dakal Posted March 20, 2007 Share Posted March 20, 2007 if the aftermarket fly wheels don't have a dish to them, does this mean my only recourse is the dealer? or is there someplace else to score one? :bowdown: Link to comment Share on other sites More sharing options...
Duner Posted March 20, 2007 Share Posted March 20, 2007 I'm not sure that the flywheel is actually dished. The service bulletin just refers to the surface being special which is probably related to a crosshatch pattern in the finish and most shops cut flywheels straight. We this in the brake rotors as well now. I don't know for sure but maybe some of the jeep experts could answer this, maybe jeep did something special to try soften drive train shock like the dual mass flywheel on ford's powerstroke and most of the exotic german cars. Link to comment Share on other sites More sharing options...
87manche Posted March 20, 2007 Share Posted March 20, 2007 the factory flywheel does have a concave shape to it,. Link to comment Share on other sites More sharing options...
dakal Posted March 21, 2007 Author Share Posted March 21, 2007 no the deaaler :eek: Link to comment Share on other sites More sharing options...
rejeep Posted March 21, 2007 Share Posted March 21, 2007 I have about (5) 4.0L flywheels... $50-$60 shipped.. there heavy as you know. Link to comment Share on other sites More sharing options...
jeepthing07 Posted March 21, 2007 Share Posted March 21, 2007 I can only speak from my ONE experience in the other flywheel post... I have read on other forums it was machined concaved for softer clutch engagement. I think the reason machining causes problems is because the flex plate must have been machined to match the concaved flywheel. But I really don’t know what’s causing my clutch issue since I not only did the clutch but swapped in a NV4500 at the same time. Link to comment Share on other sites More sharing options...
dakal Posted March 21, 2007 Author Share Posted March 21, 2007 i'm checking with a dealer in another town to see their recommendation for package or what ever.be back Link to comment Share on other sites More sharing options...
jeepthing07 Posted March 21, 2007 Share Posted March 21, 2007 I would really like to get to the bottom of this cause no one seems to really know the deal on the concaved flywheels. I have been looking up Part numbers on www.partsamerica.com and it seems once the 4.0's/2.5's went MPFI the flywheel changed maybe they are the only ones with the concaved surface? I'm pretty sure the renix and HO starters are the same so it probably has the same amount of teeth on the ring gear. The part #'s listed are for 4.0 flywheels are.... 1988 MJ Part No. 501004 1990 MJ Part No. 501004 1991 YJ Part No. 501002 1992 YJ Part No. 501002 1993 YJ Part No. 501002 1994 YJ Part No. 501002 1995 XJ Part No. 501002 And Part #'s for 2.5 flywheels... 1989 MJ Part No. FRA118 1990 MJ Part No. FRA118 1991 MJ Part No. 501008 1992 MJ Part No. 501008 1993 YJ Part No. 501008 1994 YJ Part No. 501008 1997 TJ Part No. 501008 1999 TJ Part No. 501008 I don’t know if this proves anything but I thought it was kind of interesting. I'm guessing you could get away machining the Pre '91 flywheels. Link to comment Share on other sites More sharing options...
JOMJ87 Posted March 21, 2007 Share Posted March 21, 2007 That change also marks when CDX finally decided to do some major changes on the Jeeps they were still producing. They made the CDX instead of half amc and half CDX. Just some info i discovered while writing a jeep history research paper in High school. ;) Cole Link to comment Share on other sites More sharing options...
carnuck Posted March 21, 2007 Share Posted March 21, 2007 The number of teeth is the same, but the "tone ring" for the EFI is different. HO has 1 style ('91 up), Renix another, and earlier ones (or YJ without EFI) don't have a ring for EFI. NAPA also sells the new flywheels under the same part numbers. I would really like to get to the bottom of this cause no one seems to really know the deal on the concaved flywheels. I have been looking up Part numbers on www.partsamerica.com and it seems once the 4.0's/2.5's went MPFI the flywheel changed maybe they are the only ones with the concaved surface? I'm pretty sure the renix and HO starters are the same so it probably has the same amount of teeth on the ring gear. The part #'s listed are for 4.0 flywheels are.... 1988 MJ Part No. 501004 1990 MJ Part No. 501004 1991 YJ Part No. 501002 1992 YJ Part No. 501002 1993 YJ Part No. 501002 1994 YJ Part No. 501002 1995 XJ Part No. 501002 And Part #'s for 2.5 flywheels... 1989 MJ Part No. FRA118 1990 MJ Part No. FRA118 1991 MJ Part No. 501008 1992 MJ Part No. 501008 1993 YJ Part No. 501008 1994 YJ Part No. 501008 1997 TJ Part No. 501008 1999 TJ Part No. 501008 I don’t know if this proves anything but I thought it was kind of interesting. I'm guessing you could get away machining the Pre '91 flywheels. Link to comment Share on other sites More sharing options...
