Jeep JK Wrangler 2.5″ Budget Boost
Installation Write-Up

Thanks to the wide open fender design that the Jeep JK Wrangler has, you can pretty much run a 33″ tires bone stock and get up on a set of 35″ tires with very little effort. Of course, the easiest and most cost effective way to get the extra clearance you need to run them is to install a 2.5″ coil spacer lift. More commonly known as a budget boost, coil spacers are cylindrical blocks that are made of a polymer or sometimes steel and they are designed to sit on top of your factory coils to give you as much lift as they are tall. When installed with a set of shock adapters, you will effectively have a small lift that will not change the quality of your ride and do it all for about $350. This write-up will give you a general idea just how easy it is to install a budget boost on your Jeep JK Wrangler.

Jeep JK Wrangler 2.5″ Budget Boost Installation Write-Up


  1. hey will, you will need to run wheel spacers if your 33’s measure 12.50″ wide. if you get 10.50’s, you should be okay. regarding the rear sway bar links, no, if you do not have a rubicon, you will not need to install the new taller links.


  2. Hi
    Thanks for the great write up, it was very helpful as the Teraflex destructions stink!
    Just an FYI they now put the track bar reclocation bracket in the kit.

    Just an FYI to all.


  3. OK I have read thew the whole list of Q&A and i have this Q
    2007 JK Sierra
    2.5 in. BB
    can you fit 17×8 4.5 in backspacing wheels with 35×12.5 on it with no spacers?

  4. I have had the BB in about a month. If you have the right tools the install is pretty much like you say.
    I also installed 1 1/2 spacers and new Nitto 32″x12.5″ tires on the stock 18″ rims on my Sahara 4 door.
    I do have a lot of sway when I hit ruts in the road at higher 30+ speeds. I am not sure if I missed something (installed all the parts) or if this is typical. I did have the swaying before I changed out the stock tires about two weeks ago.

  5. Other words might be floating? or slight jerking or feeling like I need to overcorrect when I hit a rut in the asphalt etc. Sorry, that it the best I can do.

  6. Do you think if I install a stubby bumper and a WARN M8000 (not the heavier PowerPlant), I’ll still see drooping in the front? Wondering if I should bother with the 3/4″ coil spacers. Looks like the M8000 is about 42lbs lighter than the PowerPlant 9500.

  7. it’s added weight and so you will see some droop – just not as much. personally, i would install things as you really need them. in other words, do your lift without the 3/4″ spacers and then add them if you need them.

  8. WOL,

    after wheeling last friday, my front passenger spring is slightly bowed. i checked the lower perch and it seems to be seated properly. the driver side is straight. Neither side rubs or touches the bump stops.

    what has caused this? is this a problem?

  9. Did mine today, it was a PIA. Had some tech problems, pretty much all the ones listed above. I installed the new rear sway bars on the INSIDE? Is that ok? Thanks for the write up, much better than the directions.

  10. ben, did you opt for the replacement coils or are you just using the coil spacers? a slight bowing really is no big deal and if you got new coils, it is pretty common.

    john, if you were able to get them install, having the links on the inside is okay.

  11. Eddie,

    Did the Terraflex 2.5 bb lift on my 08 Rubicon 2 dr. about a month ago and thanks to your articles , personal help and the pdf.s you sent the installation was a breeze.The ride and handling are at least as good as stock and possibly a tad better. Have put about 4000 miles on it including 7 days at Moab and a 120 mile beach run at Padre Island , Texas, with zero problems. At Moab we ran some of the more difficult trails, including “Golden Spike” and was able to do golden crack with no damage, this with stock 32’s and stock plastic bumpers and air dam and once again no damage. Needless to say ,but I am very happy with the results.

