Can we assume you're referring to exhaust manifold studs and gasket(s)? If so, you should probably replace the gaskets anyway after loosening/replacing the studs.

 

Gaskets only reside between head and manifold. The OEM double/triple gaskets which are metal layered type are usually in poor enough shape that you should replace them. Kroil won't hurt them further..the stench of that stuff might freeze your brain...worse than Simple Green.

No gaskets on the ball or flange at the Y connect. Although, going around the ball with a finger full of Ultra Copper won't hurt before bolting it together.

I gave yuh a link to some good replacements earlier...Mahle and Victor Reinz are one and the same, can't do much better .

The flange bolts will most likley bust.

 

...

 

Yes, exhaust manifold studs. My intent is to remove the two broken studs without disturbing the rest. If it doesn't work, then yes, I'll do the whole manifold.

 

So here's a weird one. I went offroading today, and when I got on the highway to come home, I noticed this funny vibration when coasting above 65 mph. Imagine the noise a rumble strip makes - like that, but much quieter. I could feel it in the steering wheel. My first thought was suspension, but then I heard the exact same noise/vibration at idle. Makes no sense! When I got home, I poked around a little bit with a flashlight. Nothing seems out of place, but the weirdest thing is the noise seems to be coming from the middle of the truck - not the engine.

What could this be? Engine/trans mount, maybe?

 

Most common first with your symptoms.

1. The exhaust Y and/or exhaust from the mid pipe back isolators. The Y isolates directly at a connection to the plate which is between the trans mount and transmission...plate is sandwiched in the two. The rear Y bushing (The exhaust hanger for this bushing is located center of the exhaust Y crossover. Follow the hanger to locate that bushing) can eventually wear at that connection. It's a heavy and critical bushing as it supports the entire back half of the Y. The forward section of Y isolates at the motor mount bushings.

2. Trans Mount. Located between the main trans support crossover and transmission. The bushing material within the mount can actually disintegrate and break down to nothingness. You can check the mount just by crawling under and taking a look.. once you know what it suppose to looks like. Look up a trans mount replacement for these trucks, that should give yuh the right idea.

3. Is the motor mounts, generally not the issue...can't rule it out though.

Once you loose a bushing in any of these location, the vibration can transfer to anywhere on the vehicle..through the steering wheel, under your seat...anywhere. It can ruin and bust shiii up as well if you let it go.

 

Bad trans mount bushing and new.

Also a bad Y hanger bushing (that orange material)...what's left of it. 165,000 miles E4OD/4R100...it's heavy. The support plate took a hit and cracked across the bottom. Heavy plate, had to be welded before bushing replacement. Also screwed the converters up and bent the Y vs tearing up the manifolds.

 

Hard to tell from the pic, to give you some idea, you could grab the trans bushing by the studs and flop it all around inside the housing. It wasn't doing nothing...metal to metal, no support.

I've seen them break the cross-members on these trucks as well. The bushing will come right through them if you ignore it long enough lol. Once the bushing totally went, it vibrated the truck pretty good. Actually that was at 185,000 miles..not 165.

 

Thanks, Jbrew. I'll look into these suggestions.

 

Thats probably it right there, yeah? It's touching on the right.