Considering what I went thru putting the hub assembly in my 20 ton shop press and watching the press bow up some I am not surprised the 3/4 bolt snapped. When they stick, THEY STICK.

There is a formula to determine linear force from turning a nut. It worked out to about 30-35,000# to remove my front bearing from the carrier. It was maybe 22-25,000 # to install. (bearing was negative 10°F to reduce the size by about 0.003" diameter.

Greasing the threads is absolutely necessary.

The rod that came with and the proto tools replacement both looked very decent and based on when they failed were at least Gr5.

3/4 Gr2 has 15,380# force
3/4 Gr5 has 23,780# force
3/4 Gr8 has 33,570# force

It is possible based on my torque to force calculation the original rod was G8 since the math worked out to > 30,000# to remove the bearing. That being said the threads came off like corn coming off the cob. I ended up with almost smooth cylinders. So I'm pretty sure they were G5.

If you can find Gr 8 bolt in 3/4-20 that has 34,760# rated clamp force that should work without having to bore out the plates to 1".

It takes 325 ft·lb lubricated torque to achieve that level of force.

The 1" Gr8 I now have however can push 61,190# but takes 765 ft·lb of torque to get there. Even with my monster torque wrench it's only 700 ft·lb so I guess I can only push with 56,000# of force but 28T force and way below the limits of the bolt so I won't possibly strip it.

The smaller bearing from the back wheel probably took 15-20,000# to install and it went on like butter. No heating or cooling needed just assemble and into a stack around the bolt and turn the nut until things stopped moving.
https://uploads.tapatalk-cdn.com/201...3362ac2da0.jpg

I need to replace my 3/4" rod to use with the smaller plates I didn't drill out to 1". I may just look for bolts rather than the official threaded push rods which seem to be Gr5.

I paid something stupid low for the 1" bolts maybe $6 each. I have to stack extra plates as shown because the bolt is not full thread but I figure that makes it stronger.

I also usually use an oil infused bronze thrust bushing not shown in this picture. It needs to be over 1/8" though, as when I used the 1/16" it just squirted out like it was made of clay! (What a surprise!)

I use a priceless app called iEngineer.

https://uploads.tapatalk-cdn.com/201...131834eda6.jpg

Screen shot of grade 8 3/4 bolt specs.

The shaft of a 3/4 bolt might yield at 50k but I'm very confident in the data in the app that I use having reliable sources.

Tensile strength of Gr 8 is 150ksi. That puts a theoretical strength of about 120,000# but the problem is the nut to bolt threads are what's holding things together. The problem isn't the shaft breaking it's the threads folding over.

33,570# is the clamp force of 3/4" Gr8 bolt. That's 100% rated. There is surely some safety margin but not 17,000# worth.

I do think that a Gr8 bolt 3/4 has a very good chance of pulling out the front bearing of the X5 but I would definitely heat up the carrier!

When I applied on the order of 30-33,000# of force in my case it laughed at me. When I heated the carrier to 250° F while pre-loaded to 15T it suddenly moved with a literal BANG.

That bearing is no sh%# stuck in there tight! Be prepared with some muscle to push it out!

Even with my 28T press I might heat the carrier to ease things along.

Got it, thanks for the info.

This all seems a bit confusing. I see that I can purchase a new hub which bolts on through the rear of the front cradle. The axle slides through the hub and gets bolted tight. SO, where is this bearing pressed into the hub? Is it pressed into the rear of the hub? If so, when buying a new hub will it come with a new bearing already in place? I am getting a loud howl and vibration from left and right i think. I would prefer the easiest replacement. This X 5 has 232K miles and these hubs/bearings are original. Thanks for clarifying. OH, the front axles are replaced at 180K miles.

The bolt-on bearing is for the rear only - the front bearing is pressed into the steering knuckle. You are either going to pay some one to do this for you or you are about to buy a metric crap-tonne of new tools! :rofl:

http://static.bmwfans.info/images/epc/MTI4ODg4X3A=.png

https://i.ebayimg.com/images/g/ZZYAA...Yw0/s-l300.jpg

Easiest replacement, bring it in and let a Real mechanic replace the bearing.

