Build sheet for my 98 XJ says 117 amp alternator. Went to O'Reilly's they have 90 and 136. I got the 136 and the housing was to big, it won't fit. Measured the 90 amp alternator and it's pretty much identical to what I pulled of my rig. I also went to Pep Boys and it looks to be the same with them.

The mounts seem a little different on the 98 from earlier years. The alternator I pulled off appears to be original equipment, DENSO. Is anyone aware of an higher amp alt that will definitely fit the 98?

What am I risking by running the 90 v the 136?

 

Haven't had to buy one yet (knock wood) but NAPA has Bosch 120 amp alternators.

 

Mechman has alternators that go over 200 amps in the factory housing.

 

The 90 amp is the normal OE replacement alternator, your XJ must have been ordered with an upgrade. Also does anyone know if the fleet service (forest service, police...) XJs came with a slightly higher output alternator?

 

I believe the fleet service came with at least the same 117 mine did.

 

Thanks to all for the input I'm going to install a 90 amp Alt in the morning(unless someone can up with a compelling reason not to) mostly just because I need to get it running. The 90 is available and I guess we'll see if it's enough to get through the winter...

 

No offense, but you not telling us what accessories you run makes your question as useless as a winch on a Prius. A 90 might be perfectly fine for you. Remember the alt will delivery what's requested from your accessories. And the 136alt, good chance that's the GC one and they are *******es at the store. The GC one fits with some minor nodding. There is write ups on it. So in short, if you're stock with no extra lighting or have a big system, the 90 is fine

 

Alternators should have a dual rating.


The 90 Amps is the Test Amps and the 117 Amps is the Rated SAE Amps.

 

Cool. Good to know.

 

mine came with a 117a unit and I replacedit with a 90a. the only strain I have is upgraded headlights. it made it through 2 of the worst winters IN has seen in decades.

 

I got lucky. Mine crapped out the day before hurricane sandy. My local auto zone had (1) 117a tested unit left. I grabbed it and its been decent so far.

 

I haven't added any electrical accessories but from the factory it has PW, PL, AC, CC, Power Heated Mirrors, Fog Lights, Trailer Tow Pkg, Rear Window Defrost and Premium Sound.

So while typing that out it looks to me the factory put the 117 amp alternator on for a reason. I guess I need to hunt around some more and try to find a better solution then the 90.

 

To mount a 136 amp Durango alt wondering if that isn't the same all that's required for mounting is a small amount of grinding on the mount for it to fit. I have one on mine that I had rewound FYI its no big deal a lot of people here run them.

 

When trying install the 136 I could see where it hit the mounting bracket and considered a little grinding but looking closer it appeared the housing was very close or hitting the block also. I am not comfortable grinding on the alt's housing to clear the block. Those kinds of mods are outside my pay-grade.

 

Read pot #8 again.