HellCreek

Awesome, Taz :thumbsup: Are you sure you're not from Mississippi? :rotf:

Thanks :thumbsup: That's all I need to know. :D

Can someone tell me what dual diaphram brake booster and master cylinder combination would be a direct, bolt-on replacement for the single diaphram booster/master cyl. in my 1989 Sport Truck with a 2.5L engine and standard 4 speed tranny? Thanks, Tom

Eagle, I plugged in some figures from springs with known rates to test this formula. I left off the bottom 2nd stage leaf, since it doesn't come into play until the spring is flexed enough to touch that leaf. Also, where the springs are made from different sizes of steel, I used an average thickness. This is what I came up with: 3 leaf MJ springs made from .291 steel -- rate = .97 (obviously, you have to take the result of the equation and multiply it by 100). The actual rate of these springs is 108, so it was close on these springs. 4 leaf MJ springs made from .291 and .262 steel -- rate = 1.23 x 100 or 123. The actual rate is 130, so it is still close on this spring. 3 leaf MT springs made from .291 and .323 steel -- rate = 104. The actual rate is 130, so this one is way off. 6 leaf full-size J-300 truck front spring made from .262 and .237 steel -- rate = 178. The actual rate is 216, so this one is also off. 7 leaf full-size J-300 truck rear spring made from .360 and .323 steel -- rate = 279. The actual rate is 400. The actual rates for these springs were furnished by the Spring Research Institute using a load tester, so they are accurate. I am not an engineer, but there would appear to be variables in the springs which are not accounted for in this formula. -Tom

I was not aware of that. So, following your reasoning, a 50 inch long, 4 leaf spring with all of the leaves made from .323 thick steel and having all of the leaves the same 50 inches long, would have exactly the same rate as a spring 50 inches long with 4 leaves made from .323 thick steel with the main leaf being 50 inches long, the #2 leaf being 42 inches long, the #3 leaf being 34 inches long and the #4 leaf being 26" long. Is this correct? I was thinking that a fully tapered beam would have a lot less capacity and rate than a beam that is full thickness from end to end, but I could be wrong. Also, what if you decreased the length of the #4 leaf to 12 inches and the #3 leaf to 24 inches; would that have any effect on the rate or capacity? Also, if a full thickness beam has the same rate as a tapered beam, what is the point in tapering the ends of the spring leaves in an effort to make the spring ride smoother? Seems like a waste of labor to me.

That's still only part of the story. It doesn't take into account that the thickness of the leaves varies from one spring/capacity to the next. The bottom line is that the factory service manual lists a ride height for the rear suspension, measured from the top of the axle tube to the frame rail next to the bump stop. They list ONE height (plus-or-minus 1/2") for the 4WD chassis, and ONE height (plus-or-minus 1/2") for the 2WD chassis. The 2WD height is 1" less than the 4WD height. BTW -- I don't believe I even mentioned free arch. I'm not interested in free arch and I don't pay attention to it. I want to know what height my truck is going to ride at, and how much weight I can put in before I sit on the bump stops. Free arch is important (I guess) to spring shops, but not to me. Hi, Eagle, As I stated earlier, the first five springs are identical except for the free arch, i.e., they are made from the same thickness steel with the same length leaves. Yes, I believe Don was the first to mention "free arch". As you pointed out, that formula only holds true for springs made from the same thickness of steel throughout. A 4 leaf spring made with, say, a .323 main leaf, a .291 #2 & 3 leaf, and a .262 #4 leaf will have a totally different rate than a spring with all four leaves made from .291 steel. Also, this formula does not take into account the variations in the lengths of the leaves below the main leaf. For example, a spring made with leaves 4 inches progressively shorter will have a vastly different rate than a spring made with leaves 8 inches progressively shorter, i.e., 4 inches shorter on each end of each leaf. This formula is only helpful in comparing apples to apples, so to speak. We have not found any formula adequate in determining an accurate spring rate, since there are too many variables which are not accounted for. If anyone has a formula for calculating an accurate spring rate, taking into account any and all variables, I would love to see it, but I'm afraid it would be about as long and complicated as this thread. -Tom

Hi, Don, That would be correct. :thumbsup: Where in Alabama are you? We will need to get together one of these days. :cheers: -Tom

