Strokermjcomanche Posted September 30, 2017 Share Posted September 30, 2017 Looking to possibly put a 6 speed in my 88 SWB with a 4.7 stroker that currently has a NV 3550 with 4:10 ratio and 31x10.5x15 tires . Just seeing if if someone has done this swap and if it was worth it ...My biggest issue is that the engine is at a higher RPM (2700@70mph) then I'd like to have it , even though I know that's in the allowed range . I'm doing a lot of highway driving and would like to lower the RPMs if possible . I have plenty of low end power and it's much quieter in the cab too . Just in the planning process right now , thanks for your insight Link to comment Share on other sites More sharing options...
Marine1Texas Posted October 1, 2017 Share Posted October 1, 2017 If you have NV 3550 you have a .78 overdrive with your 4.10 rear end You should be at 70 mph when your at 2427 rpms. Do you have the right gear for speedo? at those specs you are doing almost 78 mph at 2700 rpms. With that power you could easy do 35's. at 70 mph you be at 2150 rpms in 5th. That would bring you down closer to factory gearing specs. Most of the manual 5 speed 4.0's came with 3.07 and those 225/75r15's. that is 2015 rpms at 70 mph. I run the 4.10 with 31's and all day long at 2500 rpms up and down hills. I seen no improve or negative on mpg Link to comment Share on other sites More sharing options...
HOrnbrod Posted October 1, 2017 Share Posted October 1, 2017 I think about that every time I drive my 2015 JKU Adam. I have the same setup in my MJ as you do except there's no transfer case (2WD): AW4 with the 4th speed O/D gear ratio of .75, 31's and 4.10 final drive ratio. I'm also churning 2700RPM @ 70MPH. And yes, the speedo gear is correct. The JKU has a 5-speed Benz W5A580 A/T with an O/D gear ratio of .83, 31" dia. tires and it turns 2350RPM @ 70MPH. I think that's ideal. The only difference is the JK's final drive ratio of 3.73. If I ever regear it'll be with 3.73 gears. Link to comment Share on other sites More sharing options...
Marine1Texas Posted October 1, 2017 Share Posted October 1, 2017 HOrnbrod with .75 at 4.10 on 31's at 2700 rpms the math comes out to be around 81 mph. I can do the math on excel, however I like to use http://spicerparts.com/calculators/transmission-ratio-rpm-calculator The .83 on 3.73 with 31's is about 2350 for 70 mph your right on that one Link to comment Share on other sites More sharing options...
HOrnbrod Posted October 1, 2017 Share Posted October 1, 2017 I know how the math comes out Nori. Maybe my and Adam's tachs are off. I know my speedo checks out....... From Gojeep's site: RPM's at 65 MPH/105 KPH w/ 4.10:1 axle gears running 31's: 2,166 RPM Link to comment Share on other sites More sharing options...
Marine1Texas Posted October 1, 2017 Share Posted October 1, 2017 yea tachs off on a old truck and old electronic could be a big deff. I never updated my gear I just use a GPS mph gauge. it is off 1.2 mph but close enough Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted October 1, 2017 Author Share Posted October 1, 2017 I can assure that I'm at 70mph at 2700 rpms on my Toyo Open Country AT 31s . I'm using Nicks R.E.M. Along with a GPS and the correct speedo gear , and I've pace matched my buddies car at 70mph . Don , is the Benz trans bigger then the Nv3550 , I wonder how the clutch setup would work ..... I don't care what speed it is as long as it would considerably drop the rpms , as it stands I can be at 40mph in 5th gear and have power to accelerate. Link to comment Share on other sites More sharing options...
HOrnbrod Posted October 1, 2017 Share Posted October 1, 2017 Don't know Adam. Just in looking at them both, it seems about the same size as the AW4. It was used in the Jeep Liberty, Grand Cherokee, and tons of Chrysler vehicles. One of it's advantages is it can handle big power and has a small size. The AMG hot rod Benz's and 12 cylinder vehicles used it too. It has a neat slap shifter too where you can slap the shifter handle left or right and go up and down the gears. Would be neat if you could get it in an MJ. Me - I'd just rather regear. Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted October 1, 2017 Author Share Posted October 1, 2017 http://www.grimmjeeper.com/gears.html Just seen this , might look at putting in the NSG370 , according to the site above I'd be losing a decent Rpm at 70mph If I would have known earlier I would have ran 373 gears , but now since I just installed 4:10s I'd like to explore other options. Link to comment Share on other sites More sharing options...
