knever3

I have posted this on another site also but can't seem to find the right answer. Here goes:

Specs first,

1987 Jeep Comanche had 4.0L 2wd ba-10/5

Installed aw-4 trans, 242 case and all under hood wiring and fuse box from 1990 XJ. Ran fine until I noticed the flex plate knock. Thought it was a rod bearing so I decided to install my stroker motor. '96 block and head, kept all the renix stuff including the flywheel from the last motor, which was from the '90 donor.

After noticing the noise was on the new motor I removed the flex plate and ordered a new one for an '87 Comanche. I noticed that the windows in the outer ring were in different locations than the old one I pulled. Sure enough, installed it and the timing is so far off it won't start. Ordered one for the '90 XJ and it turned out to be the same part.

So here's the update today. I went to Advance to get yet another flexplate for a '90 XJ/MJ. It was sealed and when I opened it up to compare it was exactly the same as the first three I saw. I took some comparison pictures for you all to noodle on.

Old one with the crack, reason for the whole debacle.



Old one vs. new one.



New one sitting on top of the old one indexed with the crank bolt pattern.













As you can see what I was talking about the timing windows are "off" between the two.

Here's some pics of the CPS.








I bought a flexplate from Crown, I even checked the box to make sure. The same result. The windows are in the wrong spot. I guess I should put it back in and just adjust the dist untill the timing is correct. That is really crazy since the dist is supposed to be set to TDC 0 degrees and the computer is supposed to adjust the timing according to the knock sensor and such.

Picture of all three, my original on the bottom, Advance Auto's ATP/Dorman, and the Crown is on the top. The flexplates do have different holes drilled in them in some locations most likely for balancing.



Back to square one...


Please direct me to anyone that can help with this problem. I need to get my truck going ASAP. Thanks!!!!

caldwell_sean

I had a similar problom except it was the sickness of the flexplate that was off on all after market plats i called the dealer and they said the only thing u can do is get one from them.

xKHANx

What's a flexplate run from the dealer, $763.72?

Lowrange2

Hmmm, what's the part number on the new flexplates pictured?

"A Renix style flexplate and an AW4 flexplate will not work. 1990 and older sensors had different trigger notches."

I can't make the link work but I see this on a google search.

Try a different year. Look at a 1987 AW4 Flex Plate and a 1993 Flex plate. One of the two is bound to be the right one. I think your old one is a Renix plate and the new ones from the store are HO plates.

I bet you're tired of dropping the transmission aren't you?

Lowrange2

Part numbers:

1987 AW4 Flex Plate Pioneer: FRA333 Dorman: 04423
1993 AW4 Flex Plate Pioneer: FRA480

Which one do you have? Or rather what's the number so I can cross it over to one of these.

freegdr

Those are both renix plates ho has a lot fewer holes ...

Lowrange2

Hmm, I'm not sure then.

91+ shows one plate
90- shows a different plate. There are no other options in between.

All pre-90 AW4s used the FRA333.

Evo8

I had a similar problem when I replaced my transmission. I went through multiple aftermarket company all with issues. I eventually went to Jeep and purchased one for about $150 - good luck and try the stealership.

Scott_Sport99

I bought a flex from dealer--$120. Oem

caldwell_sean

Here in south texas new from dealer mine was $100

freegdr

90 is renix 91 is HO ...

freegdr

flip one over do hole line up then maybe crankshaft holes got press on wrong side ?

Lowrange2

I know. Just reading what the catalog says.

freegdr

What year is the stroker motors crankshaft ?

freegdr

No listing for aw4 in 87 ?...http://www.factorychryslerparts.com/...=0&searchTerm=