TJ 4.0 2004 split header to dual cat leak again

[jsheathcote]

After removing the front nearside wing for the fourth time to check and tighten the four fasteners that hold the headers to the cat, and now needing to do it again, I'm hoping someone knows a solution.

I have used 4 new fasteners, added butterfly washers and tried a small dab of threadlock, and still it has opened again. TIC TIC TIC TIC........

I noticed that the '96 - '00 uses a 6 into 1 exhaust manifold onto a single system pipe utilising a donut gasket. Mine didn't have any fitted, I can't see any evidence that they are required on the later TJs but this is the way I am heading - measure the header exit and the cat joints to see if a suitable donut would fit.

Anyone else had similar issues? What were your fixes?

Thanks for reading.

Jay

 

[mudmaster]

Mine hasn't loosened since using these: https://regionoffroadparts.com/prod...D1LX10-xW-mlcFEywkjpE3ajMKnNcXFUaAhYlEALw_wcB

 

[macleanflood]

Yeah I'd order a 97-99 Banks Torque Tube exhaust, get it ceramic coated and run the one cat next to the transfer case.

That's how my 97 is set up. When I worked on the neighbor's 04 WJ with your CAT setup it took me four hours to deal with the exhaust and an hour to change the head gasket.

-Mac

 

[jsheathcote]

Mine hasn't loosened since using these: https://regionoffroadparts.com/prod...D1LX10-xW-mlcFEywkjpE3ajMKnNcXFUaAhYlEALw_wcB

Great idea! Thanks. These would have cost me £31 plus £33 shipping so I found an alternative Nord-Lock nut in the UK which should do a similar job. Ordered and due for delivery tomorrow.

https://www.nord-lock.com/nord-lock/combi-nuts-product/

I still might look into seeing if I can find a donut gasket to double down on any possible future leak.

Thanks.

Jay

 

[jsheathcote]

Yeah I'd order a 97-99 Banks Torque Tube exhaust, get it ceramic coated and run the one cat next to the transfer case.

That's how my 97 is set up. When I worked on the neighbor's 04 WJ with your CAT setup it took me four hours to deal with the exhaust and an hour to change the head gasket.

-Mac

I battled with mine for days when originally swapping out the old cast split header for the stainless Banks. Once I realised that the left side wing (fender) comes off in about 30 minutes, that's what I've done each time. Quicker and less skin and blood loss.

 

[GoldenGorilla]

After removing the front nearside wing for the fourth time to check and tighten the four fasteners that hold the headers to the cat, and now needing to do it again, I'm hoping someone knows a solution.

I have used 4 new fasteners, added butterfly washers and tried a small dab of threadlock, and still it has opened again. TIC TIC TIC TIC........

I noticed that the '96 - '00 uses a 6 into 1 exhaust manifold onto a single system pipe utilising a donut gasket. Mine didn't have any fitted, I can't see any evidence that they are required on the later TJs but this is the way I am heading - measure the header exit and the cat joints to see if a suitable donut would fit.

Anyone else had similar issues? What were your fixes?

Thanks for reading.

Jay

The stock precat setups are designed for a ball and socket connection, no gasket.

Are you using headers or the stock cast manifolds? Example headers bottom.

If stock manifolds, I'd loosen their connection to the head slightly so that the connection with the precat assembly gets situated. Then tighten them back to spec.

If headers, you might want to check the surface of the precat socket is clean (ie scotchbrite abrasive cleaned) as the mating surface might be a little different.

Then I'd make sure the back part of the connection at the main cat to exhaust side is loosened, so that you can properly cinch up the front end securely. Tighten front and back a little at a time.

I suspect threadlock will not hold due to the heat there.

 

[Mud Mixer]

Used a high temperature locknut like a Stover.

 

[GoldenGorilla]

While I agree with the stover in general, the Mopar speednut part 0650 6546 AA - 004 is still available for $25.

 

[Daryl]

Once I realised that the left side wing (fender) comes off in about 30 minutes, that's what I've done each time.

I learned something today. Across the pond, a fender is called a “wing”