Rod Bearing Installation Q&A Thread

[Richbot]

When y'all say "let it hang" are you letting it hang off the struts?

[rymerc]

Originally Posted by Richbot

When y'all say "let it hang" are you letting it hang off the struts?

When you unbolt the mounts it will drop a few inches, and you can pull it down (I needed to) another few inches to gain more clearance. Yes, it's hanging off the struts/suspension

[bigjae1976]

It will hang by the 2 control arms and tie rods/steering rack which are attached to the king pin which is bolted to the front strut

All of which are easy to unbolt and takes 10 min to save you lots of pain, frustration, and oil in the face.

[Scharbag]

Originally Posted by bigjae1976

It will hang by the 2 control arms and tie rods/steering rack which are attached to the king pin which is bolted to the front strut

All of which are easy to unbolt and takes 10 min to save you lots of pain, frustration, and oil in the face.

Late to the game but yeah, dropping the subframe is quick and then you have awesome access to the engine. I tied up the power steering lines and put rubber gloves over the ends after I had one drip right in my ear canal. Yuk.

[///Mobbin]

Second post BE Bearings oil change and Blackstone report. About ~7k miles and 9 track days in, looking good so far.

[marone]

Guys, sorry for digging it out. Do you always need to replace top and bottom or bottom is usually sufficient? I ride 2010 M3 with 95 000km on it. Regulary serviced.

I dont' hear any strange metal noise, i just follow the path that 100K km / 65K miles is the time to replace it.

[Helmsman]

Originally Posted by marone

Guys, sorry for digging it out. Do you always need to replace top and bottom or bottom is usually sufficient? I ride 2010 M3 with 95 000km on it. Regulary serviced.

I dont' hear any strange metal noise, i just follow the path that 100K km / 65K miles is the time to replace it.

If you refer to the shells, the top gets the most stress. Regardless, you replace both.

[marone]

Originally Posted by Helmsman

If you refer to the shells, the top gets the most stress. Regardless, you replace both.

Thank you Sir!

[jvictormp]

Originally Posted by ///Mobbin

Great question. This actually gave me a ton of grief as both my steering wheel and the lower steering sections each moved at some point during the install. At that point I had to improvise (even with the lines drawn on the steering column). I should also point out that I am no expert here, so please look this up elsewhere but I am happy to share what I did. A few things to keep in mind, first, your steering wheel only rotates so many turns in each direction and when centered you need to maintain that so you can have an equal turn radius in each direction. Second, it is highly desirable to have a centered steering wheel when going straight down the road. What I ended up doing is probably not the preferred method but it seemed to work and I am having a new suspension installed and alignment done in a few weeks anyway so small adjustments could be made then if needed. I basically turned the steering wheel full lock each direction, calculated the center point, and then did my best job to center the steering wheel there. I did the same thing with the bottom end, centering each rotor to point straight ahead as best I could. Then of course the alignment keys on the lower steering shaft had to line up as they entered the upper steering wheel shaft receiver. I slowly lowered the sub-frame back up check the steering shaft with each pump of the jack and I made sure the lower steering shaft keys mated to the upper receiver properly as they first engaged. Then actually I had to physically pull the lower steering shaft and upper shaft receiver together at one point as they weren't fully mating on their own, didn't take much force at all, just pulled them tight with my hands.

I had my concerns about this as my steering wheel wasn't perfectly straight after I lowered the car but after driving the car a bit center is actually center and my wheels do appear to turn equally in each direction at full lock. My backup plan was to have the lower steering joints adjusted with my upcoming alignment but I don't think that will be needed (beyond what is typically done in an alignment of course).

Glad you asked and I hope others have some thoughts on this as well.

The only alignment problem we have on hanging the subframe is related to the steering wheel, or the individual angle of the front wheels (toe) can be messed up too?

[ha9981]

Did anyone do this job with just raising the front?

Would this work:
1. Raise the front 1/2 foot and place on stands
2. Raise the back 1/2 foot and place wood planks under the tires with chokes
3. Raise the front again to add another 1/2 foot

I’ll have to perhaps raise more. Avoiding rear jack stands as I feel having the wheels as base is more stable.

