Should I buy a Comanche? New buyer needing advise.

[JeepJoe]

Hi guys, just looking for some advice if I should get into this Comanche project.

 

Here's the story I live in Tennessee and am 3 weeks from moving to Colorado springs CO. I was planning on buying an early 90's Cherokee to build a trail rig to explore Colorado in, with my family. But this week a coworker said he recently received orders (we're both army) to move overseas and is selling his 1990 Comanche project (4.0, AX15, LWB, 4x4, pioneer edition). He bought it running but was having problems shifting so started taking the trans out to change the clutch. It's almost out just one of the top transmission bolts got stripped. I'm trying to decide if I want to buy another man's torn apart project for $1000 and trailer it to Colorado in a few weeks, or just wait until I get there.

 

Pros for this truck

1) 90% rust free, just a few small rust holes

2) Cheap, I could probably get for less than $1000

3) motor currently runs

 

Cons

1) I would have to trailer it to Colorado

2) I don't know if it is a bad clutch or possibly bad transmission?

3) it's 1/2 taken apart by someone else, always a big unknown, he is a mechanic though

4) it needs a complete rebuild, but that could be a lot of fun

5) can't fit my family in it for road trips

 

Any way I would love some advice from people who own Comanches, is it worth it? How difficult is it to get a new transmission or rebuilt if it is bad? Do projects like this take so much time my wife will want to divorce me? 

 

Any thoughts?

[NHMJXJ]

The answer is always, "Yes, you should buy a Comanche".  The next question is, should you buy that one?

 

90% "rust free" is an oxymoron.  "Rust holes" are called rot and trust me, it's worse than it looks. 

 

I would wait and pick something up in CO, unless you feel compelled to help a brother out.

 

I'm always looking and it seems to me there are a fair number of MJ and XJ projects to pick from in the northwest.

 

Take your time and one will come along.  You might spend more, but you'll get more with fewer headaches.  

 

Just my two bits.

[JeepJoe]

Here are pictures of the Comanche, I think I figured out how to attach them.

 

Anyone know of Comanche projects in Colorado springs area?

[Eagle]

For me, the answer lies in this statement from your opening post:

 

Quote

I was planning on buying an early 90's Cherokee to build a trail rig to explore Colorado in, with my family.

 

As you know, the Comanche is a standard cab. With the bench seat, it holds 2-1/2 people -- but if it's a standard transmission, you won't be putting anybody in the center seating position on the bench seat. That eliminates "family" unless you don't have kids, or dogs.

 

I love both Cherokees and Comanches, and I own multiples of both. For family use, I would definitely go for a Cherokee.

 

Second consideration: His is a long wheelbase. Those make lousy trail rigs. Poor breakover angle, worse departure angle.

[neohic]

I’d wait until you get out here. I brought a whole fleet of vehicles out here when I moved to CO three years ago. Two of which are still sitting in storage, one got stripped and scrapped, another got sold.

 

There’s plenty of great Jeeps out here! I’d wait for a nice XJ if you’ve got family to tote around. 

[JeepJoe]

1 hour ago, Eagle said:

 

I love both Cherokees and Comanches, and I own multiples of both. For family use, I would definitely go for a Cherokee.

 

Second consideration: His is a long wheelbase. Those make lousy trail rigs. Poor breakover angle, worse departure angle

 

I definitely want a trail rig I can put my wife and grimlins in, I was thinking I could make this Comanche my daily driver once it's fixed up and sell my 06 Dakota then use that money to build a Cherokee. 

 

I think this Comanche would only be worth it if I can get it for less than $700, that price would compensate for dragging it to Colorado. But yes there is always another Jeep out there.

[MJXJjeepguy]

It might be good idea to take the MJ since it harder to find MJ than XJ, and use MJ as DD, use XJ as trail rig.

[Minuit]

A nice Comanche is worth taking cross-country with you. That one leans heavily towards "not a nice Comanche" on my patented "Not a Nice Comanche to Nice Comanche" sliding scale.

 

For any rust visible from outside, here's my rule of thumb: imagine it being twice as bad on the other side, and then multiply that image by 10 - that's probably what it's really like. If you buy that, I see lots of rust repair in your future.

