rejeep Posted March 20, 2007 Share Posted March 20, 2007 I know its an XJ, but i know this has been talked about here a lot.. What option is there for a tranny with the 2.8L? Is an aw4 an option or no? what about a fulll 4.0L swap? or is this the year with the firewall issue? Link to comment Share on other sites More sharing options...
JeepcoMJ Posted March 20, 2007 Share Posted March 20, 2007 aw4 was not an option, and keeping the 2.8 in it is also not an option (in my opinion) find a wrecked cherokeee with a good front end, tranny, engine, and harness, and swap it all into the 86. make it something worth keeping. Link to comment Share on other sites More sharing options...
rejeep Posted March 20, 2007 Author Share Posted March 20, 2007 4.0L won't swap into it without major rad and firewall mods... from what i understand, thought of that.. IMHO.. time for a new XJ... BTW....... its not mine.. researching for a friend. Link to comment Share on other sites More sharing options...
JeepcoMJ Posted March 20, 2007 Share Posted March 20, 2007 no firewall mods. and the radiator mods really aren't that bad...you just need a donor xj or a few trips to the junkyard. everything bolts in with the exception of the 4.0 header panel/radiator support...that will require some minor cutting and welding. and you would need a new hood to go with the 4.0 style header panel. 4 or 5 weekends of workin on it (at most) and you could convert it to a 4.0. here's an easier mod...put a 3.4 camaro engine in it. the 3.4 is the same motor, with fuel injection and a different intake and bore. the computer is mounted in the engine compartment, it's still a v6, and you can use the stock 2.8 exhaust so no custom exhaust need be done. the only thing is that you cannot use one with air conditioner as the a/c pump makes it too wide to fit in the frame. the 2.8 and 3.4 share the same bellhousing pattern, same motor mount pattern, same block. the 1 thing the 3.4 doesn't have is a mechanical fuel pump (the 2.8 does) so you would need a electric fuel pump (either in-line or in-tank) to get gas to it. for the fact that you don't have to alter anything when doing this modification, it's a good one. here's some sites on the swap or information on the engines. the 1st one is the best page, with pictures. I recommend putting the 2.8 oil pan on, but NOT converting it to carbeurator. a good 50% of the 2.8's problem is that damned carbeurator. obviously you don't need to use any other parts from the 2.8 if you stay FI. if you decide on this swap and need wiring diagrams, i'm your man. i can get anything you could possibly need. http://www.lunghd.com/Tech_Articles/Pro ... ect_XJ.htm http://images.google.com/imgres?imgurl= ... n%26sa%3DN http://images.google.com/imgres?imgurl= ... n%26sa%3DN p.s. the wiring for that would be run in conjunction with the original wiring harness. you would only need the harness for the engine, and the engine computer. Link to comment Share on other sites More sharing options...
JeepcoMJ Posted March 20, 2007 Share Posted March 20, 2007 http://www.comancheclub.com/forums/viewtopic.php?t=3582 that is my truck. it's an 86 and had the 2.8, i decided to go with a 1996 3.8 camaro engine (engine made by buick). for that one, i had to convert to a 4.0 radiator, but I made my own supports for it. and my own hood latches as well. Link to comment Share on other sites More sharing options...
Landoloops Posted March 20, 2007 Share Posted March 20, 2007 I'm not exactly sure but I have heard that MJ had a different firewall. So all MJ's will fit a 4.0 with a few hammer taps. I only needed like an inch of clearence in one spot when I did the swap. The radiator wasn't that bad either like Jeepco said. However I have also read that 84 to 86 XJ's have a different firewall then the 86 MJ and the 87+ XJ's and MJ's so they will not fit a 4.0 but I have never actually looked myself. Hope this helps Link to comment Share on other sites More sharing options...
JeepcoMJ Posted March 20, 2007 Share Posted March 20, 2007 i had an 86 xj that i used as a donor. it had a factory 2.8 (same as my truck came with) and had the same firewall, at least up top. with a little inginuity, you can do anything with a small amount of effort. if the 86 xj means something to him or he just needs a project, do the swap regardless of firewall issues. otherwise, if he doesn't want that big of a project, sell the xj and buy a newer one. OR do the 3.4 swap like i said. talk to The Yak on here...he's got an 86 manche with a 3.4 and i'm SURE he's impressed with it Link to comment Share on other sites More sharing options...
feerocknok Posted March 20, 2007 Share Posted March 20, 2007 I know its an XJ, but i know this has been talked about here a lot..What option is there for a tranny with the 2.8L? Is an aw4 an option or no? what about a fulll 4.0L swap? or is this the year with the firewall issue? Wouldn't be the AW4. Maybe a 909 or 999? Link to comment Share on other sites More sharing options...
Eagle Posted March 20, 2007 Share Posted March 20, 2007 I'm not exactly sure but I have heard that MJ had a different firewall. So all MJ's will fit a 4.0 with a few hammer taps. I only needed like an inch of clearence in one spot when I did the swap. The radiator wasn't that bad either like Jeepco said. However I have also read that 84 to 86 XJ's have a different firewall then the 86 MJ and the 87+ XJ's and MJ's so they will not fit a 4.0 but I have never actually looked myself. Hope this helps Year-for-year, the MJ did NOT have a different firewall from the XJ. As to a difference between the '84-'86 vehicles and the '87+ vehicles, reports are inconsistent. Some who have swapped in a 4.0L into an earlier vehicle saw they had to cut out a section of the firewall and weld in a new section. Others say they just reshaped it with a big hammer. And at least one person claims he dropped in a 4.0L with no firewall mods. On the extreme other end of the spectrum. I have a friend with an '86 XJ who wanted a 4.0L conversion. He took it to a shop that specializes in Cherokees, and they decided the easiest route was (are you ready?) to cut the two vehicles in half just behind the 'A' pillar and weld the new front half to the rear section of his original chassis. IMHO, the logical upgrade for a 2.8L in an XJ or an MJ is the GM 3.4L V6. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now