Backspacing, backspacing, backspacing

[Kejtar]

OK, I did run a search and I couldn't find anything close to my setup (or what I want to have) so here's the question:
I will be running 33x1250x15 with 15x8 rims on about 5" of lift with fairly well trimmed front fender and rear that could probably use a bit more trimming. What do you guys recommend?

[dennisuello]

3.75"

[Kejtar]

3.75"
How well will those tuck in?

[StevenJ]

I have that same setup and have 4.5" of back spacing. If you want the tire to stuff into the wheel well without hitting the fender I would go with 4"-4.5" of back spacing. I think that 3.75" would need more trimming or more lift. In the rear I cut the pinch seam and bent it over and my 33"X12.50" MTR's don't rub.

SJ

[Yucca-Man]

I have 15x7 with 4" BS on a 4.5" lift. They clear nicely inside the wheelwells, so expect a 8" rim with the same backspace to keep the inner edge of the wheel approx 1/2" farther out.

[Kejtar]

I have that same setup and have 4.5" of back spacing. If you want the tire to stuff into the wheel well without hitting the fender I would go with 4"-4.5" of back spacing. I think that 3.75" would need more trimming or more lift. In the rear I cut the pinch seam and bent it over and my 33"X12.50" MTR's don't rub.

SJ
How much lift do you have?

[poppabear]

less trimming 4.5" bs

more trimming 3.75" bs...

you make the call.

[gearwhine]

smaller turning radius (good), beat ball joints (bad), more trimming (you make the call), go3.75

the other way around, go for more BS.

[Yucca-Man]

Smaller turning radius? It already turns tighter than my mom's Mustang or Outback - I don't want to flip it turning around on flat ground! :cheers:

[GSequoia]

I have that same setup and have 4.5" of back spacing. If you want the tire to stuff into the wheel well without hitting the fender I would go with 4"-4.5" of back spacing. I think that 3.75" would need more trimming or more lift. In the rear I cut the pinch seam and bent it over and my 33"X12.50" MTR's don't rub.

SJ

Steven, with the 12.50's and 4.5 BS can you turn the wheel to stock full lock, or did you have to adjust the turning stops (or just let it rub)?

[poppabear]

dude... 4.5" bs is perfect for 33x12.50's but is not perfect for 35's.


full lock to full lock the tires don't rub anything.

[sintax]

You can view my pics of my 33x12.5's w/ 3.75 back spacing here...

http://www.naxja.org/forum/showthread.php?t=28337

-Scott

[Safari Ary]

I know you're talking about 33s and not 35s, but with 35s and 3.75" BS I rub like crazy on the LCAs. This is also with an axle that's an inch wider overall than stock. If you're planning to go with 35s in the future and you only wanna buy one set of wheels, I'd run 3.25. I'm probably going to end up with 4.5" BS and some spacers to make up the difference.

Ary

[Nay]

3.75" eats D30 ball joints on a daily driver. Remember that on a 15x8 rim, the extra inch of rim width is all to the outside. I run 15x7 rims with 3.75" and the tires are still well outside the flares (which I want).

I would get 4.5" in 15x8 for a 5" lift and 33x12.5...just remember you'll be getting new rims for 35's most likely. Of course, you'll probably also be getting new axles and a new bolt pattern, so that's no big deal.

Nay

[offroadman83]

I have 3.75 " bs on 15x8's with 35s and rub slightly on my lower control arm when a really sharp turn is negated. I have never had a problem with balljoints ever. On my old jeep I had 3.25" bs and didn't rub anywhere and I never had a problem will balljoints. These are all on daily drivers. My brother also runs 3.75" bs with 33s and doesn't have any problems as well.-------Kyle

[kraziexj]

3.75 inch backspacing does not and will not eat ball joints alive. There are way to many people here running them with absolutley no problems. There are also many people running 3.25 bs with also no problems what so ever with ball joints or wheel bearings. I personally have been running 3.75 bs for the last year and a half with no ball joint problems, (i have removed the knuckles to check them for my new experiment). this is also on my daily driver. I have a set of wheel spacers on order to get my total backspacing to 2.25. The extra stability will be worth it imo. I will get to see if the difference between 3.75 and 2.25 will be the difference between night and day on a daily driver and eat my ball joints ALIVE.

[gearwhine]

3.75 inch backspacing does not and will not eat ball joints alive. There are way to many people here running them with absolutley no problems.


go and check your ball joints then, to me it seems you never have. You don't notice they are bad very easily by just driving it. Your steering stabilizer, and tightness of your steering TRE's may mask it, but I can pretty much guarantee your ball joints are beat if they've been run on 3.75 BS for a while now. If you run on them bad for a while, you will notice the inner part of your tires wearing out very unevenly with the rest of the tire.

I've ran 3.75 for a long time now...3 years at least (only because they ordered the wrong BS for me) Whatever, but I thought my ball joints were fine, then I finally noticed my tire wear in the front was absolutey horrid. I changed them last year, and they just broke apart trying to get them out rather than "coming out".

