Hm, what's wrong with this picture?
06-30-2008, 12:24 PM
#1
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Hm, what's wrong with this picture?
<IMG SRC="http://pictureposter.audiworld.com/14421/bustedtranny.jpg">
This is where the exhaust downpipe bracket attaches to the transmission. I had to fab a custom bracket between the APR exhaust and the transmission, and I think the steel we used was too strong and didn't allow enough flex/expansion.
Nevertheless, I've now got a transmission with a busted exhaust mount fitting on it. Any options at this point? Not sure what to do with it. Guessing it can't be welded back on, or if it was it would just break again. There appears to be another fitting about 8" aft of this one. Anyone know if it's threaded?
I wish I still had the original exhaust bracket, to see how it fit on. Anyone have a picture? 6spd transmission by the way.
On the plus side, at least I know my nasty rattle is not internal to the transmission, as I was starting to suspect...
This is where the exhaust downpipe bracket attaches to the transmission. I had to fab a custom bracket between the APR exhaust and the transmission, and I think the steel we used was too strong and didn't allow enough flex/expansion.
Nevertheless, I've now got a transmission with a busted exhaust mount fitting on it. Any options at this point? Not sure what to do with it. Guessing it can't be welded back on, or if it was it would just break again. There appears to be another fitting about 8" aft of this one. Anyone know if it's threaded?
I wish I still had the original exhaust bracket, to see how it fit on. Anyone have a picture? 6spd transmission by the way.
On the plus side, at least I know my nasty rattle is not internal to the transmission, as I was starting to suspect...
06-30-2008, 12:31 PM
#2
Did you have the mount rubber isolated?
More than likely the crack was caused from vibrations and exhaust flexing.
Thats a pretty hefty steel bracket you have bolted onto the aluminum gearbox!
It can be welded, but finding a welder, who will weld it while your gearbox its still inside your car, will be the challenge. ;o)
You might consider finding another nearby mounting bracket, on your gearbox, to attach the exhaust too?
Fabricate some sort of rubber isolation type mount so the vibrations and flex doesnt make it to the gearbox.
Thats a pretty hefty steel bracket you have bolted onto the aluminum gearbox!
It can be welded, but finding a welder, who will weld it while your gearbox its still inside your car, will be the challenge. ;o)
You might consider finding another nearby mounting bracket, on your gearbox, to attach the exhaust too?
Fabricate some sort of rubber isolation type mount so the vibrations and flex doesnt make it to the gearbox.
06-30-2008, 12:46 PM
#3
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Yes, the steel was clearly too strong
The mount should be weaker than the exhaust/transmission 
Sigh live and learn. I don't think isolating the vibration is going to fix the issue, I think I just need a piece that will expand enough to allow the exhaust to move when it heats up. That, and stop going to the dragstrip with Tgr_Clw, I'm sure that's when I cracked it.
Like I said, there's another mount point just aft of that one, but I'd hate to use it and then have the same thing happen again...
I'd just leave it unmounted if I hadn't already had experience running that way; my old crappy Brullen exhaust was not bolted to tranny, and it would flex and blow out the gasket at the dp/cat coupling every few months. I have a huge burn through my heat shield next to the gasket there... oops.
Sigh live and learn. I don't think isolating the vibration is going to fix the issue, I think I just need a piece that will expand enough to allow the exhaust to move when it heats up. That, and stop going to the dragstrip with Tgr_Clw, I'm sure that's when I cracked it.Like I said, there's another mount point just aft of that one, but I'd hate to use it and then have the same thing happen again...
I'd just leave it unmounted if I hadn't already had experience running that way; my old crappy Brullen exhaust was not bolted to tranny, and it would flex and blow out the gasket at the dp/cat coupling every few months. I have a huge burn through my heat shield next to the gasket there... oops.
06-30-2008, 12:50 PM
#4
here is the ext. braket for a 6 speed. awe exhaust. as u can see there is a spring.
<center><img src="http://disguisemyip.com/browse.php?u=Oi8vcGljdHVyZXBvc3Rlci5hdWRpd29ybGQuY 29tLzc3MTgyL2RkZGRkZGRkZGRkZC5qcGc%3D&b=29"></center><p>
06-30-2008, 03:58 PM
#7
The OEM mount is rubber isolated...
<center><img src="http://pictureposter.audiworld.com/6607/xhaust1.jpg"></center><p>
and the OEM exhaust is much heavier.
I have had my Thermal exhaust bolted to the OEM mount for over 2 years, without any issues.
You might want to reconsider, and fabricate a bracket which utilizes the OEM mount.
and the OEM exhaust is much heavier.
I have had my Thermal exhaust bolted to the OEM mount for over 2 years, without any issues.
You might want to reconsider, and fabricate a bracket which utilizes the OEM mount.
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07-02-2008, 07:21 AM
#10
The stock support has a spring to accomodate changes in exhaust length from cold <> hot....
The Bentley has specific instructions on adjusting the exhaust to prevent thermal expansion stress fatigue failure problems.