Rob Bearing Question

e30gentry · 05-19-2026, 03:41 PM

Need some help to see if anyone has answers.
I was either shipped two sets of upper, two sets of lowers or have no issues at all but can’t seem to get a definitive answer.
My WPC treated ACL rod bearings have the stamping/part number.
STD
DEC24
1580H
This is on every bearing with no other markings.
I will not half the bearings have this stamp where the bearing tang/tab is while the over half has the stamp/markings on the side with no tang/tab.

Does anyone have answer if the set is wrong or know which side is upper vs lower?

Brandoch · 05-19-2026, 04:18 PM

Quote:

Originally Posted by e30gentry

Need some help to see if anyone has answers.
I was either shipped two sets of upper, two sets of lowers or have no issues at all but can’t seem to get a definitive answer.
My WPC treated ACL rod bearings have the stamping/part number.
STD
DEC24
1580H
This is on every bearing with no other markings.
I will not half the bearings have this stamp where the bearing tang/tab is while the over half has the stamp/markings on the side with no tang/tab.

Does anyone have answer if the set is wrong or know which side is upper vs lower?

I believe ACL bearings are the same for upper and lower. However someone chime in if I'm wrong.

omgzirra_exe · 05-19-2026, 05:51 PM

Quote:

Originally Posted by e30gentry

Need some help to see if anyone has answers.
I was either shipped two sets of upper, two sets of lowers or have no issues at all but can’t seem to get a definitive answer.
My WPC treated ACL rod bearings have the stamping/part number.
STD
DEC24
1580H
This is on every bearing with no other markings.
I will not half the bearings have this stamp where the bearing tang/tab is while the over half has the stamp/markings on the side with no tang/tab.

Does anyone have answer if the set is wrong or know which side is upper vs lower?

Well, if you bought regular ACL 1580H bearings and then sent them out for WPC treatment, the top and bottom bearings would still be identical.

Normally with ACL bearings, we like to mix and match the 1580H and 1580HX variants to get an ideal clearance of around .0024".

Quote:

Originally Posted by Brandoch

I believe ACL bearings are the same for upper and lower. However someone chime in if I'm wrong.

correct!

e30gentry · 05-20-2026, 08:03 AM

These were purchased as a package from Turner Motorsport and not by me directly from ACL

omgzirra_exe · 05-20-2026, 09:14 AM

Quote:

Originally Posted by e30gentry

These were purchased as a package from Turner Motorsport and not by me directly from ACL

unless they specified mix and match pairings, they are most likely the same top and bottom.

e30gentry · 05-20-2026, 09:30 AM

Quote:

Originally Posted by omgzirra_exe

unless they specified mix and match pairings, they are most likely the same top and bottom.

Thank you, definitely looking for an absolute yes obviously.
Turner/ECS are trying to get a real answer because to their knowledge they’re still supposed to be color or number matched

tdott · 05-20-2026, 10:09 AM

ACL 8B1580H-STD

They are definitely all the same.

Scrippy · 05-20-2026, 10:29 AM

I would email pictures of a top and bottom to ECS support and put it on them. They fuck up a lot and it’s in the warehouse.

e30gentry · 05-20-2026, 10:54 AM

Quote:

Originally Posted by Scrippy

I would email pictures of a top and bottom to ECS support and put it on them. They fuck up a lot and it’s in the warehouse.

I did, I also did not get back the best response. So I’m speaking with someone else about it

e30gentry · 05-20-2026, 10:55 AM

Quote:

Originally Posted by tdott

ACL 8B1580H-STD

They are definitely all the same.

I’m really hoping so, this way I can replace the oil pump gears and get these bearings in too!

omgzirra_exe · 05-20-2026, 11:03 AM

Quote:

Originally Posted by e30gentry

Thank you, definitely looking for an absolute yes obviously.
Turner/ECS are trying to get a real answer because to their knowledge they’re still supposed to be color or number matched

hopefully they figure it out, i know ACL mentions they are same top and bottom for the 1580H

e30gentry · 05-20-2026, 11:32 AM

Quote:

Originally Posted by omgzirra_exe

hopefully they figure it out, i know ACL mentions they are same top and bottom for the 1580H

I’m hoping it’s as easy as that!

