Backspacing and steerability

bmkrinne

Active Member
Thinking of buying new wheels with less backspace and am wondering if this will have an adverse affect on steering.

Currently at 5.2” backspace on 17” AEV Savagre wheels with 37x12.50 STT Pros and rubbing everything. I do NOT have hydro assisted steering and don’t want to upgrade. I’m having no steering issues now.

Should I go 4.5” or 3.5” backspace on new wheels?

Has anyone seen an issue being able to steer with the 3.5” backspacing?

Anything else I’m missing?




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A.J.

Active Member
The less backspacing you have the more scrub radius you create. Think of it like the tire is reaching forward and backward as you turn. IMO 3.5 is better for 37’s as far as rubbing is concerned. Normal driving you won’t really notice much of a difference. If you do a lot of crawling you will notice.


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jeeeep

Hooked
I've run both 4" and 3.5" beadlocks on my JK, 3.5" causes faster wear to hubs and ball joints.

currently running Cooper STT pro 13.5x37 on KMC Machete 3.5" bs

ran BFG KO2 12.50x37 on the Machete and ATX Chamber Pro II, 4.06" bs

4" wear on hubs and ball joints was less often, I really didn't think such a small difference in bs would make such a big difference in wear but it does

my :twocents:
 

fiend

Caught the Bug
Thinking of buying new wheels with less backspace and am wondering if this will have an adverse affect on steering.

Currently at 5.2” backspace on 17” AEV Savagre wheels with 37x12.50 STT Pros and rubbing everything. I do NOT have hydro assisted steering and don’t want to upgrade. I’m having no steering issues now.

Should I go 4.5” or 3.5” backspace on new wheels?

Has anyone seen an issue being able to steer with the 3.5” backspacing?

Anything else I’m missing?




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Consider the 4.5” over the 3.5” for the reasons stated. Only concern would be rubbing. FWIW, I’m running 13.50” tires on 4” backspaced wheels and don’t have any serious rubbing. So you might be ok with the 4.5” BS running 12.50” tires. .


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14ACES

New member
I am running bfg 39x13.50 KM3 on KMC Beadlocks with 3.5” back spacing. No issues with rubbing or steering.


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bmkrinne

Active Member
The less backspacing you have the more scrub radius you create. Think of it like the tire is reaching forward and backward as you turn. IMO 3.5 is better for 37’s as far as rubbing is concerned. Normal driving you won’t really notice much of a difference. If you do a lot of crawling you will notice.


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The scrub radius increase is exactly what I was wondering about. I do sometimes get bound up when in the rocks and can only imagine it gets worse with the increase in scrub radius. Good to know normal driving will not change. Thanks!

Consider the 4.5” over the 3.5” for the reasons stated. Only concern would be rubbing. FWIW, I’m running 13.50” tires on 4” backspaced wheels and don’t have any serious rubbing. So you might be ok with the 4.5” BS running 12.50” tires. .


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You may be right with the 4.5" backspacing and 12.50 tires. The decrease from 5.2" to 4.5" would give 0.700" additional clearance and would likely clear the Core4x4 lower control arms and swaybar e-disconnect skid plate where most of the rubbing is occurring. 3.5" would really get the tires out away from everything and allow me to take the washers out from behind the steering stops on each knuckle.

The front tires are rubbing my AEV front bumper at full stuff and slight turn and I'm thinking any amount the wheels get pushed out with either the 4.5" or 3.5" will result in a harder rub. Guess I'll have to do the same mod that Bill did to Bison's front bumper - shorty mod!

Thanks for the input!!!
 

bmkrinne

Active Member
I've run both 4" and 3.5" beadlocks on my JK, 3.5" causes faster wear to hubs and ball joints.

currently running Cooper STT pro 13.5x37 on KMC Machete 3.5" bs

ran BFG KO2 12.50x37 on the Machete and ATX Chamber Pro II, 4.06" bs

4" wear on hubs and ball joints was less often, I really didn't think such a small difference in bs would make such a big difference in wear but it does

my :twocents:

3.5" looks really good and performs just fine to me. You will go through unit bearings faster.

You guys are both hitting on something I really hadn't thought about - increased wear on the unit bearings. Makes sense with the larger moment arm from the wheels sticking out further. I've got fairly new Prosteer ball joints but I'm sure they are not indestructible.
 

MericaMade

Active Member
Thinking of buying new wheels with less backspace and am wondering if this will have an adverse affect on steering.

Currently at 5.2” backspace on 17” AEV Savagre wheels with 37x12.50 STT Pros and rubbing everything. I do NOT have hydro assisted steering and don’t want to upgrade. I’m having no steering issues now.

