Lifting the Grand Cherokee to fit 31” tire. ~ Cars and Bikes
Cars and Bikes

Tuesday, 8 June 2010

Lifting the Grand Cherokee to fit 31” tire.

To fit 31” tire in ZJ Jeep required body lift around 1.5” to 2”. There are plenty of suspension lift kits available in the market. Before lifting the jeep, please check the front drive shaft type, if your ZJ equipped with U-joint drive shaft, it is save to lift the body up to 2”, but if the ZJ equipped with CV-joint front drive shaft, please do not lift the body more than 1.5”. To gain 1.5” to 2” body lift, we can use:

Budget Boost / Polyurethane Suspension Lift.This is the cheapest way to gain 1.5 to 2” lift, just add polyurethane spacer on the top of the coil spring. Usually the spacers sold together with bump stop extension. For this method will cost around 60 dollar up to 150 dollar.

Change the suspension system with taller coil spring.There are many suspension products are available on the market, one of them is Old Man Emu brand (picture above) manufactured byARB. The Old Man Emu suspensions are not typically noted as a lift kit. They are usually regarded as suspensions systems. However, depending on vehicle weight and application, a lift of 1-1/2" to 2-1/2" can be gained. Many lift kits require a sacrifice of ride quality for off-road performance, but Old Man Emu is able to combine both to give outstanding ride quality with excellent spring articulation. Old Man Emu recommends using 31" tires for best performance. This suspension system will cost around 500 to 700 US dollar.
Combination of the above system.
This is what I did with my ZJ. After installed the OME spring and shock, the 31” tire still rubbing the fender. I suspect that the installation of the new OME spring and shock have not reach 1.5” lift as their claimed. So, I added ¾” polyurethane coil spacer (cost me 59 USD, bought from 4WD store) and the tire just fit, not rub the fender anymore. However, the tire still rubbing the front lower arm in the maximum turn position. To avoid this, we can add a wheel spacer or reduce the maximum wheel turn through an adjustable bold.

The pictures below showing the ZJ jeep with 29" stock tire and with Dunlop Grantrek A/T 31" new tires.

So what we got after installing 31” tire?
- Higher ground clearance
- Better look
- Plenty options of tire type (HT, AT, MT, super swamper, etc.)

- Don’t forget to re-align the will after installing the lift-kit
- After one year using the OME system in normal road driving condition, I feel the shock absorber going weak, this is much shorter life than I expected. In near future I have aplan to change the OME shock with Pro Comp which is much cheaper with almost the same quality. 

- Further observation, actually the shock wasn't weak, but the bushing start to worn due to change of suspension geometry. This problem made the the jeep sway and some noise start.

1 comment:

Anonymous said...

Amiable post and this fill someone in on helped me alot in my college assignement. Thanks you for your information.