Torque tube swap was succesful, but I still have a rattle.
08-01-2006, 11:06 PM
#16
Team Owner
Hi I would not try to remove the TC bolts to the flex plate and then run the engine as the hub on the TC will probably seize onto the flexplate bore, this is a precision fitany chance that you left the bowden cable mount off of the top bellhousing bolt on top of the transaxle? maybe that could rattle
08-02-2006, 01:54 AM
#17
Rennlist Member
Thread Starter
I don't think the rivets are the problem either. But, if we get that far back into it, I think I'll replace them just to be safe. As good as the rear converter bearing felt, its just hard to imagine it causing this much noise. Obviously, we would find a machine shop to press on the new bearing once we get that far back into it. But, my fear is that this will not solve the problem, and I will have to go back into this for a third time. I mean, we had a good time and all, but I don't think anyone would want to tear into their car this deep three times just for fun. LOL. The noise is really noticible at shut down as mentioned above.
I drove the car another 150 miles today with no problems. If it were the converter or trans it just seems like there would be some other symptoms, and there are none.
So, my only option thus far is to tear back into it, replace the rivets and replace the rear bearing in the TC housing. Reconnect the trans to the TT and fire it up to see if this solved the problem. I could leave the suspension down, and temporarily re-connect the resonators so that we could hear the rattle if still there. If this doesn't fix it, then I could swap out a known good converter and go from there. Does this sound logical?? After these two steps, the only thing left spinning at idle would be one of the splined shafts on the transmisison.
Mike
1987 S4 Auto
I drove the car another 150 miles today with no problems. If it were the converter or trans it just seems like there would be some other symptoms, and there are none.
So, my only option thus far is to tear back into it, replace the rivets and replace the rear bearing in the TC housing. Reconnect the trans to the TT and fire it up to see if this solved the problem. I could leave the suspension down, and temporarily re-connect the resonators so that we could hear the rattle if still there. If this doesn't fix it, then I could swap out a known good converter and go from there. Does this sound logical?? After these two steps, the only thing left spinning at idle would be one of the splined shafts on the transmisison.
Mike
1987 S4 Auto
08-02-2006, 01:59 AM
#18
Rennlist Member
Thread Starter
"any chance that you left the bowden cable mount off of the top bellhousing bolt on top of the transaxle?"
I do remember bolting up a rigid line on the very top of the transmission casing. This was a 10mm bolt and was difficult to get to. But I did manage to get it back on. I think this is what you are talking about.
Mike
I do remember bolting up a rigid line on the very top of the transmission casing. This was a 10mm bolt and was difficult to get to. But I did manage to get it back on. I think this is what you are talking about.
Mike
08-02-2006, 02:02 AM
#19
Rennlist Member
Thread Starter
"as the hub on the TC will probably seize onto the flexplate bore, this is a precision fit."
I wonder if this fit is not so precision any more and could cause a rattle?????
Mike
I wonder if this fit is not so precision any more and could cause a rattle?????
Mike
08-02-2006, 03:16 AM
#20
Team Owner
Hi No the fit of the TC into the flex plate is a precicion fit to center the TC to the plate once the plate is bolted to the TC there are no moving parts, but if you remove the 6 bolts that hold the flex to the TC then turn the flex at anything over 20 rpms then the bore will probably seize onto the TC snout, as it is a close fit , also to note when trying to hammer out the flex from the bearings be careful not ot hit the edge of the bore you will deform the bore and make fitting the TC into it, best to use a Hydro press
08-02-2006, 10:28 AM
#21
Rennlist Member
Thread Starter
We did use Roger's hydraulic press to get the shaft/flex plate out of the housing, and then we used it to press the front bearing out of the housing and press the new one back in. But, we had no way to get in behind the other bearing which was still on the rear flex plate shaft. I have seen a set of dies before that are shaped like a wedge which fit behind a bearing and allow you to press it off. Any competent shop should be able to take care of this for me.
So, the consensus is to try the rivets and other bearing first??
Mike
So, the consensus is to try the rivets and other bearing first??
Mike
08-02-2006, 10:42 AM
#22
Rennlist Member
Mike,
Before tearing into the transmission again I would replace the motor mounts. During one of our tech sessions at Roger's we were trying to find a similiar rattle in Ernie's GT. It turned out to be the rear belly pan ratteling against a mount with a missing bolt. My point is the MM's drop the engine and change the clearance between heat shields, brackets, stand offs and everything else. Also with bad MM's a lot of noise is transmitted into the cabin. With a little luck it may become a non-issue.
Jim Mayzurk
93 GTS 5-spd
Before tearing into the transmission again I would replace the motor mounts. During one of our tech sessions at Roger's we were trying to find a similiar rattle in Ernie's GT. It turned out to be the rear belly pan ratteling against a mount with a missing bolt. My point is the MM's drop the engine and change the clearance between heat shields, brackets, stand offs and everything else. Also with bad MM's a lot of noise is transmitted into the cabin. With a little luck it may become a non-issue.
Jim Mayzurk
93 GTS 5-spd
08-02-2006, 11:00 AM
#23
Rennlist Member
Thread Starter
I was wondering if this would have an effect (MM). I have the new Rock Auto MM in my possesion along with the Real gasket and GTS baffle. I could do these repairs myself and see if that helps. I guess I could also jack the motor up and see if this changes the noise. Here at my work, we use some heavy duty vibration isolation pads to set large Chillers/Air Handlers on. It is made out of a dense rubber compound. They come in 18" x 18" squares and are cut to fit. I could sandwich this between my jack/plywood and oil pan and then lift the motor off the shot motor mounts and see what happens. This would be something I could do in 10 minutes.
