Was getting 35s but found out for sure I have the 3.21 ratio by the rpm's at 70.so no bigger tires. Running 30 inch tires right now so I wonder if 33's be OK. I'm cool with how it runs right now. Good acceleration. Will 33's take very much away if I go with a lighter tire? Muds on it right now. Also, how high can I lift? I have at least 4 inch now. Was lifted when I bought it. Can I go higher?
33's and how high?
- Thread starter METALHEAD
- Start date
You should be able to do 33" tires, but you may need new wheels if you have stock. The whole backspacing issue. Wider than stock (the 32" stock tires: 255/75/r17 I think) will not fit because they rub on various things. Don't use spacers, they are bad in so many ways.
a popular size for 33" is 285/70/17 and I promise they will not work with stock wheels. I tried. Thankfully the tire guy is a buddy and I just got picked on for awhile. I had to go buy new wheels before we could get them on.
If you have a 4" lift, keep it. There isn't any reason to go higher, even if you get 35"s down the road. I would ensure that it was installed correctly. At that height they had better have upgraded the control arms so that your camber is correct.
If the jeep came with 30"s and a 4 inch lift it sounds like the previous owner put on the lift and probably bigger tires, then put the original tires back on to sell.
I would verify that the speedometer is correct. I'm not sure what the ratio to rpm method you are talking about is, but I bet it would be wrong if the speedometer wasn't calibrated correctly. I've always checked by jacking up the back and counting the rotations of the tire vs the drive shaft.
a popular size for 33" is 285/70/17 and I promise they will not work with stock wheels. I tried. Thankfully the tire guy is a buddy and I just got picked on for awhile. I had to go buy new wheels before we could get them on.
If you have a 4" lift, keep it. There isn't any reason to go higher, even if you get 35"s down the road. I would ensure that it was installed correctly. At that height they had better have upgraded the control arms so that your camber is correct.
If the jeep came with 30"s and a 4 inch lift it sounds like the previous owner put on the lift and probably bigger tires, then put the original tires back on to sell.
I would verify that the speedometer is correct. I'm not sure what the ratio to rpm method you are talking about is, but I bet it would be wrong if the speedometer wasn't calibrated correctly. I've always checked by jacking up the back and counting the rotations of the tire vs the drive shaft.
Hey MacGyver, thanks for your reply. The wheels are not stock I'm sure. It has LT265/70R17 on it and all the rims show is the emblem in the pics.
I was going for 35s but then I was advised to find the gear ratio. I did read about the shaft rotation but I didn't get a jack with it. THE RPM method refers to a chart I'll include a pic of. You get the RPMs at 70 MPH and the tire size and that gives you the ratio. Mine was 3.21. I would like bigger tires but I don't want to give an inch of performance away. Right now I'm comfy with acceleration and overall speed but don't want any less. So I wondered if I got 33s in a lighter all terrain rather than the muds on it if it will take any power away?
I'm not sure if anything was upgraded with the lift but I can get some pics if you would like. Most everything is different than my first Jeep. It was an 84 CJ7 and I ran it like an escaped convict. Been in love with them when I first saw one with the top and doors off as a kid. ad it about a year when me and the x separated and she sold it out from under me. That was 11 years ago and I finally have another one.
When I look at it from the front it looks like one of the wheels is off a bit. Thought maybe that was normal now. I'm still trying to figure out which bolt to pull on the tranny for fluid check. To me it felt like I was moving a little faster than the speedo said so I checked that with a GPS speedo. It was off. 3MPH at 50, 5 at 60. I used that to mark RPM at 70 also.
I got it in mid March and just went off road the first time yesterday.
So you don't think it will take any power away if I go to 33s?
I was going for 35s but then I was advised to find the gear ratio. I did read about the shaft rotation but I didn't get a jack with it. THE RPM method refers to a chart I'll include a pic of. You get the RPMs at 70 MPH and the tire size and that gives you the ratio. Mine was 3.21. I would like bigger tires but I don't want to give an inch of performance away. Right now I'm comfy with acceleration and overall speed but don't want any less. So I wondered if I got 33s in a lighter all terrain rather than the muds on it if it will take any power away?