That's not entirely accurate. Here is the run down: 980 lb. capacity = 7.62" free arch, OEM part #89-52-002-312, 3+1 configuration 1100 lb. capacity = 8.75" free arch, OEM part #89-52-001-240, 3+1 configuration 1160 lb. capacity = 9.25" free arch, OEM part #89-52-002-351, 3+1 configuration 1220 lb. capacity = 9.75" free arch, OEM part #89-52-001-824, 3=1 configuration 1280 lb. capacity = 10.25" free arch, OEM part #89-52-002-350, 3+1 configuration 1440 lb. capacity = 9.12" free arch, OEM part #89-52-001-825, 4+1 configuration 1700 lb. capacity = 9.50" free arch, OEM part #89-52-003-676, 3+2 configuration The first 5 springs are identical except for the free arch. The 1440 lb. spring has the 1st two leaves made from .291 thick steel, the next two leaves made from .262 steel, and the thick two-stage leaf from .625 steel. The MT spring has the 1st leaf made from .291 steel, the next two made from .323 steel, the long two-stage leaf made from .590 steel, and the bottom two-stage leaf from .625 steel. The same main leaf fits all seven springs. In the spring industry, the term "Free Arch" stands for the arch of the spring measured perpendicularly from the top of the main leaf at the center bolt location to a line drawn through the centers of the eyes, while the spring is in its free state (unloaded and off the vehicle). It's an industry term. :smart: -Tom

The 6.5" lift is an SOA kit. It includes: 6.5" front coils drop pitman arm sway bar disconnects Adjustable upper and lower control arms T-Case drop Brake line drop brackets adjustable track bar rear SOA spring plate rear u-bolts rear adjustable shackles Hydro shocks LCA drop brackets, SYE kit, replacement drive shaft, Nitro shocks and SS brake hoses are all options. I really shouldn't be selling in the Tech section, but this is just info, and you asked. Thanks, Tom

Hi, Our 6 inch lift is a Rough Country kit, which we have just started selling, so we have had no feedback on it yet. Your question should be," has anyone run a 6 inch Rough Country lift on their MJ?" We make 3", 4.5" and MT springs for MJs, but not 6". Thanks, Tom

Thanks to jeepcoma for posting those pictures. From those pics, I would guess that his original springs were either the 1160 lb. capacity or the 1220 lb. capacity. The 1160 lb. capacity spring has a free arch of 9-1/4" (original part number 89-52-002-351); the 1220 lb. capacity spring has a free arch of 9-3/4" (original part number 89-52-001-824). Both springs are identical except for the free arch. Our MT springs are made to stock specifications (original part number 89-52-003-676) and have a free arch of 9-1/2". As jeepcoma pointed out, it is the extra capacity (1700 lbs.) that raises the truck bed, not any extra arch. Where you see the biggest gain in height is when the MT springs replace the stock 980 lb. capacity springs, which have a free arch of 7-5/8" (original part number 89-52-002-312). BTW, the stock 4+1 springs have a capacity of 1440 lbs. and a free arch of 9-1/8" (original part number 89-52-001-825). These are the springs on which we based our 3" and 4.5" lift springs. We just added a little arch and a little extra length to compensate.

Hi, Dan, All Comanche leaf springs measure 26 inches in front of the center bolt and 31 inches to the rear of the center bolt. The free arch will vary from 7-5/8" to 10-1/4" depending on the load carrying capacity of your particular leaf packs. I hope this is what you needed. If you need any other information, I have the blueprints. Thanks, Tom

You should be able to get your windshield replaced professionally for around $150.00. It's not worth the hassle to try it yourself, especially if you have never done it before. -Tom

Hi, Congratulations and welcome to the Club. That is the exact model that I have. Mine came without power steering, but I quickly added it. If you convert to power steering, you will need a pump from a 2.5L. The 4.0Ls have a different length shaft and the pulley will not line up correctly with the other pulleys. I know because I tried. -Tom

HellCreek's real name is...............................Tom. .... no faults that I know of except that he's from Looseiana. :D That's MISSISSIPPI, Don :no: An Alabama boy should know better. :shake:

Hi, Rob, With a 6 inch kit, a control arm drop would probably be a good idea. They would certainly make handling mush better. I really don't have much experience with control arm drop kits, though. What do some of you other guys think? -Tom

