what is a reputable place to get an alignment ? do you recommend anywhere specific?

I can't say since you're on the left coast and I'm in Virginia, but that is something you need to do some local research on. Find reviews and personal recommendations for places near you.

Find out where some of the guys with SCCA or road racing cars take them, the guys who tune racing suspensions generally have a really good knowledge of how stuff works, just be sure to tell them to compensate the caster angle(if you have adjustable upper front CAs) for larger tires. 7 degrees is for 29s-31s, 5 degrees is good for 35s, 6 degrees is likely a good spot for 33s. Otherwise if you have 35s they may try and set the angle to the factory 7 degrees because that's what the computer will say. Also print out the factory specs before you pick up your vehicle to make sure they didn't screw with the target alignment specs to make it look like things are okay.

Sears is worth a shot, there's usually an old guy or two working there that know all kinds of stuff. A coworker of mine worked there for about 8 years doing nothing but alignments, and he gave me a crash course in doing them. For any of the master techs or more experienced alignment guys reading this, the guy who taught me can shim a completely screwed up S10 front end without using the computer aids for calculation and put the camber and caster nearly dead center first try. That's a hell of a feat if anyones tried aligning those POS trucks

[never monday]

Originally Posted by flatlander757

Find out where some of the guys with SCCA or road racing cars take them, the guys who tune racing suspensions generally have a really good knowledge of how stuff works,

and when we get old we turn into web wheelers

[flatlander757]

Originally Posted by never monday

and when we get old we turn into web wheelers

What?

[flatlander757]

Added the sections on the SAI/caster angle, pivot radius, pivot point, scrub radius, etc to the main body of the write-up.

If you see any needs for correction please PM me or post here!

[Pumbaa]

Awesome writeup by an obvious expert. Right on time for me too. Just replaced a bent front axle assy, steering goofy with the new front assembly. Alignment shop said axle assy too big??!? I'll find a Jeep literate shop next time.

Web Wheeler: my guess is old guys who have seen and done everything and now dispense their sage wisdom via forums like this. Somebody here even has that as their avatar sig.

[sadass]

I just want to say that this has been a very useful thread and I wanted to thank you as well for taking the time to lend us you expertise's . Thank You for the education, I needed this thread big time! :thu mbsup:

[BomberJeep]

Great write up Tony. Oh not sure if I told you but I got that bracket on. Do you have a cut-off wheel so I can cut off the stock T-case bracket?

[flatlander757]

Originally Posted by Pumbaa

Awesome writeup by an obvious expert. Right on time for me too. Just replaced a bent front axle assy, steering goofy with the new front assembly. Alignment shop said axle assy too big??!? I'll find a Jeep literate shop next time.

Web Wheeler: my guess is old guys who have seen and done everything and now dispense their sage wisdom via forums like this. Somebody here even has that as their avatar sig.

What do they mean axle assembly too big? Sounds like BS to me.

Originally Posted by sadass

I just want to say that this has been a very useful thread and I wanted to thank you as well for taking the time to lend us you expertise's . Thank You for the education, I needed this thread big time! :thu mbsup:

Thanks! Glad you liked it, I wish I had this knowledge the first time I took my steering and suspension ASE, failed it once before getting it a couple years ago.

Originally Posted by BomberJeep

Great write up Tony. Oh not sure if I told you but I got that bracket on. Do you have a cut-off wheel so I can cut off the stock T-case bracket?

Yeah, I'll be sending you a PM.

[mistertierney]

You may have put a few alignment shops out of business with that info. lol. probly not. adj control arms. here i come.

[stedwest]

This thread is a 'keeper'... thanks for all the work you put in it.

[Pumbaa]

I found who wears the avatar line of web wheeler in JF. He dispenses useful info and ideas at every word:



Frankly, I'm surprised he hasn't posted to this thread yet.


What does the OP think of the driveway measuring tape alignment method ? (still looking for thread)

[flatlander757]

Originally Posted by Pumbaa

I found who wears the avatar line of web wheeler in JF. He dispenses useful info and ideas at every word:



Frankly, I'm surprised he hasn't posted to this thread yet.


What does the OP think of the driveway measuring tape alignment method ? (still looking for thread)

See the next two quotes:

Originally Posted by flatlander757

Total toe = left side toe + right side toe.

+0.15 toe in on the left side and +0.15 toe in on the right side would equal +0.30 total toe.

Reason I say total toe is that on an alignment machine, you can't adjust either side independently of the other, so total toe is the only true measurement that is accurate. The machine could say +0.30 on the left side and an even 0.00 on the right side, but the fact is going down the road, the wheels will center themselves to more like 0.15 and 0.15(short of a tire pull or other mis-alignment issue).

As far as differing tire sizes and the measurement being taken further away front vs rear of the front tires, yes 1/32 difference between them on a 30" tire will net more actual toe-in than 1/32 difference between the front and rear of 35" tires.

You can use pretty simple trigonometry to figure it out, but in all reality it's not a huge issue, I'd say as you get into bigger tire sizes, more like 1/16" difference when measuring the front and back of the front tires to set toe would net you closer to the same measurement.

Honestly, just make sure that the front tires are toed in a small amount and it will be okay. 1/32 to 1/16" of toe-in using a tape measure is pretty well accepted as the standard for TJs with 33"+ tires. Like said earlier, aim closer to the 1/32" with smaller stock size tires.

That's my view on it anyways

Originally Posted by flatlander757

Since toe is the only adjustment you can make in stock form on a TJ, it is not really necessary to get an alignment just to set toe. Save $80 by doing it at home with a tape measure and some basic hand tools. You'll need to adjust toe and/or recenter your steering wheel any time you replace any of the tierod ends, there is a great write-up on this at www.4x4xplor.com which is worth taking a look at. There is also a good diagram of the steering components and their terms as well.

I have edited the first few posts a couple times to add in more stuff and whatnot. Don't be surprised to find something slightly different or small stuff added from time to time.

And MrBlaine has posted in here on pages 1 and 2 IIRC.

[99TJtoy]

That is an awesome write up! Thanks for the info.