Should I go 4.5” or 3.5” backspace on new wheels?

Has anyone seen an issue being able to steer with the 3.5” backspacing?

Anything else I’m missing?




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Had 37s on 3.5 method and only had trouble steering with lockers on. Sometimes it was not an issue other times I couldn't steer if my life dependent on it.
 

treys1

Member
Had 37s on 3.5 method and only had trouble steering with lockers on. Sometimes it was not an issue other times I couldn't steer if my life dependent on it.

Yeah it's crazy how sometimes everything is fine when you are locked up and then others it's like "oh well, guess my steering is broken", but it's not.
 

jeeeep

Hooked
You guys are both hitting on something I really hadn't thought about - increased wear on the unit bearings. Makes sense with the larger moment arm from the wheels sticking out further. I've got fairly new Prosteer ball joints but I'm sure they are not indestructible.

i've got Prosteer ball joints and have already rebuilt them once and it's feeling like it's time to do it again. IMO they don't last that much longer than the Crown HD lower I used when I screwed up the 1st rebuild.

IMO as much effort as it takes to rebuild them (still have to take everything apart) and the amount of time required to wait for the lower seal glue to set, I'd stick with a standard ball joint so when the job is done you can drive immediately. This is what I plan to do.

I already have rebuild kits so I'll rebuild them out of the Jeep and keep them on hand for the next time.

3.5" bs also seems to wear ball joints out faster. I've had hubs go and really didn't notice it until they were ready to fall apart. I've since been better at checking them with each tire rotation but I'm pretty sure bad hubs cause ball joints to take a beating
 
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zimm

Caught the Bug
I started out on AEV's- they rubbed really bad with just 315's. On 37x13.5 SST's, I ran 4" (ATX Camber Pro 2) and they cleared just right. Now I"m on Method at 4.5" and 35x12.5 with no rubbing.

Can't speak to the "steering feel" since I too am on hydro and that was one of the best mods I've done. You should consider it.
 

bmkrinne

Active Member
Had 37s on 3.5 method and only had trouble steering with lockers on. Sometimes it was not an issue other times I couldn't steer if my life dependent on it.

Yeah I can’t steer very well when the front is locked either when in the rocks. Steers much better when locked in the dirt or sand.


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bmkrinne

Active Member
i've got Prosteer ball joints and have already rebuilt them once and it's feeling like it's time to do it again. IMO they don't last that much longer than the Crown HD lower I used when I screwed up the 1st rebuild.

IMO as much effort as it takes to rebuild them (still have to take everything apart) and the amount of time required to wait for the lower seal glue to set, I'd stick with a standard ball joint so when the job is done you can drive immediately. This is what I plan to do.

I already have rebuild kits so I'll rebuild them out of the Jeep and keep them on hand for the next time.

3.5" bs also seems to wear ball joints out faster. I've had hubs go and really didn't notice it until they were ready to fall apart. I've since been better at checking them with each tire rotation but I'm pretty sure bad hubs cause ball joints to take a beating

This is exactly why I like this forum! You guys all chime in with honest, relevant experiences with the exact setup I’m asking about.

About how many miles did you get on the Prosteer ball joints?


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bmkrinne

Active Member
I started out on AEV's- they rubbed really bad with just 315's. On 37x13.5 SST's, I ran 4" (ATX Camber Pro 2) and they cleared just right. Now I"m on Method at 4.5" and 35x12.5 with no rubbing.

Can't speak to the "steering feel" since I too am on hydro and that was one of the best mods I've done. You should consider it.

What made you go back to 35’s?

Hydro may be in the future, but right now I just want to get rid of the rubbing without causing additional drivability or new maintenance/reliability issues. May not be that simple though!!!


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rubiDave

Active Member
I'm running 315/70r17 on AEV Savegre wheels and using 1.25 spacers. This is essentially a 4 inch backspace combo and have absolutely no rubbing. Looks like plenty of room to go to 37s in the future. I've got about 10k miles on it, wheel moderately hard and no unit bearing issues yet. Steering is only an issue when bound up with lockers on.

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zimm

Caught the Bug
What made you go back to 35’s?

I got stationed to Italy- so had to meet European rules of no tire sticking out the fenders. So full fenders and 35x12.5's. My Coopers were worn out and one of the ATX chamber pros was so bent I couldn't run it on the highway- so I sold the wheels to a wheeling buddy who couldn't afford new beadlocks (retired, living on social security) for cheap. When I ever get back to the states I'm going 37's and beadlocks again.

Just heard we're going to Japan this summer for 2 years- so Jeep will go into storage state side. Bummer.
 
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