Raising a 242 - Part 2 (How-2 with pics)

A few months back, I first posed the question of whether or not it would be possible to slightly raise a 242. Essentially, install a TC lift as opposed to a TC drop. The responses I got were get a 231, clock your case, or build a custom crossmember/skid plate. Well, I like my full-time for snowboarding trips, clocking seemed pretty labor/skill intensive, and I have no welding skills so a homemade skid was out of the question...

Why would I want to lift my TC? I thought you might ask. I have a '99 XJ Classic with an auto trans and the 242. This whole idea started when I shopped around for belly skids. Most were advertised as "not for use with the 242" or they had a different version specifically for the 242 that hung down lower than the 231. I wanted something totally flat on the bottom and decided I liked the DPG Belly Skid, one of the ones specifically advertised as "Not recommended for Cherokees equipped with a 242 transfer case". Not willing to give up, I called Dirk and asked what exactly the issue was. He advised me that his skid was flush with the bottom of the crossmember and that on 242 equipped vehicles the case and the exhaust typically hang just slightly below the crossmember resulting in clearance issues. I measured mine and sure enough, if I put a straight edge on my crossmember, it would just barely touch my case and my (ridiculously large California) catalytic converter. If I could just lift it 1/2" or so....

I inspected how exactly the transfer case, transmission, transmission mount, exhaust, and crossmember were are all related to each other and decided that the easiest route would be to simply increase the distance between the crossmember and the transmission. I looked for taller transmission mounts with a similar bolt pattern but couldn't find one. I then decided that it would be nearly as easy to just install a spacer between the transmission mount and the crossmember. No special tools required, (almost) no fabrication skills required. Here's how I did it:

1. Find a suitable material to make the spacers out of. I found that 1/2" thick material gave me just the amount of extra clearance I needed. I happened to have a 1" wide strip of 1/2" thick Delrin laying around at work so I decided to give it a shot. I thought metal might be better suited to the job, but so far the Delrin has held up really well. You need two pieces, each one measuring 1" x 5" x 1/2".





2. Remove your transmission mount. Use a floor jack with a board on it under your tranny pan. Lift just until all weight is taken off the transmission mount and then remove all the nuts and bolts. This may be done with the crossmember in place though I highly recommend removing it as it makes access to the bolts holding the mount to the transmission much easier. (Unless of course you run into some of the typical issues with crossmember bolt/stud removal, then you'll be cursing having ever tried to remove it.) Be sure to use a jack stand to support your transmission if you do remove the crossmember.

The studs on the bottom of the mount will be too short after installing the spacers so they need to be removed. They are hardened and pressed in place and need to be drilled out. Place the mount in a vice and cut them as short as possible to reduce the amount of hardened bolt drilling you have to do.



3. Studs drilled and punched out



4. Drill 5/16" holes in your spacers matching the holes in your mount. You can't really use a punch to mark the holes as the upper half of the mount is in the way. Instead, I used some chalk line chalk to transfer the location of the holes to the spacer. For hardware you need 4 bolts, 4 nuts, and 8 washers. All hardware should be 5/16" and the bolts should be just barely long enough to pass through the upper crossmember plate, the mount, the two washers, the nut, plus whatever thickness of spacer you decide to use. You don't want a bunch of extra thread hanging out or it will start tearing into the rubber part of the mount over time. I used Grade 8 as that is the only zinc coated hardware available at my local hardware store, but I'm sure Grade 5 would be fine as well.



5. Finally, bolt it all in place. Use blue LocTite on the threads and torque everything to factory specifications. As you can see in the picture, there's a decent amount of clearance between the bolt and the rubber isolator up front, but in back it's pretty close.



Here's a couple of after pictures. A straight on view from behind shows that the bottom of the case is now safely above the bottom of the crossmember. I've since removed my TC drop kit as the DPG belly skid won't work with that either. Removing it has no effect on the relationship between the crossmember and the case, but it will move the top of the case closer to the transmission tunnel.



