Yes...just remove the liners on the wheel wells...When we did the lift on my truck yesterday, found that I was missing 2 bolts on the driver's side manifold in the rear....(Last 2 bolts on the manifold)

 

Same problem here other than the same broken bolt will not come out! I've heated up, used penetrating oil, easy outs. Just so rusted and stuck. I really don't know without damaging threads and having to heli-coil.

 

well since last time ive removed two broken studs and had to leave one in. Not that bad, cant even tell. sounded way better. But of course now driver side is broken. At least three same rear studs. ugh.. I hope i can get all of the studs out this time!

 

Mine haven't snapped yet knock on wood or they were replaced before I bought the truck but wouldn't hurt to have a set on hand when they do eventually break, what brand of bolts ( stainless steel etc.) did you replace with?

 

I used oem bolts and hardware. I know others have sourced their's elsewhere.

 

Same problem here. Both bolts broken on cylinder #8 (passenger side) and #7 (driver's side). Lucky for me it looks like just the tops of the bolts snapped off. The remaining studs are still in place so I should be able the grab them with visa grips and turn them out.

What size are the down pipe to manifold flange bolts? I doubt those will come off without snapping. The dealer wants and atrocious cost for those bolts and nuts. A trip to the local bolt shop is the plan. For the manifold bolt set, I am going to use the Dorman 03211 and FelPro gaskets. (this is a 5.7 Hemi). The manifolds will be cleaned up and along with the new bolts will be VHT painted aluminum colour.

I am also going to apply a different tightening sequence than specified. Starting at the back and working to the front. The rear will be snugged first to the tightest torque, to spec, and each set closer to the front will be tightened to a slightly lower torque. Intent being to allow the expansion stresses move forward instead of rearward. Will that help or fix it and prevent it again, dunno. I may just have front bolts broken instead of the back ones, lol! ... It could also be just years of heat and rust ... (stress corrosion cracking, SCC).

There is no fix for this so long as the heads and the manifolds are not made of materials with matching themo-expansion properties at operating conditions between the head and the manifold. Thermal expansion of aluminum expands 2.2 times more than cast iron or steel. There is aluminum head and cast iron manifold here, and huge differences in temperatures between them at different engine loads. The geometry of the manifold is also very rigid. There is no place for the movement forces to go other than straight front-back which flexes the bolts, (like trees swaying in the wind). There is no flex in this manifold like the bunch of bulbous tubes of aftermarket headers would have. I would expect the guys running headers probably have few or none of these broken bolt problems for that reason. Again, the point being the issue here is NOT the bolts. It is the differential expansion stresses between the aluminum head and a very rigid iron manifold. As a result there is alot of surface movement between them, where the bolts and gasket are constantly flexing to adjust to that movement. Eventually the bolts fatigue and crack, snapping off at the most flexed point, the base where it goes into the head. The hottest most flexed bolts will give up first, the rear ones. Think about flexing a paper clip back and forth, eventually what happens to the paper clip. Same is going on with these bolts. If they do not break, eventually the surface fretting of the exhaust gasket will leak anyways. So if you do not experience broken bolts, great, however for reasons stated do not be surprised if you eventually have leaking gaskets anyways.

Putting stainless bolts or high grade steel bolts in will not solve the problem either. Because as explained, the bolts are not the problem. Stainless bolts are weaker, and stainless also expands 2 times more than cast iron or steel, depend on the grade of course. The problem will just be worse with stainless. The best we can do is use low grade mild steel bolts, that are very ductile (stretchy, bendy, and tough) and very good quality gaskets. When installing, if you want to experiment then use less torque as opposed to the temptation to go more. Even perhaps drill out the manifold bolt holes just slightly to make a little more room for some of that TE movement around the bolt stems. Eventually any bolt here will fatigue and break, however a mild grade steel bolt will last alot longer here than any high grade hardened/stiff bolts which will crack and snap much sooner.

IMHO. Hope that helps!

Why does Chrysler not fix this? Probably because the manifold, as is, is very compact and very efficient. It fits in tight places, has small surface area for easily controlling radiant heat with shields, and it flows well. They can't make it more flexible without being more bulbous which takes up alot of space and is tougher to control the heat. The only options they have are to use ductile tough mild steel bolting or make the manifolds out of some other material that has better thermal properties. Bolts are the easiest and most economical choice ..... fully knowing that they will eventually fatigue. - like the paper clip. Therefore, this will continue to be a recurring problem and perhaps we should all just accept it to become a regular planned maintenance activity, like changing the oil or brake rotors. Like pre-emptively plan/schedule to change the bolts every 40k - 60K - 80k, just short of whatever seems to be the most common time that these are failing?

 

I recently did a 2011 Ram hemi. Bolts were broken flush if not below head surface. Used a mig to weld a tiny ball of weld onto broken bolts. Enough to get a small pair of vice grips on. Worked beautiful! Much better than drilling as I did on my 03 at the start of this post! Will try mig from now on.

 

Pipe flanges to manifold are m10 x 115 mm. Or 3/8 × 4. Roughly. 7/16 × 4 may also work

 

Got it, thanks!

 

Got into it an got mine done over the break. Slow going process. Some Kroil soaking the night before. I was very pleased that all of the bolts unscrewed without much problems. They were stiff but once the loctite cracked, they each came out. I ultimately had to cut the small nut and stem off the top of two of the shield studs. The nuts were so corroded that they were round and would not budge, yet the flange of the bottom of the nut blocks a socket from getting onto the stud hex.

So, once I got both manifolds off the assessment was that I had only two broken bolts, both on the passenger side, both on exhaust #8. I opted to pull both sides and do them all new bolting anyways. The two bolts had broken off at the top of the manifold, head of the bolt broken off. So I had the full stems to work with. Yay, I am a lucky one! ... or so I thought. Those two buggers just would not budge. The strongest vise-grips I had as tight as I could make them, they still slipped, and even a bunch of heat from the heat gun couldn't back them out. What looked like two easy bolt stems that should come out with finger tips, just totally kicked my ***!

I really dreaded the fire risk of getting out a torch or the welder, but alas that is what I ultimately had to do. Welded nuts on the ends. They came out, but not without alot of torque!

Thankful to the boy for helping get everything cleaned up. I took one of the old bolts and point filed a groove along one side through the threads. Turned it into a tap slash thread chaser. Used it to chase all holes. The two where the bolts had broken off where stiff holes. Cleared out a bunch of material, recapping them. I wonder if it is possible that the CNC machine that made the heads perhaps the tap for those rear cylinders was dull or undersized? Would explain them being so tight and snapping. If not originally tapped properly, it would take alot of torque to seat the bolts on the manifold, to the point of over stressing them. .... Just a wandering thought.

Anyways, going back together was using FelPro gaskets (nice!) and the Dorman manifold bolt kit. A note on the Dorman kit; It comes with the correct number of bolts, however for the very front bolt on the passenger side below the EGR port, the slot in the manifold is too thick to use the supplied bolt. I had to pick the best of the left over old longer studs and use it there. I used two Dorman kits to complete it all. I reused one of the old studs. Was left with two new Dorman manifold bolts left over in the box when it was all done.

Took my time. Was very cautious and nervous about ending up with more snapped bolts and bigger problems. I am glad that no matter how hard this thing kicked my ***, I won in the end.

PS: this is also a great time to turn the motor over by hand and have a look in all the ports to see condition of each exhaust valve, at least the visible ones.

Enjoy the read and the pictures. Post a question or PM me if you think I can add any more info or value for you.