Replacing Your Exhaust Manifold/Header on a TJ/LJ
Tech Tips January 7, 2019 Corey Osborne
CHALLENGING BUT NOT DIFFICULT MANIFOLD SWAP
Are you tired of your Jeep making that horrible ticking sound? Do you have an exhaust leak? Sometimes the “ticking” will start out loud when the engine is first started and will get quiet as it heats up, basically sealing the small leaks. But when the ticking continues, you will know it’s time to look at replacing your exhaust manifold and/or gasket. At some point in the ownership of your TJ or LJ you will experience the dreaded sound of an exhaust leak. ALL exhaust manifolds seem to crack…eventually.
Even the aftermarket headers with lifetime warranties will fail. The LJ (4.0 L) that we will be working on actually has a Banks exhaust header on it…and its cracked in a couple of places. I will say it again; they will all crack in due time. It’s the nature of the expansion and contraction of the part itself.
While this job isn’t difficult, it can be challenging! But with some patience and attention to detail, it is a job you can perform yourself.
The tools required for the job are not extensive…but there are a few bolts that can be VERY challenging to get to. Having the drivers side inner fender out of the way can be helpful but is not necessary. A camera will be helpful to take a couple of pics of the connections before you start pulling them apart.
- You will need a basic socket set (extensions and flexible head ratchets will be helpful).
- Flexible head ratcheting wrenches (Gear Wrench).
- Your new manifold, gasket and some loctite. We chose a Drake stainless header as a replacement.
While I won’t go into every detail in taking things apart and the reassembly, I’m hoping that the pictures will help give you an idea of what this project entails. There are a lot of resources out there in case you get yourself in a bind. Just be patient, take a deep breath and get to it!
The absolute most difficult part of this project is getting to the bolts that are located under the intake manifold, next to the exhaust tubes themselves. This is where the extensions, wobble head sockets and ratcheting head wrenches will be beneficial.
Those two electrical looking plugs are O2 sensors. One of them was froze into the header tube and we wrecked the threads removing it, so it was replaced.
Using a little anti-seize when reinstalling these into the new header helps.
Remove the existing gasket and clean the surface well before installing the new ones.
That’s NOT a grinding wheel! Just a detail pad to clean the surface. You don’t want to create dips or any uneven portions in the mating surfaces.
This ends the easy part of the installation. Since the intake and exhaust share the gasket, the intake manifold gets installed over the top of the exhaust manifold, making getting to the remaining bolts a really fun time 🙂 So, take your time and think things through. There were two bolts that gave us a hard time but using a mix of extensions and wobbles…in the end, we won.
Because of the particulars of this Jeep build, we realized that the exhaust, as it left the header tubes, would hit the front driveshaft. This LJ sits on a Metalcloak long-arm suspension system and a TeraFlex Tera60 full float front end. That said, Jimi from Alpine Offroad had to be a little creative with the exhaust in order for the driveshaft to clear.
A shout out to the guys at Alpine Off-Road in Montrose, Colorado for helping us with this project!
Additional resources:
Alpine Off-Road & Performance, 970-24o-9000
http://www.dailydriventj.com/forum/viewtopic.php?t=847
Redneck Garage You Tube Channel