1990 Comanche Build - The Wilderbeest

agamble

Member
Specifications
1990 Jeep Comanche Pioneer, LWB, 4WD
4.0L I6, AX-15 manual transmission
206,000 miles

I originally had the truck about 10 years back. At the time it had a 4" lift, 29x9.5x15 tires and the stock 3.07 gear ratio. Interior entailed a very posh, bench seat with head rests. Needing a vehicle a family member gave me the truck and being new to jeeps I never thought much of it. At the time it had a 4" lift, 29x9.5x15 tires and the stock 3.07 gear ratio. I drove it around for a couple years and that was that. As I started reading and learning more about jeeps and offroading I thought that an XJ Cherokee would be a better vehicle to build. Most of the information I could find online was about XJs, as well as most of the aftermarket support being geared towards the XJ. Going with what was thought to be a better move I bought a 98 Cherokee Sport. The Comanche was given back and away I went building, modifying, and learning as I went.

10 years later with a second jeep replacing the Cherokee, the Comanche came back into my possession when the family member decided to upgrade to a newer, nicer rig. They asked if I wanted the truck back, and you can bet that I wasn't going to pass it up. When they handed it over they listed a few changes they had since done: an engine rebuild, the addition of the WilderNest, some airbags and power windows......only functioned on the corresponding control, the drivers side and passenger side if you reach across the cab, and stated that it was a no maintenance truck. So with that I have already got my plans, for the direction that I want to go with this jeep. I have already built, wheeled and sold the XJ. Then moved on to a SWB Comanche that I have been building the last 4-5 years. That one I kept rather stock, all mods can easily be undone. This time I find I want to go between the last two and have a moderately built overland rig. To speed up the process, the plan is to take all the aftermarket parts from the SWB and move them over to the Wilderbeest. As much as I would love to keep both, I don't have space and I know I won't drive both. So I am going to consolidate down to one. I am going to take the best parts from the two and make good one. But enough with the chit chat, on to the pics.













 
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agamble

Member
A common rust issue with Comanches is the floorboards. I was told some metal had been placed on the floor board to cover a small hole. I pulled the interior carpet and sound insulation to assess and to see the small hole for myself and indeed found a wee hole. The metal patch was half a stop sign molded to fit and sitting over the hole.





Passenger side was a little better.




The first thing that needed to be addressed was the lack of floorboards. Started the process by removing all of the rust affected metal. A wire wheel was used to remove all the flaking rust to see the integrity. Passenger side was pretty easy to prep, a 18"x8" area was all that needed to be removed. Driver's side (neglected to take a photo) required most of the floorpan and portions of the transmission tunnel be removed. With the rusty floors removed, new ones were ordered. The closest floorpan I could find was for an XJ. I read mixed reviews on the fit of the pans during installation into both the XJ and MJ. But for having all the bends made and being made of 19 gauge steel, I figured I didn't really have to much to lose.

 

agamble

Member
While I was waiting for the floor pans to arrive I took the opportunity to start swapping over parts and making repairs. I started with the engine bay. The first thing that I swapped over was the set of brown dog motor mounts with the flex rubber bushings to replace the stock motor mounts. I went with the flex rubber bushings to help reduce cab vibes. Initially they don't do a lot in dissipating the vibrations, but once the rubber has a chance to break in that actually do dampen vibrations from the engine. I've run these on 2 different rigs now and thing, I ran these mounts in the XJ I had previously and never had a problem.



With the motor mounts in I then moved onto doing a tune up. Tune up wise I pulled and checked all the spark plugs (which included recapping them to .035 mm). put in new spark plug wires, new ignition coil, cap and rotor, and installed some Bosch 4 hole injectors to give some better fuel atomization. I found a good price on a set of six refurbished on eBay.



The throttle body and the IAC were inspected and cleaned. This one was long over due as the photos can attest to. It took awhile but with some throttle body cleaner, elbow grease and time all the carbon build up was successfully removed.

Before




After




A common problem on Renix era jeeps is that of blow-by created by the towers located under the aluminum valve cover being to low. One of two approaches can be used to correct the issue; 1 - shorten the towers or 2- replace the aluminum cover with a steel valve cover with baffles from a later Cherokee.



The air filter showed signs of oil getting on it from some blow-by, so to eliminate this issue I installed an extra steel valve cover with baffles from a 98' XJ I had laying around.



Not wanting to have oil rain down all over the garage floor during oil changes, to allow for an easier time locating and a more ample selection of oil filters an oil filter adapter with SAE threads from a 95' Cherokee was placed on the engine block.

