View Full Version : 89 xj

06-08-2006, 09:45 PM
just picked up a 89 xj 4.0 litre fuel injected 5 speed, was wondering if there are any tricks to put more ummph in the motor without spending alot of dough?? also if anyone knows of any known weaknesses they tended to have in the vehicle? any suggestions or knowledge would be appreciated ty [cheers] [cheers] [15]

06-08-2006, 10:25 PM
More ummppphhh, Try a k&n air intake tube with a free flow muffler and throttle body spacers. As for weaknesses, Those dana30 and dana35 diffs are garbage.

06-08-2006, 10:34 PM
so what diffs would you suggest out of a what?????? lookin' to make it good in the bush but also a daily driver so not huge tires maybe 32 at the biggest prob just 31s at the most 5" of lift 2" to start right now( so i don't have to change a bunch of stuff right now) :rolleyes: [cheers] [cheers]

06-08-2006, 10:51 PM
Run 31's and open diffs, use a light throttle and those diffs will last..........longer!

As for more power, make sure all the basics are working, a good tune up will sometimes make the difference.

If you want more acceleration, I'd lean more towards 4.10's then any motor mods. It will feel like you gained 50hp! The 5 speeds usually had 3.07's, which is fine for prarie driving, but not around BC, especially with anything larger then stock tires.

06-08-2006, 11:14 PM
The D30 front is good for 33s.

The rear is garbage. D35s don't live through anything. Breathe wrong and they break.

What ya need is a ford 8.8 out of an exploder for the rear. I just so happen to have one with 4.10s, LSD, disk brakes, and spare parts for sale. I think the spring perches are even at the right width to just bolt right up. It'll hold up to 38s, leaving you some wiggly room.