Easy and Inexpensive Exhaust Flange Repairs

[Sharps40]

So, did this on a GMC Jimmy recently to save the purchase of an entire new exhaust manifold and the attendant days of work removing and replacing it.....something similar should work for about any exhaust manifold where the manifold studs are broken off in the flange.....

 

1987 GMC Jimmy 350 Sierra Classic

 

The problem was a 30 year old exhaust flange doughnut on the passenger side.....puff, puff, puff, and stink in the cab with the windows down.

Before replacing the entire manifold, (yep, studs rusted to the point I knew they'd break off in the flange), try this.

Go ahead and break off the three studs close to the flange and take out the doughnut.  Salvage and reuse the three hole flange connector.

 

 

I have 2.25" OD pipes, duals with no cats.  There are two sizes of exhaust doughnuts, so bought both at $4 each.....after removing my old leaking doughnut, I noted I needed the smaller of the two.......old and small new one on the right.  Ill take the big one, on the left, back.

 

 

For $5 each, I bought two of the 2.5" opening hand cuff clamps. (Called split flanges and they come in scads of sizes and shapes and two hole and three hole, etc.....)  Knowing the bolts would not be long enough I fished around in the parts bins at home and came up with two longer bolts, nuts, washers, spacers, etc.  I selected the 2.5" opening size as its just barely big enough to go around the throat of the exhaust flange and still take a 3/8" bolt,  coulda used a smaller id clamp on the down pipe, but at 2.5" opening it slides up and down freely, smashing the doughnut real good for a fine seal.

 

 

One new bolt goes through the handcuff clamp, down through one hole of the original three bolt flange and through the hole of the lower handcuff clamp.  Slide in another bolt on the other side of the two hole handcuff clamp and squeeze the doughnut but good by tightening the nuts.  You could also use all thread and eliminate spacers as you won't run out of thread if like me, you had short threaded bolts.

 

 

Test ride......no fumes in the cab, finally, I can put the windows down, just in time for spring.....and, no embarrassing noises, just the ever irritating rumble and drone of two magnaflow mufflers behind that good running 350......well, the mufflers may be too noisy for an old man but at least it no longer smells so bad my eyes sting nor sounds like a cockerspanial being squashed every time I get on the gas pedal.

Edited March 13, 2018 by Sharps40

[plymouthcranbrook]

i used something like this on my 2001 Astro:

 

https://www.ebay.com/i/152879906941?chn=ps