06 Grand Cherokee Build

[leaveyourego]

So, here's the brief. I'm back driving Jeeps. My driving history started with a '91 XJ when I was 17. Ten years later, I bought a '08 Wrangler to replace it. I ran it for a while, but ended up falling in love with a BMW for my commute at the time. Last year, I transferred to a job that involves a much longer commute, 140 miles round trip. Some of this driving was at night and as you might expect, I encountered local wildlife in short order:

It was a real shame, becuase I had just put in quite a bit of wrench time getting this thing ready for a 2800 mile-a-month drive. So, I went with another bimmer, and less than two months later:

At this point I was done. Time to return to my driving roots and get a Jeep. I figured I could get a hefty steel bumper from ARB to protect myself. I also didn't want to lose all of the comfort and luxury of the bimmers, so I went with a Grand Cherokee.

Bought the Grand straight out and when I got the insurance payment, I bought the ARB:


Great bumper, real solid. It added about 200lbs to the front of the (at the time) 11-year-old suspension. There was quite a bit of sagging. The Grand rode ok under most circumstances, but would bottom out pretty easy up front. I did take it off-road a couple of times to see what it could do and the results were mixed. I've been impressed with the Grand's ability to wheel in comparison to my old Wrangler. The suspension limitations were pretty significant though:

This trail section was only mildly off camber, but the front passenger tire is already almost stuffed. Next step was some research and I ended up getting a set of front coils from a 5.7L Jeep Commander. Those with a set of Bilsteins handled the extra weight and even lined up the CV joints almost straight across. This should help with wear and tear. I've also got on the order of 11" clearance at the front crossmember.

I love being back in a Jeep. Even moreso, it's nice to drive on the highway. This thread will mostly chronicle the odds and ends of things I do to it. Some of it will be trail-related, maybe some maintenance stuff too. At this point, I've got the beginnings of a pretty nice luxury overlander here, and I want to see how far I can go with it. It's handling trails at Grand Lake pretty well, but I want to do things like the Trans Am trail, or take the wife to the north side of the Grand Canyon.

 

[leaveyourego]

Here you can see the results of the Commander front springs:

As you can see there's significantly more room in the front wheel well. The new springs handled the extra weight of the bumper and leveled out the Jeep overall. Next step suspension-wise will be a stiffer spring set for the rear to help handle the Hitchgate and some cargo. I think I'll be looking for about an inch more lift in the back to restore some rake to the body. For reference, the part number for the Hemi springs: 52124207AA.

 

[Utah KJ]

I put the OME HD lift to hold up the weight of my ARB bull bar and winch.


Sent from my iPhone using Tapatalk

 

[leaveyourego]

I looked at that as an option, but height is an issue for this build. I needed to keep as close to stock height as possible and the extra lift from the Commander springs was unintentional. A bonus I'm happy with, for sure, but it wasn't a goal. My wife is short and I want her to be able to get into the thing comfortably. She hated my wrangler haha.

The truth is, 99% of the travel in this Jeep is going to be on highway. So, things like tire setup and suspension will focus on highway driveability with some added off-road performance for mild trails. Were height not an issue I'd have definitely gone with OME. First choice.

 

[Saint Nick]

Ooops, some seriously bad luck with those BMW's! Good luck with the Jeep.

Nick

 

[leaveyourego]

Thanks, Nick. So far, so good.

So what I've done is put together a series of upgrade packages that will help me make progress on the build in an organized way. Armor, suspension, lights, etc. I'll buy a package as disposable funds are available. First up is armor. The recent excursion to the Grand River Dam spillway left me wanting to protect the undercarriage. I never had much interest in this with my old Wrangler, but the angles on that Jeep were a lot better. The breakover angle on this one without lift is a concern.

I got the first set of items during the week and set about installing them this morning.

Mopar skid plates and a new diff cover for the Chrysler 8.25".

I went with the Mopar skids, because it was cost effective. We're only going to be doing mild trails, not much of the rocky stuff. This at least will protect from branches, dirt, and gravel. The diff cover was also a balanced choice between cost and effectiveness. I looked at the ARB cover for the rear diff, and it's really nice looking, but it's just not worth twice the price of this one to get a logo and dip stick. This is listed with Quadratec and Amazon as a Crown Automotive HD Cover. It's 3/8" forged steel and it feels pretty hefty. I'm happy.

So, I went for the diff cover install and I was going to replace fluids in both front/rear diffs. I have a 5 liter jug of Miller's Oils 75W-140. Went to do the front diff and completely forgot that I needed a 14mm Hex that I don't have. That will have to wait until next weekend. I took off the rear diff cover and found muddy fluid:

Not the best picture, but you can see the brown discoloration on the bottom half of the ring gear. So, to clean it out I loaded the old cover back on and filled the diff with diesel. The whole Jeep was already on jack stands at all four corners, so I was able to run it at idle to get the diesel circulated around the axle to pick up the remaining mud. I didn't see any leaks while it was running, so good deal. I put the old cover back on and loaded the axle with some Castrol 85W-140 I still had leftover from my last fluid change. The new cover will have to wait for the Allen socket to come in.

