94 Dakota- Fixed an exhaust leak and broken studs

So I was on here a while back asking questions/complaints about my 94 Dakota 3.9L.

I had the tranny rebuilt it solved some problems after taking it back 3 times and having to wait 3 days the last time then be told nothing was wrong! Yet they had no test results to show me. I dove it home and they obviously did something because it worked right.

So later on I notice I had a broken exhaust manifold stud, then I found another. My CAT was also a bit clogged (way hotter in back). The last 3 days I removed the manifolds drilled out the two broken studs one each side and replace the manifolds with gaskets and correct studs, bolts, nuts and Belleville washers. Then ran all new pipe with new CAT and Muffler.
No more ticking sound, it wasn’t lifters it was the exhaust leak. It kicks down at the right times, my RPM”s go up over 4k when I punch it, it rides drives smoothly at any speed.

Who would have thought an exhaust leak would cause so many problems? Not me. Apparently the O2 sensor and the PCM are a lot more sensitive than I realized. Heck the PCM is so good it let it idle and rev to 2500 while I did the break in on the CAT with the #1 and #3 plug wires reversed. It’s odd the MT 2500 didn’t show me any indication that I had crossed the plug wires.

Anyway thee it is probably another Dakota common problem. Oh yea the threaded end of the stud that goes into the head is 5/16 course and only ½” long. The hole it is in is a bit longer so don’t get discouraged if you ding up the threads at the front end. One of the two I drilled out ( variously using center drill, drill, remover, and rotary file then chased the threads) sets an 1/8 deeper than the surface of the head. The dealers replacement studs are ½” longer on the other side (5/16 fine threads) than the OE stock studs.
Snug the nuts and bolts up don’t pull hard it only gets torqued to 18 foot pounds. They get real hot and expand a lot I expect the bozo who put it together before me with no gaskets or washers thoughgt making it real tight was good for it.