545 rfe question when testing

[SD2020]

Hey guys just a quick question. I need to unbolt the TC from the flex plate to help isolate a whine noise. When pushing the TC back into the transmission, how mush clearance should I have approx? I then want to start the motor briefly. Should I be using something to keep the TC from vibrating towards the flex plate? 2011 Ram hemi 1500.

 

[Hagar1]

Hey guys just a quick question. I need to unbolt the TC from the flex plate to help isolate a whine noise. When pushing the TC back into the transmission, how mush clearance should I have approx? I then want to start the motor briefly. Should I be using something to keep the TC from vibrating towards the flex plate? 2011 Ram hemi 1500.

If memory serves me correctly, you will have less than a half inch. Further to that, in all my years of automotive work, I have never seen a problem so bad that there was a need to disconnect the torque convertor from the flex plate. I would use a good stethoscope or a set of chassis ears before I would try that.
Just my opinion.

 

[GeauxinUp]

I don't have much experience with the 545, but this sounds like a disaster waiting to happen!

 

[Sherman Bird]

Hey guys just a quick question. I need to unbolt the TC from the flex plate to help isolate a whine noise. When pushing the TC back into the transmission, how mush clearance should I have approx? I then want to start the motor briefly. Should I be using something to keep the TC from vibrating towards the flex plate? 2011 Ram hemi 1500.

IF you think the torque converter is the cause of the whine, you can isolate it in less than 30 seconds WITHOUT doing something fraught with risk such as what you propose.
Start the truck up. listen to it whine, if it does. Put your foot on the brakes and put the transmission in REVERSE.
Did the "whine" go away? Did it change noticeably? Was there any "thrashing noises emanating from the transmission while it was in reverse? If so, did it go away when the transmission was put back into park?

IF you own an oscilloscope, and IF you have NVH attachments, you can accurately isolate where the whine comes from due to the algorithm of the software and the chart which elucidates the pattern into categories of likely culprits.
When I began using mine, the diag time dropped dramatically.

 

[Hagar1]

I don't have much experience with the 545, but this sounds like a disaster waiting to happen!

YUP!!!! ....... What possibly could go wrong? Well, almost anything.

 

[SD2020]

IF you think the torque converter is the cause of the whine, you can isolate it in less than 30 seconds WITHOUT doing something fraught with risk such as what you propose.
Start the truck up. listen to it whine, if it does. Put your foot on the brakes and put the transmission in REVERSE.
Did the "whine" go away? Did it change noticeably? Was there any "thrashing noises emanating from the transmission while it was in reverse? If so, did it go away when the transmission was put back into park?

IF you own an oscilloscope, and IF you have NVH attachments, you can accurately isolate where the whine comes from due to the algorithm of the software and the chart which elucidates the pattern into categories of likely culprits.
When I began using mine, the diag time dropped dramatically.

The whine will not go away no matter what gear you are in, it just changes tone. I do not have an oscilloscope with NVH attachments. ( a buddy may have though ) The whine will get much quieter but always exists. When the truck is cold and parked outside, I can hear it inside the house 40 ft away. When hot and on the road, I can just make it out over the factory exhaust.

 

[Sherman Bird]

The whine will not go away no matter what gear you are in, it just changes tone. I do not have an oscilloscope with NVH attachments. ( a buddy may have though ) The whine will get much quieter but always exists. When the truck is cold and parked outside, I can hear it inside the house 40 ft away. When hot and on the road, I can just make it out over the factory exhaust.

Is that all 5 forward gears? If so, does the whine change pitch in different gears?

 

[Hagar1]

Hey guys just a quick question. I need to unbolt the TC from the flex plate to help isolate a whine noise. When pushing the TC back into the transmission, how mush clearance should I have approx? I then want to start the motor briefly. Should I be using something to keep the TC from vibrating towards the flex plate? 2011 Ram hemi 1500.

What part of the country are you in? Maybe someone on these boards could lend an ear.

 

[SD2020]

Is that all 5 forward gears? If so, does the whine change pitch in different gears?

Yes all gears. No change in pitch from D to R either. Just quieter when the truck is warmed up fully. I’m up in Saskatoon Canada. I have an appointment to get my truck up on a hoist and go over it all at the shop.

 

[Wild one]

Man you guys got alot of horror stories about disconnecting the convertor and i doubt one of you have anything to back up your horror story.I've disconnected alot of convertors and slid them back over the years and not once has one of them slid forward and contacted the flywheel when the engines running,and that's even after flooring the engine a few times with the convertor unbolted. With the convertor disconnected there's no internal pressure being built up in the trans so there's nothing forcing the convertor ahead,once pushed back,they stay pushed back,you physically have to give it a good tug or pry on it to move it back ahead to engage the flywheel so you can bolt the 2 back together.

