Need new wheels and tires—do I have this right?

[mcarthey]

Hey all! I'm brand new to the Wrangler community as I only just picked up my 2004 Wrangler LJ Unlimited late last summer. I only had time to clean it and do some basic fixes. When I purchased it I had noticed the wheels were in bad shape and, as luck would have it, one went flat over the winter. Of course, the spare was also flat. Both leak all around the bead. I call that "luck" as I wanted to upgrade anyway.

So I've been researching and want to make sure I have this right. Through a combination of measuring my actual wheels and taking a look at wheel-size.com and tiresize.com and believe I've identified I have the following,

* 30x9.5x15
* 25.4mm offset, which equates to about +6" of backspacing.

I'd like to upgrade to 32x11.5x15, and I am looking at a 2" suspension/leveling lift.

So a few questions...

Is that the minimum lift size I need for 32s?
I see people mentioning 4" of backspacing necessary but since this is so far from the current 6" will I have problems?
The equivalent offset on 11.5 seems to be -6mm according to tiresize.com?

I'm sure I'm confusing this subject, but ultimately I just want to make sure I get the correct offset on the new rims for the 32x11.5s, so I don't need spacers or have to trim anything.

Thanks for any clarifications you can provide as I'm definitely looking forward to the melting of the snow and getting it fixed up and ready for warmer weather! I'm not planning any major off-road events, but I do want to hit all the ORV/MVUM trails in my area for sure!

EDIT: I realized I'm confusing the offset/BS based on the tire and not the wheel when entering my calculations. Assuming a 15x8 wheel with 4" backspacing it looks like that equates to about a -13mm offset. According to https://tiresize.com/wheel-offset-calculator/ it will move the wheel about 0.5" out from the back of the wheel. I have no idea if that's enough based on the new wheel size.
Realizing this, though, also has me wondering about something I saw posted here. Someone mentioned that their wheels were still tucked inside the wheel well with all these same dimensions, but it looks like the wheels are moving out about 2.5" ? Won't these definitely stick out quite a bit if so?
Thanks again!

Mark

 

[JEEPCJTJ]

You've got a lot of stuff going on in that post. I'll just reply to what I know from my experience or at least what I think.

My current tires are closer to 32" than 31" diameter and only 9.5 inches wide on 16 x 8 wheels with 5" backspacing. I only experience minor rubbing when turning as sharp as possible. I haven't bothered to stop that by adding a washer to each bolt that limits how sharp I can turn nor by adding wheel spacers which basically would change the backspacing and offset.

Even though a zero offset being about 13mm off from a backspace with the same number as 1/2 the wheel width drives me nuts here's a picture that at least helps it make some sense.

Just ignore the offset numbers unless they are the only number offered by the wheel seller or manufacturer.

I think the 32 x 11.5 tire will probably need a wheel with more less than a 4" backspacing to push it out even with a lift. Hopefully someone with the experience can remove the word "probably" and say either "will need" or "won't need" and help you out with everything else too.

Edit 8 hours later: added the strike-trough and the bolded words in the last paragraph because what I meant was definitely not more.

 

[Rubicon88]

Ok...your post is everywhere.

You want new 32's?
Ok...
Get 15x8 wheels with 3.75 BS.

yes they stick out past the flares a minor amount but they don't rub, add a great stabile stance to your jeep, and no need for spacers.
You can run up to a 12.50 wide tire should the desire arise.


You should get a 2 5 lift.
2 inch is ok but 2.5 even better.

Get some...(any) brand of 2.5 springs
Even rough country makes an ok coil spring. Yes ....they really do.

After that you need new shocks. I'd recommend Rancho 5000x or
Skyjacker black max.

Extended Sway bar links for new spring height that disconnect.

Done!!

Optional...
Adjustable track bar (or if yours is tired now is a good replacement time)

The above can be done without any additional components ahd it works better off road than stock and better on the road as well.

Good luck.

 

[D M]

@Rubicon88 has great advice, just one more thing worth mentioning, you may or may not have driveline vibes at that lift height, each jeep is different. That puts you in SYE territory, and if you wheel you might want a tummy tuck.

Here are some good threads to answer your future questions

https://wranglertjforum.com/threads/a-beginners-guide-to-lifting-your-jeep-wrangler-tj.733/page-2https://wranglertjforum.com/threads/the-official-sye-slip-yoke-eliminator-thread.100/https://wranglertjforum.com/threads/the-official-tummy-tuck-faq-thread.173/

 

[Rubicon88]

@Rubicon88 has great advice, just one more thing worth mentioning, you may or may not have driveline vibes at that lift height, each jeep is different. That puts you in SYE territory, and if you wheel you might want a tummy tuck.

Here are some good threads to answer your future questions

https://wranglertjforum.com/threads/a-beginners-guide-to-lifting-your-jeep-wrangler-tj.733/page-2https://wranglertjforum.com/threads/the-official-sye-slip-yoke-eliminator-thread.100/https://wranglertjforum.com/threads/the-official-tummy-tuck-faq-thread.173/

We've found with that setup no danger in pulling the drive shaft out the Tcase...and we get in all types of wheeling from extreme washouts, ditches and rocks and of course extreme mud and snow.

We also found ujoints that aren't in great working order can pose some vibration. (Not always but sometimes)

This is the time to freshen up your u-joints anyways with some new Spicer units.