 
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agamble

Member
While in the engine bay I started doing a list of electrical maintenance items identified for the Renix era jeep Mj and XJ, Cruiser's Mostly Renix Tips. The various grounds were refreshed by unbolting, removing years of backed on dust and grease, buffing connections to a new luster with fine grit sand, and a healthy dose of anti-corrosion gel was applied be reattaching them.



Battery cables were then upgraded. I did some research on battery cable replacements and came to the conclusion that the stock 6-gauge battery cable wasn't going to cut it. I float around several other jeep forums and have seen several people going with 2-gauge cables and others with 4-gauge cables. The general consensus is 2-gauge is best suited for heavy demand situations, while 4-gauge was a good upgrade for stock applications. At the moment everything is stock with no after-market accessories, so 4-gauge is sufficient. The setup I ran is as follows:

Positive battery terminal = (B+); Negative battery terminal = (B-)

Battery clamps are brass wing nut terminals.

Battery Cable Cable Length Cable Termination
(B+) to starter motor 40" 3/8" on both ends
(B+) to starter motor relay/distribution 12" 3/8" on both ends
(B-) to engine block 40" 3/8" on both ends
(B-) to inner fender 12" 3/8" on one end, 1/4" on other
Engine block to firewall 12" 1/2" on one end, 3/8" on other



And the final item on fixing and/or upgrading electrical related items was to install a headlight harness, headlight housings, and the bulbs.
 
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agamble

Member
By this point the replacement floor pans that were ordered had arrived. Although it took a little massaging to get them into place they were installed. I worked my way around tacking the floor pans into place about every 1/4". Once a small section was tacked into place, using a ball peen hammer I would massage the next portion of floor pan to match the contours of the existing floor then tack a little more. This manner was followed until the floors were replaced. The passenger side was done first as it was less material.



Some rust was reassessed on the passenger side transmission tunnel. For the most part it was more superficial than anything. There were two spots that I was able to punch through using a screw driver while tapping around. I cut out the pitted metal and then used some of the extra material from passenger floor pan to cut out the two patches.





The drivers side floor pan definitely was not a close fit. Took quite a bit more than massaging to get it into place, I'd venture as far as saying it was more of a forceful coaxing to get into place. As with anything though patience pays dividends.



 

agamble

Member
With the floor pans welded into the truck it was time to prevent remaining rust from spreading and keep the new pans from succumbing to the same fate as the previous floor pans. I spent more time that I should have reading and debating on which rust inhibitor to go with. I really could not decide whether to go with POR15 or Chassis Saver. Both products have great reviews, so it seemed that I couldn't really go wrong. I finally decided to go with the Chassis Saver as there was less upfront prep work involved. I read through several forums and watched multiple online videos to get any tips for making the process go smoother. The main take aways were remove the loose flaking rust, it does not adhere to bare metal, and don't to let the stuff get on your hands. The directions on the can also recommends scooping only the needed amount into a secondary container and thinning the stuff out with their S8 reducer. A quick check of the SDS sheet shows the S8 is an aromatic hydro carbon, the exact same stuff as xylol.



Prep work was straight forward, yet time consuming. As everyone always states, it's all in the prep work. I started with a wire brush to remove any remaining loose/flaky rust. The sections of floor without any rust I scuffed with 60 grit sand paper to remove any sheen on the factory paint for the Chassis Saver to have something to bite onto. Once all the sanding and grinding was completed I vacuumed out all the dust, and wiped everything down with warm soapy water.

An idea of how it looked before.


And after


To cover up the bare metal of the recently installed floor pans, they were scuffed with 60 grit sand paper, cleaned with denatured alcohol, and covered in two coats of automotive primer.







Chassis Saver can be applied by spraying or with brush. I went with the brush method.



Chassis Saver was applied to the areas where the rust came through as well as areas where there is a potential for water to pool.





 

Heavyopp

Observer
agreed -- great truck

The breathers on the valve cover are backwards -- short one goes up front, tall one to the rear near the firewall -- I'm surprised the tall breather up front doesn't hit the hood when closing, leaving a small dent -- at least it did on my cherokee with new motor mounts

also .035 spark plug gap isn't Millimeters -- it's .035 of an inch -- just picking on you now...