 

Putting someone else's project back together is always annoying ESPECIALLY if it's your introduction to the platform - One of my trucks was unmolested, the other one was multiple people's project before it fell into my hands. I had to spend a significant amount of time undoing someone else's shoddy work before I could get started fixing underlying problems, and I'll never really be free of "previous owner $#!&" on it. If your previous owner was a talented mechanic that took pride in his work, it'll be easier, but you'll still have to get inside his head a little bit to figure out what's going on.

 

Just some thoughts. From what I see, I wouldn't move that truck across the county. At this point, I'm not sure I'd bring my '89 with me across country yet. I'd bring my '91 to the moon if I had to. Start with a nice shell, unless you plan to bounce it off rocks or drive it through mud holes - in that case, don't ruin a nice example.

[Smokeyyank]

Decent comanches out here are upwards of 3k+ probably closer to 4. There's is a guy on FB marketplace with a 91 eliminator 2wd hes asking 5 for it. Its clean and from texas. Just to give you a general idea. I look daily just because and whenever there's a decent, not great just decent deal it's gone in a day. As for exploring get an XJ or WJ depending on the size of your family. I've owned all of them. XJ was my favorite to wheel MJ is my favorite to drive. WJ is the best of both. Comfy and drives great and does decent offroad. Its built for more road duty and not as flexy as I'd like but hasn't had issues with what I do. Its also my daily because can't fit a car seat in the MJ. Otherwise I always drive the MJ. 

[JeepJoe]

Anyone have experience with a good transmission shop in Colorado springs area that can rebuild a AX15? I made the mistake of putting modern trans fluid in my 94 XJ AX15, and destroyed the syncro gears. I'm suspecting that could be the problems with this Comanche transmission. Although the owner says it was the slave cylinder and bad lines. 

 

Anyone know how to test the transmission when it's pulled?

[JustEmptyEveryPocket]

6 hours ago, JeepJoe said:

Anyone know how to test the transmission when it's pulled?

Besides pop it open and look? Nothing I know of. If you crack it open, get a dial indicator with a magnetic base and check runout and play on all bearings. Look for metal shavings and chipped teeth, etc. 

 

From what I have read, its not terrible to rebuild an AX-15 if you can get a shop to press on gears and bearings. Any chance you want to learn to do it yourself?

[JeepJoe]

8 minutes ago, JustEmptyEveryPocket said:

From what I have read, its not terrible to rebuild an AX-15 if you can get a shop to press on gears and bearings. Any chance you want to learn to do it yourself?

 

I'm always willing to get in over my head (that's how I got my first kid!). I'm not a pro mechanic but I can do quite a bit. I've just never messed with transmissions, except to replace a clutch plate. 

 

Is there a good rebuild thread I could read, that would give me an idea if I could do the work. Any specialty tools required?

[gogmorgo]

What "modern trans fluid" did you use?

Most of the modern manual trans oils (Royal purple Synchromax, Redline MTL-90, etc) are pretty good and make for some pretty decent shifting. Might be worth it just to drain and refill with known good oil to see if it makes a difference. 

[JustEmptyEveryPocket]

I don't have any particular threads to check out. Like I said "what I have heard". I have no first hand experience with it. Then again, I also tend to jump without looking. Thats how I got my first Comanche 

If the transmission isn't working as is, what have you got to lose by taking a look, eh?

[89 MJ]

Do you want the truck to be done or do you want it to be a daily driver right now?

[JeepJoe]

14 hours ago, gogmorgo said:

What "modern trans fluid" did you use?

Most of the modern manual trans oils (Royal purple Synchromax, Redline MTL-90, etc) are pretty good and make for some pretty decent shifting. Might be worth it just to drain and refill with known good oil to see if it makes a difference. 

 

I believe I used Lucas 75/90 synthetic gear oil. Within a week it was getting harder and harder to shift, soon I had to use two hands to pull it into gear. Did some reading and apparently new gear oils have to much sulfur and it eats up the syncro gears in older ax15s. Sold that 94 XJ for a loss. Just worried that someone put new gear oil in this truck.

