ingsy

Hi All,

I have my eye on a lifted XJ but think the lift height may be too high. Did some research (and copied the info below), but reaching out here to see what other Massachusetts based XJ owners have gotten away with. I would be grateful for any tips you may have on getting an inspection sticker for a modified XJ, especially given the cameras at the station, and risk the inspectors has w/ being a 'nice guy'. Apologies if this has been covered before, I did a search and did not come up w/ much. Please let me know what you can.

Here is a copy of the law

Here is some info I found a poster (Hurricane91) another forum (Tacomaworld) which appears to be useful:

Regarding ride height. Yes, the RMV standards do state you cannot alter ride height any more than 2" +/-. HOWEVER, there is a separate clause for 4 wheel drive trucks. It says that 4x4 trucks must comply with 540 CMR 6.00. What is this you ask? Well it's a formula, which goes as follows:
(Vehicle Wheel Base x Vehicle Track Width) / 2200 = Maximum Mechanical Lift
Track width is measured on the widest axle, from center of tread.

Example:

2013 DCLB

If I have a wheel base of 140.6" and a track width of 63".
(140.6x63) /2200= Lift
8857.8/2200=4.026"

So according to this, a 2013 DCLB can have a maximum mechanical lift height of 4".
This does not take into account that you can also widen your track width by up to 4" (2" each side) through the use of offset wheels, as per 540 CMR 6.00. If you take that into account, you can have a total mechanical lift of 4.28" which we will call 4 1/4" on a 2013 DCLB.
A 2013 ACLB with a WB of 127.4, with offset wheels, can have a maximum mechanical lift of 3.65".
In addition, you are only permitted to plus size your tires the equivalent of the maximum mechanical lift. So, if you are allowed 4" of mechanical lift, you can upgrade your tires from 31" to 35", as an example.
This would mean that a truck that is allowed 4" of mechanical lift, is allowed up to an additional 2" of lift from tires; for a total of 6". This is known as combined height. Remember, the additional 2" can ONLY be from tires. So 6" lift kits are a no go.
The combined height measurement is taken from the ground to the bottom of the door, lowest portion where it meets the body OR where it reasonably would be for vehicles lacking doors (jeeps). You cannot exceed those measurements over stock height.
540 CMR 6.00 alsp stipulates that on order to be deemed non-compliant, your vehicle would have to exceed the limit by over 1". So, if you just happen to measure at 6.5" in the combined lift height above, your vehicle still passes; according to the law.
Know the ENTIRE regulation before going for an inspection. Most techs, though knowledgeable, fail to comprehend the law in its entirety. They then, err on the side of "I'm not ****ing sure, so It's illegal".
Hope this is somewhat helpful to someone.

SatiricalHen

That's interesting. My state doesn't have inspections so I can't help too much, but I wonder if the wheelbase is measured or based off of the factory specs because I know mine is stretched a couple inches or so.

SatiricalHen

Another thing would be if they base it off of an upcountry which was an inch or two taller from the factory or if they base it off of whatever package you have. How much lift does the Jeep you're looking to buy have? Has it passed inspection before?

ingsy

Per the post I quoted above, it appears that you can include offset wheels in the calculation, which would be good for me. The XJ I am looking at has a 6 inch lift, but apparently it can be lowered by changing a few parts. I am getting the measurements tonight to see how much it will need to be brought down. Going to be fun breaking out a calculator at the inspection station.

SatiricalHen

So I know for sure the factory wheelbase is 101.4. From what I'm finding online is the factory track width is 58. So with the extra 4" of width you're allowed thats 62. (101.4x62)/2200 is only 2.858. Then you're allowed 3" taller tires so that's 31s (I'm pretty sure the factory size was about 28"). I'm on 5.5" with 35s so I doubt the Cherokee you're looking at is 6" with 31s.

ingsy

Thanks very much - that is helpful

Waynerd

https://www.mass.gov/files/documents...19/540cmr6.pdf

not sure how lenient some of the inspectors could be. Back in the day a lot of them wouldn’t really care as long as the vehicle was safe. The place I worked at I was actually working under someone else’s inspector license and was told to pretend I was that guy if anyone came asking questions. Also the shop owner would tweak people’s cats to get them to pass the emissions testing and he would have me pass vehicles that were borderline on safety inspections.

On the the other hand I was talking with someone recently. I can’t remember if it was NY or MA and they were saying that the state has cameras installed at all of the inspection stations now. Maybe before buying it you should stop and have a talk with someone at the location where you plan on getting it inspected and see what they have to say.

Waynerd

Lol. I totally missed the part where you mentioned the cameras until I just reread it.

ingsy

Hi Folks,

I got my sticker today. Before this, the seller of the jeep swamped out the springs from 6 to 4.5, and changes the shackles, taking it down a few inches. I then put 10*29 snow tires on instead of the 12*33 tires originally on there. The end result is still 'lifted' but much less than it was originally. The tires were also now w/in the extended flares.
The first place I took it to for the sticker said they could not do it due to the height. Apparently they were on 'probation' for a prior infraction and did not want to take the risk, but they gave me a recommendation for a place down the street. Before going to the next place, I calculated the maximum mechanical and tire lift based on the measurements and formula noted in the original post, and found that I was 1 inch less high than the max allowed. At the second place they were fine with it - they even said I could have the larger tires on and it would have been fine. They were real nice guys who seem to understand how a lift would / would not impact the safety of a vehicle, as opposed to just being worried about the cameras. PM me if you need an inspection in Boston.
Thank you both for your help with this, I appreciate it.

Cheers, Matt