compatibility questions

ALL,
I am pondering the build up of my xj (1990) and wanted to discuss a few things.

1. I would like to roll on 33's, however I have concerns about the steering and brake system holding up. Any thoughts?

2. I am pondering the RE 5.5 lift or the RC 6.5 lift. Any reviews on these kits? How well does 6" of lift handle on the road because this is my daily driver.

3. I would like recommendations on headers and exhaust systems.

Thanks for you help.\
Jason

Well...

1) The earlier XJ's are a little underbraked, and the D35 (reportedly) is borderline for anything 33" and up. You will probably want to install a late vacuum booster (dual diaphragm, vice single - applies brakes faster) and consider going to a Dana44, Ford 8.8", or Ford 9" rear axle.

2) Dunno. Haven't lifted any of my XJ's yet - and probably won't get to lift my 88 for another year or so (got a restomod to finish first...)

3) I've used Borla on quite a number of vehicles, and I favour it. There are also good reports out on Banks, and I think there are a couple other headers out there.

WARNING - check your engine bay to see if you have an EGR valve! The 1990MY was the transition from RENIX to HO - so the late 90's have ended up with HO engines. The HO can be readily distinguished by the lack of the EGR valve. If you have a RENIX engine, you will need a header with the EGR port, in addition to the HEGO sensor bung.

While you're changing the header, I'd like to suggest you get some bronze bolts for the header, brass nuts for the collector, and some brass allthread to make new studs for the ends and centre - everything's threaded 3/8"-16. Also make sure you have a set of Belleville spring washers (you can get a box of them from MSC Direct if you can't find them locally - www.mscdirect.com.) to replace any that are missing - or just replace the old ones - since they spread out the clamp load and make life for the bolts a little easier. I have also found that a thin layer of RTV Copper (and nothing else!) goes well on the gasket.

Last, use LocTite 272 on the bolts, if you use anything at all. They'll work loose enough on their own - so you don't want to use Never-Seez. #272 is the only LocTite that will hold up to exhaust heat - that's what it was designed for - and it works well.

Reasons - I suggest brass because it won't gall or sieze on the steel/iron surfaces or in the holes, so it will be easier to deal with them the next time. You're also less likely to break something with proper planning.
The RTV Copper adds a little "forgiveness" to the gasket - which is needed later, when things get used. It's a known problem with inline sixes that the manifold gaskets - especially exhaust or combination manifold gaskets - tend to lose their seal over time unless you watch over them. This isn't a design flaw - just a materials issue and there isn't much that can be done about it. I also check torque on my manifolds once a year (part of a regular inspection) - while I'm checking other things. I don't usually find many loose bolts, but it's enough that I'm glad I check. (I'm picky on maintenance - just ask my wife!)

Anything else?

5-90

1) Brake issues- I went with rear disc brakes and a dual diaphram brake booster. My 1994 had a single. As for steering problems I had none, but it wouldn't be a bad idea to reinforce the steering box with a brace such as that made by C-Rok.

2) I've got a RE/DPG hybrid kit that gave me 5" of lift. It doesn't ride like a stock XJ anymore, but nothing strange either. I'm happy with it.

3) I've got a Banks header and Flowmaster muffler. I think that it's got a little more power, but I've never put it on a dyno or anything. It sounds good and the header won't crack like the stock exhaust header.

Robert

I have the RE 5.5 kit on my MJ which clears 33's in the front (same as XJ)with little trimming even when stuffed and allmost no trimming in the back (which is different from the XJ) My tired old renix MJ is down on power even with 4.56 gears and braking is only OK even with the larger D44 drums in the back so look into upgrades in both areas. I've driven a freinds 96 XJ with 33's and 4.56's on a little less lift, a Borla exhaust and a k&n fipkit and it has much better power so those upgrades definitly work.

Anyone else? Your thoughts are only going to improve my comprehension of what I buy,so spit 'em out.

Jason

sorry to hijack, but, can you swap in a dual diaphram booster from a later model cherokee for better performance insted of one from a grand so you dont have to swap the pedal thingys? i got a 94, so im assuming i should look for one outta a 96+?

With 33"s, you will need to change gears to at least 4.10's.

The 96/97 booster upgrade works great.

Don't use poly bushings....unless you like to feel all of the pebbles in the road.

Okay change 2. I have bought a 90 XJ. The previous owner had a 3" ProComp kit placed using Rancho RX9000 Adj shocks. I repaced the 9.50 ProComp AT's with 31x10.50 BFGAT's using the stock Limited wheels. I have been considering placing budget boost on top of the ProComp lift to gain additional clearance. I owned a 93 with 3" lift and 31x10.50's and experienced rubbing during higher levels of articulation. I would like to install Bushwacker flares for added fender well clearance as well as asthetic reasons. I plan on installing heavy duty bumpers in the front and rear and moving the spare tire from the cargo area to the rear bumper.
Regarding the lift, I am planning on either replaceing or extending the brake lines, and installing Rusty's T-case cross member with the 1" drop. I am concered about the shock travel. Any one have any knoweldge regarding the RX9000 shocks that fit a 90 XJ on 3" lift?

Thanks.

Jason

Jason,
quick question....did you notice any difference in ride between the Procomp tires and BFG's?

Yeah, The BFG's really grab the road. I can feel the bumps more, however that may be due to the wider contact patch. The ride is still a great comprimise between street and off road. I do weekend trips off road when I can and primarily drive on the urban assult course (otherwise known as the highways and surface streets of our beloved nation). I did notice some feedback (wobble) after about 1500 miles, but I have not located the source as of yet. The lugs had loosened so I had to retighten them, and i am thinkin gthat either the rancho steering stablizer has failed or the idler arm is finished. Don't know yet. I have to look into to it more. The only problem I have with the set up right now is the rubbing on the rear during extreme articulation.

I hope I have helped you some.

Jason