Scrippy · 05-21-2026, 12:31 AM

As I see online there are two parts. One ending in “H” and one ending in “HX”. There is no mention of mixing the two as they are said to be of different tolerances. So a set pack should be just that, a paired set.

e30gentry · 05-21-2026, 09:52 AM

Quote:

Originally Posted by Scrippy

As I see online there are two parts. One ending in “H” and one ending in “HX”. There is no mention of mixing the two as they are said to be of different tolerances. So a set pack should be just that, a paired set.

I wish! I’m really leaning towards I was shipped two upper/two lower

Scrippy · 05-21-2026, 02:42 PM

Quote:

Originally Posted by e30gentry

I wish! I’m really leaning towards I was shipped two upper/two lower

So are they physically two packages, one of tops and one of bottoms?

omgzirra_exe · 05-21-2026, 05:32 PM

Quote:

Originally Posted by e30gentry

I wish! I’m really leaning towards I was shipped two upper/two lower

that's impossible unless ECS/Turner packaged them that way, you can only get those custom matched, you have to literally buy 2 sets of bearings.

And turner literally doesn't sell any mixed sets.

tdott · 05-21-2026, 06:00 PM

Quote:

Originally Posted by e30gentry

I’m really hoping so, this way I can replace the oil pump gears and get these bearings in too!

Quote:

Originally Posted by e30gentry

I’m hoping it’s as easy as that!

Too much hoping.

It's a fact, all the ACL 8B1580H-STD shells are the same.

Not sure how many more times you want everyone to tell you.

05-19-2026, 03:41 PM	#1
e30gentry This Guy 201 Rep 164 Posts Drives: 4x335d X3d E92 M3 Join Date: Jul 2013 Location: Corpus Christi Texas iTrader: (0)	Rob Bearing Question - ACL specifically Need some help to see if anyone has answers. I was either shipped two sets of upper, two sets of lowers or have no issues at all but can’t seem to get a definitive answer. My WPC treated ACL rod bearings have the stamping/part number. STD DEC24 1580H This is on every bearing with no other markings. I will not half the bearings have this stamp where the bearing tang/tab is while the over half has the stamp/markings on the side with no tang/tab. Does anyone have answer if the set is wrong or know which side is upper vs lower? Attached Images
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05-20-2026, 08:03 AM	#4
e30gentry This Guy 201 Rep 164 Posts Drives: 4x335d X3d E92 M3 Join Date: Jul 2013 Location: Corpus Christi Texas iTrader: (0)	These were purchased as a package from Turner Motorsport and not by me directly from ACL
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05-20-2026, 10:09 AM	#7
tdott S.FL S65 Specialist 4545 Rep 4,341 Posts Drives: M3 Join Date: Nov 2010 Location: South FL / 6ix iTrader: (4)	ACL 8B1580H-STD They are definitely all the same. __________________ N/A S65 Headers Before/After Dyno Results tdott's Spec E9X Build Thread https://www.youtube.com/@tdottme
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05-20-2026, 10:29 AM	#8
Scrippy Lord Scrip 2390 Rep 3,419 Posts Drives: 2011 M3 Coupe Join Date: Jan 2012 Location: LA,Ca iTrader: (0) Garage List [10.00] 2007 BMW 335i [10.00]	I would email pictures of a top and bottom to ECS support and put it on them. They fuck up a lot and it’s in the warehouse. __________________ Last edited by Scrippy; 05-20-2026 at 10:29 AM..
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05-21-2026, 12:31 AM	#13
Scrippy Lord Scrip 2390 Rep 3,419 Posts Drives: 2011 M3 Coupe Join Date: Jan 2012 Location: LA,Ca iTrader: (0) Garage List [10.00] 2007 BMW 335i [10.00]	As I see online there are two parts. One ending in “H” and one ending in “HX”. There is no mention of mixing the two as they are said to be of different tolerances. So a set pack should be just that, a paired set. __________________
	Appreciate 1 e30gentry201.00 Quote