If its not an engine vibe or a driveline vibe. WTF is that vibe?
07-13-2010, 08:31 AM
#22
I just spoke to Joey at Tick performance and he told me that 99% of all folks who send them a tranny complaining of vibes are disappointed when they get it back because it was not the tranny causing the problem. Thats certainly discouraging.
I just submitted a request for information to their tech line posing the question to folks who rebuild the trannys.
I also just found this on the board by Texas drivetrain performance:
Originally Posted by TDP
The T56 mainshaft tends to get worn at the spot where the 5-6 driven gear is pressed on. Simply put, it is a bad design from the factory. The gear starts moving back and forth as it loses its press fit. Then it wears the splines down. From that point it gets progressively worse. I've been running into this more and more with the rebuilds that I do. There is a fix that I offer. I get the mainshaft re-machined to .005" thicker than stock so the gear presses on a lot tigher, and this eliminates the problem. I wouldn't have thought that this would cure a driveline vibration until I "accidently" fixed a vibration in a customer's car. He had been chasing the vibration issue for 2 years and pretty much gave up. While rebuilding his tranny I noticed the mainshaft was worn, so I had it re-machined. At this point I did not know he even had a vibration. After he got his car back he called to tell me his vibration was gone. I'll have to post up some pics soon so its easier to understand. Anyway, I offer this service for $100 exchange. You just have to send in your mainshaft.
I just submitted a request for information to their tech line posing the question to folks who rebuild the trannys.
I also just found this on the board by Texas drivetrain performance:
Originally Posted by TDP
The T56 mainshaft tends to get worn at the spot where the 5-6 driven gear is pressed on. Simply put, it is a bad design from the factory. The gear starts moving back and forth as it loses its press fit. Then it wears the splines down. From that point it gets progressively worse. I've been running into this more and more with the rebuilds that I do. There is a fix that I offer. I get the mainshaft re-machined to .005" thicker than stock so the gear presses on a lot tigher, and this eliminates the problem. I wouldn't have thought that this would cure a driveline vibration until I "accidently" fixed a vibration in a customer's car. He had been chasing the vibration issue for 2 years and pretty much gave up. While rebuilding his tranny I noticed the mainshaft was worn, so I had it re-machined. At this point I did not know he even had a vibration. After he got his car back he called to tell me his vibration was gone. I'll have to post up some pics soon so its easier to understand. Anyway, I offer this service for $100 exchange. You just have to send in your mainshaft.
07-13-2010, 08:36 AM
#23
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alot of miles on the tranny, it could be the gears, or bearings.
you could check pinion nut make sure its still snug, never heard of a 9inch backing off though.. you could also pull the third member and check the runout on the ring gear and dbl check backlash... i've seen street and pro gears both needing a small adjustment after they got some miles on them.. i always set gears up tight because they usually wear a little (couple thousandths), and if they were set loose they will wear out of the backlash tolerance... it sounds like gear chatter from somewhere either trans or rear..
you could check pinion nut make sure its still snug, never heard of a 9inch backing off though.. you could also pull the third member and check the runout on the ring gear and dbl check backlash... i've seen street and pro gears both needing a small adjustment after they got some miles on them.. i always set gears up tight because they usually wear a little (couple thousandths), and if they were set loose they will wear out of the backlash tolerance... it sounds like gear chatter from somewhere either trans or rear..
07-13-2010, 08:40 AM
#24
alot of miles on the tranny, it could be the gears, or bearings.
you could check pinion nut make sure its still snug, never heard of a 9inch backing off though.. you could also pull the third member and check the runout on the ring gear and dbl check backlash... i've seen street and pro gears both needing a small adjustment after they got some miles on them.. i always set gears up tight because they usually wear a little (couple thousandths), and if they were set loose they will wear out of the backlash tolerance... it sounds like gear chatter from somewhere either trans or rear..
you could check pinion nut make sure its still snug, never heard of a 9inch backing off though.. you could also pull the third member and check the runout on the ring gear and dbl check backlash... i've seen street and pro gears both needing a small adjustment after they got some miles on them.. i always set gears up tight because they usually wear a little (couple thousandths), and if they were set loose they will wear out of the backlash tolerance... it sounds like gear chatter from somewhere either trans or rear..
07-13-2010, 02:34 PM
#27
I plan on doing some more diagnosing once it stops raining.
07-13-2010, 05:29 PM
#28
I just had a long conversation with Jason at Texas Drivetrain Performance and after giving him all of my details, he is 95% confident that the problem is the 5/6 gear cluster losing its tightness on the back of the main shaft which causes it to dance and wobble when on the gas at high RPM. Jason provided very useful information and seemed very eager to help me resolve the problem. 
For $80 plus a core, he will provide a refurbished main shaft that has the problem area "built up" and machined round to ensure a much tighter fit with the 5/6 gear cluster. If the 5/6 cluster gear shows no damage, it can be reused however if its trashed, he has those for sale new. Of course all of this requires full disassembly of the tranny which I am willing to tackle.
Of course while its gutted, I would replace the 3/4 fork, springs, rings and pads at the same time.
This is very good news considering I have eliminated the usual suspects that cause vibes and the overall expense to rebuild the tranny will not be unreasonable. After searching, I have seen where others on thirdgen and some Stang boards, came to the same conclusion on the 5/6 gear and after a rebuild, the vibes were gone so this does appear to be something new.
This seems like a good winter time project. I really hope this works. I dont think buying a third driveshaft or screwing with the angles over and over is helping much.
