Landoloops Posted February 26, 2007 Share Posted February 26, 2007 What gearing would a 86 2.8l automatics have? 3.55? 4.10 Anybody know? Link to comment Share on other sites More sharing options...
JeepcoMJ Posted February 26, 2007 Share Posted February 26, 2007 What gearing would a 86 2.8l automatics have? 3.55? 4.10 Anybody know? ahhhhh! the dreaded combination...2.8 and auto...man i hope you're switchin that to a 4.0... umm, i think it was 3.72 or 3.73 that was in the 2.8 auto cherokee i had. not too certain though... Link to comment Share on other sites More sharing options...
Landoloops Posted February 26, 2007 Author Share Posted February 26, 2007 Thank JeepcoMJ, I just finished installing Engine, Transmission, Transfercase, Dash, Steering Column, fuel pump/gauge sending unit, and all the electrical over. It was actually a pretty easy swap, and I have never pulled an engine before. The only things I am still working on is the hood latch (bungy cords in the mean time) and the CAD system. (I want my 4wd back) Any ideas on the CAD system? I would like to keep the feature but I need to find a vacuum switch or something to make it work. I could tell my speedo was off but was trying to figure out how much it was off. Thanks again Link to comment Share on other sites More sharing options...
GirsMJ86 Posted February 26, 2007 Share Posted February 26, 2007 my 2.8 ayto had 3.73 gearing in it. but yes i would swap to the 4.0 and an aw-4 or at least swap to the 3.4 enigines. those 2.8s are junk all around. Alex Link to comment Share on other sites More sharing options...
GirsMJ86 Posted February 26, 2007 Share Posted February 26, 2007 as for the CAD. just get rid of it. it is not needed and turns out to be more of a problem then its worth. do the "fix" that is in my 91 eliminator project thread and you will never have to worry about 4wd again. just pull the lever and you are in 4wd. Alex Link to comment Share on other sites More sharing options...
Landoloops Posted February 26, 2007 Author Share Posted February 26, 2007 I guess I failed to mention my swap was from a totaled 95 cherokee with a 4.0 aw4 and NV231, and I agree the 2.8 was and is junk and the 4.0 with the aw4 is a huge improvement. Link to comment Share on other sites More sharing options...
GirsMJ86 Posted February 26, 2007 Share Posted February 26, 2007 I guess I failed to mention my swap was from a totaled 95 cherokee with a 4.0 aw4 and NV231, and I agree the 2.8 was and is junk and the 4.0 with the aw4 is a huge improvement. you should have also got the axles (gearing i mean) from it since they would have been a much better ratio for the 4.0 then those 3.73s, unless you happen to have the amc20 rear end rather then a d35. get us some pics of this thing when you get the chance. Alex Link to comment Share on other sites More sharing options...
Landoloops Posted February 26, 2007 Author Share Posted February 26, 2007 I don't have the AMC20 unfortunately. Well i still have the whole jeep with axles. You think going to 3.55 would be better than 3.73? I thought everyone is always trying to get lower gearing like 4.10 or 4.56. Forgive me for my lack of knowledge I'm new to the gearing thing. Link to comment Share on other sites More sharing options...
GirsMJ86 Posted February 26, 2007 Share Posted February 26, 2007 Well i still have the whole jeep with axles. I don't have the AMC20 unfortunately. You think going to 3.55 would be better than 3.73? I thought everyone is always trying to get lower gearing like 4.10 or 4.53. Forgive me for my lack of knowledge I'm new to the gearing thing. just depends what your xj has in it. if its 3.55 don't bother. if you have a lucky one with 4.10s... see what i mean. some xjs had 4.10s in them, not sure if it was only the ones with the d44 or not though (i have only ever been around MJs and K-10s, don't know much about xjs spec-wise). what are you planning on doing with this mj? lift and bigger tires and the 3.73s will do great as long as you don't over do the tire size. but the d35 is really weak (yours isnt as weak as the c-clip ones though since yours should be a non-c-clip one). Alex Link to comment Share on other sites More sharing options...
Landoloops Posted February 26, 2007 Author Share Posted February 26, 2007 Well when i'm driving it the speedo is fast, when i'm going about 50 it says i'm going 55 or faster.... So if I understand it right it would mean that the XJ the engine and transmission and speedo came out of was geared higher than the gears in my xj axles.... So I am assuming the XJ had 3.55 gears. Does my logic make sense? Link to comment Share on other sites More sharing options...
Landoloops Posted February 26, 2007 Author Share Posted February 26, 2007 In regards to your CAD fix, does that cause the front drive shaft to spin regardless of whether or not you are in 4wd? Link to comment Share on other sites More sharing options...
GirsMJ86 Posted February 26, 2007 Share Posted February 26, 2007 Well when i'm driving it the speedo is fast, when i'm going about 50 it says i'm going 55 or faster.... So if I understand it right it would mean that the XJ the engine and transmission and speedo came out of was geared higher than the gears in my xj axles.... So I am assuming the XJ had 3.55 gears. Does my logic make sense? seems about right. then i would just keep the 3.73s unless you are wanting a serious off-road machine then i would find a better rear axle with 4.10s all around. but my 86 had the d35 with 3.73s and my 91 has the d35 with 3.55s and i had 31"s on both of them and they do fine in mud and stuff. have not had a 35 blow on me yet. the CAD fix in my project turns a command-trac d30 into a selec-trac d30. the command-trac d30 is a 3 piece axle, the selec-trac is 2 piece. this just makes the one side into a "solid" shaft rather then split shaft, IT DOES NOT MAKE IT STAY IN 4WD like most people think it does. you engage it from the lever in the cab on the t-case. that is what puts it into 4wd. i know people that have had their CAD like this for years with no problems. i didnt get it in that video in my project but before i pulled the lever neither front tire was spinning, they were just sitting there till i pulled the lever in the cab. you could also swap out the shafts in the front axle to the newer ones from a newer xj ot tj with selec-trac and the bigger u-joints. or just swap to the newer selec-trac d30. Alex Link to comment Share on other sites More sharing options...
feerocknok Posted February 26, 2007 Share Posted February 26, 2007 Both 2.8 autos I've seen are 4.10s... Link to comment Share on other sites More sharing options...