I have seen something similar somewhere on the web. A company is using a custom cut piece of rubber pad and sandwiching it between the oil pan and cross member as an alternate solution to replacing shot motor mounts.
Mike
I have seen something similar somewhere on the web. A company is using a custom cut piece of rubber pad and sandwiching it between the oil pan and cross member as an alternate solution to replacing shot motor mounts.
Mike
08-02-2006, 11:27 AM
#24
Drifting
Killav, when I replace my TC carrier bearings I used a triprong gear puller to get the last bearing off of the flexplate shaft. Came out with no problems.
08-02-2006, 11:36 AM
#25
Rennlist Member
Originally Posted by killav
I was wondering if this would have an effect (MM). I have the new Rock Auto MM in my possesion along with the Real gasket and GTS baffle. I could do these repairs myself and see if that helps. I guess I could also jack the motor up and see if this changes the noise. Here at my work, we use some heavy duty vibration isolation pads to set large Chillers/Air Handlers on. It is made out of a dense rubber compound. They come in 18" x 18" squares and are cut to fit. I could sandwich this between my jack/plywood and oil pan and then lift the motor off the shot motor mounts and see what happens. This would be something I could do in 10 minutes.
I have seen something similar somewhere on the web. A company is using a custom cut piece of rubber pad and sandwiching it between the oil pan and cross member as an alternate solution to replacing shot motor mounts.
Mike
I have seen something similar somewhere on the web. A company is using a custom cut piece of rubber pad and sandwiching it between the oil pan and cross member as an alternate solution to replacing shot motor mounts.
Mike
That is the sorbothane mat sold by Paul Jager (Jageng.com ... I think) that is used with success by many to avoid the MM job: as you have the material, it is worth a trial to stuff a slice ( how imprecise
) between the crossmember and sump.I only mentioned the rivet issue in the context of 'brain storming' - you know what internet diagnostics are like ....
08-02-2006, 11:55 AM
#26
Rennlist Member
Is the bearing of the rear flex plate shaft? If yes here is what I would recommend:
Dig into the bearing and remove the cage that holds the ***** in place. All the ball can be moved to one position and will fall out. Remove the outer bearing and the only piece left is the inner part on the flex plate shaft. Take a DREMEL tool with a metal cutter and put a slid into the metal part.
Talk to Roger he has seen this in my garage already. That's how I remove old stubborn and hard to access bearings (timing belt tensioner roller) with this method. It's simple and effective.
Dig into the bearing and remove the cage that holds the ***** in place. All the ball can be moved to one position and will fall out. Remove the outer bearing and the only piece left is the inner part on the flex plate shaft. Take a DREMEL tool with a metal cutter and put a slid into the metal part.
Talk to Roger he has seen this in my garage already. That's how I remove old stubborn and hard to access bearings (timing belt tensioner roller) with this method. It's simple and effective.
08-02-2006, 03:28 PM
#27
Rennlist Member
Thread Starter
O.K. guys. I have some good stuff to go by. I plan on being at Einstein's in Lewisville Saturday. I'm hoping we all can give it a listen and brainstorm some more from there. It always helps to actually hear the problem for yourself. I'm not sure if I will leave here Friday night or drive up Saturday morning and be there around mid morning.
Mike
Mike
08-03-2006, 01:12 PM
#29
Rennlist Member
Thread Starter
Update:
I performed a stall speed test on my TQ converter last night. I did not have a separate tach, but my dash tach refused to rise above 1000RPM's in gear with the throttle floored and brakes on. My car has always been lackluster right off the line, but I just attributed that to the gearing and the general nature of the beast, meaning open highway brawler, not stop light to stop light bandit.
I pulled this info from one of Wally Plumley's posts:
"Transmission Models A28.01/02/03/05/06/08/09/11 should show a stall speed of 2200 - 2600 RPM.
A28.04/07 should show 1650 - 2050 RPM.
A28.12/14/16/18 should show 1750 - 2150 RPM.
Adjust these speed specifications downward 125 RPM for every 1000 M of altitude.
If the stall speed is 400 - 700 RPM low, the torque converter freewheel (one-way sprag clutch) is slipping.
If the stall speed is 300 or more RPM high, the transmission is slipping.
If the stall speed is correct, but the car has limited top end speed, the torque converter freewheel is frozen".
I have the A28.12 which calls for a minimum of 1750 RPM. So, my question is, could a bad "one-way sprag clutch" be causing my rattling noise?
Mike
1987 S4 Auto
I performed a stall speed test on my TQ converter last night. I did not have a separate tach, but my dash tach refused to rise above 1000RPM's in gear with the throttle floored and brakes on. My car has always been lackluster right off the line, but I just attributed that to the gearing and the general nature of the beast, meaning open highway brawler, not stop light to stop light bandit.
I pulled this info from one of Wally Plumley's posts:
"Transmission Models A28.01/02/03/05/06/08/09/11 should show a stall speed of 2200 - 2600 RPM.
A28.04/07 should show 1650 - 2050 RPM.
A28.12/14/16/18 should show 1750 - 2150 RPM.
Adjust these speed specifications downward 125 RPM for every 1000 M of altitude.
If the stall speed is 400 - 700 RPM low, the torque converter freewheel (one-way sprag clutch) is slipping.
If the stall speed is 300 or more RPM high, the transmission is slipping.
If the stall speed is correct, but the car has limited top end speed, the torque converter freewheel is frozen".
I have the A28.12 which calls for a minimum of 1750 RPM. So, my question is, could a bad "one-way sprag clutch" be causing my rattling noise?
Mike
1987 S4 Auto
