Manifold to Y-Pipe Exhaust Gasket Replacement

[Indiana80]

Is it easiest to replace the donut gaskets in y-pipe to manifold connection from top of engine (pulling off manifolds) or from underside? It looks like it will be easiest from top. If top is best, should I replace manifold to head studs and nuts while doing the gaskets?

 

[Seth_O]

I replaced mine while doing a HG. So I pulled everything from the top.

That being said, it was a right PITA getting them to reseal. To reassemble I had to attach the manifolds to the down pipes and crank them down tight and then attach the whole assembly to the head. Doing it the other way resulted in an exhaust leak every time.

I reused my hardware no problem.

 

[Tools R Us]

I find it much easier, quicker to drop the y-pipe.

 

[JeepinPete]

You can reach all four nuts from underneath the truck, just going to take a few long extensions.

The chance of opening the proverbial can of worms is high, depending on the condition of the nuts and studs. I did this job, ended up stripping one of the studs. Had to pull the manifold to replace it (did both while I was in there). The studs broke off, so after many nuts welded to the remains of the stud, I finally got the busted studs out.

Good luck

 

[NLXTACY]

100% easier lying on your back with some extensions. The flange on the Y down pipes have domed inverted flares that are designed to help center the pipe into the exhaust manifolds but more importantly to hold the exhaust donuts in place while putting everything back together. Perfect time to change out the studs and hardware with new OEM:

Exhaust Manifold Downpipe Kit

Exhaust Manifold Downpipe Kit (EMK-1)

absolute-wits-end.com

 

[midfat]

I found heating up the manifold flange with some MAP gas BEFORE your start unscrewing the lock nuts and/or stud (from beneath) helps prevent this...