Thanks for the info Jason.
For $80 plus a core, he will provide a refurbished main shaft that has the problem area "built up" and machined round to ensure a much tighter fit with the 5/6 gear cluster. If the 5/6 cluster gear shows no damage, it can be reused however if its trashed, he has those for sale new. Of course all of this requires full disassembly of the tranny which I am willing to tackle.
Of course while its gutted, I would replace the 3/4 fork, springs, rings and pads at the same time.
This is very good news considering I have eliminated the usual suspects that cause vibes and the overall expense to rebuild the tranny will not be unreasonable. After searching, I have seen where others on thirdgen and some Stang boards, came to the same conclusion on the 5/6 gear and after a rebuild, the vibes were gone so this does appear to be something new.
This seems like a good winter time project. I really hope this works. I dont think buying a third driveshaft or screwing with the angles over and over is helping much.
Thanks for the info Jason.
07-15-2010, 11:06 AM
#30
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I just had a long conversation with Jason at Texas Drivetrain Performance and after giving him all of my details, he is 95% confident that the problem is the 5/6 gear cluster losing its tightness on the back of the main shaft which causes it to dance and wobble when on the gas at high RPM. Jason provided very useful information and seemed very eager to help me resolve the problem.
For $80 plus a core, he will provide a refurbished main shaft that has the problem area "built up" and machined round to ensure a much tighter fit with the 5/6 gear cluster. If the 5/6 cluster gear shows no damage, it can be reused however if its trashed, he has those for sale new. Of course all of this requires full disassembly of the tranny which I am willing to tackle.
Of course while its gutted, I would replace the 3/4 fork, springs, rings and pads at the same time.
This is very good news considering I have eliminated the usual suspects that cause vibes and the overall expense to rebuild the tranny will not be unreasonable. After searching, I have seen where others on thirdgen and some Stang boards, came to the same conclusion on the 5/6 gear and after a rebuild, the vibes were gone so this does appear to be something new.
This seems like a good winter time project. I really hope this works. I dont think buying a third driveshaft or screwing with the angles over and over is helping much.
Thanks for the info Jason.
For $80 plus a core, he will provide a refurbished main shaft that has the problem area "built up" and machined round to ensure a much tighter fit with the 5/6 gear cluster. If the 5/6 cluster gear shows no damage, it can be reused however if its trashed, he has those for sale new. Of course all of this requires full disassembly of the tranny which I am willing to tackle.
Of course while its gutted, I would replace the 3/4 fork, springs, rings and pads at the same time.
This is very good news considering I have eliminated the usual suspects that cause vibes and the overall expense to rebuild the tranny will not be unreasonable. After searching, I have seen where others on thirdgen and some Stang boards, came to the same conclusion on the 5/6 gear and after a rebuild, the vibes were gone so this does appear to be something new.
This seems like a good winter time project. I really hope this works. I dont think buying a third driveshaft or screwing with the angles over and over is helping much.
Thanks for the info Jason.
No problem! I am seeing this more and more (about 2 out of every 3 T56s). It usually doesn't cause a vibration unless it is really bad, though. I'll take some before and after pics today and get them posted late this evening.
-Jason
07-15-2010, 04:02 PM
#31
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the only problem i see with his fix is hes going to weld up your mainshaft and remachine it...
i'm not the smartest guy in the world,just an old machinist, but i do know that welding on something that is already hardened can be iffy and not the best fix..
i'm not the smartest guy in the world,just an old machinist, but i do know that welding on something that is already hardened can be iffy and not the best fix..
08-08-2010, 02:01 PM
#33
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Several other people had this as their first thought, as did I. However, I can assure you that it is done right. If it was a questionable repair, then I wouldn't even consider doing it. I can get the pilot bearing surface repaired on the input shafts, any bearing journals repaired or re-sized, while maintaining the hardness of the material. The machinist who does these repairs for me is the same guy who did one of the first stroker crankshafts for Keith Black, by changing the stroke of the crank. He has also done fab work for the space station while he was in the military. So, yeah, I think he knows what he's doing.. :p
I'm not going to bother explaining how the process works, but I guarantee that it is very effective and I've had zero problems.
08-08-2010, 06:20 PM
#34
Sorry, haven't been on here in awhile..
Several other people had this as their first thought, as did I. However, I can assure you that it is done right. If it was a questionable repair, then I wouldn't even consider doing it. I can get the pilot bearing surface repaired on the input shafts, any bearing journals repaired or re-sized, while maintaining the hardness of the material. The machinist who does these repairs for me is the same guy who did one of the first stroker crankshafts for Keith Black, by changing the stroke of the crank. He has also done fab work for the space station while he was in the military. So, yeah, I think he knows what he's doing.. :p
I'm not going to bother explaining how the process works, but I guarantee that it is very effective and I've had zero problems.
Several other people had this as their first thought, as did I. However, I can assure you that it is done right. If it was a questionable repair, then I wouldn't even consider doing it. I can get the pilot bearing surface repaired on the input shafts, any bearing journals repaired or re-sized, while maintaining the hardness of the material. The machinist who does these repairs for me is the same guy who did one of the first stroker crankshafts for Keith Black, by changing the stroke of the crank. He has also done fab work for the space station while he was in the military. So, yeah, I think he knows what he's doing.. :p
I'm not going to bother explaining how the process works, but I guarantee that it is very effective and I've had zero problems.
I will definitely be contacting you and purchase the shaft in the Fall. This is going to be my Winter time project. Looking forward to kill the damn vibe.
