Downpipe bolt frustation and correction

[eburrows]

In the 7 years I've had my disco, I've had to drop my downpipe three times. Every single time, at least one of the studs snapped off. The first time that happened, I bought a whole new exhaust manifold to really fix the problem. The last two times I was too upset at the designers to give them more of my money, so I'm running now minus two. Of course, this causes a bad seal, exhaust gas leak, and noise.

So... Two questions:

1. How can I care for these studs better so that they don't snap on me next time? Anti-seize? PB Blaster every 3000 miles? Titanium?!?!?

2. What about just drilling them out, and using a real bolt instead of the double-sided threaded stud? Anyone tried this? Can you effectively get a wrench (or maybe a crow's foot) up there to hold it?

Whoever thought of threading a hole in a cast-iron part that cycles 500 degrees in temp several times per day needs to have their head put in a vice!

 

[monkeyboy]

You have been using the copper / bronze looking shouldered nuts that are supposed to be there, right?

I don't really want to say it too loudly.....but I've never had an issue with that particular fastner...shhhhh...

 

[landrovered]

Monkeyboy, I think all 6 studs on your truck just froze solid. You better go check.

 

[eburrows]

That statement HAD to move my gremlins to your house...

 

[btp98w]

Everytime I know I am going to be messing around with a job like that on my trucks I simply soak it with PB every day for a couple days leading up to the job. With PB and maybe a torch for some heat here and there I have been good. Helps I don't drive my truck daily so it can sit and soak I guess.

 

[monkeyboy]

Hey, I do what I can to help out

 

[agbuckle98]

take the manifolds off so you can work them on the bench and get those broken studs out, it's not hard to do. Heat up the areas of broken studs red hot, and they come right out with vice grips. Chase the threads, install stainless studs, never have this problem again.

 

[MUSKYMAN]

I think the first key to not breaking these is in tool selection...I use a 1/4" drive ratchet with a 6" extension to put some spring in the game. This prevents overloading the studs.

if the extension just springs as you turn it you know anymore force will break the stud. then I try taking a large brass drift and placing it on the stud and tapping it with a hammer as well as using either kroil or PB blaster in liberal amounts.

often spraying from the top as well.

the end result on really stuck ones is often the stud comes out of the manifold and thats really not a issue because then you just replace it with a new fresh one and away you go.

 

[JohnB]

I've had the inner stud closest to the engine break on mine. When the stud did come out it took the threads with it. I simply drilled it out and used a new exhaust stud with a copper bolt on each end. This will only work on the inner stud. You can't drill out the other two.

Soaking them really helps. I'm on the fence with using a ratchet. I always use air impact tools and go for it. The shock of the Hi-power ratchet usually breaks it loose(usually).

Of course in Oregon we don't have near the rust that you guys out east get. I had an employee a few years ago who was from Vermont. Every bolt he installed he would coat with anti-seeze, overkill for Oregon(we don't use salt out hear).

 

[squirt]

In the past, whenever I've had issues with downpipe studs, I simply grind off the remainder and drill out the stud and all the threads. Then use a through-bolt. This way the next time the bolt breaks, you just pull out the other half and replace the whole thing. Just did this on the '02 that I picked up for a song because of an "engine knock" that was, in fact, a missing downpipe stud.

 

[alex]

Yep, just get rid of the little studs and replace with 3/8.

 

[ptschram]

Of course in Oregon we don't have near the rust that you guys out east get. I had an employee a few years ago who was from Vermont. Every bolt he installed he would coat with anti-seeze, overkill for Oregon(we don't use salt out hear).

LOL, when I was working for L-R PDX, the techs all made fun of me whining about the rust until things got slow and I gave one of the techs my trail rig to do the fuel tank recall...

Well, between the mud and the rust, I did not do anything to improve our relationship.

As far as the studs are concerned, if they break, the owner is getting a new manifold, I've spent WAY too much non-billable time trying to get manifolds flush and able to seal.

Good luck, use LOTS of PB blaster. I don't know that anti-seize is a lot of good on stuff that gets THAT hot, I doubt it can hurt though.

PT

 

[monkeyboy]

...non-billable time...

I'm unfamiliar with this phrase......please explain






KAA