JeepcoMJ Posted February 26, 2007 Share Posted February 26, 2007 Well when i'm driving it the speedo is fast, when i'm going about 50 it says i'm going 55 or faster.... So if I understand it right it would mean that the XJ the engine and transmission and speedo came out of was geared higher than the gears in my xj axles.... So I am assuming the XJ had 3.55 gears. Does my logic make sense? in regards to your speedometer, the simple thing to do is get a GPS (borrow not buy) that can tell miles per hour, drive and figure out exactly how much it is off via that. then go to your local jeep dealer and tell them you need a speedo gear that will fix that problem. They should be able to tell you how many teeth you need to add to make it right, then you can either be robbed by buying one from them (whatever their price is), or buy one off ebay for cheap. MAKE SURE that if you do it that way, you order one for your tranny style (i.e. the speedo gear coming off the right side of the tcase or the left side...yours being left side). I ordered one that was correct for mine, but it was for a speedo drive on the right side of the tranny which means the gear teeth were slanted the wrong way...so it hopped all over the place! and don't go down to 3.55 from a 3.73 ... it's pointless you'll be riding 200rpm lower at speed than with the 3.73, so it won't save you mileage or anything. 3.73 is a good ratio for mild off-road use and on-road (highway) use as well. you should run about 2000 rpm at 55 to 60 mph and get about 16-19 to the gallon with those gears, unless you have some radical engine mods. p.s. i'm glad you got rid of the 2.8...i did that with mine but installed a v6 1996 camaro 3800 instead (more torque + horsepower w/o mods). Link to comment Share on other sites More sharing options...
razrwild Posted February 26, 2007 Share Posted February 26, 2007 my friend has an 86 manche and it came with 3.52 gearing he told me. Don't know if that helps but just giving the info i have at hand. Link to comment Share on other sites More sharing options...
Eagle Posted February 26, 2007 Share Posted February 26, 2007 Most of the 2.8L automatics came with 3.73 gearing, and that's actually an excellent ratio for a 4.0L automatic. Especially if you run tires slightly larger than stock, like maybe 235/75-15s or 30x9.50-15s. Just swap in the speedo gear from your old transfer case and you should be all set (but check the shaft length on the two speedo gears, they may not be the same). Link to comment Share on other sites More sharing options...
JeepcoMJ Posted February 26, 2007 Share Posted February 26, 2007 Most of the 2.8L automatics came with 3.73 gearing, and that's actually an excellent ratio for a 4.0L automatic. Especially if you run tires slightly larger than stock, like maybe 235/75-15s or 30x9.50-15s. Just swap in the speedo gear from your old transfer case and you should be all set (but check the shaft length on the two speedo gears, they may not be the same). speedo gears are not interchangeable between the 2.8 tranny's and the 4.0 trannys, in my experience Link to comment Share on other sites More sharing options...
Pete M Posted February 27, 2007 Share Posted February 27, 2007 86 was a crazy year for gearing and the only reliable way to tell is to look for a tag, turn the tire and count the d-shaft rotations, or check the stamping in the side of the ring gear. Link to comment Share on other sites More sharing options...
carnuck Posted February 27, 2007 Share Posted February 27, 2007 I've seen 3.55, 3.73 and 3.07 with the 2.8 auto! Link to comment Share on other sites More sharing options...
Oizarod115 Posted February 27, 2007 Share Posted February 27, 2007 my friend has an 86 manche and it came with 3.52 gearing he told me. Don't know if that helps but just giving the info i have at hand. he most likely had an AMC 20 rear axle. the front (if it was 4x4) was 3.55. i have heard of differences up to 3% -Nick Link to comment Share on other sites More sharing options...
GirsMJ86 Posted February 27, 2007 Share Posted February 27, 2007 I don't have the AMC20 unfortunately. Well i still have the whole jeep with axles. You think going to 3.55 would be better than 3.73? I thought everyone is always trying to get lower gearing like 4.10 or 4.56. Forgive me for my lack of knowledge I'm new to the gearing thing. already stated that it is not the amc20. Alex Link to comment Share on other sites More sharing options...
Kenosha Warrior Posted February 27, 2007 Share Posted February 27, 2007 I don't have the AMC20 unfortunately. Well i still have the whole jeep with axles. You think going to 3.55 would be better than 3.73? I thought everyone is always trying to get lower gearing like 4.10 or 4.56. Forgive me for my lack of knowledge I'm new to the gearing thing. already stated that it is not the amc20. Alex Oiz was talking about what razrwild said. His buddy with a 3.52 geared rear end. Link to comment Share on other sites More sharing options...
GirsMJ86 Posted February 27, 2007 Share Posted February 27, 2007 I don't have the AMC20 unfortunately. Well i still have the whole jeep with axles. You think going to 3.55 would be better than 3.73? I thought everyone is always trying to get lower gearing like 4.10 or 4.56. Forgive me for my lack of knowledge I'm new to the gearing thing. already stated that it is not the amc20. Alex Oiz was talking about what razrwild said. His buddy with a 3.52 geared rear end. oops. i have been out of it all day. stupid me. Alex Link to comment Share on other sites More sharing options...
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