Project: a daily driver off roader (4-cylinder)

[TJim]

The next steps for my TJ will be some brake maintenance (less sexy, but important), and shock replacement (they are shorter than they should be).

I am currently taking some measurements in order to decide which ones to buy, and whether to use some spacers, in order to set my up travel and down travel ratio of the new shocks as close to 50/50 as possible.

 

[TJim]

Today, I finally aligned my TJ. It was time to set my toe in and center my steering wheel.

I followed the instructions of this amazing thread (*Τhanks @Jerry Bransford , for this amazing method): https://wranglertjforum.com/threads/how-to-align-your-jeep-wrangler-tj.85/

It was a pretty easy and straight forward process, which didn't take more than 15-20 minutes. For more info, and detailed numbers see next post.

Photos

 

[TJim]

Firstly, my aluminum tubings, are 1 meter (39.37”) each. I marked their center, in order to place them in the rotors. I decided to not mark my tire diameter (31”) on them, but to calculate the desired total toe in angle, which is 0.3 degrees, using the total length of the tubings. (It was an unnecessary step for me)

 

[TJim]

Time for some before results:

My toe in was set by an alignment shop before, but unfortunately as the measurements showed it was completely off.
My toe in was set at 1.43 degrees. That was way off! Time to set it right.


Calculation of correct toe in measurement

Having as a fact that I should set my toe in at 0.3 degrees total, I calculated my toe in measurement using this calculator: https://robrobinette.com/ConvertToeDegreesToInches.htm

Don’t be spooked by the tire diameter (39.73”). It is just the length of my aluminum tubings, since I use metric system.

So, my measurement was 0.2” toe in. The front side of the tubings should be 0.2” closer than the rear side of the tubings.

I quickly unbolted the tie rod clamp bolts, and adjusted the correct measurement. I ended up with a 0.3 degrees toe in, which is the Factory spec.

Thanks to this method, I finally set up my toe in, which was about 1.13 degrees off. Congrats to the alignment shop that set it up before.

 

[TJim]

Here is a list of the toe in measurement, to have a 0.3 degrees as a result, for the most common tire sizes.

29" Tires
0.152" toe in

30" Tires
0.157" toe in

31" Tires
0.162" toe in

32" Tires
0.168" toe in

33" Tires
0.173" toe in

35" Tires
0.183" toe in

37" Tires
0.194" toe in

40" Tires
0.21" toe in


As you can see, the larger the tire, the largest the toe in measurement, in order to keep the factory spec.

**You can calculate your own measurement using this calculator:**
https://robrobinette.com/ConvertToeDegreesToInches.htm
It's a process that everyone should do to their rig, since it is so easy. Have fun!

 

[OldBuzzard]

Great job! And you picked handy metric values for your measurements, 5 mm toe-in at 1 meter length.

For folks using feet-inches, 1/8" toe at 24", or 3/16" toe at 35.75" gives the same 0.30° total toe-in per the FSM.

I think listing tire sizes and measurements just confuses the matter. That only counts if you're measuring on the tires. When using the square tubing, the tire sizes are irrelevant.

Nice looking Wrangler, by the way. I like your rear bumper. I need to change mine, and I like fabbing my own stuff. But I don't think I want to put that much work into it.

 

[TJim]

Great job! And you picked handy metric values for your measurements, 5 mm toe-in at 1 meter length.

For folks using feet-inches, 1/8" toe at 24", or 3/16" toe at 35.75" gives the same 0.30° total toe-in per the FSM.

I think listing tire sizes and measurements just confuses the matter. That only counts if you're measuring on the tires. When using the square tubing, the tire sizes are irrelevant.

Nice looking Wrangler, by the way. I like your rear bumper. I need to change mine, and I like fabbing my own stuff. But I don't think I want to put that much work into it.

Thanks! I picked metric values, because mainly this is what I use in everyday life here in Greece. I am more familiar with metric.

I know, it is more practical to just use the full length of the tubing. No extra steps needed. That's what I did.

Thanks for the bumper! I have a whole thread about it.

 

[PickeringFarms]

Thanks TJim for this awesome write-up.

Your descriptions and pictures helped me decide to keep the lift the PO put on, and my 31's are waiting for the pinion seal and speedometer gear to arrive.

This forum has been so helpful to me. Thank you all.