    Thanks again


  12. Eddie,

    Getting ready to install the 2.5BB lift on my 08 2-door X. I installed a new much heavier front bumper and I am planning on installing a winch in the near future. I ordered 3/4in spacers to level out the front end due to the extra weight. With the addition of the 3/4in front spacers along with the 2.5in BB, is using the rear sway bar links on the front and installing the new longer ones in the back necessary. When I asked you earlier about this you said it was only necessary for rubi’s but I did not know if the added height due to the extra spacer would change this. Also, with the lift the warning says that the longer sway bar links for the rear will only touch the stock wheels at full suspension compression. I know that you did not have the knew links with your kit but I didn’t know whether or not you knew if this was the case or if they rubbed during most normal driving. I am getting 16×10 Pro Comp 8089 rims and 35×12.5 BFG All-Terrains, but they won’t be in for a couple of weeks and I wanted to install the budget boost kit now, but I also want to be able to drive my Jeep around on the road until I get the new wheels without worrying about rubbing.

    Thanks for all your help,

  13. And also, I know with this lift a dropped pitman arm is not necessary, but would you recommend installing a new one? Did you have any trouble just using the stock one after you put the lift on?

  14. hey will, if you don’t have a rubi, you really don’t need to install the new links. the new links will help with articulation on the trail and if you plan on doing a lot of wheeling, i would install them. as far as your tires go, yeah, you be fine riding around with what you have until you get your new ones. oh, as far as the dropped pitman arm goes, no, you will not need one.

  15. The picture shown next to step number 41 shows the sway bar link on the outside (closer to the wheel) of the sway bar and sway bar bracket. This contradicts both the instructions and pictures on the Teraflex instructions. You may want to update your pic to avoid confusion.

  16. the outside is how the links were installed from the factory and how they should be installed unless you do not have wheels with less backspacing or wheel spacers.

  17. Hello Eddie,

    I installed the kit according your write up. Thank you!
    Because I did something like this the first time I have the following questions:
    1) In Step No 8, I did not disconnect the front track bar (I forgot it 🙂 I still did everything else. Is this a problem? Why would I need to do so?
    2)While taking the nut off my left shock (Step No 6, Stud mount nut), I broke the complete thread (RUST!) I had about 8mm thread left on the shock to install the shock extension. How big is this problem? Can I drive on pavement for a couple weeks or should I get a new shock right away? Is this a warranty thing?

    Thank you!


  18. Hi again,
    I just learned that there should be bracket to extend the rear track bar. I did not receive this with the kit and the write up does not mention this. I do have an rear axle offset of 1 inch!! (The upper driver link bolt is touching the wheel now!)

    Please help,


  19. Hi Eddie,

    I love your write ups, and the Project-JK site and forums! I’m from Australia, and have learned so much from your write ups. I have a question. I have a 2″ lift, from a local manufacturer – which consists of Shocks and coils. The front coils have basically sagged to near stock height! I was thinking of getting coil spacers, or a BB like this Terraflex kit, but local mechanics tell me it would put too much strain on the coils? I don’t know what to do…and figure that I would actually be better positioned with my aftermarket coils/shocks, as they are longer than stock. What are your thoughts on this (adding a 2.5 BB or spacers, to a Rubicon with already replaced aftermarket shocks/coils)?

  20. so long as you install the bump stop extensions like you are supposed to, you will not have any problems with installing a BB on top of what you already have.

  21. Hey WOL,

    I followed your instructions and it was really quite easy. However, I was so “into it” that I didn’t install the new rear track bar relocation bracket. I just went by your instructions and used a ratchet strap to pull it back to the factory location. Is there any real advantage to using the bracket? Do you suggest that I go back in and install it or just roll with it the way it is?

  22. I have a 4 door sahara unlimited with a 2″ body lift. Plan on installing the 2.5″ spacer lift also. Will this cause any problems. It does not have the dana 44 ax. Is going with 35″ tires a problem with the smaller axle. what gears should I go with for 35″ tires. What tires would you recommend? I do alot of highway driving so I want something that looks good and will last. WHat do you think about cooper STT? No rock climbing just mud if anything. Can you put locking hub on the sahara?

  23. just about all brands will work find and as i said, you might just see some minor rubbing at a full turn. if you do have some rubbing, you can fix it by adding washers to your steer stops.

  24. I have a question that I don’t think has been asked. So here it goes.

    If I install this 2.5″ BB, and then a year from now, have a buddy give me his 3″ lift coils from his jeep that is now getting a larger lift. Could I, (if I had all the correct track bar bracket’s and adj track bar’s and shocks etc etc) use the 3″ coil with the 2.5″BB for a total of 5.5″ of lift? and then install the Long Arm Upgrade Kit?