 

Anyone smarter than me know for sure about gear oils for the AX15? And what happened

[JeepJoe]

5 hours ago, 89 MJ said:

Do you want the truck to be done or do you want it to be a daily driver right now?

 

My plan would be to fix it up to become my daily driver. I currently drive a 06 Dakota and it just doesn't feel right, I've always been a rusty old truck guy. Anyway I'll drive the Dakota until I'm confident in the MJ then sell the Dakota. Plans always work out perfectly right???

 

[87MJTIM]

20 hours ago, JeepJoe said:

 

Is there a good rebuild thread I could read, that would give me an idea if I could do the work. Any specialty tools required?

 

There are some good youtube videos on the AX15.  A series of videos are on RobinsonAuto channel.  Lot of detail and the camera focuses on the work, but he makes it as interesting as paint drying.

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[gogmorgo]

53 minutes ago, JeepJoe said:

 

I believe I used Lucas 75/90 synthetic gear oil. Within a week it was getting harder and harder to shift, soon I had to use two hands to pull it into gear. Did some reading and apparently new gear oils have to much sulfur and it eats up the syncro gears in older ax15s. Sold that 94 XJ for a loss. Just worried that someone put new gear oil in this truck.

 

Anyone smarter than me know for sure about gear oils for the AX15? And what happened

The sulfur content is a much more long term corrosion issue than that. The factory recommended gl5 gear oil won't immediately trash your synchros like that. Many people have gotten away with running it for the long term. Jeep's solution was just to recommend running synthetic 10w30 engine oil in the ax15, which works fine (I have it in my ZJ) but if there's a small amount of damage done already a modern oil intended for manual transmissions will probably do a better job. What you're looking for is that it's safe for yellow metals and that it has a weight somewhere around 75w90. You may have to do some digging to uncover this info, but it's pretty much a guarantee with any name-brand manual trans oil.

As far as running engine oil in it, many people will have concerns that it's too thin, but that's not the case. The weights were deliberately standardized on different scales to help avoid confusion between gear oils and engine oils. 75w90 and 10w30 are close enough in viscosity not to worry about. Synthetic is important due to lubricity – my understanding is manual trans oils rely on the deposition of additives onto the synchros for smooth operation, but engine oils don't have those so you're relying on the the oil itself, and coventional oils don't have less molecular consistency which leads to higher friction.

I'd go for a decent manual trans oil before running engine oil myself, but when I filled my trans after I picked up the ZJ my local parts store didn't have any available. The engine oil was better than the gear oil that I drained out (you can tell by smell) but not perfectly buttery smooth like I'd like it to be. I've never used Redline MTL-90 but it's got excellent reviews on here. I've used Royal Puprle Synchromax in other brass-synchro transmissions and it did quite well, it's what I'd use next time if I planned my change in advance because I can pick it up the next town over, although I'm trying to track down the MTL-90 to use. Most oil manufacturers have their own manual trans oil, they're probably all pretty good. 

[JeepJoe]

Well guys I'm balls deep in it now, bought it for $700 and drug it home on a uhaul trailer. Only thing that works right now is the breaks. More to follow

[eaglescout526]

Be sure to put it in the registry and you'll get a build date and sheet!

[Eagle]

On 9/10/2019 at 2:02 PM, gogmorgo said:

The sulfur content is a much more long term corrosion issue than that. The factory recommended gl5 gear oil won't immediately trash your synchros like that. Many people have gotten away with running it for the long term.

 

Actually, few if any people have gotten away with running GL5 for long periods. It does eat the synchros. Probably not overnight, but rather quickly. The factory recommended gear lube was GL3, not GL5. When the specs were changed and GL3 became GL4 and then GL5, with corresponding increases in sulpher content, the factory quickly realized what the issue was and changed the recommended gear lube to 10W30 motor oil.

 

Is anyone running Pennzoil Synchromesh gear lube in an AX-15 (or AX-5, or BA 10/5)?

[Ls2xjcomanche]

If it turns out that the AX15’s only issue is the slave cylinder I would get a different bell housing and switch to an external slave cylinder. That way you won’t have to drop the transmission when the clutch goes out. Way easier for changing out the clutch! 👍🏼