dakal Posted March 21, 2007 Author Share Posted March 21, 2007 what about the pressure plate? does it need to be convex on the side that faces the flywheel? i just remembered, my 88 mj has an ax15, not stock in it. so i better get the exact yr of motor, an transmission before i buy anything. i put urethane motor mounts in it, and bought a urethane tranmission mount. but the transmission mount is to big. the junk yard writing says its off a ax15, but what yr? or what vehicle? i have the urethane mount i will sell cheap,$20.00. so i need to find out what its out of. buy the way there is a little vibration, but the directness of engagement is more than worth it. but i really need the urethane trans mount. replace all three or none at all. i can feel the trans go up an down when i shift. not bad, but i'm a perfectionist. Link to comment Share on other sites More sharing options...
87manche Posted March 21, 2007 Share Posted March 21, 2007 dakotas also used the AX-15, it's possible you got that mount. Link to comment Share on other sites More sharing options...
dakal Posted March 21, 2007 Author Share Posted March 21, 2007 i'll check Link to comment Share on other sites More sharing options...
Tracker Posted March 21, 2007 Share Posted March 21, 2007 I would really like to get to the bottom of this cause no one seems to really know the deal on the concaved flywheels. Me too- That's why I've been laying a machinist's straightedge across a lot of jeep flywheels and pressure plates lately. New, used, MJ, XJ; they have all been flat as can be. I'm not saying that the FSM doesn't say as it has been quoted, or that it is wrong. But I'm starting to think that the concave surface might have been an idea that didn't catch on or didn't have the intended long term benefits someone might have hoped for. Some of them are 20 years old now. Go to your favorite parts house and lay a good edge across the flywheel they would sell you. Or, check your own next time it's out. I have. Link to comment Share on other sites More sharing options...
Eagle Posted March 22, 2007 Share Posted March 22, 2007 The '91 and later flywheels are different because the flywheel incorporates the teeth that trigger the CPS, and the pattern is very different for the Chrysler injection system than for the Renix system. That's why if you drop an HO engine into a Renix chassis, unless you swap out the complete computer and wiring harness you have to use the original Renix flywheel ... so it'll trigger the CPS. Link to comment Share on other sites More sharing options...
dakal Posted March 22, 2007 Author Share Posted March 22, 2007 8) Link to comment Share on other sites More sharing options...
carnuck Posted March 22, 2007 Share Posted March 22, 2007 The '91 and later flywheels are different because the flywheel incorporates the teeth that trigger the CPS, and the pattern is very different for the Chrysler injection system than for the Renix system. That's why if you drop an HO engine into a Renix chassis, unless you swap out the complete computer and wiring harness you have to use the original Renix flywheel ... so it'll trigger the CPS. That's what I was trying to say when I said "tone ring". I was just about on my way to work and typing too fast! Link to comment Share on other sites More sharing options...
Oizarod115 Posted March 22, 2007 Share Posted March 22, 2007 i've got a flywheel off a 1990 i can lay a straightedge across tonight. ill post up what we find. Link to comment Share on other sites More sharing options...
Eagle Posted March 22, 2007 Share Posted March 22, 2007 The '91 and later flywheels are different because the flywheel incorporates the teeth that trigger the CPS, and the pattern is very different for the Chrysler injection system than for the Renix system. That's why if you drop an HO engine into a Renix chassis, unless you swap out the complete computer and wiring harness you have to use the original Renix flywheel ... so it'll trigger the CPS. That's what I was trying to say when I said "tone ring". I was just about on my way to work and typing too fast! I knew that but I wasn't sure if everyone could translate so I thought I'd just tack on a layer of redundancy :) Link to comment Share on other sites More sharing options...
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