Clearance Questions: 37s on a 2.5" Coil Lift
12-04-2010, 03:03 PM
#11
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Looks like the body lift will be the preferred lift choice based on your recommendations plus that will keep a lower COG versus spacers.
Planman, do you have a comment on the 13.5" tires on stock wheels? Am I insane? Also, do you think there will be a clearance issue with my stock rear or front bumper? I don't plan on upgrading those right away.
BTW - bad a$$ Jeep you got there. My fiance runs a 2010 white 2 door so you got me thinking about 40s on hers!
12-05-2010, 12:16 AM
#12
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You seem to have forgotten about:
So you need to modify what you see in planmans thread. Without the extra clearance from the flat fenders, you are stuck with adding coil spacers, which will likely necessitate new driveshafts,
, or adding so much bumpstop that you are running with them touching (that is a guess, but without the flats, you are limited in your options for keeping the tires off the flares)... 
And Planman, help me out here with the backspacing. How much turning radius is he going to lose running those 37x14" tires (mfg's specs) on stock rims? Even with 1.5" spacers, he is only down to 4.75, so the steer stops would still need to be brought in quite a bit? So, 2" spacers? 2.5"? What point is the right compromise between too much spacer and too much steer stop reduction?
(I guess that wheel spacers are an assumption, anyway. He doesn't want to go to flats, and he doesn't want to add new driveshafts, so probably doesn't want to add wheel spacers either...
)
I do not want to cut my fenders.
I am hoping I won’t need to address the driveshafts yet either...
And Planman, help me out here with the backspacing. How much turning radius is he going to lose running those 37x14" tires (mfg's specs) on stock rims? Even with 1.5" spacers, he is only down to 4.75, so the steer stops would still need to be brought in quite a bit? So, 2" spacers? 2.5"? What point is the right compromise between too much spacer and too much steer stop reduction?
(I guess that wheel spacers are an assumption, anyway. He doesn't want to go to flats, and he doesn't want to add new driveshafts, so probably doesn't want to add wheel spacers either...
)
Last edited by nthinuf; 12-05-2010 at 12:36 AM.
12-05-2010, 05:32 AM
#13
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Thanks guys. Looks like I have more to think about now 
I think the 13.5" tire is out as I would be nervous running a spacer wider than my existing 1.5" Spidertrax and I really don't want to lose the stock wheels...yet. BFG makes a 37" KM2 in a 12.50" width which might suit the Jeep better anyway. I feel as though I may still have to address the steer stops as noted.
I'm also not too keen on chopping the factory front bumper. Most I have seen look like crap (sorry) so I would probably find another alternative in the form of a new stubby bumper.
My plan is a clean, well put together Jeep that looks mean but still retains the factory look. And again guys, I am not a serious off-roader, just some light trails an deep mud is all it will ever see.
I think the 13.5" tire is out as I would be nervous running a spacer wider than my existing 1.5" Spidertrax and I really don't want to lose the stock wheels...yet. BFG makes a 37" KM2 in a 12.50" width which might suit the Jeep better anyway. I feel as though I may still have to address the steer stops as noted.
I'm also not too keen on chopping the factory front bumper. Most I have seen look like crap (sorry) so I would probably find another alternative in the form of a new stubby bumper.
My plan is a clean, well put together Jeep that looks mean but still retains the factory look. And again guys, I am not a serious off-roader, just some light trails an deep mud is all it will ever see.
12-05-2010, 05:51 AM
#15
JK Super Freak
Who cares? He can have 37's because his great grandmother came to him in a dream and said "Get 37's".
He's asking how, not your opinion of a non HARDCORE XXXTREME WHEELER running 37's.
He's asking how, not your opinion of a non HARDCORE XXXTREME WHEELER running 37's.
12-05-2010, 06:16 AM
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Thanks guys. Looks like I have more to think about now
I think the 13.5" tire is out as I would be nervous running a spacer wider than my existing 1.5" Spidertrax and I really don't want to lose the stock wheels...yet. BFG makes a 37" KM2 in a 12.50" width which might suit the Jeep better anyway. I feel as though I may still have to address the steer stops as noted.