I've used POR15 and chassis saver -- I like the chassis saver better and it's cheaper -- I don't have any long term projects with the chassis saver yet -- still up in the air as to how it holds up over time

What did you end up doing for the underside of those floor panels? Might be worthwhile for you to start using weld thru primer as well -- clean your metal before welding, then prime it with weld thru, then weld -- should give some protection to the steel that got covered up by the new pieces -- once again not sure of long term results but it's gotta be better than raw steel sandwiched in between
 

agamble

Member
Awesome truck and great work so far! Can't wait to see it progress.
Thanks, appreciate the encouragement.

agreed -- great truck

The breathers on the valve cover are backwards -- short one goes up front, tall one to the rear near the firewall -- I'm surprised the tall breather up front doesn't hit the hood when closing, leaving a small dent -- at least it did on my cherokee with new motor mounts

also .035 spark plug gap isn't Millimeters -- it's .035 of an inch -- just picking on you now...

I've used POR15 and chassis saver -- I like the chassis saver better and it's cheaper -- I don't have any long term projects with the chassis saver yet -- still up in the air as to how it holds up over time

What did you end up doing for the underside of those floor panels? Might be worthwhile for you to start using weld thru primer as well -- clean your metal before welding, then prime it with weld thru, then weld -- should give some protection to the steel that got covered up by the new pieces -- once again not sure of long term results but it's gotta be better than raw steel sandwiched in between
The breathers on the valve cover have since been switch since taking the picture. Oddly enough the tall breather didn't hit the underside of the hood when it was closed.

Someone has to keep people honest. I could edit the post to say of an inch but, then it would look weird when reading it later. I'll just have to leave my mistake for all to see.

I didn't do any welding on the underside of the floor pans. I installed the floor pans like they were from the factory, I drilled multiple plug welds to weld it directly to the U-channel of the unibody. I tried to not have too much over lapping steel, most of the floor pans were situated to mate up. The biggest issue I had was when I tried to stitch weld it all together I would repeatedly burn through. I ended up applying multiple tacks around the circumference of the patch like I saw on a couple youtube videos. Once it was all tacked in a bead of seam sealer was applied over the the weld joints both inside and outside. On the outside the seam sealer is going to be covered with Chassis Saver.









 

Heavyopp

Observer
What did you use as seam sealer?

I use sikaflex from the big box stores -- seems to work really well -- dries hard but remains flexible -- looks exactly like what you used

I debated weather or not to post that MM and inch thing -- probably erased it 3 times before hitting the submit button...
 

agamble

Member
The Comanche was also suffering from another common issue with both the MJ and XJ. The driver's side door had broken free from the factory welds. To get the door to unlatch you had slightly lift the door up to get the door up over the striker.





While surfing the web I came across these products from hooliganoffroad: https://www.hooliganoffroad.com/collections/xj/products/xj-door-hinge-support
I placed an order for them about the same time I ordered new floor pans. I figured I could do all the necessary welding at once. The shipping box came complete with instructions and couple decal stickers that come with a guarantee to increase horsepower output and offroad prowess when adhered to your jeep.



The instructions are brief, literally 4 steps, but clearly lay out installation.

After getting to bare metal the bracket, a 4lb. hammer was used to close the gap between the body and the door hinge. With it as closed as it was going to get, the bracket was clamped into place to get a snug fit. A mini C-clamp placed into the opening that is visible in the picture below to secure the bracket to the body.

 

agamble

Member
What did you use as seam sealer?

I use sikaflex from the big box stores -- seems to work really well -- dries hard but remains flexible -- looks exactly like what you used

I debated weather or not to post that MM and inch thing -- probably erased it 3 times before hitting the submit button...
It is indeed sikaflex. First time using it but I've only heard great thing about it. And thus far that has proven to be the case.
 

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Heavyopp

Observer
It is indeed sikaflex. First time using it but I've only heard great thing about it. And thus far that has proven to be the case.
Be sure to let the sika cure for a week before putting another coat of chassis saver over it — you will need to scuff sand the previous coat of chassis saver though — it’s really not as bad to do as it seems — use those 3m scotch brite pads in the paint section of Home Depot and just take off the shine
 

agamble

Member
Finished with the door support brackets from Hooligan Offroad. Applied two coats of Rust-O-leum paint and primer to cover up the bare/exposed metal and then as overkill put some seam sealer on the outer edges to keep any water from getting in between the bracket and the body.





Between applying coats of paint I installed a new red top steering box and Borgeson intermediate steering shaft. To make access easier I removed the brake booster and brake lines.







While attempting to remove the power steering lines I broke the plastic nipple for the return line off of the reservoir. So until a replacement reservoir is arrives, the steering refurb is on pause.

 
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