Rear Wheel Bearing on Wagon, Sir B90-M and cold?
 

Hi everybody
I have to change to wheel bearing on my wagon (1992 300TE 170kmiles). I have consulted a few threads about this and the consensus seems that you'd rather leave it to a professional with the proper Mercedes tool.
I have found a SIR tool (B90-M) that is built for the job, however the wagon's bearing seems to be double row bearing that is too tough for that puller?
Nevertheless, would it be possible to use tis tool successfully if I apply cold (liquid nitrogen, or dry ice) to the bearing to be extracted so it would shrink?
Every time I bring my car to a mechanic it costs a fortune and they break something etc.
Regards, Bruno

The best DIYer way is to remove the complete hub assembly & have the bearing & flange pressed in/out at machine shop.

Thank you
 

I will get quotes from dealerships (Boston, MA and Haverhill, MA).
If that will be >900$ I'lll get a wheel hub from a junkyard, replace the bearing and then replace the one on the car.
Bruno

Rear Wheel Bearing Success on Wagon using Sir B90-M
 

I bought the tool before reading that it would not work on my 92 300 TE 4matic (see Other Thread as well as instructions). A little ignorance goes a long way. However, from the post in the other thread about stripping the tool I did suspect a problem and therefore examined the toolset closely. What I noticed was that appropriately sized washers for my 92 300 TE 4matic rear bearing were missing. I also saw that the dust shield between the wheel carrier and the axle shaft flange would be smashed by the tool if I didn't do something to prevent this.

Here is how I made this tool work for me:

1. I protected the dust shield from compression by the tool by using masking tape to secure several 5/8" nuts (purchased home depot - they are the right thickness) to the dust shield where it is direct contact with the wheel carrier as well as the the horseshoe.

2. To slip the tool's #3 bracket with horseshoe between the dust cover / wheel carrier and the axle shaft flange I removed the bolts that secure the horseshoe to the #3 bracket and just held the horseshoe and bracket in the intended orientation while tightening the tool to the hub.

3. There don't appear to be any extracter washers of the appropriate size with this kit. Perhaps there would be with the full kit (Sir B90 Master Kit). I went to the local Fastenal with the measurements and bought washers that did the trick. For pulling the axle shaft flange I used a total of 20 7/8" hardened washers with part #1133821. They have a 24 mm inner diameter and a 44.5 mm outer diameter. I bought the hardened ones only because they were the right size. For removing the bearing from the carrier, I used 5 regular 1 1/8" washers with part #33024. They have a 31.5 mm inner diameter and a 70 mm outer diameter. Total cost about $22. I used some masking tape around the circumferance of the 5 big washers to keep them in alignment as a unit as I initially tightened the tool since the 70mm diameter just fits through the hole in the wheel carrier.

4. Of course I greased the nut and bolt of the tool itself before cranking away. I used a lever arm of about 2 feet to pull the axle flange out. Probably around 200 Nm of force.

5. Maybe I got lucky but when I pulled the axle flange as the lateral inner bearing race did not come out with it. However if it had, I would just use a grinder to take if off the flange since the bearing was trash anyway.

6. For pulling the axle flange back onto the bearing the MB instructions state that the supporting washer should fit tightly against the bearing inner race. I used the same washers as for pulling (70 mm OD) before seeing these instructions. If I were to do it again, when pulling on the axle flange I would do what I did later - remove an inner race from the old bearing using a grinder to cut away the outer race (takes 5 minutes with the bearing in a vice) then use this as the washer for pulling the axle flange onto the inner race. It is then perfectly sized for the job.

7. Finally for dealing with the circlip holding the bearing onto the wheel carrier I did not have a special tool. Read the rest of this only when you meet the circlip and wonder what you are going to do. I used a pair of needle nose pliars, pushed them into the holes in the circlip using a board in my right hand and took a very large pair of vice grips in my left hand to squeeze the pliars shut. I then took let go of the vice grips which where locked on the needle nose pliars and stuck a sloted screwdriver between the circlip and the hub at one end of the circlip. I then put the pliars down and used another screwdriver with the first to work the circlip out. To put the new circlip back I used the large vicegrips to close the circlip, put needle nose pliars into the holes of the circlip then took the vice grips off and clamped the jaws of the needle nose pliars together. The circlip was then small enough to slip into the slot. Seems like I could have done this on the way out but my vice grip/pliar combo would not have been able to squeeze enough.

8. As an aside, to get enough space to drop the axle from the differential I had to jack up the wheel carrier. This was counter intuitive to me but relates the the motion of the wheel carrier as it is jacked up - e.g. it moves out.

Total time for the right side: 3-4 hours.
Time to prepare this post: maybe 1 hour.
Cost quoted by MB dealer $1600!! (maybe they meant for both sides)
Parts: $90
Tools: $320

Cool! Thanks a lot.
 

BoxfordBenz
Actually, I bought the SIR tool as well, before making sure it does not work... was just a tad embarrassed to admit:o I had my wheel bearing changed by a retired Mercedes mechanics that had access to the original tool.
Still, that SIR tool is just sitting useless in the box. Your instructions thus come very handy! It is only a matter of time till the other wheel bearing is starting to make noise.

BTW I am sure they were talking about one side... especially if it was at Chambers.