E21 Wheel Bearing repacking guide (PICTURES)

[maxthegearhead]

I noticed there didn't seem to be much in the way of information on repacking wheel bearings, so I decided I'd throw a sort of DIY guide together

So start by pulling off the wheel, brake caliper, and brake rotor. Remove the cotter pin and the castellated nut and pull the whole wheel bearing assembly out.

After cleaning with brakeclean and a shop towel, your bearing shaft should look like this.
IMG_3310.jpg
If your shaft is pitted, rusty, or scoured, it should be replaced. The entire knuckle assembly will unfortunately be bad then.

Put a thick layer of quality grease on the shaft like so
IMG_3314.jpg

Clean the bearings and carrier with brakeclean or a parts washer and brake clean(if you have one). Make sure you get all of the old grease out, it likes to hide in the nooks and crannies.
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Once clean, fully pack the entire carrier with new grease. It'll take more than you think. every surface on the inside should have a thick layer of grease and all the bearings should be swimming in it.
IMG_3313.jpg

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Slide the carrier back in, then the outer bearing, cone side in. Place the washer back and tighten the castle nut by hand.
IMG_3316.jpg

Torque the castle nut to 30 lb*ft, then back it off until there is a VERY SLIGHT amount of play in and out when you pull on the carrier towards and away from you. I cannot overstate how small the amount of play should be.

Insert the cotter pin and slap the dust cap back on (if you still have it!)

Reassemble brakes and put the wheel back on and do the other side!!

[Tom D]

thank you max for this, but i'd like to counter a few points for a better understanding of packing and adjusting tapered bearings.

a rusty axle is not a problem and doesn't require replacement......providing the treads are good shape and the bearings have not spun on the lands, ruining the surfaces.

coating the entire axle is not necessary, but it will help protect against surface oxidation.

this next point of overpacking is a common misbelief.
any grease not applied directly to the bearing's contact (load) surface is completely unnecessary, a waste of grease and will not migrate onto the bearing's contact surface. while it is a good idea to pack a uninstalled bearing well, as soon as you seat that bearing all excess grease will have squeezed out.

my preferred method of adjusting the bearing requires no exact torque value per se.
* mount the hub and nut on the axle
* while turning the hub by hand tighten the axle nut until you feel the hub not rotating freely, this is called preloading. this not only assures that the hub is fully seated, but also that all excess grease is expelled from between the rollers and the race.
* once the preload is done and without moving the hub, loosen the axle nut and then turn it back down until it just makes contact with the washer. if the cotter pin's hole does not align with the castle nut but will if you tighten the nut, then do so, but if you have to tighten the nut more then say 10 degrees of rotation then you should loosen the nut instead until you align the cotter pin.

[maxthegearhead]

Thanks for the addition Tom, I got the 30 lb*ft figure from the service manual so I just relayed it here.

I've always been a better safe than sorry kinda guy so I always covered everything. Worst case it just prevents some rust. I did not know that the axles can be used if rusty, thank you for clarifying that. Hopefully the knowledge will help someone out there.

[jaredmac11]

A few questions, is it better safe than sorry and to just replace the bearings? Can I assume if the bearings are still greased when I remove them they are good?

Is lithium based grease ok to use?

I noticed each of my 4 wheels' bearings make a noise when I rotate the wheel so I'll be doing this while Im working on the suspension overhaul.

[Somjuan]

I’d add the fun of driving the old bearings from the hub hahaha

Takes me about an hour a corner for the front, maybe 45 if I’m in a rush. Machined down an aluminum round as a driver.

[maxthegearhead]

I wouldn't bother replacing the bearings unless they were visibly damaged or scoured.

[320iAman]

A few questions, is it better safe than sorry and to just replace the bearings? Can I assume if the bearings are still greased when I remove them they are good?

Is lithium based grease ok to use?

I noticed each of my 4 wheels' bearings make a noise when I rotate the wheel so I'll be doing this while Im working on the suspension overhaul.

Yes, No, Yes High Heat LG is okay, I prefer Moly Grease although I have used both.



Randy

[Tom D]

......is it better safe than sorry and to just replace the bearings?........

no, imho, it is not better to replace then to repack and adjust....... if the bearing show no discernible wear.

the reason i say this is because during the production of the E21 BMW used 'made in west germany' bearings made from west german steel, which is of high quality. today's market demands outsourcing, a lot of this to china and we have seen repeatedly that china does not have a great quality control program. personally i have seen german made wheel bearings on an E21 with 400K and they were in great condition, all i did was repack and adjust.

[320iAman]

"I noticed each of my 4 wheels' bearings make a noise when I rotate the wheel so I'll be doing this while Im working on the suspension overhaul." Replace them all be on the safe side.


Randy

[gsumzzz]

steel quality true for head bolts as well. i noticed a great quality difference in the original '77 bolts versus a purchased replacement set. i cleaned and reused the originals. german standards are hard to beat.

