jkrubcon

Not sure if starting a new thread for this is the right thing to do. I started looking around on the Jeep because people with the "new head" on the drivers side say the number ends in AB. Are we sure that AB means its a newly designed head or maybe one made by a different shift in the factory. Just throwing this out there, trying to keep an open mind, maybe its not what we think it means. I have AA and AB all over my Jeep. Just look around. Ive included some pics, there are dozens more I haven't included. Again not trying to stir anything up here, just saying maybe we don't know what we think we know.







Look for more pics in post - Pentastar Head AA - AB Issue-2

lanslide

hmmm - interesting

ccuchris

wow that is interesting... I believe since the article states it is a result of gas it has something to do with whether the vehicle is flexfuel or not. Wragnlers are not flexfuel vehciles such a the Charger Challenger and many others. It seems from I read this issue os happening in the non flexfuel vehciles but since its, the same engine oh except for the heads, how could that be?

silverwrangler

hi all

those are common endings on jeep oem parts........ the one you should look at is a sticker on head or engine block or etched/molded number on the same. Build sheet is probably best for accurate info..............................


check 2007 parts catalog and you will see alot AA AB AC endings........................................

jkrubcon

My point exactly...........just because a head says AA or AB means what then if they are in common use?

Gort

Early on, when this AA/AB issue first surfaced, I went over my build sheets several times. And I say build sheetS, because there's one that came with the vehicle that has part numbers, but only for what appears to be optional equipment or stuff that varies between model/country (speedo, radio, inverter, off-road switches, etc.) No engine or anything like that on the single-page build sheet that came with the vehicle.

So I submitted a request through the Jeep site for the build sheet, and their response has a LOT more information on it (including engine, transmission, etc) but it uses option codes instead of part numbers -- the engine code on the build sheet from Jeep is ERB.

Is there another one hiding somewhere -- like stuck under the seat, perhaps, like GM used to do (or maybe still does)?

BigSteve

The only thing that the AA means is that it was the original version of the part. As the part gets revised it becomes an AB. If it gets revised again it becomes an AC and so forth. All manufacturers do this, part gets revised all the time. Some times it because the current part isn't manufactured properly or has durability issues. Some times it is just because they found a way to make the part simpler or cheaper. The AB in the cylinder head issue simply means that the part has been redesigned in some fashion and is now on its second version. Think of it as cylinder head V2.0!

jkrubcon

Can you please explain in detail how you get the build sheet from the jeep site?

Gort

Just go to the Jeep customer assistance page at

http://www.jeep.com/wccsapp/universal/J/index.jsp

and enter the required info (last 8 digits of VIN, etc). In the comments, ask specifically for the build sheet. They replied to me within 24 hours with a detailed build sheet with the option codes (not part numbers, though, as on the paper one that came with the vehicle). It's a LOT longer than the paper one.