I'm also not too keen on chopping the factory front bumper. Most I have seen look like crap (sorry) so I would probably find another alternative in the form of a new stubby bumper.
My plan is a clean, well put together Jeep that looks mean but still retains the factory look. And again guys, I am not a serious off-roader, just some light trails an deep mud is all it will ever see.
I think the 13.5" tire is out as I would be nervous running a spacer wider than my existing 1.5" Spidertrax and I really don't want to lose the stock wheels...yet. BFG makes a 37" KM2 in a 12.50" width which might suit the Jeep better anyway. I feel as though I may still have to address the steer stops as noted.
I'm also not too keen on chopping the factory front bumper. Most I have seen look like crap (sorry) so I would probably find another alternative in the form of a new stubby bumper.
My plan is a clean, well put together Jeep that looks mean but still retains the factory look. And again guys, I am not a serious off-roader, just some light trails an deep mud is all it will ever see.
I know it's against Man Card rules to not want bigger and badder but I honestly would suggest that you ditch the 37" idea. 37s are a BIG tire...I mean BIG for a JK and I think 35s would still give you what you are after and be much easier to get to work on your Jeep.
Hambone....chill out man.......you're not the internet police.
12-05-2010, 08:23 AM
#17
JK Super Freak
Originally Posted by joshzilla
My wife came to me in real life and said "why is everything so expensive?" Thats why I have 35's
I got 37" toyo's for 1000$ canadian with 2000 miles. That frees up the rest of my tire purchase money for axle mods and gear swaps.
Last edited by Harbourone; 12-05-2010 at 08:33 AM.
12-05-2010, 12:37 PM
#18
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Pretty much.
I am aware of the need to regear. In this thread I am only asking about potential clearance issues. Of which there seem to be many.
I don't have a problem cutting the pinch seam. Can you please describe what other modifications you performed other than pinch seam trimming and flats to get your 37s to fit?
Good info. I may just end up going with flat fenders weather they are Bushwacker's, Xenon's or other.
Again - I realize the need to regear - I'm only asking for advice here on fitment.
I'm trying to do this right the first time and not have buyers remorse the second I drop my Jeep off the jack stands. I don't see too many threads titled "Damn, I wish I would have went with 35s instead 37s." Hell, if they dont fit I'll rip the fenders and front bumper off and make do until I find a solution.
Thanks again everyone for the information.
I am surprised that nobody has brought up gearing. You may be able to get them to fit but your drivability will be terrible with 37's on a Sahara Automatic. Also if you are considering this because you like the looks of the Sahara rims you can get after markets that have the same look that will give you proper width and backspacing. If you are just going for the mall crawler bling look why not go up to the 20"x10" SRT repos for the wrangler?
Didn't even see that about not cutting the fenders. 
I'd suggest you stick with 35's. You have no chance of running 37's with your current thought process.
I'm on 37's with a 2.5" TF and 1" BL and used the sawzall quite a bit. If you not willing to AT LEAST chop your fenders and hammer in a couple pinch seams, you have no idea of what it's gonna take.
I'd suggest you stick with 35's. You have no chance of running 37's with your current thought process.
I'm on 37's with a 2.5" TF and 1" BL and used the sawzall quite a bit. If you not willing to AT LEAST chop your fenders and hammer in a couple pinch seams, you have no idea of what it's gonna take.
To answer some of the additional questions above:
With regard to backspacing and increasing turning radius:
Yes, he could run 37x14s with 4.75" backspacing, but he will rub his frame, lower control arms, and swaybar without significantly adjusting his steering stops.
For a short period of time, I ran my 40x13.50R17s on my 4.5" backspaced wheels. I had to buy aftermarket bolts to adjust my steering stops to not rub. My turning radius was worse than with my 1 ton crewcab dually. Shortly thereafter, I added 1.5" Spidertrax wheel spacers to net 3" wheel backspacing so that I could back off the steering stops some.
With regard to flat flares:
Yes, in my write-up I show that with a 2.5" lift and 1" body lift, it takes flat flares to run 0"-1.25" front and 2.5" rear extended bumpstops.