[82Kashmir]

Need to do my rear bearings this spring, can you make some makeshift bearing removal tools from common supplies like this idea from an e36 video.
https://www.youtube.com/watch?v=wKYL9_4mXRI

[320iAman]

Not the same thing,, back bearings are 2 not one, same size and from what I gather 323i use different size ones Big-Small. The guy in the video said he had the drive flange off before yet he did not mention what he did to get it off.

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The Drive flange #6 has to be removed and this can be a tough job if it has been on there a long time, next the side shaft is knocked out and then the bearings are removed and replaced, measure the shim #11 , usually its the same,, I did a complete left side with all new parts same shim size new as old and been running for years no problems, in fact a new trailing arm as well got a good deal on this new one.

To knock out the side shaft from the drive flange you want to use a copper bar( with big sledge hammer) and have the nut on the side shaft so the thread is not damaged, just smashing it without the copper bar-the end can mushroom and the shaft can bend, a heavy duty bench press and heat is your friend with the trailing arms removed. Huge multiple arm pullers, impact hammers and so forth was used and just barely nudged the side shaft, can get off this way or the heavy duty bench press, it takes time, proper tools, and planning. The nuts on the side shafts have a torque of around 210 ft lbs. My impact wrench had them off in a few seconds--fastest part of the job.

Randy

[82Kashmir]

Looks like the Hub on e36, was removed with a bearing separator and lug nuts pulling the hub off. Is the hub the drive flange part on the e21 I'm assuming? I would probably do the bearing on the car so removing the half shaft from the differential and brake parts. Then what You said above form their

[320iAman]

Yes hub is drive flange with or without wheel studs.

Randy

[tlapham]

"I noticed each of my 4 wheels' bearings make a noise when I rotate the wheel so I'll be doing this while Im working on the suspension overhaul." Replace them all be on the safe side.


Randy

I noticed my engine "makes a noise" when I crank it, should I replace that as well?

[jaredmac11]

I noticed my engine "makes a noise" when I crank it, should I replace that as well?

How does one diagnose when bearings are bad or good? It's difficult to do. I guess I can try and repack em and see if the noise goes away.

Sent from my LG-H830 using Tapatalk

[320iAman]

I noticed my engine "makes a noise" when I crank it, should I replace that as well?

Thats comparing apples to oranges, they are not the same.

Randy

[320iAman]

How does one diagnose when bearings are bad or good? It's difficult to do. I guess I can try and repack em and see if the noise goes away.

Sent from my LG-H830 using Tapatalk

When you hear a low noise, kind of dull bass coming from the front end when driving, one or both of the front end bearings are wore out. The rear end ones sound like a whine, higher pitch noise,going out.

As too bearings good or bad, you inspect and see if they have pits in them. spin them in your hand cleaned up and if they bind at all, should replace them. The trailing arms have two bearing where as later models I have seen use 1- two bearing is superior to one bearing--they last much longer.

Since your there, front end bearing dont cost much and these bearings do have the most weight on them, back bearings are a tough job to replace, it requires some special tools when the drive flange and the side shaft have been meshed or joined together for a long time.

Bearings should not make a noise when spinning, they should be almost quiet, you may be hearing brake items rubbing and so forth, checking bearing and listening and feeling for binding bearings is standard preventative maintenance.

To check the trailing arm bearings, you'll need to remove the half shafts and the brake components and then spin the drive flange and side shaft and feel for binding.

Randy

[karlkormann]

I'm working on gathering parts in the wrong order to install later front suspension on my 1981 316. Thus far ive gathered the subframe, strut assemblies, Bilsteins, and control arms.

Will I need new hubs or are these interchangeable with a set of bearings?

[maxthegearhead]

I'm working on gathering parts in the wrong order to install later front suspension on my 1981 316. Thus far ive gathered the subframe, strut assemblies, Bilsteins, and control arms.

Will I need new hubs or are these interchangeable with a set of bearings?

Your 81 should have the late front suspension already AFAIK. In 81 only the 323i still used the old hub design with larger bearings, so if you are using non-323i spindles it should work fine.

[karlkormann]

My 316 strut assemblies have the threads on the outside of the housing. The Bilsteins that I bought need the threads on the inside of the assembly. Ive been doing some digging through the fourums and the car has the early style suspension.

Ive got most of the parts ordered but am uncertain on the hubs. Keep in mind that this is the most basic e21 you could get. No sunroof, no pop out windows, carburated car.

[cgifool]

My 316 strut assemblies have the threads on the outside of the housing. The Bilsteins that I bought need the threads on the inside of the assembly. Ive been doing some digging through the fourums and the car has the early style suspension.

Ive got most of the parts ordered but am uncertain on the hubs. Keep in mind that this is the most basic e21 you could get. No sunroof, no pop out windows, carburated car.

This thread looks relevant...

https://www.bimmerforums.com/forum/s...rmation-Thread!

[karlkormann]

So the Bilsteins have are a 46.82mm. Part number 34-276440. They do not fit in early or late strut housings yet all the sites have them listed for all years E21. I have no idea where im going wrong here.

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Goodness. Looks like I have inserts for a 323.