    Or would it be dangerous to run this set up?

    Hope this question wasn’t to wild.


  25. no, it wouldn’t be dangerous and you may not even “need” a set of long arms to do it. but, if you can just get the right coils for the job, that would be the better way to go.

  26. Could you still run the stock front and back bumpers with the 35s you put on?? Did you install wheel spacers with the 35s? If so, what size? Im looking to install this Teraflex BB with M.T. MTZs(35×12.5/r17) with M.T. Sidebiter wheels. I was thinking about installing some Spidertrax 1-1/4″ spacers to prevent rubbing. What do you think. Thanks.

  27. yes, you can still run factory bumpers with 35’s. up front, you will see some rubbing of the air dam at a full turn and in the rear, it will be a tight fit but doable. if you get new aftermarket wheels, just make sure that the backspacing on them is 4.5″ or less and you will not need wheel spacers.

  28. is that really the only size back spacing it’s available in? i would ask to make sure because most wheels come in a variety of back spacing. if so, the smallest wheel spacer you can get and still be safe is 1.25″ and even at that, you will need to grind your wheel studs a bit. otherwise, you will need to get 1.5″

  29. Im interested in lifting my 08 jk sahara 4 door and have some questions. Ive bought the rough country 2.5″ bb lift that is very similiar to this one and is also capable of clearing 35’s. My real concern is the backspacing of my wheels. Im buying new wheels that offer a couple of different options. The lift recommends 4.5″ backspacing but can more be acceptable to ensure against rubbing? Ive read on other posts that too much can actually cause rubbing so Im pretty lost in my decisions. How will wheel offsets effect rubbing also?

  30. more back spacing will pull your wheels in closer to your frame and this is where rubbing issues come into play. less back spacing will push your tires out from under your fenders and this will help you to clear them. 4.5″ or less is what you want.

  31. How important are the use of bumpstops in a lift like this? I have a similiar lift that didnt include bumpstops so Im planning on buying some from teraflex. What size would be right for my lift?

  32. WOL, many thanks for all you do for us at this site. I picked up both a 2008 Sahara 4×2 Unlimited and 2008 Sahara 4×4 Unlimited (during the crazy sell-off by Chrysler earlier this year) that are both stock. My wife and I both like the lifted look that the BB gives. Can this kit be used on the 4×2 also, to your knowledge? If so, are there any significant changes? I appreciate any info you might have.

  33. Firstly – nice forum (just joined).

    Me : 2007 JK 2DR Rubicon – Stock Factory setup.

    Mission : 80% pavement (sadly), 20 % trails and rocks but not necessarily the Rubicon trail (not immediately anyway). I want to attempt to retain the stock ride feel ( i like it) but not the look. On 35s, it looks right.

    My final targeted config:
    35″ tires with 2.5 – 3″ suspension lift + Bumper/winch upgrades (sorry i don’t believe in the Unichip snake-oil nor cooling air unless i see Dyno results)

    I’ve read the entire thread.

    My conclusion :

    Option (1) : Do a 3 inch body lift. Cheesy yes i know.

    Option (2) Do the Teraflex 2.5″ BB suspension, keep the Rubicon stock shock-absorbers and get extensions, put in spacers to deal with the wider tires.

    Downside : with 35″ tires, I’ll have minor rub at full flex in a full deflection turn.


    Option (3): Do a 3″ suspension lift, replace shock absorbers (which manufacturer?) and not have any issues.
    Downside : Cost.

    Questions :
    a) Are my conclusions correct ?
    b) Any suggestions on the 3″ lift manufacturer ? Which shock absorbers? I see lots of options but not many independent reviews.

    e.g ZONE, AEV, Skyjacker, Rubicon express and so on.

    c) For someone who lives in NYC (and doesn’t have access to a garage to do the job himself), how would i validate that the shop i give the job to (don’t have a choice) does it correctly. Any Reputable shops in NJ/NY who know what they’re doing ?


Leave a Reply

Your email address will not be published.