One final note...
2.5 is the max you can do a simple suspension mod like this.

3" onward things start becoming mandatory.

And I stress (other posters seem to overlook this)
The TJ suspension is great off road but really limited with an attached sway bar. It isn't much better travel than IFS designs and they suck.
GET SOME disconnects!! And always reconnect them before getting back on the hard road!!!

Good luck.

 

[TheBoogieman]

32s with no lift (Rubicon). I wouldn't run them without at least a 2" lift. I had a 3" lift (2" suspension/1" BL and MML) when I ran 32s. Most aftermarket 15" wheels are 3.75-4.5" backspacing. I prefer 3.75" because they stick out farther.

 

[mcarthey]

Thanks for the replies all, and sorry for the rambling nature of it. I'm learning about all this as I work through projects, like most of us I'd imagine. It's hard to know what to ask when I'm not sure what I might be missing. Your replies have helped greatly!
I should have mentioned that I was trying to avoid any driveline modifications which is also why I was planning on going with as minimum a lift as possible. It sounds like I should be able to get away with a 2" suspension lift and 32s without any SYE or transfer case drop? And I had been looking for a 2" suspension lift kit but I hadn't been able to find anything less than 2.5". I'll look to see if I can find the coils separate from the shocks as that might be a better option for the quality anyway.

Thanks again!

 

[JEEPCJTJ]

Technically you can get every suspension part piece by piece. If you were going for a 4" lift with all new parts buying that piece by piece could be quite pricey but just 2" or 2.5" springs and shocks shouldn't be a problem and whichever you end up with you'll never really see, and probably never feel the 1/2" difference.

 

[Rubicon88]

-

 

[il buono]

Thanks for the replies all, and sorry for the rambling nature of it. I'm learning about all this as I work through projects, like most of us I'd imagine. It's hard to know what to ask when I'm not sure what I might be missing. Your replies have helped greatly!
I should have mentioned that I was trying to avoid any driveline modifications which is also why I was planning on going with as minimum a lift as possible. It sounds like I should be able to get away with a 2" suspension lift and 32s without any SYE or transfer case drop? And I had been looking for a 2" suspension lift kit but I hadn't been able to find anything less than 2.5". I'll look to see if I can find the coils separate from the shocks as that might be a better option for the quality anyway.

Thanks again!

You have an LJ, so you can get away with a higher lift compared to TJs without needing to do driveline mods. My relatively stock '05 LJ came with a 4" lift and a transfer case drop. I removed the transfer case drop to see if I would get vibrations. None appeared. However, before I did this, I looked around the forum and some said LJs could get away with a 4" lift without needing to do a SYE. Probably not the most ideal situation if you plan on wheeling hard, but it works for my usage. If you plan on staying in the 2"-3" zone, you should be fine.

 

[Gunnersmate]

And down the rabbit hole you go

 

[LukesfirstJeep]

I should have mentioned that I was trying to avoid any driveline modifications which is also why I was planning on going with as minimum a lift as possible. It sounds like I should be able to get away with a 2" suspension lift and 32s without any SYE or transfer case drop?

I think you're on the right track.

As a point of reference, I had a 3" suspension lift and 32" tires installed on my LJ. They dropped the skid about 3/4" with spacers, and I had no vibration until I regeared. My wheels have 4.5" backspacing, and I don't have any rubbing. I have since removed the skid spacers, added a SYE and adjustable upper rear control arms. What transmission do you have? My automatic 42RLE has that ultra high overdrive and was miserable until I regeared.

When I bought my Jeep it had 31" tires on OEM Ravine wheels (5.5" backspacing), and no lift. I would rub slightly when turning at full lock.

 

[mcarthey]

I think you're on the right track.

As a point of reference, I had a 3" suspension lift and 32" tires installed on my LJ. They dropped the skid about 3/4" with spacers, and I had no vibration until I regeared. My wheels have 4.5" backspacing, and I don't have any rubbing. I have since removed the skid spacers, added a SYE and adjustable upper rear control arms. What transmission do you have? My automatic 42RLE has that ultra high overdrive and was miserable until I regeared.

When I bought my Jeep it had 31" tires on OEM Ravine wheels (5.5" backspacing), and no lift. I would rub slightly when turning at full lock.

Thanks so much for this. It's nice to have real world experience on the spacing.
I am a bit worried about the 42RLE and my 3.73 gears with 32" tires as this chart shows that the RPM range is going to be more optimal for highway use.
https://www.quadratec.com/c/reference/gear-ratio-guide-for-larger-tiresGiven that it's really just a fun vehicle right now that I use with the family in the summer, I'm not overly concerned, but it looks like there's another project in my future to change out the gears as well. As someone mentioned, "down the rabbit hole" I go.

 

[mcarthey]

Also based on a recommendation in this thread, I gave Rough Country a call about their 2.5” suspension lift coil springs. They indicated that they both lift and level. Apparently it is 2.5” in the front and 1” in the rear. I’m sharing in case that helps anyone else, because it wasn’t obvious to me and it’s not stated in any of the information on their site.
I’ll then add the Rancho RS5000 hydro shocks to the install and hope that’ll cover me until I can put together some more cash.

EDIT: I just realized that if it truly is a 1” rear lift to level then that means I can’t just buy a set of 4 shocks intended for a 2-4” lift, correct?