HOrnbrod Posted October 1, 2017 Share Posted October 1, 2017 Neat site! Did you try the Dodge WA580 tranny? Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted October 1, 2017 Author Share Posted October 1, 2017 4 minutes ago, HOrnbrod said: Neat site! Did you try the Dodge WA580 tranny? I couldn't find it on the list Link to comment Share on other sites More sharing options...
HOrnbrod Posted October 1, 2017 Share Posted October 1, 2017 It's there...... Ever since my tanker days driving a 20-speed Mack for Sunoco, I swore off manuals. My knees couldn't take it then; now it would be much worser. Is that a word? Link to comment Share on other sites More sharing options...
Jeep Driver Posted October 1, 2017 Share Posted October 1, 2017 http://www.rsgear.com/products/off-road-truck-transmissions Link to comment Share on other sites More sharing options...
Pete M Posted October 1, 2017 Share Posted October 1, 2017 3 hours ago, Strokermjcomanche said: Looking to possibly put a 6 speed in my 88 SWB with a 4.7 stroker that currently has a NV 3550 with 4:10 ratio and 31x10.5x15 tires . Just seeing if if someone has done this swap and if it was worth it ...My biggest issue is that the engine is at a higher RPM (2700@70mph) then I'd like to have it , even though I know that's in the allowed range . I'm doing a lot of highway driving and would like to lower the RPMs if possible . I have plenty of low end power and it's much quieter in the cab too . Just in the planning process right now , thanks for your insight I don't understand the problem. are you looking for better mpgs? I mean, it's a perfectly normal combo. TJ Rubicons had it. 2.5L Jeeps had 4.10s and, what, 28"ers? Hell, my Dakota R/T has 3.92 and 28" tires and a giant v8! Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted October 1, 2017 Author Share Posted October 1, 2017 4 hours ago, Jeep Driver said: http://www.rsgear.com/products/off-road-truck-transmissions I don't have an LS nor do I have an NV4500.. Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted October 1, 2017 Author Share Posted October 1, 2017 4 hours ago, Pete M said: I don't understand the problem. are you looking for better mpgs? I mean, it's a perfectly normal combo. TJ Rubicons had it. 2.5L Jeeps had 4.10s and, what, 28"ers? Hell, my Dakota R/T has 3.92 and 28" tires and a giant v8! I wouldn't go and say it's a problem, just would love to lower the RPM for a quieter ride , MPG was never an issue as I know it was never meant to be a gas saver . My other 88 MJ with a 4.7 /AW4 / 355 ratio and 235/70/15 tires rides nice at 70-75 mph ( and lower RPM ) and I'd like to match that if I can . Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted October 1, 2017 Author Share Posted October 1, 2017 5 hours ago, HOrnbrod said: It's there...... Ever since my tanker days driving a 20-speed Mack for Sunoco, I swore off manuals. My knees couldn't take it then; now it would be much worser. Is that a word? Yep I skipped over it , but I think the bell housing would not bolt up to the 4.0 anyhow . Link to comment Share on other sites More sharing options...
Jeep Driver Posted October 1, 2017 Share Posted October 1, 2017 4 hours ago, Strokermjcomanche said: I don't have an LS nor do I have an NV4500.. Which 6 speed did you plan to use? NSG370When the NSG370 was first put in Wranglers for the ’05 model year, we were psyched. We were excited to lose that huge gap between Third, Fourth, and Fifth gears. We even got a Rubicon to test drive to Moab that year, and the next year we swapped one into an MJ. That said, today this transmission walks the walk of shame. We just haven’t had good luck keeping them alive, and they’re not as durable as the AX15s and NV3550s they replaced. Kicking out of First gear, losing gears, making noise, and so forth are pretty common. And we hear similar stories from friends and readers with these transmissions.Found in: ’05-to-current WranglersIdentify by: Integral bellhousing, the only six-speed behind six-cylinders.Gear ratios: 4.46; 2.61; 1.72; 1.25; 1.00; 0.84; 4.06 (Reverse) http://www.fourwheeler.com/how-to/1311-manual-meltdowns-jeep-transmissions-we-love-to-hate/ Link to comment Share on other sites More sharing options...
