Plastic under front bumper

[NickS]

What the hell is the plastic trim piece underneath the front bumper called? I tried to get one from a Cherokee at pull a part but they were all already taken.

 

Mine is all wonky so I wanted to replace it. Are they supposed to be flat or have some curve to them?

 

Thanks!

[Pete M]

a generic term would be an air-dam.

[NickS]

Thanks! I'll see if I can find something online.

 

Do you know if it is supposed to be straight/flat?

[SVPete]

Straight-ish. It will curve some tying into the fender flares, plus the years of wind beating on it.

[HOrnbrod]

The official name is DEFLECTOR, Air, Front, Lower. No longer available. I do have a NOS Mopar one that will fit all 96 and below XJ's and MJ's I'll be listing soon in the classifieds, but it won't be junkyard cheap. 

 

[NickS]

I'm either going to attempt to straighten mine out with a heat gun or just not put it back on and trim the very bottom piece of fender flare so it doesn't look like something is missing. Decisions decisions...

 

If I fail at straightening it and decide I still want one I may be interested HOrnbrod.

[Pete M]

what about using a small piece of stiff metal to hold it straight?

[boxyjeep]

I don't know why anyone keeps these.  Take them off and dremel the flares to match.  Looks much better IMO.

[HOrnbrod]

I disagree. But it's your truck and you can hack it up any way you like.    

 

The purpose of the air dam is mainly for better engine cooling. It creates a low pressure zone on the engine side of the radiator that reduces underbody turbulence and helps to increase CFM airflow through the radiator for better engine cooling at highway speeds.

 

BUT it does nothing to help improve the aerodynamics of our brick-like trucks to improve mileage. Edited just now...

[JMO413]

The OEM all had a number change and went to 5AH08JX9. They are available aftermarket.

[NickS]

9 hours ago, HOrnbrod said:

I disagree. But it's your truck and you can hack it up any way you like.    

 

The purpose of the air dam is mainly for better engine cooling. It creates a low pressure zone on the engine side of the radiator that reduces underbody turbulence and helps to increase CFM airflow through the radiator for better engine cooling at highway speeds. It does nothing to help improve the aerodynamics of our brick-like trucks.

So you are saying that airdams normally serve a purpose but in Comanches it doesn't do much? 

[HOrnbrod]

19 hours ago, JMO413 said:

The OEM all had a number change and went to 5AH08JX9. They are available aftermarket.

 

Those are junk - another flimsy POS C.R.A.P. part.

 

The XJ/MJ front air dam went through several part number changes, the last being 5EV24SX9 for the 1996 XJs. They are all interchangeable and compatible from 84-96.  

[HOrnbrod]

13 minutes ago, AntiNicker said:

So you are saying that airdams normally serve a purpose but in Comanches it doesn't do much? 

 

Nope. Read it again. I said it does nothing for the MJ aerodynamics, or lack thereof.

But it does help with engine cooling at speed..