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99xj distributor rotor wobble

N

ninewon

NAXJA Forum User
Location
Seattle
I just got a 99xj classic aw4 4.0L with roughly 64K miles. Mostly in good shape. Did the renew all fluids and tune routine when I noticed the distributor rotor had some side to side movement. Ok it's toast, I'm good with that. Looked at at many threads I could to see about some knowledge on a good replacement distributor. Personally I'd like a new one. Checked online at napa and O'reilly Autoparts and they list two. I called the store and asked what's the difference between the regular distributor and the electronic??? No one seams to know.
I don't have coil packs, the one I have has the Cam sensor.
Mopar has a part # 56027028 that they used to make, it's NLA. I'd like to get one tomorrow so I can fix rig on my day off and not loose a day of work.
Anyone have knowledge on this mess???
Thanks ~M
 
There are no bearings in the distributor, just steel bushings. These wear over time and cause the slop. The drive gear can also wear. I would head down to NAPA and get one. If it doesn't go in right, look closely at the drive gear. Cardone only specs 1 distributor in their catalog for both the 2.5/4.0 engines, but Jeep specified two. The difference is in the drive gear. There is about a half tooth offset between them. So if it doesn't work, return and get another one. Or re-use your existing drive gear if its in good shape. Or try to replace the bushings with good used ones. You can use a Jeep 2.5L distributor if you can swap your drive gear. Jeep sourced distributors from Standard and at least one other company. I am not sure what the difference in catalog is between regular and electronic, but I can guess that earlier distributors didn't use a flat cam position sensor that sits on top, they used some beefy magnetic pick up deeper in the distributor. Have them put both on the counter and compare. The good news is that there really isn't much to these, so you should be able to cobble something together with what's available. Jeep distributors are not like the old school vacuum advance deals, etc. There is no advance whatever in them. Its just a shaft that turns, and a sensor to pick the signal up. The computer takes that signal and does what it needs to do.
 
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Much thanks I'll try napa tomorrow. Hopefully it works better than the TPS they sold me that was bad from the start ��
 
I buy things like crank and cam sensors & TPS from the dealer. I live in an area where XJ's are on every street corner so the local dealers stock anything that will leave you stranded. On my 97, the NAPA oil pressure sending units wouldn't work with a crap, but the Mopar one worked just fine. At our last NAXJA Fest here in Colorado, an out of towner needed a distributor and got a good one on the first shot from the nearest NAPA.
 
md21722 said:
There are no bearings in the distributor, just steel bushings. These wear over time and cause the slop. The drive gear can also wear. I would head down to NAPA and get one. If it doesn't go in right, look closely at the drive gear. Cardone only specs 1 distributor in their catalog for both the 2.5/4.0 engines, but Jeep specified two. The difference is in the drive gear. There is about a half tooth offset between them. So if it doesn't work, return and get another one. Or re-use your existing drive gear if its in good shape. Or try to replace the bushings with good used ones. You can use a Jeep 2.5L distributor if you can swap your drive gear. Jeep sourced distributors from Standard and at least one other company. I am not sure what the difference in catalog is between regular and electronic, but I can guess that earlier distributors didn't use a flat cam position sensor that sits on top, they used some beefy magnetic pick up deeper in the distributor. Have them put both on the counter and compare. The good news is that there really isn't much to these, so you should be able to cobble something together with what's available. Jeep distributors are not like the old school vacuum advance deals, etc. There is no advance whatever in them. Its just a shaft that turns, and a sensor to pick the signal up. The computer takes that signal and does what it needs to do.
Click to expand...

OK I am not arguing that the casting, shaft, etc. are the same but wouldn't the reluctor or whatever have to be different by definition between a four and six cylinder engine?
 
N8N_99xj said:
OK I am not arguing that the casting, shaft, etc. are the same but wouldn't the reluctor or whatever have to be different by definition between a four and six cylinder engine?
Click to expand...

Nope. The pickup is the same. The drive gears even have the same number of teeth. The only difference is the offset of the drive gear and the part number. :) If you try to stuff a 4 cyl distributor into a 6 cyl and use the FSM procedure for alignment, it will never work. If you swap on a 6 cyl drive gear, it works perfectly. Internally they are indexed differently, which is a matter of putting an alignment punch in the correct hole during installation, per the FSM.
 
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Needed it fixed today so went to O'reilly auto (Shucks) and got a spectra with a lifetime warranty. Will definitely keep that receipt!! Would have liked a mopar.... couldn't find a site to order from that didn't say "no longer available" I kept the old one. Need to find a place that rebuilds them so I have a spare.
 
md21722 said:
Nope. The pickup is the same. The drive gears even have the same number of teeth. The only difference is the offset of the drive gear and the part number. :) If you try to stuff a 4 cyl distributor into a 6 cyl and use the FSM procedure for alignment, it will never work. If you swap on a 6 cyl drive gear, it works perfectly. Internally they are indexed differently, which is a matter of putting an alignment punch in the correct hole during installation, per the FSM.
Click to expand...

I would believe all of the above, but wouldn't the rotating bit on the shaft that the pickup is reading have either four or six bits on it as appropriate? NB: I really am asking out of curiosity as I could very well be wrong, but it's been that way on every distributor that I personally have worked on.
 
N8N_99xj said:
OK I am not arguing that the casting, shaft, etc. are the same but wouldn't the reluctor or whatever have to be different by definition between a four and six cylinder engine?
Click to expand...
Yes, the reluctor ring would be different.
 
Now THAT makes my head spin! :spin1:
 
N8N_99xj said:
I would believe all of the above, but wouldn't the rotating bit on the shaft that the pickup is reading have either four or six bits on it as appropriate? NB: I really am asking out of curiosity as I could very well be wrong, but it's been that way on every distributor that I personally have worked on.
Click to expand...

Hypoid said:
Yes, the reluctor ring would be different.
Click to expand...

I pulled the distributor from my spare parts. The "reluctor ring" has one tooth. Unlike older ignition systems, this one tells the ECU which stroke #1 is on. The ECU controls the spark pulse and advance.
 
ah. weird hybrid of old school and new. I thought that that kind of setup would just use a cam position sensor and coil packs, but I just learned something. Never got into the dist. of my '99 other than to change the cap and rotor, and my 2000 obviously doesn't even have one.
 
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