JeepcoMJ Posted December 2, 2008 Share Posted December 2, 2008 So along with my other extreme list of mods to the truck, I just bought a xj 44 rear with 4.88's, welded, disc conversion, and matching 4.88 gears for the front with setup/install kit. this is all new with zero miles anyways, The truck is an 87 swb with dana 44 rear and 4.10 gears, and 33" tires...but they're bald and need replacing by spring. I'm running 6.5" of lift on shortarms, and am not into trimming excessively. power is no problem...It's mid-HO conversion with a punched 4.0 with borla, 62mm TB, 2k intake, etc. what size tires do I need in order to run decent RPM at 65 mph? I don't mind if it's 2700 or 2800 rpm, but as it is with 33's and 4.88's I think I'd be somewhere around 4000...and that's no good. the truck won't be driven on the interstate regularly, but if I don't have a tow rig/trailer, I still need to get the 4 hours to McCaslin, Rib Lake, or Attica. similarly, what size tires do you think I can fit in there? I'm thinking I should longarm it and lift it another couple of inches... as I say, I don't want to trim up the body...at least not the bed. front fenders I could care less about. the inner fenders will be trimmed for clearance too. also, I'm keeping the dana 30 front, unless I can sell the gears and get a waggy 44 front or something along those lines, shorten it, and regear it. does anyone have full info on what needs to be done regarding shortening the axle? I don't need specs or anything on mounting it...that's easy. but, turning and shortening then getting the right shafts made, and if the hubs can be altered to be a 5 on 4.5 bolt pattern. Thanks, Pat Link to comment Share on other sites More sharing options...
BREEZE1 Posted December 2, 2008 Share Posted December 2, 2008 37's :banana: Link to comment Share on other sites More sharing options...
redneck23ms Posted December 2, 2008 Share Posted December 2, 2008 why would you want to narrow a waggy 44? to narrow one is pretty simmple. cut thru the weld on the inner C. then with a bfh knock the C off and cut to to desired length. then drive C back on. set castor to desired angle and weld C back on. then order a custom length shaft of send the stock one off to get re-splined. however 4.88's should be perfect for 35's. i don't suggest running a tire any bigger than that on a dana 30 Link to comment Share on other sites More sharing options...
mjeff87 Posted December 2, 2008 Share Posted December 2, 2008 my experience.... 33's + 2.5/AX5 + 4.56's= crap on highway 33's + 4.0/AX15 + 4.56's= ok on highway, about 2500 @ 65 mph 35's + 4.0/AX15 + 4.56= just about perfect, @2100 @ 65 mph (my junk is not safe to take much past 65 ;) ) I've got a buddy with the same setup (4.0/AX15) in an XJ down here but he's on 4.88's and he's fine with it. Jeff Link to comment Share on other sites More sharing options...
Rockyrider367 Posted December 3, 2008 Share Posted December 3, 2008 anyone know about how wide the waggy 44 front is compared to the stock 30? Link to comment Share on other sites More sharing options...
redneck23ms Posted December 3, 2008 Share Posted December 3, 2008 waggy 44 = 62.5" wide stock dana 30=60" wide Link to comment Share on other sites More sharing options...
Darren Posted December 3, 2008 Share Posted December 3, 2008 You don't need to shorten the waggy 44. You won't be able to convert the waggy to 5 on 4.5 but you can convert it to 5 on 5.5. then you can easily convert the xj 44 to 5 on 5.5 with a set of alloys with a dual bolt pattern. (they arent very expensive.) Link to comment Share on other sites More sharing options...
JeepcoMJ Posted December 3, 2008 Author Share Posted December 3, 2008 You don't need to shorten the waggy 44. You won't be able to convert the waggy to 5 on 4.5 but you can convert it to 5 on 5.5. then you can easily convert the xj 44 to 5 on 5.5 with a set of alloys with a dual bolt pattern. (they arent very expensive.) is the waggy 44 a 5 on 5 bolt pattern? I have a set of 17" rubicon's that are that pattern...so, I could re-drill it to that, and just do some spacers in the rear. if it's wider, I'd want to space the rear out to match... Link to comment Share on other sites More sharing options...
Darren Posted December 3, 2008 Share Posted December 3, 2008 waggy is 6 on 5.5 Link to comment Share on other sites More sharing options...
JeepcoMJ Posted December 3, 2008 Author Share Posted December 3, 2008 waggy is 6 on 5.5 ah. any interchange to 5 on 5? Link to comment Share on other sites More sharing options...
Darren Posted December 3, 2008 Share Posted December 3, 2008 they can be changed to 5 on 5.5 using chevy outers i believe (someone correct me if i'm wrong). Link to comment Share on other sites More sharing options...