I'm not sure if anything was upgraded with the lift but I can get some pics if you would like. Most everything is different than my first Jeep. It was an 84 CJ7 and I ran it like an escaped convict. Been in love with them when I first saw one with the top and doors off as a kid. ad it about a year when me and the x separated and she sold it out from under me. That was 11 years ago and I finally have another one.
When I look at it from the front it looks like one of the wheels is off a bit. Thought maybe that was normal now. I'm still trying to figure out which bolt to pull on the tranny for fluid check. To me it felt like I was moving a little faster than the speedo said so I checked that with a GPS speedo. It was off. 3MPH at 50, 5 at 60. I used that to mark RPM at 70 also.
I got it in mid March and just went off road the first time yesterday.
So you don't think it will take any power away if I go to 33s?
I have the next size up in gear ratio with 3:73's. I have 35" tires and there is a definite loss in power. I will be changing gears in about a month. I'm putting in 4:56 gears to get me back to OEM specs. If you have 3:21's and go to 33's you can count on some power loss.
Those would be considered 32"s so really you would increase by about 1", but it would also be wider.
I use this site to check tire sizes and such. https://tiresize.com/calculator/ it has a bunch of tools to check things out for this.
I use this site to check tire sizes and such. https://tiresize.com/calculator/ it has a bunch of tools to check things out for this.
Ok, looking at the picks. I see some fox shocks under there and those wheels are probably 17 x 9s and will have the backspacing for larger tires. If they spent the money on those shocks, they probably spent the money on new control arms.
Going to 33s wouldn't be that big of a deal. You would loose only a bit of power, I highly suggest getting the JScan app and then the bluetooth dongle it suggest so you can make your own changes to the jeep and ensure your speedometer is correct, as it is what the jeep uses to determine shift points.
You can download the app for free, The dongle is going to be around $20 - $30 and a single license to fully unlock all features is around the same. If you plan on doing really anything to the jeep, this app is indispensable.
Also, that chart and info speaks to why I don't like the drive and use the speedo/ tach for gearing info
Love the color btw
Going to 33s wouldn't be that big of a deal. You would loose only a bit of power, I highly suggest getting the JScan app and then the bluetooth dongle it suggest so you can make your own changes to the jeep and ensure your speedometer is correct, as it is what the jeep uses to determine shift points.
You can download the app for free, The dongle is going to be around $20 - $30 and a single license to fully unlock all features is around the same. If you plan on doing really anything to the jeep, this app is indispensable.
Also, that chart and info speaks to why I don't like the drive and use the speedo/ tach for gearing info
Love the color btw
Yea I have heard about the app. A definite in my plans. . Anything you can tell me about the gecko pearlcoat? Noticing some spots where the paint is gone. Especially on the door jambs. I'd also like to get rid of the heavy rear swing gate bumper. Prolly the front to. Rather have something more modern and lighter.
Yea, MacGyver was saying the same thing. So now it's hard to decide. I'm just not sure I want to give up any power at all. I'm also not so sure now of my gear ratio. If my tires are considered 32s then I marked the wrong RPM to reference in the chart. Think I might put tires on hold a bit and get some rims maybe. Thanks Steve.
Thanks. I saw it online when I started looking. Never thought I'd end up with it. Thanks for your help .
Jack up the rear axle, put it in neutral and count how many turns of the driveshaft to one turn of the tire. Then you will know for sure what you have.
Read about that but no jack came with it. Have to get one. Would count the teeth but don't want to pull the diff cover right now. Trying to figure out which bolt I pull to check tranny fluid.
For the paint you can go to a local O'reilles. The one in my town can mix a rattle can for you, just grab the paint code from the data plate in the drivers door.
There is no reason to pull the diff plate and count the teeth. You may actually just need to crawl under the back and look around the diff plate and find the little data plate that tells you.
Or this post from our sister site gives all the instructions you need:
https://wranglertjforum.com/threads/how-do-i-determine-my-axle-gear-ratio.72/
There is no reason to pull the diff plate and count the teeth. You may actually just need to crawl under the back and look around the diff plate and find the little data plate that tells you.
Or this post from our sister site gives all the instructions you need:
https://wranglertjforum.com/threads/how-do-i-determine-my-axle-gear-ratio.72/
Cool. Never would have thought I could get it there and thanks for the site. I looked for the tag. It's not there. Don't know if it came off or someone upgraded gears. Thanks for all ur help.