2wd to 4wd

[86jeep]

I got a 86 mj 2.5 auto 2wd I found a 84 2 door xj 2.5 auto with Selec-Trac 4wd both is 2.5 both is auto so i can keep my auto on the colume is this a good donner i would use my motor and the xj tranny and use both axel out of the xj

[jimoshel]

Only problem I can think of is whether the shift mechanism for the auto would interfere with the shift linkage for the transfer case. Not sure if it's cable or linkage. I've got a column shift auto. Go out in the morn and take a look.

[Pete M]

check the ratios in those axles. if the XJ front matches your MJ rear, there's no need to swap the MJ axle out. :thumbsup:

[86jeep]

would it be better to get a newer xj to start with or would u even keep the 4 banger what do ya think my 4 banger runs good is the Selec-Trac a good choice

[dasbulliwagen]

Your biggest issue with the selectrac out of the 84 will be all the vacuum hoses and routing them all correctly. The NP228 has a butload of vac hoses to deal with, along with the sliding lever actuator. Youll either need to take very carefull notes as to routing of these hoses when you take it apart, or find a good diagram so you can put it all back together correctly when the swap is finished. And like was said, both these vehicles may have the same axle gearing, so that might save you from having to weld new perches on the 84 XJ rear axle. Confirm what the gears are in both vehicles and go from there. Good luck.

[86jeep]

thanks i found 86 mj 4x4 that has been a roll over it is a 2.8 stright drive would this be a better swap then the xj

[Pete M]

what gear ratio do you have in your truck's axle now? do you want to keep the automatic trans?

[86jeep]

i have no ideal what it is now being it is a 2wd 2.5 auto my girlfriend wants it to stay auto but i don't care my self just wondering which be the best bet to buy

[Pete M]

a quick and dirty way to check gearing:

 

-jack up one rear tire

-put trans in neutral

-rotate that tire around exactly twice

-while doing that, count the number of times the driveshaft rotates. that number will be your ratio. 3 and a half times is 3.55, just over 4 times is 4.10, 4 and a half times is 4.56, etc.

 

there's a chance that both your truck and that XJ (being 2.5l/autos) will have 4.56 gearing, and if that's the case, the XJ is a GREAT buy because that ratio is hard to find. worry about the t-case later. :thumbsup:

[86jeep]

thanks

[86jeep]

let me throw this out there two i got a 91 burb 350 motor 704 brand new tranny with posa out back would u just take that drive train and fab it under the mj i got the know how and go ahead and leaf spring the front or trade the burb for that xj the burb has a bad body and bad motor but i got a sbc400

[Pete M]

that's a ton of work compared to a 4wd conversion (which is essentially bolt-in). all depends on how long you want this to take (and how much money you want to spend).

[86jeep]

mild to moderate wheeling ill never do lockers and all that stuff i just want to do some mild to moderate wheeling i Uwharrie brown mtn snow rds

[Car RamRod]

thanks i found 86 mj 4x4 that has been a roll over it is a 2.8 stright drive would this be a better swap then the xj

 

No. Avoid the 2.8 like the plague.

[86jeep]

thanks all of ya