DIY: S65 M3 Rod Bearing

[KevM3UK]

yes it will but a 6 wont work on a 12 point, thanks for a great write up SYT Shadow, I shall be undertaking this job myself next month, ill be dropping the subframe and repainting etc like I did to the rear subframe 3 months ago, one question what it like removing and refitting the shell in the conrods, is it a bit of a fiddle or quite easy? cheers
Im on M3cutters mainly ,a British forum and have a build thread on there of my car, although I posted a write up on this forum of fitting M4 brakes on my '92

[SYT_Shadow]

Originally Posted by KevM3UK

yes it will but a 6 wont work on a 12 point, thanks for a great write up SYT Shadow, I shall be undertaking this job myself next month, ill be dropping the subframe and repainting etc like I did to the rear subframe 3 months ago, one question what it like removing and refitting the shell in the conrods, is it a bit of a fiddle or quite easy? cheers
Im on M3cutters mainly ,a British forum and have a build thread on there of my car, although I posted a write up on this forum of fitting M4 brakes on my '92

The shells are quite easy to install/remove. Make sure they're fully seated in the cap/rod

PM me if you run into issues

[Helmsman]

Originally Posted by KevM3UK

yes it will but a 6 wont work on a 12 point, thanks for a great write up SYT Shadow, I shall be undertaking this job myself next month, ill be dropping the subframe and repainting etc like I did to the rear subframe 3 months ago, one question what it like removing and refitting the shell in the conrods, is it a bit of a fiddle or quite easy? cheers
Im on M3cutters mainly ,a British forum and have a build thread on there of my car, although I posted a write up on this forum of fitting M4 brakes on my '92

Not very popular with RB replacement over at M3Cutters so better be careful with advice from there mate...😎

[KevM3UK]

so do people plastigauge their bearings or not?

[SYT_Shadow]

Originally Posted by KevM3UK

so do people plastigauge their bearings or not?

I did it once as curiosity but haven't done it since

[Helmsman]

Originally Posted by SYT_Shadow

I did it once as curiosity but haven't done it since

Assumingly with BE SYT? Remember what max/min they showed?

[SYT_Shadow]

Originally Posted by Helmsman

Assumingly with BE SYT? Remember what max/min they showed?

In the first page I have the information and results as well as targets. I don't recall them offhand.

Actually I did it a second time, on a forum member's car.

In the case of BE bearings which are all I use, each one has been measured so I don't feel the need to measure again myself with a significantly less accurate process (plastigage) vs what BE did at the origin

[KevM3UK]

ive allready purchased oem shells, had a good deal on them but after reading many threads im inclined to go with ACL HX using ACL bolts, i use ACL bolts reguardless whether i use oem shell or ACL, far easier on the torque process, will be undertaking the job myself 4 weeks from now when i have 4 days off in the week , dont particularly want to go down the plastiguage route.

[Scharbag]

Originally Posted by KevM3UK

ive allready purchased oem shells, had a good deal on them but after reading many threads im inclined to go with ACL HX using ACL bolts, i use ACL bolts reguardless whether i use oem shell or ACL, far easier on the torque process, will be undertaking the job myself 4 weeks from now when i have 4 days off in the week , dont particularly want to go down the plastiguage route.

Plastigauge will only show you if you are way too loose or way too tight. Not a terrible idea to check a shell or two, but given you really do not have any other size choices, what are you going to do?

Cheers,

[pbonsalb]

What bolts does ACL use?

[SYT_Shadow]

Originally Posted by KevM3UK

ive allready purchased oem shells, had a good deal on them but after reading many threads im inclined to go with ACL HX using ACL bolts, i use ACL bolts reguardless whether i use oem shell or ACL, far easier on the torque process, will be undertaking the job myself 4 weeks from now when i have 4 days off in the week , dont particularly want to go down the plastiguage route.

Originally Posted by pbonsalb

What bolts does ACL use?

I have the same question.

So far the standard arp bolts have been shown to distort the caps. The BE-ARP ones are specifically built to avoid that.

No idea what ACL uses but be mindful they may be worse than oem bolts

[Helmsman]

Originally Posted by pbonsalb

What bolts does ACL use?

Don't believe ACL have bolts, they recommend ARP or OEM the self.

[Helmsman]

Originally Posted by SYT_Shadow

In the first page I have the information and results as well as targets. I don't recall them offhand.

Actually I did it a second time, on a forum member's car.