With 4.5" backspaced wheels, it takes at least 4" front and rear extended bumpstops to run 37s with stock flares and no body lift.
With a 1" body lift and stock flares, you might be able to get away with 3.25" front and rear extended bumpstops. This is still way too much to run on 2.5" springs because you would be hitting your bumpstops too frequently with just daily driving.
So to do the 37s with a 2.5" lift and 1" body lift, flat flares are the way to go. If the OP wants a more finished look, he could do Bushwacker flat flares instead of trimming his stock flares.
With regard to gearing, 37s would be miserable on the street with an automatic unless you have 3.73 gears and run with the OD turned off all the time--results in the equivalent rpm as 5.38s with the OD turned on. They would be miserable with 4.10s--either 6 speed or automatic. Especially something heavy like the Toyos, you want 5.13s with a 6 speed or 5.38s with an automatic. Although, with a Dana 30 front axle, 5.13s are as low as you can go.
With a JK, you can run 35s without relatively expensive modifications.
When you go with 37s, that is really where you need to allocate more funds towards the drivetrain, a HD rear tire carrier, etc.
With regard to backspacing and increasing turning radius:
Yes, he could run 37x14s with 4.75" backspacing, but he will rub his frame, lower control arms, and swaybar without significantly adjusting his steering stops.
For a short period of time, I ran my 40x13.50R17s on my 4.5" backspaced wheels. I had to buy aftermarket bolts to adjust my steering stops to not rub. My turning radius was worse than with my 1 ton crewcab dually. Shortly thereafter, I added 1.5" Spidertrax wheel spacers to net 3" wheel backspacing so that I could back off the steering stops some.
With regard to flat flares:
Yes, in my write-up I show that with a 2.5" lift and 1" body lift, it takes flat flares to run 0"-1.25" front and 2.5" rear extended bumpstops.
With 4.5" backspaced wheels, it takes at least 4" front and rear extended bumpstops to run 37s with stock flares and no body lift.
With a 1" body lift and stock flares, you might be able to get away with 3.25" front and rear extended bumpstops. This is still way too much to run on 2.5" springs because you would be hitting your bumpstops too frequently with just daily driving.
So to do the 37s with a 2.5" lift and 1" body lift, flat flares are the way to go. If the OP wants a more finished look, he could do Bushwacker flat flares instead of trimming his stock flares.
With regard to gearing, 37s would be miserable on the street with an automatic unless you have 3.73 gears and run with the OD turned off all the time--results in the equivalent rpm as 5.38s with the OD turned on. They would be miserable with 4.10s--either 6 speed or automatic. Especially something heavy like the Toyos, you want 5.13s with a 6 speed or 5.38s with an automatic. Although, with a Dana 30 front axle, 5.13s are as low as you can go.
With a JK, you can run 35s without relatively expensive modifications.
When you go with 37s, that is really where you need to allocate more funds towards the drivetrain, a HD rear tire carrier, etc.
Again - I realize the need to regear - I'm only asking for advice here on fitment.
I'm trying to do this right the first time and not have buyers remorse the second I drop my Jeep off the jack stands. I don't see too many threads titled "Damn, I wish I would have went with 35s instead 37s." Hell, if they dont fit I'll rip the fenders and front bumper off and make do until I find a solution.
Thanks again everyone for the information.
12-05-2010, 12:51 PM
#19
As for clearance issues, I've got a 2 1/2" lift, with 2 1/2" extended bumpstops, and plan on running the 37" tires on 17x8 wheels with 4 1/2" backspacing, with GenRight aluminum flat fenders, and a little trimming of the pinch seams. Right now I'm planning on 5.13 gears, as a compromise gear set that doesn't produce quite so much driveshaft RPM, and is a little stronger set of gears than 5.38s. I think everything will work out just fine.
01-08-2011, 10:19 AM
#20
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I decided to be reasonable and ordered the 35's today. After doing more research it seemed like the most logical choice. 37s will have to wait till stage 2. Thanks everyone for their input. Tires should be in Monday but I probably won't mount them until it thaws out here in Michigan...