Second easiest method is trade the X in for a truck that has the hub and bearing bolted to the knuckle.

cn90 - I used the "FWD Wheel Bearing Adapters" kit from Harbor Freight to press the outer race out from the knuckle - I needed to replace the rod and nut in the kit though, for some heavier duty rod, wider washer, and lock washer from Home Depot, the threads were more coarse than the rod included in the Harbor Freight kit but it worked just fine as it was super strong and greased up -

I wish I remember the size I bought but it was a few years ago, I just took the rod from the Harbor Freight kit to Home Depot with me and got something of similar length that was a bit thicker and looked more heavy duty for the job -

Also, the handle of my jack was absolutely my friend as it gave me more leverage when turning the wrench to press it out -

The rod that comes with is 3/4-16. I went through three of them while replacing two bearings as 3/4" is not big enough to support the forces involved. I think the fine pitch rod with the kit and the better quality replacements I used may have only been grade 5. If you get a grade 8 bolt it can supply over 15T of force. That will still be on the edge of possible as I calculated close to 35,000# to remove the bearing with MAP gas to heat the carrier to 250°F.

I bought a 3rd replacement rod (3/4) but I only use that for the smaller sizes: I drilled out the biggest plates to 1" and bought a couple 1" grade 8 bolts, nuts, washers and an oil infused bronze thrust bushing. Combined with my big impact wrench it can press about 28T makes the job loud but almost effortless.

I bought my copy of the HF bearing press about half price because some idiot stripped the rod and returned it. I was already planning to ditch the rod and upgrade to 1" so that worked well for me!

Somebody may make a kit with just the right size needed for the x5 bearing so you don't need all the parts.

I had my brother drill out the large holes since he works at a machine shop so I don't know how difficult it would be to drill out the holes but the 3/4" rod is right at the edge of possible and a 1" rod is double the strength needed for the job and made the last bearing a breeze to change.

You need to remove the inner race from the hub which most people will cut a diagonal groove with a right angle grinder or Dremel and break it with a chisel.

The first time won't be "easy" but well worth the effort. I've replaced 3/4 of wife's and one of mine so far. Two with 3/4" bolts and long handled ratchet (I used 2" PVC pipe much more comfortable on my hands than steel) the last two I had my upgraded 1" bolt and what a difference. Bolt looks unused after pressing three bearings.

Based on my guess that the fine pitch rods were only grade 5, it does greatly increase the chance you can copy the previous poster success with a grade 8 3/4-10 bolt. It takes 300 ft·lb of torque to get the rated 30,100# of force so plan accordingly. Grease well buy a couple spare bolts and nuts if you stick with 3/4 size.

The kit pays for itself with one bearing since it will usually cost $40-60 to have a shop press out and in a replacement bearing and another $100 for a proper alignment if you remove the hub carrier to take to the shop. I'm very glad I bought mine. I borrowed a friend mechanic's press for the first bearing and had to buy him a replacement threaded rod as I was converting the threaded rod into cylinders each use. I was able to get the bearing out in spite by stacking plates to use a fresh part of the rod that wasn't stripped over and over.

If you know of a shop that can drill out the plates to 1" I highly recommend copying me and bump the bigger plates up to 1" holes.

It takes 700 ft·lb to maximize the force of a 1" lubricated fine pitch bolt but with any luck you will only need 400, something doable with hand power.

I couldn't remove my axle nut on the second bearing I did with a 4# hammer and 24" breaker bar so I bought the big Milwaukee impact wrench that can supply 700 ft·lb of torque and that is close to but less than the max torque spec for a 1" bolt so it can't strip the bolt but will supply about 56,000# of force quite reliably and with minimal effort (just holding the nut from turning while running the impact wrench)

7/10 difficulty with 3/4" bolt. 4/10 difficulty with 1" bolt. (doing the rear bearing was 2/10 difficulty I almost laughed when I watched the bearing get sucked onto the hub. )

Oh: to remove the hub I used some long 14-1.5 bolts and some metal angle, drive the bolts through the lug holes in the hub into the carrier knuckle (with the metal angle as a shim). This will destroy the dust cap so I usually cut that off in the process and buy a new one when I buy the bearing. For the rear I used a slide hammer kit that I rented from Auto part store. That would probably work on the front but I don't like to hammer on all the ball joints it is cheap insurance to spend $10 on a new dust cap.

Most people strip those HF bolts because they fail to lubricate the bolt. I use a punch hydraulic as shown in this Youtube video to remove and replace press in bearings. The bolt that comes with the HF wheel bearing kit is strong enough in tensile force which is what my punch press is applying to the bearing to remove it from the hub. I also put the bearing in the freezer over night to "Shrink it" enough so less force is required to push it back into the hub.

https://www.youtube.com/watch?v=m3dgrgmMZw0