In the case of BE bearings which are all I use, each one has been measured so I don't feel the need to measure again myself with a significantly less accurate process (plastigage) vs what BE did at the origin

Cheers SYT, found the 0.0076mm (assuming one zero too many) hence "upper limit" of 0.003inch. I realize plastigage only provide an indication though.

Yep understand BE is measuring their shells (is that to check within tolerances after coating?). According to BE and ACL spec assumption of shaft/housing tolerances, this is where a good portion of the possible stack up seems to be hence my wondering. Anyways, awesome DIY and interesting thread.

[bigjae1976]

Originally Posted by SYT_Shadow

In the first page I have the information and results as well as targets. I don't recall them offhand.

Actually I did it a second time, on a forum member's car.

In the case of BE bearings which are all I use, each one has been measured so I don't feel the need to measure again myself with a significantly less accurate process (plastigage) vs what BE did at the origin

Weren't the BE shells co-developed with some people on this forum to specifically address the clearance issue?

Not a no brainer yet. Time will tell but the proof is in the data we collect on what the 2nd set of bearings look like after 50k miles.

If for no other reason, the BE bearings are the way to go since you can use oil analysis as a tool to monitor wear.

[pbonsalb]

I think VAC sells lead based clevite bearings as well. Not sure of the ACL material but it might be lead based also since it’s aftermarket. It may be that the only aluminum based bearing is the bmw one.

[Helmsman]

Originally Posted by pbonsalb

I think VAC sells lead based clevite bearings as well. Not sure of the ACL material but it might be lead based also since it’s aftermarket. It may be that the only aluminum based bearing is the bmw one.

Yes, believe ACL has a lead-tin overlay. OEM 702/703 are the only I've seen that has a alu aloy on top. On the other hand, from what we've seen on the board oil test seems far from a secure way to identify the shell shape?

[KevM3UK]

Originally Posted by Helmsman

Don't believe ACL have bolts, they recommend ARP or OEM the self.

ARP bolts i meant, thinking of using these with either oem or ACL shells

[pbonsalb]

Probably an ok tool if you bought the car new and have a test from every change or you do a test at every change after replacing the bearings. I have never done a test and don’t plan to.

[bigjae1976]

Originally Posted by Helmsman

Yes, believe ACL has a lead-tin overlay. OEM 702/703 are the only I've seen that has a alu aloy on top. On the other hand, from what we've seen on the board oil test seems far from a secure way to identify the shell shape?

It's an indication of something when you start seeing copper. Oil analysis would have saved me an S54 if it was in my mailbox the Thu before a track weekend vs the Mon after.

[Theodore]

For those considering the use of plastigauge in their DIY project, this is a very convincing video:

[Green-Eggs]

Originally Posted by Theodore

For those considering the use of plastigauge in their DIY project, this is a very convincing video:

We have the opposite experience, and I know Bert @ BE has too. We had a customer who bought BE Bearings, used Plastigage and measured 0.0010 inch clearance. He swapped shells around and still measured no more than about 0.0012 inch clearance. Bert had us send him new shells and we sent Bert his shells. Bert measured the same shells in new rods with new rod bolts using bore gauges. The shells measured 0.0024 inch or somewhere in that neighborhood. In that case, Plastigage was way off of actual.

I know Bert was putting together a video just like this one. Not sure what happened to it. It might have been on these same shells above, but I'm not sure. I know he confirmed the Plastigage method was far off the bore gauge method on the same shells.

That's been our experience. Your mileage may vary.

[deansbimmer]

Originally Posted by Green-Eggs

We have the opposite experience, and I know Bert @ BE has too. We had a customer who bought BE Bearings, used Plastigage and measured 0.0010 inch clearance. He swapped shells around and still measured no more than about 0.0012 inch clearance. Bert had us send him new shells and we sent Bert his shells. Bert measured the same shells in new rods with new rod bolts using bore gauges. The shells measured 0.0024 inch or somewhere in that neighborhood. In that case, Plastigage was way off of actual.

I know Bert was putting together a video just like this one. Not sure what happened to it. It might have been on these same shells above, but I'm not sure. I know he confirmed the Plastigage method was far off the bore gauge method on the same shells.

That's been our experience. Your mileage may vary.

We have also experienced plastigage readings far tighter than actual. We don't like relaying the plastigage results to customers because there's a good chance the false numbers would cause them unnecessary alarm.

It's an ok spot check but far from accurate.