I read that some of the early '03 trucks came with a 4" cast elbow instead of a 3.5" cast elbow like the later trucks. Does anyone know if this is true? If so, without taking the downpipe off, is there a way to figure out if I have the 4" elbow?

My truck is an early '03 and I have an exhaust leak at the connection between the elbow and the downpipe of an aftermarket exhaust system that was designed for a 3.5" outlet. I am wondering if I have a 4" elbow and that is the source of the problem.

Does anyone know when they quit putting the 4" elbows on the '03 trucks (assuming they actually DID put 4" elbows on the '03 trucks)?? If this is the source of my problem then I'm thinking I may need to find another downpipe that has a 4" connection instead of a 3.5" connection.

 

All 3.5" that I can remember.
4" didnt start until 04.5.

 

I thought I read on here somewhere that the very early '03 trucks (like mine) had a 4" elbow. I just haven't been able to confirm that.

 

Mine is also an early 03, and the elbow is sitting on a shelf in my garage (I put on a Jake). It does taper to 3.5".

I don't think you could have gotten the wrong size pipe to fit at all, so I don't think that is likely to be the problem.

 

Okay then. I'll go with that.

 

I remember reading the same thing Hoss. Mine is 3.5" but it's sitting on the workbench as I have the Banks DP now. There is a gasket in there. Did you remember to put it in?

 

I didn't see any gasket when I took the old DP off or when I put the new one on....so if there's one there then it was stuck to the cast elbow.

The good folks at DPPI are sending me another downpipe to try out. If that doesn't fix the problem then I think I'm just going to get a Banks downpipe and eliminate that joint altogether. I hate to do that after I paid so much for this exhaust system, but I don't like exhaust leaks.

Any trouble with the Banks DP?

 

You have to reuse the stock clamps that came off the turbo and once you take them off, they have a tendancy to come loose over time. Mine does this and then the DP has a tendancy to spin a little bit until it hits the trans and then I get a little vibration. I've got to put a lock nut on it but I haven't done it yet. Seems simple enough.....
The gasket goes against the turbo so if your exhaust bolts to the elbow then I guess there would not be a gasket..

Good Luck...

 

How does the DP spin? I would think that the support hanger that goes to the transmission (at least on my truck) would keep it from doing any spinning.

Can you not prevent the clamp from loosening up by simply putting another nut on the clamp bolt and tightening it down against the first one?

 

Lock tite the threads with a heat risistant type.

 

A lock nut is the plan. I just have to get out there and do it.
Even with the hanger rod that goes into the trans it will vibrate and spin just enough to rub against the trans.