JeepcoMJ Posted December 3, 2008 Author Share Posted December 3, 2008 hmm. I'll just keep the 30 unless I get a killer deal on a 44. I don't need to add more $$$ to the list. Link to comment Share on other sites More sharing options...
redneck23ms Posted December 3, 2008 Share Posted December 3, 2008 they can be changed to 5 on 5.5 using chevy outers i believe (someone correct me if i'm wrong). chevy outers are also 6 on 5.5. ford, dodge, older waggy, and jeep cj outers will all swap over to convert to 5 on 5.5 Link to comment Share on other sites More sharing options...
pingpong Posted December 3, 2008 Share Posted December 3, 2008 OK to go to 5 on 5.5 you need one a set of knuckles that can take small bearing spindles and a set of ford rotor's. Not very hard to do.. but pricey. New small bearing spindles are around 90 a piece... and used ones are not that much cheaper. For the rear a set of Alloy USA shafts with all the goodies could be at your house for under 300, heck you can even upgrade to 33 spline if you want :smart: If you are set on keep ing your d30 I would buy some 30 spline alloy shafts for the front. Gp with some nice u-joints... and depending on your wheeling satyle and how heavy of a wheel and tire you select.. 37 could live on it.. 36's would be more realistic. Your Last issue is the amount of lift required to clear 36 or 37" tires. The front with proper bumpstopping is going to need 7-8" the rear.. well maybe with a "custom bed lift" and proper bumpstopping you could clear them.. but I don't know. To me the option would be to pull the good bed.. and find a less then stellar one and use that for wheeling. If that all fails. how much you want for the gears? Link to comment Share on other sites More sharing options...
JeepcoMJ Posted December 3, 2008 Author Share Posted December 3, 2008 OK to go to 5 on 5.5 you need one a set of knuckles that can take small bearing spindles and a set of ford rotor's. Not very hard to do.. but pricey. New small bearing spindles are around 90 a piece... and used ones are not that much cheaper. For the rear a set of Alloy USA shafts with all the goodies could be at your house for under 300, heck you can even upgrade to 33 spline if you want :smart: If you are set on keep ing your d30 I would buy some 30 spline alloy shafts for the front. Gp with some nice u-joints... and depending on your wheeling satyle and how heavy of a wheel and tire you select.. 37 could live on it.. 36's would be more realistic. Your Last issue is the amount of lift required to clear 36 or 37" tires. The front with proper bumpstopping is going to need 7-8" the rear.. well maybe with a "custom bed lift" and proper bumpstopping you could clear them.. but I don't know. To me the option would be to pull the good bed.. and find a less then stellar one and use that for wheeling. If that all fails. how much you want for the gears? lol, thanks. I'll not be selling the gears...$850 into them plus the axle, and I'd spend whatever $$$ i make on the gears just to replace them, so they'll stay in the axle... I've found that it should run around 2600 rpm on 33's at 65-70mph, and get roughly 17mpg while doing so. I need new tires anyways, so the option I've decided to go with is to run 34" tires with a 1" spacer kit up front, and 4wd leafs in the rear (plus shackles maybe), then trim and bumpstop accordingly. that should drop it another 100 rpm, and give me pretty darn decent mileage around 55mph Link to comment Share on other sites More sharing options...
Eagle Posted December 4, 2008 Share Posted December 4, 2008 Pat is probably pretty well dialed-in with that setup. For anyone else contemplating gears and tires, I'll pass along my frame of reference: the original vehicles this engine family was designed for. I used to have, back when I was in the Army, a 1966 Rambler American. It had the original, 1-bbl carbureted version of what many years later developed into the 4.0L engine. I don't remember the tire size, but they weren't huge. My American had a 3-speed manual tranny (no overdrive), and 3.08 gears. One of the first things I did was buy a factory tachometer kit for it and install it, so I know (and still remember) the speed-to-RPM relationship. 24 MPH per 1,000 RPM. Which worked out to 60 MPH being exactly 2500 RPM. 3000 RPM got me a 72 MPH cruise, and it would run at 3000 RPM all day. With all the overdrive transmissions and such we have today, there's a tendency to think that anything over 2000 RPM is going to "burn up" the engine. Not so. I sold my American short of hitting 100,000 miles, but my brother had a '72 Gremlin with the same setup that went at least 308,000 miles with NO work inside the engine. I say "at least" because he sold it to one of the local parts stores and they used it to deliver parts. We lost track of it after 308,000 miles, but it was still going strong at that point. Back to my Rambler American -- cruising at 60 MPH/2500 RPM, I reliably pulled down 28 miles per gallon highway. The point of all this is -- don't be afraid to put in a bit more gear than what came from the factory. The factory chose the ratios to try to score well on the gummint's very artificial fuel mileage and emissions tests, not for what would be best for actually driving the vehicles in real life. On stock tires, my '88 5-speed turns about 1650 RPM at 65 MPH on the highway. That's well BELOW the torque peak of the engine, which is not optimal for anything. Link to comment Share on other sites More sharing options...
