Small Block Mopar Thrust Bearing issue

mike natoli · 01-07-2011, 12:29 PM

what part of the thrust bearing is showing wear?

donc · 01-07-2011, 01:12 PM

if the thrust is worn on the back side another words look like crank is moving forward. its most likely the converter is putting pressure on the crank ,or something in the tranny is at fault. also check timing chain alignment.

BlueOval Ralph · 01-07-2011, 02:20 PM

Converter Balloning or Input saft to long on a 4 speed

magnumv8 · 01-07-2011, 07:42 PM

What I have seen that has caused excessive thrust clearance is misaligned pulleys on the front of the engine....this creates pressure forward or rearward on the crank causing either the bearing or crank flange to wear....it takes very little misalignment to create this internal drag especially with a V-belt set up.....

D L Rambo.....

mopar · 01-07-2011, 09:15 PM

check the back of the crank where the pilot bearing would be. have found that to be the problem even with convertor spinning free. do not have any measurements.

Ron Waters s/st 1346

Michael Beard · 01-07-2011, 10:05 PM

Converter ballooning, had it happen even on a low 12-sec bracket car. Had too much line pressure in the valve body at the time, too... no idea if that had any part in it.

Peter Ash · 01-08-2011, 03:52 PM

If any part needs surface lapping. It should be done in a figure "8" pattern on a surface plate(glass or a highly finished checkerboard steel lapping plate). This is how I was taught when we used to rebuild fuel injection components.

Peter

Mopar Mike · 01-09-2011, 09:04 PM

Quote:

Originally Posted by Michael Beard

Converter ballooning, had it happen even on a low 12-sec bracket car. Had too much line pressure in the valve body at the time, too... no idea if that had any part in it.

Mike,
The converter is due for a freshening up and we were planning on sending it out anyways. Thanks for the response.
Mike

Mopar Mike · 01-09-2011, 09:13 PM

Quote:

Originally Posted by mopar

check the back of the crank where the pilot bearing would be. have found that to be the problem even with convertor spinning free. do not have any measurements.

Ron Waters s/st 1346

Ron, will check the crank again. Thanks,
Mike

Mopar Mike · 01-09-2011, 09:09 PM

Quote:

Originally Posted by magnumv8

What I have seen that has caused excessive thrust clearance is misaligned pulleys on the front of the engine....this creates pressure forward or rearward on the crank causing either the bearing or crank flange to wear....it takes very little misalignment to create this internal drag especially with a V-belt set up.....

D L Rambo.....

D L Rambo, Will check that out also. Thanks for the response.
Mike

01-07-2011, 12:29 PM	#1
mike natoli Member Join Date: Mar 2007 Location: Valley Stream mini Gasoline Alley & Div I Posts: 100 Likes: 25 Liked 51 Times in 16 Posts	Re: Small Block Mopar Thrust Bearing issue what part of the thrust bearing is showing wear?

01-07-2011, 01:12 PM	#2
donc Junior Member Join Date: Dec 2010 Posts: 15 Likes: 0 Liked 0 Times in 0 Posts	Re: Small Block Mopar Thrust Bearing issue if the thrust is worn on the back side another words look like crank is moving forward. its most likely the converter is putting pressure on the crank ,or something in the tranny is at fault. also check timing chain alignment.

01-07-2011, 02:20 PM	#3
BlueOval Ralph Banned Join Date: Feb 2008 Posts: 852 Likes: 0 Liked 0 Times in 0 Posts	Re: Small Block Mopar Thrust Bearing issue Converter Balloning or Input saft to long on a 4 speed

01-07-2011, 07:42 PM	#4
magnumv8 Member Join Date: Feb 2009 Location: Coraopolis, Pa. Posts: 172 Likes: 0 Liked 0 Times in 0 Posts	Re: Small Block Mopar Thrust Bearing issue What I have seen that has caused excessive thrust clearance is misaligned pulleys on the front of the engine....this creates pressure forward or rearward on the crank causing either the bearing or crank flange to wear....it takes very little misalignment to create this internal drag especially with a V-belt set up..... D L Rambo.....

01-07-2011, 09:15 PM	#5
mopar Junior Member Join Date: Sep 2010 Posts: 11 Likes: 0 Liked 0 Times in 0 Posts	Re: Small Block Mopar Thrust Bearing issue check the back of the crank where the pilot bearing would be. have found that to be the problem even with convertor spinning free. do not have any measurements. Ron Waters s/st 1346

01-07-2011, 10:05 PM	#6
Michael Beard VIP Member Join Date: Sep 2002 Location: Columbus, OH Posts: 4,060 Likes: 0 Liked 13 Times in 9 Posts	Re: Small Block Mopar Thrust Bearing issue Converter ballooning, had it happen even on a low 12-sec bracket car. Had too much line pressure in the valve body at the time, too... no idea if that had any part in it. __________________ Michael Beard - NHRA/IHRA 3216 S/SS

01-08-2011, 03:52 PM	#7
Peter Ash Member Join Date: Jan 2010 Posts: 262 Likes: 2 Liked 0 Times in 0 Posts	Re: Small Block Mopar Thrust Bearing issue If any part needs surface lapping. It should be done in a figure "8" pattern on a surface plate(glass or a highly finished checkerboard steel lapping plate). This is how I was taught when we used to rebuild fuel injection components. Peter Last edited by Peter Ash; 01-08-2011 at 10:24 PM.

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