Eagle

Custom 4x4 used to sell a kit with the side braces. No longer available?

Is there supposed to be a question or a link in this post?

One of the most frequently asked questions in the Jeep world is "What gears should I run with [___] tires?" There are a lot of quick calculators for this on the Internet, but they often aren't very accurate. The reason is that they are based on total (or nominal) tire diameter, and that ignores how tires work. First, the actual size often isn't the nominal size. This is more true for the off-road tire sizes in the format such as 31x10.50-15. That tire is nominally 31 inches in diameter but, if you start researching tires in that size, most actually are closer to 30.5 inches in unloaded diameter. When you put tires on a vehicle and then let the vehicle down to put weight on the tires, the sidewalls squash down and out. The further lowers the centerline of the axle relative to the road surface. There was a time when most tire specs included a number for the actual rolling radius, but those days seem to be long gone. Back then, most manufacturers also gacve us a number for revolutions per mile, which is the most useful of all numbers for calculating engine RPM vs. road speed. When I look at tires today, it seems the manufacturers are competing to see who can provide the least useful information to prospective buyers. Many years ago, when such information was still available, I created a spreadsheet using as much actual manufacturers' data as possible to get a better, more accurate look at the relationship between tire size and engine RPM at various road speeds. I have uploaded that spreadsheet to Google Sheets to make it available to members of the Comanche Club. Here's the link: https://docs.google.com/spreadsheets/d/1pHFuhGgj6dQDfzyfFJH5z7NCDLW2KX3ABQgAJr3lBvM/edit?usp=sharing Note: I'm not sure if this file allows anyone viewing it to make edits. If it does, please DO NOT make any changes. If you want to muck around in it, make a copy and then experiment with your copy. Don't screw it up for everyone else.

My tire/gear ratio spreadsheet is still up on Google Docs, so let's see if this link works: https://docs.google.com/spreadsheets/d/1pHFuhGgj6dQDfzyfFJH5z7NCDLW2KX3ABQgAJr3lBvM/edit?usp=sharing

Good choice.

Video won't play for me. What's your oil pressure? What oil do you use, and what brand of oil filter?

You can find Monroe Load Levelers that fit the Comanche, but they won't be listed for it. The reason is that (obviously) they change the spring rate, and that changes the way the height-sensing brake proportioning valve works. Monroe doesn't want to make themselves liable if the end user doesn't take that into account.

IMHO you'd be better off sending your bank account to the secretary of that Nigerian banker, the woman who needs a reliable partner to help her transfer $50 million out of the country, and she'll give you half for pretending to be his long-lost heir.

If you want an additive that works, look at Mr. Moly. Molybdenum sulfide gear oil supplements have been around for a very long time and they have a proven track record. Do NOT run Mr. Moly in a manual transmission with brass synchronizers. Mr. Moly also has a product formulated for automatic transmissions. I have not tested it. Or just buy Redline gear oil and move on to the next decision.

Welcome to the borg. You have been assimilated.

I highly doubt it.

You also can't tow a vehicle with any wheels on the road if it isn't currently registered and insured.

My spreadsheet with all this data seems to have disappeared from Google Docs. I guess I've been canceled. I'll look into getting it posted again but, for the moment, here's a screen shot for 31" tires: 75 MPH in overdrive is 2645 RPM. That won't destroy anything. In the "good old days," before overdrive transmissions became commonplace, standard gearing for cars with the AMC 6 (basically the same engine as the 4.0L, but without fuel injection) was set up for 25 MPH per 1,000 RPM. So, 2500 RPM was 60 MPH, and 3,000 RPM was 72 MPH. And back then the engines would still go 300,000 miles if you did routine maintenance.

Part numbers: Dana 35 10" backing plate -- 8350 0988-9 Dana 44 10" backing plate -- 8350 2386-7

I don't think that's needed.

I don't think so.

From personal experience, 31" tires with 3.73 gears is EXACTLY the same overall drive ratio as stock tires with 3.55 gearing. Personally, for the way you use the vehicle I probably wouldn't regear but, if you're going to do it, go to 4.10s. A Trac-Lok (the factory limited slip) is probably the cheapest limited slip you'll find. They're decent and more than adequate for the use you describe. Next step up is a TruTrac, which is a gear-driven limited slip. It doesn't require friction modifier, because it doesn't use clutches. Engagement is a bit more positive than a Trac-Lok. When buying parts -- buy two sets of carrier bearings. Take one set and hone out the ID enough that you can slide them onto and off the carrier by hand. Use those bearings for trial fitting the shims. Once you have the shim packs set correctly, then set aside the setup bearings and press on the other new set.

It's probably in that Blazer.

There are two types of flares -- the SAE double flare shown in the post above, and the "bubble" flare. MJs use the SAE double flare. The brake line layout on your truck isn't any different or more complicated than what's found on 90% of vehicles built since about 1960 (or whenever the industry changed to separate circuits for the front and rear wheels). Your brake system is not stock. The OEM Comanche system, with the rear height-sensing proportioning valve, trips up a lot of people who are new to MJs.

The story of your previous job isn't surprising. I don't know what the big universities are teaching in their business schools and management programs, but it seems like they've all decided for the rest of us that a high five and an "Attaboy!" is supposed to be better than a cost of living increase. Screw that mentality. Good for you for bailing out.

Here's a better photo -- I added labels.

No. Check again, when you get the truck back. You should have one hard line that runs to a termination above the rear axle. From there, there should be a single rubber hose that connects to a tee fitting mounted to the axle tube. From that tee fitting there's a hard line to each rear brake cylinder. You should not have separate lines from the proportioning valve to each rear wheel. Which is what you wrote. The proportioning valve should have two lines going into it (the two on top, from the master cylinder), and three coming out of it. Here's what it looks like inside: And remember, you have a TJ (or maybe an XJ or ZJ) proportioning valve. That's very different from the stock MJ front distribution block, which looks similar on the outside but which does NOT have any proportioning function.

They're pretty good, actually. I have two of them, for my older generators. They don't work on grass or gravel, though

There is no way to be sure without measuring. The 2-1/2" drums were an option on the Renix-era Dana 35 axle, so you need to verify.

Wait -- individual lines to each REAR wheel? That's definitely NOT right.