Exhaust Flange Bolts

I have a '02 3.4L Double Cab. Both of the exhaust gaskets are going bad, one is pretty much gone I think and there is an exhaust leak that seems to be getting worse by the day because of it. Question is i know sometimes the flange bolts can actually be studs. They looks like a normal nut and bolt but i can't tell because they are pretty much rusted through (NH winters will do that). I looked online and can't seem to find an answer. I was going to just break the current ones free and replace with SS bolts. Any one see an issue with this solution. I did see a video online of some guy replacing from the cat back and he had bolts but just wanted to confirm. Thanks.

 

Just looked at mine. Clearly nut and bolt.

 

Thanks, at this point it has all melded into one piece of rusty metal. Thanks again. Should be fun getting them off.

 

Mine are nut and bolt, although I have an 06 haha. I replaced mine with better hardware.

 

When you say both, do you mean before and after cat? Maybe just cut off the pipes and clamp on new material?

Maybe try using a sawzall or angle grinder to cut the bolt head and nut off, then heat up the remaining bolt shank with a torch and drive it out with a punch? Assuming the flange itself is not so rotted that you won't ever get a good seal with it.

 

I would like this answer as well. I have a very similar issue with my 08'. When I broke the studs removing them I drilled the hole out and put in grade 8 nuts/bolts/washers I had in my spare parts bin. Once side now leaks even though they are torqued to all hell and I used new gaskets.

I assume my issue is related to the nut/bolt/washers not expanding and contracting at the same rate as the flange.

I would be hesitant to throw any old bolt in there until someone on here that is a pro can comment further. I have my 2nd set of new gaskets ready and as soon as we get this answer I can finally stop the leak I have that's driving me crazy

 

make sure before you replace the gaskets to check the muffler bearings, they can cause issues later

 

Just wanted to be sure you are talking about manifold flange to downpipe. Not sure if nut n bolt or if stud and nut. But if you replace with nut and bolt, be sure to use lock washers. Grade 8 is fine and so is stainless. These fasteners should not be more than snug tight, at least enough to flatten the lock washers. If you over tighten, your gasket will fail sooner.

The thing with the bolts is that they need to be able to withstand extremely high heat. You can talk to the professional bolt guys at fastenal, or you can take my word that grade 8 or stainless will be fine. As before, overtightening exhaust fasteners will lead to premature failure of your gasket material. Use lockwashers to keep things together better.

 

Basically I am looking to replace the Gaskets on both sides of the second Cat. Not the exhaust manifold. I think I will be working on it this weekend as well as replacing a bad u-joint. I grabbed some SS hardware with lock washers so lets hope it does the trick.

 

Did this finally over the weekend. it was standard nut and bolt (or at least used to be) had to grind down the bolt heads to the flange and punch them out. replaced both gaskets and upgraded to SS hardware. no more exhaust leaks.