This next picture shows the relationship between the catalytic converter and the crossmember. Again, removing the TC drop has no effect on this, but it will push your exhaust system up closer to the bottom of the vehicle. After installing the skid plate, I still had no clearance issues with my exhaust u-bolt hanging downwards.



This next picture shows the one place where the TC gets relatively close to the transmission tunnel. Right at the pointy part at the top of the case there's just a little over an inch of clearance. You can pound out the tunnel with a BFH, but I found it unnecessary. (Keep in mind however that I have the Rubicon Express Control Arm Drop Brackets which essentially act as a 1/4" TC drop kit since they bolt on between the crossmember and unibody rails.)



I have been running it like this for about 2 months now (including one pretty extreme rock crawling trip) and have not heard or felt any clunking, scraping, rattling, knocking or other unwanted noises. The auto tranny and TC both shift just fine without any adjustments to the linkages. I figure if people routinely run with everything dropped 1" below stock (as I have for the past 6 years) then raising everything up 1/2" above stock shouldn't be a problem either.

You may of course have to adjust your driveline angles. While lifting your TC does have a negative effect on your rear driveshaft angle, you will find that it has a positive effect on your front driveshaft angle as it actually points your front output yoke slightly further down.

So there you have it, a very long write up for a very simple mod. I now have the belly skid I want and a little extra ground clearance to boot. Hope someone finds this helpful someday...

Watch out for the Black Helicopters, you just did a reverse T-case drop lol j/k. Nice write up and good work.

That's a nice write-up. I'm surprised you aren't getting much thumping against the hump.

BlueCuda said:

Watch out for the Black Helicopters, you just did a reverse T-case drop lol j/k. Nice write up and good work.

Click to expand...

Huh?









Thanks! Don't go selling me out to the government though... I'm still working on the patent.

ehall said:

That's a nice write-up. I'm surprised you aren't getting much thumping against the hump.

Click to expand...

No thumping against my hump at all thus far! (That just doesn't sound right. :wierd I still need to go on a good rock crawling trip with my final combination of TC lift installed, TC drop removed, and belly skid installed to be absolutely sure though.

What size lift you running? Also do you have a hack & tap?

Nice write up by the way

Great idea! I have been very unhappy with my 242 TC skid because it hangs 2" lower than it needs to. I have been wanting to lift the case and modify the skid to regular 231TC height. Let us know how it holds up over the coming weeks.

scottmcneal said:

What size lift you running? Also do you have a hack & tap?

Nice write up by the way

Click to expand...

Thanks! Be on the lookout for a similarly detailed write up on how to keep your ABS when swapping in a D44 rear end. :shhh:

I'm running a RE 5.5" Extreme Duty Short Arm kit. I have actually been able to run without a SYE for the past 6 years with very minimal vibrations using only the supplied TC drop kit. I did however install a Tom Wood SYE kit in conjunction with the TC lift install and the TC drop removal.

Just to give you an idea of how this affects your driveline angles, my particular combination is a '99 XJ with 5.5" lift, 0.5" TC lift, 4.0L, auto trans, 242, Tom Wood SYE, D30 front, and D44 rear. Installing 8 degree shims in the rear and leaving the front unshimmed resulted in both my front and rear drive shaft angles being 2 degrees steeper than my pinion yoke angles. 8 degree shims seem to be working out just fine, but I wouldn't want to shim too much more than that.

the_weirdo said:

Great idea! I have been very unhappy with my 242 TC skid because it hangs 2" lower than it needs to.

Click to expand...

:cheers:

Nice write up.
I removed my cat, and removed my TC drop after I did the H&T. I then noticed that the exhaust did rise to with in 1/2 inch of the body. I went to reinstall the belly pan (242 TC), and now I noticed that the drain plug just barely sits above the belly pan, maybe a 1/4inch. Do you think this is an issue?
I really like the belly pan, but I wander if a 1/4 inch is enough for protection of the TC should I pound a rock?
What do you think?