I have a fairly cheap but unconfirmed hoist rental option. But that wouldn’t give me the leisure pace I get doing it at home.

[_X]

Are there any other maintenance items that would make sense to address while having the rod bearings replaced? I figure it makes sense to take advantage of cheaper labor to modify things that will be taken apart.

Ex. Clutch/flywheel, motor/trans mounts, etc.

[///Mobbin]

Originally Posted by _X

Are there any other maintenance items that would make sense to address while having the rod bearings replaced? I figure it makes sense to take advantage of cheaper labor to modify things that will be taken apart.

Ex. Clutch/flywheel, motor/trans mounts, etc.

Motor mounts for sure, may as well freshen them and should be no extra labor.

[pbonsalb]

Transmission does not come off so clutch is a different job.

[_X]

Originally Posted by ///Mobbin

Motor mounts for sure, may as well freshen them and should be no extra labor.

Do you have any recommendations for motor mounts? I am considering going with Turner A90s.

Originally Posted by pbonsalb

Transmission does not come off so clutch is a different job.

Thank you.

Road Race Technology in Sterling, VA lists the following description on their website for rod bearing service. http://www.rrtautomotive.com/maintenance-services/common-services/replacing-bmw-s65s85-rod-bearings/

“Rod bearing replacement is a fairly involved procedure. To access the bearings, the oil pan need to be removed from the vehicle and to do that, the subframe and front suspension needs to be moved out of the way.”

Would it make sense to do subframe bushings? Any recommendations? Leaning toward poly or solid.

If the front suspension is dropped, would it make sense to convert to monoball at this time?

Car is not daily driven.

[pbonsalb]

Front subframe — when people talk about subframe bushings they are talking about rear subframe mounting bushings. The front bolts directly to the chassis with no isolating mounts.

You could replace suspension arms or bushings but they are nearly just as easily doable with the subframe in place. You certainly could change to monoball forward strut rod mounts at this time, but no significant labor savings. Motor mounts are the one job that should be done when the subframe comes down. If you want an old school dipstick, this would be the time. Bimmerworld sells a kit and maybe other companies.

[_X]

Originally Posted by pbonsalb

Front subframe — when people talk about subframe bushings they are talking about rear subframe mounting bushings. The front bolts directly to the chassis with no isolating mounts.

You could replace suspension arms or bushings but they are nearly just as easily doable with the subframe in place. You certainly could change to monoball forward strut rod mounts at this time, but no significant labor savings. Motor mounts are the one job that should be done when the subframe comes down. If you want an old school dipstick, this would be the time. Bimmerworld sells a kit and maybe other companies.

Thank you. RRT recommended Vibra-Technics mounts. I have reached out to Vibra-Technics for the differences between their two offerings and their opinion for my use.

I was quoted $2,700. This includes all fluids, factory mounts, and the bearing service with ACL bearings and ARP bolts. Seems like a pretty good deal. What do you guys think?

Also, are ACL good for a car that sees five to ten days at the track, with track cross and auto cross events every two weeks or so?

[pbonsalb]

Vibra Technica are fine but I don’t think you need them. I run stock mounts, which are made by Corteco and cheaper if you do not buy from the dealer. I have read the vibra technics may not sell replacement inserts, so you may end up paying more for mounts that don’t last any longer. Bimmerworld sells a Group N replica mount that is stiffer but adds slight vibration at factory idle speed. 034 sells a rubber mount that is slightly stiffer than stock.

ACL bearings are fine in my opinion, but BE is the most popular and has the best quality control. BE also cost 3x as much as ACL. If the price was $2700 for BE, I would say that is probably in the ball park for a major metropolitan area like the DC suburbs. But it’s for cheaper ACL bearings. ACL bearings are $200, BE rod bolts are $300, an oil pan gasket is $100, oil and filter are $100, so you are at under $800 in parts. That leaves $1900 for labor. Any pro who has done this job before is doing it in 8 hours or less. That is about $200 per hour.

This is why I DIY.