 

[Hagar1]

Man you guys got alot of horror stories about disconnecting the convertor and i doubt one of you have anything to back up your horror story.I've disconnected alot of convertors and slid them back over the years and not once has one of them slid forward and contacted the flywheel when the engines running,and that's even after flooring the engine a few times with the convertor unbolted. With the convertor disconnected there's no internal pressure being built up in the trans so there's nothing forcing the convertor ahead,once pushed back,they stay pushed back,you physically have to give it a good tug or pry on it to move it back ahead to engage the flywheel so you can bolt the 2 back together.

Well, everyone has different mileage. What works for one, doesn't always work out for others.

 

[Wild one]

Well, everyone has different mileage. What works for one, doesn't always work out for others.

You'd have to have the rearend 6ft higher then the front end for the convertor to ever vibrate ahead if it's unbolted and pushed back. You guys are making it sound like he's automatically going to have the convertor slide ahead,and i'm gonna tell you,that's not gonna happen

 

[Fast69Mopar]

Man you guys got alot of horror stories about disconnecting the convertor and i doubt one of you have anything to back up your horror story.I've disconnected alot of convertors and slid them back over the years and not once has one of them slid forward and contacted the flywheel when the engines running,and that's even after flooring the engine a few times with the convertor unbolted. With the convertor disconnected there's no internal pressure being built up in the trans so there's nothing forcing the convertor ahead,once pushed back,they stay pushed back,you physically have to give it a good tug or pry on it to move it back ahead to engage the flywheel so you can bolt the 2 back together.

I have been pushing converters back for over 25 years to diagnose noises without a single problem.

As @Wild one stated, once the converter is unbolted and pushed back nothing is spinning in the transmission to create any pressure so the converter stays in its place.

 

[Hagar1]

Yes all gears. No change in pitch from D to R either. Just quieter when the truck is warmed up fully. I’m up in Saskatoon Canada. I have an appointment to get my truck up on a hoist and go over it all at the shop.

Try one of the dodge dealers, Dodge city or yxe or whatever it is called these days ....... used to be Auto Clearing.

 

[SD2020]

I understand the potential damage that could occur starting the motor with the TC polished back, could be a nightmare. Not sure if a person could make a TC holder that bolts to the transmission that would insure clearance. In my circumstance I would not have to rev the motor up. All it would need is 5 seconds of idle time. The guy who pulled and installed my motor was pretty scared to try it when I talked to him yesterday.

 

[Hagar1]

You'd have to have the rearend 6ft higher then the front end for the convertor to ever vibrate ahead if it's unbolted and pushed back. You guys are making it sound like he's automatically going to have the convertor slide ahead,and i'm gonna tell you,that's not gonna happen

I understand the potential damage that could occur starting the motor with the TC polished back, could be a nightmare. Not sure if a person could make a TC holder that bolts to the transmission that would insure clearance. In my circumstance I would not have to rev the motor up. All it would need is 5 seconds of idle time. The guy who pulled and installed my motor was pretty scared to try it when I talked to him yesterday.

Back in the day I made a tool to hold the convertor in place while removing and installing transmissions. Don't know where went but no longer need it.

 

[Wild one]

If the trucks on a lift,the transmission is facing downhill,and there's no way the convertor is overcoming gravity and sliding ahead.Build a holder if you want,but it's not needed

 

[Sherman Bird]

Man you guys got alot of horror stories about disconnecting the convertor and i doubt one of you have anything to back up your horror story.I've disconnected alot of convertors and slid them back over the years and not once has one of them slid forward and contacted the flywheel when the engines running,and that's even after flooring the engine a few times with the convertor unbolted. With the convertor disconnected there's no internal pressure being built up in the trans so there's nothing forcing the convertor ahead,once pushed back,they stay pushed back,you physically have to give it a good tug or pry on it to move it back ahead to engage the flywheel so you can bolt the 2 back together.

!

 

[Wild one]

I don't have any horror stories about it. One time... just once, A tech disconnected a torque converter in a TH125c behind a 3.4L V-6 in a Chevy Lumina Van to find a noise. In that case (rare) the small diameter pilot "tit" on the front of the converter galled the crankshaft hole out. It wasn't apparent at that time, but a few weeks later, the flexplate cracked. Ultimately, he (the tech) replaced the engine, and the noise was gone. Interestingly, he replaced the torque converter due to the damage to the small diameter pilot.

I think that that was a one-off happenstance.

I will say that an oscilloscope and an NVH accessory is the bee's knees to determining type and origin of noises and vibrations.

The flexplate wouldn't have cracked from the convertor,as the register the flexplate sits on,keeps the convertors pilot from touching it. That was strictly a coincidence,as i'm guessing the flexplate was already cracked before he worked on the engine,and it finally gave up the ghost shortly afterwards,and probably was on the way out,whether he'd worked on it or not.