I think it would be OK so far as protection goes. The skid is really just protecting your transfer case from getting gouged or taking a direct hit. What I think a potential problem could be is if your transfer case bangs against your skidplate when your motor / transmission / tranfer case are under load. The flex in the motor mounts and the transmission mount may allow your transfer case to hit your skid when you go heavy on the skinny pedal. Look for marks on the skid where the TC sits close to it and listen for banging while you're driving. If you don't encounter either you're probably OK.

FWIW, I have about 1/2" of clearance between the skid and both the TC and catalytic converter.

did you run it long enough to notice any problems while running the crossmember drop? as mine might be hard to remove as i welded them on when i was in a jam and tore the nutserts out of the driverside frame which i later replaced with bolts by tearin out the seat and carpet to access the inner rail but shes still welded up and i just mounted a tcase skid and dont like how low it hangs

Leaving the crossmember drop (TC drop kit) in place will actually make things better in a mechanical sense. It will leave you with more clearance between your transfer case and tunnel, more clearance between your exhaust and unibody, and will make your driveshaft angles less steep.

Only downside is that leaving the drop in place makes your crossmember closer to the ground, effectively giving you worse ground clearance. I guess you'd be regaining a little clearance if your skid currently hangs below the crossmember and installing the TC lift allowed you to tuck the skid plate a little further up.

Think of it like this... if you have a 1/2" crossmember drop installed and then you install a 1/2" TC lift, you've essentially moved the position of your transfer case output shafts back to their stock position. They cancel eachother out.

I've heard the Rubi 241 hangs low as well...I wonder if the same concept could be used with that?

Anyone try it?

[/hijack]

very nice write-up. I've been wondering about something like this for my MJ...unfortunately, I already installed the SYE and set pinion angles to match but cutting welds is possible i guess.

wish I'd seen this sooner

MoparManiac said:

I've heard the Rubi 241 hangs low as well...I wonder if the same concept could be used with that?

Anyone try it?

[/hijack]

Click to expand...

I remember seeing the 241 as being a larger diameter case all the way around...so it'd be more prone to hitting the tunnel and causing a rub and thump. You could probably move it up a little and run something like was done on mine (with a 242 though) with the flat longarm mount. It's a section of large diameter drain pipe, like 10" or 12".



Even 'hanging down' it doesn't cause any hangups.

Ah yes, this was the custom skid plate I was referring to at the start of the thread. I thought using the curved pipe to keep the skid from hanging up was a great idea. I just don't have the welding skills or materials to do it myself.

I still love how flat your skid sits against the unibody rails though! :thumbup:

is that crossmember welded to your unibody?

fyrfytr1717 said:

Ah yes, this was the custom skid plate I was referring to at the start of the thread. I thought using the curved pipe to keep the skid from hanging up was a great idea. I just don't have the welding skills or materials to do it myself.

I still love how flat your skid sits against the unibody rails though! :thumbup:

Click to expand...

I really like it, too. My buddy was the builder and prior owner of this Jeep, so I can't take credit for it. The first pic I posted was right after he built it and had taken it on an out of state trip. Somewhere in early 2003 I think. It'll probably come apart in the Spring so I can refinish it. It caught a lot of salt spray during a Baja trip when they decided to run along the beach for a day. :doh:

reelbigdundy87 said:

is that crossmember welded to your unibody?

Click to expand...

Nope. It's welded to angle iron, which is bolted to larger angle that's attached to the unibody. The angle on the unibody runs the full length and attaches to the spring hangers in back like unibody stiffeners. It's pretty simple, though. No fancy bends to follow the unibody.

I spent the afternoon doing this with my 2001 XJ w/ NV242. Figured I'd mention some of the differences I encountered or made.

I used steel instead of delrin. I figured the mount itself provides enough NVH isolation. I have the TNT belly pan and stiffeners so I was able to get away with a little more height. I stacked 3/8" and 1/4" steel to end up with 5/8" tall spacers. I still need to finish the "bucket" in the belly pan for the NV242. Hopefully it'll be a lot smaller now.

For the record, my mount is not the same shape as the OP's. It is equally shaped around the bolt holes with a ~3-1/2" long mounting flange. Also the rubber part of the mount interferes with where the nut goes. I'll take a knife to that to make clearance. Should be fine.