Hi, The front and rear upper and lower adjustable control arms is a typo :oops: . I will have to get my webmaster to change that. It should read, "upper and lower front adjustable control arms." The 6" kit that we sell is a Rough Country kit. we did prototype a set of 6" rear Comanche springs to lead-not-follow, but it was his opinion that most people who wanted a 6" kits would rather go S.O.A., so we dropped that idea. We have always sold Rough Country parts with our leaf springs. That is no secret. They make good quality products, and we use them on our own vehicles. We do manufacture our own leaf springs, though. Rob L., you don't need drop pitman arms on Comanche trucks, so they are not included. Also, since this kit has adjustable control arms, there are no control drop brackets included, either. Thanks, Tom

Don (hornbrod) has used stock Metric Tonne springs and has gotten a net 2-1/2" of lift, if I read his post correctly. We offer stock Metric Tonne spring packs. We do not have lifted Metric Tonne springs in the 3+2 configuration. We do offer 1440 lb. capacity, 4+1 springs in either 3" or 4-1/2" lift. I am running a set of 4-1/2" springs on my truck. -Tom

Thanks, Pat. I get your point. We are probably the only lift kit manufacturer that makes their own springs, but we buy everything else. -Tom

I agree with you 100%. My post was not meant as a "comeback", just a statement of facts to help clear things up. I am on here to help, not to argue. Thanks, Tom

"that's because the manufacturers don't bother looking anything up. the fact that the spring packs are different is common knowledge on CC." JeepcoMJ, that's not entirely accurate, at least for all manufacturers. We have blueprints for all of the Comanche rear leaf springs. (more later) "ya, they just make a one size fits all to save money, and make it easier for them by stocking one kit for all apps." jpdocdave, that is absolutely correct, but saving money is not always a bad thing. There are seven (7) different rear leaf packs for Comanches, ranging from a 980 lb. capacity 3+1 spring to the 1700 lb. capacity 3+2 Metric Tonne spring. The first 5 springs have capacities of 980, 1100, 1160, 1220 and 1280 lbs. They all are made from the same size steel and have the same length leaves. The only differences in any of these springs is the free arch. They are 7-5/8", 8-3/4", 9-1/4", 9-3/4" and 10-1/4" respectively. Of the other two springs, one has 4 leaves plus the 2nd stage helper and has a free arch of 9-1/8"with a capacity of 1440 lbs., and the other, the Metric Tonne, has 3 leaves, plus a 2-leaf 2nd stage helper pack and has a free arch of 9-1/2" and a capacity of 1700 lbs. We chose to make our 3" and 4-1/2" lift springs based on the 980 lb. capacity stock springs, but we make them with 4+1 leaves to have the same capacity as the 1440 lb. capacity springs. As jpdocdave said, we are making one spring for all applications. This does save us money over stocking a 3" and a 4-1/2" spring in all of the above capacities. That would be 14 springs in all to stock, hoping that someone would order springs in each category - something that rarely, if ever, happens. This would increase our inventory costs tremendously - costs that we would have to pass on to our customers. As I said earlier, saving money is not always a bad thing, as it allows us to sell springs at a lower cost to you. We also sell the stock Metric Tonne springs without any additional lift. We are also making add-a-leaves specifically designed for the MJ Comanche (basically a Comanche main leaf with the eyes cut off), and we are going to start making the extra Metric Tonne 2nd stage leaf to adapt regular stock springs to Metric Tonne capacity. If any of you would like to see us make something different, just let me know. -Tom

Are you positive that you have the correct belt? I have a 2.5, and the only adjustment that I have ever needed was at the PS pump. With the PS pump adjusted all of the way toward the engine block, the belt should be slack enough to go on without prying. Napa says the correct belt with A/C is NBH 25060820, and without A/C is NBH 25060730. -Tom

www.hellcreeksuspensions.com/springs/Springs.aspx. Just select JEEP using the forward or previous buttons, then scroll down the drop-down list until you see MJ Comanche Metric Tonne, select that, then the year. The part number button will then appear. Click that and you will be taken to the shipping calculator page. OR you can call me at (662) 534-2216. -Tom

I've got one, and it works great for what it is intended. I used mine to secure the transmission inspection cover on the floor of my son's CJ-7 after the sheet metal screw holes had stripped out. -Tom

We have those for sale. :thumbsup: We are also introducing add-a-leaves specifically made for Comanches. They are basically main leaves without the eyes. We are also introducing the longer second stage leaves from the Metric Tonne springs to add to your existing spring pack above the standard second stage leaf. These would practically convert your existing springs into a Metric Tonne set. -Tom