mvusse Posted December 4, 2008 Share Posted December 4, 2008 Assuming you're running an AW4, stock specs is 3.55 gears with 27" tires. To run the same RPMs with 4.88 gears would take 37" tires, and I don't think they will fit without major surgery on the fenders. And the few Comanches I've seen on 37s just look funny. The tires are too big for the truck. I'd go with 35" tires. You'd be running 5% higher rpms, look better and less cutting needed. Link to comment Share on other sites More sharing options...
Eagle Posted December 4, 2008 Share Posted December 4, 2008 Assuming you're running an AW4, stock specs is 3.55 gears with 27" tires. To run the same RPMs with 4.88 gears would take 37" tires, and I don't think they will fit without major surgery on the fenders. And the few Comanches I've seen on 37s just look funny. The tires are too big for the truck. I'd go with 35" tires. You'd be running 5% higher rpms, look better and less cutting needed. 28-inch, actually. A 215/75R15 is 27.7" in diameter, and a 225/75R15 is 28.3" in diameter. I hooked JeepCO up with a spreadsheet that calculates RPMs and road speeds for all the available gear ratios and for tire sizes from 205/75 up through (IIRC) 33", so he's been doing his homework. Link to comment Share on other sites More sharing options...
mvusse Posted December 4, 2008 Share Posted December 4, 2008 Assuming you're running an AW4, stock specs is 3.55 gears with 27" tires. To run the same RPMs with 4.88 gears would take 37" tires, and I don't think they will fit without major surgery on the fenders. And the few Comanches I've seen on 37s just look funny. The tires are too big for the truck. I'd go with 35" tires. You'd be running 5% higher rpms, look better and less cutting needed. 28-inch, actually. A 215/75R15 is 27.7" in diameter, and a 225/75R15 is 28.3" in diameter. I hooked JeepCO up with a spreadsheet that calculates RPMs and road speeds for all the available gear ratios and for tire sizes from 205/75 up through (IIRC) 33", so he's been doing his homework. Hmmm. According to the manual, stock tire size on my 87 4x4 4.0/AW4 was 205/75R15. That theoretically comes out to 27.1". According to my GPS, my speedometer/odometer are off almost exactly 6.5% (measured over almost 400 miles, rounded to nearest 1/10 mile. I'm running 235/75R15, so that also works out to stock being 205. Manual also specifies MT package being 225/75R15. Link to comment Share on other sites More sharing options...
Pete M Posted December 5, 2008 Share Posted December 5, 2008 You guys aren't seriously arguing about an inch are you? :shake: (or more precisely, a half-inch of rolling radius) FWIW, MJs came with anywhere from 195s to 225s. Link to comment Share on other sites More sharing options...
mvusse Posted December 5, 2008 Share Posted December 5, 2008 You guys aren't seriously arguing about an inch are you? :shake: (or more precisely, a half-inch of rolling radius) FWIW, MJs came with anywhere from 195s to 225s. My apologies, as I didn't realize we were arguing :D As far as serious, I never am. :hijack: :cheers: Link to comment Share on other sites More sharing options...
project88mj Posted December 5, 2008 Share Posted December 5, 2008 :no: you must never forget young jedi, the comanche force is no joking matter :smart: Link to comment Share on other sites More sharing options...
mvusse Posted December 5, 2008 Share Posted December 5, 2008 Young? Darned whippersnappers have no respect for their elders nowadays. No respect I tell ya... Link to comment Share on other sites More sharing options...
89eliminator Posted December 5, 2008 Share Posted December 5, 2008 Young? Darned whippersnappers have no respect for their elders nowadays. No respect I tell ya... aint that the truth :waving: Link to comment Share on other sites More sharing options...
project88mj Posted December 5, 2008 Share Posted December 5, 2008 please i offer my humble appologies to the people i offended i now realize that you two old farts are now too old to drive on public roads and have had your license revoked. those darn governement higher ups have forced you giesers to live out your life condemed to off-roading. all you can do is find out every last thing that has ever been done to a comanche and give all of the clueless users of this web sight your opinion cause you know your always right :shake: :rotfl2: :clapping: :yes: :rotf: just kidding guys yall have kinda been like a father figure to me in that my dad never EVER has time to help me with my automotive problems. when he does come out to help me he looks at the problem i got and says to me " well where is your manuel?"... all i know i had to figure out myself or seek help here. so.... in saying all that i will end with a heart felt thank you all of you :typing: Link to comment Share on other sites More sharing options...
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