The front skid was a straightforward install. I noted that it will have to be removed for the front diff service. Coming soon is a set of rock rails with steps, and a belly guard from 4XGuard. Looking forward to that one.

 

[Saint Nick]

Look forward to seeing it finished.

Nick

 

[SSF556]

Always good to see another WK!

 

[leaveyourego]

Thanks!

So pics of the recent upgrades:

Installed the RT Offroad diff cover and replaced the fluid in both diffs with Miller's.

Again, it's a pretty hefty cover. I've always needed some armor like this, because I tend to get ambitious off-road and end up backing out on a far too regular basis.

Next up I got some side steps.

These are pretty cheap, but they look nice and I'm looking at this as something I can afford to take some hits before my doors and serve as a good step for my wife. They hang low, because they were designed to install below the plastic rockers. I've removed the plastic here and I'm going to fab up some brackets to relocate the steps a few inches higher. This way I won't lose too much clearance. The steps themselves are 2" square 6061t6 aluminum tube. They should be decently strong, but the weak point here is the attachments to the unibody. I'm not going to be able to rest the weight of the Jeep on these without compromising the body in some way.

I'm having a mental debate about future tires. This is a mostly highway vehicle and it has to be comfortable and relatively quiet. I want to stick with the Advantage Sport LTs I have on now, but will be going up in size. Chances are I'm going to go with a 245/70R17, which is an extra inch in diameter, but same width. This should hopefully prevent any negative impact on MPG. This tire will also fit in the factory spare area. I'm having trouble letting go of putting 265/70/R17s on it though. They would look a lot nicer and would be a lot of help overland. Gotta remember my priorities though.

 

[Saint Nick]

I don't know much about the tyres you are using, but they are obviously road biased. IMHO if you are going to do some of your driving off road then I'd go for an all terrain tyre. Obviously BFG A/T's are well known but having used them for well over ten years, I changed to Cooper ST Maxx which are a slightly aggressive A/T and found them awesome. Good road manners and also good off road.

Nick.

 

[leaveyourego]

Yep, these are road tires. They're rated at 740 on the UTQG for wear (should get about 70k out of them, have 40k on them right now), and they're great in snow/freezing rain. I've gone back and forth about switching to BFG A/T's, but I'm a little gun shy from the noise that my JK's KM2's generated after about 10k of wear. I started wearing ear plugs toward the end of that. I don't expect the A/T's to have that degree of noise, but I don't know that I want to take that chance. I commute 140 miles a day in the WK (highway, mostly 70+mph).

How is/was the noise on the BFG A/T's and/or your Coopers?

 

[Saint Nick]

Yep, these are road tires. They're rated at 740 on the UTQG for wear (should get about 70k out of them, have 40k on them right now), and they're great in snow/freezing rain. I've gone back and forth about switching to BFG A/T's, but I'm a little gun shy from the noise that my JK's KM2's generated after about 10k of wear. I started wearing ear plugs toward the end of that. I don't expect the A/T's to have that degree of noise, but I don't know that I want to take that chance. I commute 140 miles a day in the WK (highway, mostly 70+mph).

How is/was the noise on the BFG A/T's and/or your Coopers?

I used the BFG's for 10+ years on a daily driver and found them quiet, and the Coopers IMHO are no noisier. Then again either the windows are up with the music on or the windows are down so plenty of wind noise, so maybe I just can't hear any noise!! Overall, I think the ST Maxx is a better tyre.

Nick

 

[Kraqa]

Wicked!!! Nice build. You should check out mallcrawlin.com for more grand tech.


I love the build

 

[leaveyourego]

Wicked!!! Nice build. You should check out mallcrawlin.com for more grand tech.


I love the build

Thanks, Kraqa. I started poking around mallcrawlin and I like the technical bent of the place. Definitely gonna lurk for a while there. Lots of good info and ideas so far.

Meantime, I pulled the trigger on a set of all terrains. Waiting for shipping now and my street tires will be going to my wife's Acura. On Nick's recommendation I looked into Coopers. Didn't go with the ST Maxx, becuase I think they might have been a bit too aggressive for my highway drive. Went with their recently updated AT3 LTs. Sidewall is only two ply, but the denier of the polyester is high enough to give me a fair degree of confidence. These are a balanced choice between the two roles I need them to perform in. Hopefully it works out. Will update.

 

[Saint Nick]

On Nick's recommendation I looked into Coopers. Didn't go with the ST Maxx, becuase I think they might have been a bit too aggressive for my highway drive. Went with their recently updated AT3 LTs.

I agree, the ST Maxx are aggressive for an A/T but I don't think you'll go wrong with the AT3

Nick