Jeep Driver Posted October 1, 2017 Share Posted October 1, 2017 However, individuals have reported problems with the 2005 model transmission popping out of reverse gear. This was widespread enough to garner the admission of DCx that an update may be needed, which consisted of a reverse gear kit (#05175903AA), itself comprised of a new reverse gear, slider and synchro ring, plus snap rings, an oil seal and countershaft seal plug, incidental to the tear-down required. http://www.novak-adapt.com/knowledge/transmissions/manual/nsg370 Link to comment Share on other sites More sharing options...
zomeizter Posted October 1, 2017 Share Posted October 1, 2017 5 hours ago, Strokermjcomanche said: I wouldn't go and say it's a problem, just would love to lower the RPM for a quieter ride , MPG was never an issue as I know it was never meant to be a gas saver . My other 88 MJ with a 4.7 /AW4 / 355 ratio and 235/70/15 tires rides nice at 70-75 mph ( and lower RPM ) and I'd like to match that if I can . Maybe a muffler change will alleviate noise issue? Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted October 1, 2017 Author Share Posted October 1, 2017 9 minutes ago, zomeizter said: Maybe a muffler change will alleviate noise issue? It has the original exhaust in good shape , good idea though . I never did like the loud exhaust mufflers . Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted October 1, 2017 Author Share Posted October 1, 2017 1 hour ago, Jeep Driver said: However, individuals have reported problems with the 2005 model transmission popping out of reverse gear. This was widespread enough to garner the admission of DCx that an update may be needed, which consisted of a reverse gear kit (#05175903AA), itself comprised of a new reverse gear, slider and synchro ring, plus snap rings, an oil seal and countershaft seal plug, incidental to the tear-down required. http://www.novak-adapt.com/knowledge/transmissions/manual/nsg370 There are problems with every transmission , my nv3550 sounds like it has 1500 ball bearings in it when at idle , the ax15s lose synchros too ( maybe because they used the wrong fluid , which could also be the case of the NSG370) . I have a friend that rebuilds transmissions , he will go through anything that I buy and make sure it's in good shape before installation, and he owes me several favors . Link to comment Share on other sites More sharing options...
Jeep Driver Posted October 1, 2017 Share Posted October 1, 2017 23 minutes ago, Strokermjcomanche said: There are problems with every transmission , my nv3550 sounds like it has 1500 ball bearings in it when at idle , the ax15s lose synchros too ( maybe because they used the wrong fluid , which could also be the case of the NSG370) . I have a friend that rebuilds transmissions , he will go through anything that I buy and make sure it's in good shape before installation, and he owes me several favors . The question remains- Which one? You are limited by bell housing (CPS) and or 4x TC mount. Anything other than factory will require adapters. I'm looking a year out........SBC swap. I don't want to lose my clutch, no matter what I do, I'm somewhat limited and it's going to be expensive. If you really want a 6 speed, you have one choice..........that's it, as far as I can tell. Or, like me, you'll be looking to spend $3500+++++ It's a good thing you got a buddy, I don't, and no one owes me any favors. My days of buying someone else's junk are over, long over. New, or nothing. Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted October 1, 2017 Author Share Posted October 1, 2017 I'm not sure what you're getting at , I mentioned the Nsg370 (6speed ) several times . I'm not spending $3500 on any trans , and I won't buy a junk one either . Has as anyone seen or done the Nsg 370 swap in a Comanche or Cherokee??? Link to comment Share on other sites More sharing options...
HOrnbrod Posted October 1, 2017 Share Posted October 1, 2017 12 minutes ago, Strokermjcomanche said: I'm not sure what you're getting at , I mentioned the Nsg370 (6speed ) several times . I'm not spending $3500 on any trans , and I won't buy a junk one either . It's best to ignore it. Link to comment Share on other sites More sharing options...
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