Micro Welding of bearing shell to rod housing bore

Larry Hill · 08-21-2021, 10:16 PM

Any ideas ?
Could it be when the combustion occurs the bearings take a hit in the middle causing the outer parts of the shell to move away from the housing just slightly and then return causing a fretting action and transfer of metal, from shell to housing bore.

Partsguy1 · 08-22-2021, 03:37 AM

Rods out of round or inadequate bearing crush. I'm just spit balling ideas.

Adger Smith · 08-22-2021, 08:16 AM

Bearing type/part number and rod type and application?
General answer: Fit in housing bore
Pictures?

Larry Hill · 08-22-2021, 09:18 AM

Manley rods, King not as bad as Clevite 77, housing bore round according to AG 300. No pictures all the evidence is gone, removed.

How is bearing crush measured and where can the specifications be found?

Oil is semi synthetic

pmrphil · 08-22-2021, 09:32 AM

I don't know if it's correct or not, but I use a height gauge to measure each shell and to verify that the shells are square, which I've found some that are way off. I've had rods on the small end of spec as well as the big side both do it.

FED 387 · 08-22-2021, 11:20 AM

using too thin of an oil ?---oil is not "thick" enough and not enough "pressure on the bearing" to keep the proper spacing between bearing and crank

Stan Weiss · 08-22-2021, 12:33 PM

Quote:

Originally Posted by Larry Hill

Any ideas ?
Could it be when the combustion occurs the bearings take a hit in the middle causing the outer parts of the shell to move away from the housing just slightly and then return causing a fretting action and transfer of metal, from shell to housing bore.

Larry,
Are you saying the Micro Welding is happening near the ends of the bearing?

Stan

SSDiv6 · 08-22-2021, 12:35 PM

How much clearance are you running and what oil weight?

Race bearings usually have additional crush built in them. Are you using a torque wrench or a bolt stretch gauge values? Make sure the main bore is round and check the size without and with the bearing installed.

This is a method used to check crush.

pmrphil · 08-22-2021, 01:46 PM

I have seen the microwelding almost 3/4 the length of the bearing, and probably 3/4 of the width on the most severe ones.

Larry Hill · 08-22-2021, 01:57 PM

2.375 crank pin, 5W30 oil, close to .003 vertical bearing clearance, bore is round within .0002, stretch gage.

I'm not understanding how to check housing bore diameter with the bearing installed.

Thanks

08-21-2021, 10:16 PM	#1
Larry Hill Live Reporter Join Date: Oct 2004 Location: Hickory, Ky Posts: 10,278 Likes: 1,636 Liked 9,455 Times in 1,957 Posts	Micro Welding of bearing shell to rod housing bore Any ideas ? Could it be when the combustion occurs the bearings take a hit in the middle causing the outer parts of the shell to move away from the housing just slightly and then return causing a fretting action and transfer of metal, from shell to housing bore. __________________ IHM Used Parts https://ihmusedparts.com 888-821-1817

08-22-2021, 03:37 AM	#2
Partsguy1 Junior Member Join Date: Jul 2018 Posts: 3 Likes: 0 Liked 0 Times in 0 Posts	Re: Micro Welding of bearing shell to rod housing bore Rods out of round or inadequate bearing crush. I'm just spit balling ideas.

08-22-2021, 08:16 AM	#3
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,348 Likes: 434 Liked 677 Times in 261 Posts	Re: Micro Welding of bearing shell to rod housing bore Bearing type/part number and rod type and application? General answer: Fit in housing bore Pictures? __________________ Adger Smith (Former SS)

08-22-2021, 09:18 AM	#4
Larry Hill Live Reporter Join Date: Oct 2004 Location: Hickory, Ky Posts: 10,278 Likes: 1,636 Liked 9,455 Times in 1,957 Posts	Re: Micro Welding of bearing shell to rod housing bore Manley rods, King not as bad as Clevite 77, housing bore round according to AG 300. No pictures all the evidence is gone, removed. How is bearing crush measured and where can the specifications be found? Oil is semi synthetic __________________ IHM Used Parts https://ihmusedparts.com 888-821-1817

08-22-2021, 09:32 AM	#5
pmrphil Member Join Date: Aug 2010 Location: CT Posts: 386 Likes: 1,257 Liked 248 Times in 107 Posts	Re: Micro Welding of bearing shell to rod housing bore I don't know if it's correct or not, but I use a height gauge to measure each shell and to verify that the shells are square, which I've found some that are way off. I've had rods on the small end of spec as well as the big side both do it. __________________ Phil Molski S/C 1623

08-22-2021, 11:20 AM	#6
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,349 Likes: 328 Liked 280 Times in 150 Posts	Re: Micro Welding of bearing shell to rod housing bore using too thin of an oil ?---oil is not "thick" enough and not enough "pressure on the bearing" to keep the proper spacing between bearing and crank

08-22-2021, 12:35 PM	#8
SSDiv6 VIP Member Join Date: Feb 2003 Location: Glendale, Arizona Posts: 2,991 Likes: 693 Liked 1,457 Times in 543 Posts	Re: Micro Welding of bearing shell to rod housing bore How much clearance are you running and what oil weight? Race bearings usually have additional crush built in them. Are you using a torque wrench or a bolt stretch gauge values? Make sure the main bore is round and check the size without and with the bearing installed. This is a method used to check crush.

08-22-2021, 01:46 PM	#9
pmrphil Member Join Date: Aug 2010 Location: CT Posts: 386 Likes: 1,257 Liked 248 Times in 107 Posts	Re: Micro Welding of bearing shell to rod housing bore I have seen the microwelding almost 3/4 the length of the bearing, and probably 3/4 of the width on the most severe ones. __________________ Phil Molski S/C 1623

08-22-2021, 01:57 PM	#10
Larry Hill Live Reporter Join Date: Oct 2004 Location: Hickory, Ky Posts: 10,278 Likes: 1,636 Liked 9,455 Times in 1,957 Posts	Re: Micro Welding of bearing shell to rod housing bore 2.375 crank pin, 5W30 oil, close to .003 vertical bearing clearance, bore is round within .0002, stretch gage. I'm not understanding how to check housing bore diameter with the bearing installed. Thanks __________________ IHM Used Parts https://ihmusedparts.com 888-821-1817