They do eat ball joints, and anything less will be even worse. Just because they're not totally broken, doens't mean they're not bad. _nicko_

[Nay]

3.75 inch backspacing does not and will not eat ball joints alive. There are way to many people here running them with absolutley no problems.

You are right. 3.75" backspace and 33"+ tires has absolutely no effect on Dana 30 ball joints. It is amazing how indestructible the D30 really is. :rolleyes:

Nay

[kraziexj]

i have checked them......and there was nothing wrong with them. I didn't say that 3.75 would have no effect on them, I was just stating that the extra leverage that 3.75 has on them isn't realistically a night and day difference like everyone makes it out to be. Nor was i saying that the dana 30 is indestructible, just that some people don't give it enough credit. Also just to clearify when i say "eat them alive" im meaning that they will go out every month or two.

[StevenJ]

Steven, with the 12.50's and 4.5 BS can you turn the wheel to stock full lock, or did you have to adjust the turning stops (or just let it rub)?

I just barely rub the lower control arm if I turn full lock. I rarely turn that sharp so it hasn't bothered me enough to adjust the stops. I probably will adjust the stops some day but it's down the list a ways.

Steve.

[StevenJ]

How much lift do you have?

4.5" lift, Rusty's flares, Centerline Hellcat wheels w/4.5" bs, and 33x12.5x15 GY MTR's.

[gmanxj]

If you run on them bad for a while, you will notice the inner part of your tires wearing out very unevenly with the rest of the tire.

I have this problem on the front passenger tire, but not on any other tires.

Is there any other explanation for this besides ball joints?

TIA

[Kejtar]

I just barely rub the lower control arm if I turn full lock. I rarely turn that sharp so it hasn't bothered me enough to adjust the stops. I probably will adjust the stops some day but it's down the list a ways.

Steve.

Take care of it ASAP or you'll do what I did: rip of the hardline and be running the trail on 3 brakes!

[gearwhine]

I have this problem on the front passenger tire, but not on any other tires.

Is there any other explanation for this besides ball joints?

TIA

There are other explanations, like a bent axle housing and major stuff like that. But I can pretty much guarantee you, if you haven't abused your jeep, or got in an accident, it's just the ball joints. That's the first thing I would replace.

If you notice wear as you had before in the next few months, then you can think about your housing being bent. Don't let this scare you though, It's like a 1% chance you have a bent axle rather than bad ball joints.

[Nay]

i have checked them......and there was nothing wrong with them. I didn't say that 3.75 would have no effect on them, I was just stating that the extra leverage that 3.75 has on them isn't realistically a night and day difference like everyone makes it out to be. Nor was i saying that the dana 30 is indestructible, just that some people don't give it enough credit. Also just to clearify when i say "eat them alive" im meaning that they will go out every month or two.

I was losing ball joints every 3-4 months with 33x10.5's on 3.75 BS. That is probably not typical, but to me, even having to replace them annually just from road use and moderate wheeling is way too much. Driving down the highway and that shimmy starts again...and it's off to Autozone for a ball joint press...it just drove me crazy even though I got good enough that I could do both sides in about 90 minutes.

I think the D30 is a better offroad axle than onroad in terms of heavy use. If you plan on putting 15-20K miles annually on your XJ as I was doing at the time, then I think you are well suited to a bit more backspace. Having said that, I think 3.75" is perfect for the track width of a 6" lift in terms of stability, so you gotta pick your poison (or stop polishing turds).

Nay

[kraziexj]

I was losing ball joints every 3-4 months with 33x10.5's on 3.75 BS. That is probably not typical, but to me, even having to replace them annually just from road use and moderate wheeling is way too much. Driving down the highway and that shimmy starts again...and it's off to Autozone for a ball joint press...it just drove me crazy even though I got good enough that I could do both sides in about 90 minutes.

Wow :shocked: . thats the first i've heard of someone having to replace them that often. I think that would drive everyone about crazy.

I think the D30 is a better offroad axle than onroad in terms of heavy use. If you plan on putting 15-20K miles annually on your XJ as I was doing at the time, then I think you are well suited to a bit more backspace. Having said that, I think 3.75" is perfect for the track width of a 6" lift in terms of stability, so you gotta pick your poison (or stop polishing turds).
Nay

Agreed.

[dandecicco]

I am gonna run 3.5 rough country lift, 31X11.50/15s on rock crawler 8" wheels with 3.75 bs. Am I still gonna need trimming or should I be able to stuff into the wells without a problem?

[Nay]

I am gonna run 3.5 rough country lift, 31X11.50/15s on rock crawler 8" wheels with 3.75 bs. Am I still gonna need trimming or should I be able to stuff into the wells without a problem?

I think you'll need some minor trimming. I had that much lift with 3.75 BS rims and 31x10.5 BFG MT's and I bent my front fenders at full stuff. 1" of bumpstop extension would have prevented this.

Nay

[dandecicco]

have any pictures of that or does anyone else?