Alfa Romeo Forums banner

rear wheel bearing

6K views 18 replies 10 participants last post by  CatellusEng 
#1 ·
How tight should the rear wheel bearing retaining nut be and how do you measure that.I have a factory-like tool(two handles).Thanks,Phil D.
 

Attachments

See less See more
1
#2 ·
I'll be interested to hear the experts response to this. I have just dismantled mine and they were tight, very tight! Took a lot of effort with an extension bar on a C-spanner.

What does the Alfa special tool look like? Did you have any trouble loosening the nuts?
 
#4 ·
I made this tool from a large nut and some bar stock,but much like the factory one .One of the axle nuts was tight,but not too difficult to break loose.The other was not very tight,maybe 20ft.lbs.. After getting no response to this post,I sent a few emails about "how tight?" to an experienced Alfa guru.Nothing really written in stone,so my impression is hand/arm tight if using a tool like this,around 35ft.lbs.?Not necessary to over do it.If I've got this wrong,someone please let us know.
 

Attachments

#7 · (Edited)
Thanks for that link Rick.Never knew the logic behind inside/outside star washers.I've always used them on ground cables without any problems. In this case,a tab washer is used,so bite,tension,and looks are irrelevant.According to Boker's,(tab washer manufacturer)tab washers are designed to hold a nut in place when in extreme heat and under heavy vibration.Nothing was mentioned about tightness or torque. As you can see in the picture,the nut has six spaces and the tab washer has seven tabs making it a vernier type set up,similar to our cam/sprocket adjustment.Makes me think that there "is" a target to tighten to(something like finger tight,then tighten to the next space/tab line up??).But unless someone chimes in with facts,I'm going with a 25-35ft.lbs. guess. The last picture shows something I noticed while setting these parts up to be photographed.The tab washer picked up the markings(in reverse) that are on the bearing,transferred somehow as if pressed or etched into it.Hard for me to believe that the nut I took off was tight enough to press the marks in,but I dunno,just curious.
 

Attachments

#8 · (Edited)
Ah, yes.. I see it is a locking washer with tabs rather than a star washer. In that case you have two options how you place the washer in the groove of the shaft. .. 180 degrees from each other. I would trial fit the nut each way to see which way is the best to align a nut slot with a tab and yet get it tight. I think you will find once the nut is reasonably tight it is hard to rotate a slot of the nut to line up with the washer and the distance will vary by how the washer is located. Whichever you choose will determine how much torque you need. (I am sure there is a wide range of torque numbers by this design). One position might be so much torque you can't still align. In that case I would remove the nut and rotate the washer 180 degrees and try again. There should be a happy point where it is darned tight and a washer tab can be bent into the nut to lock it. Hope that makes sense. The locking washer is not tabbed randomly so this design gives you that flexibility when assembling.

PS.. It's a little late for this advice but whenever I take a ring nut apart like this I mark he location of the tabs and position of the washer and nut to each other. This way using the same nut from that axle you should be able to replicate how much torque was on it before you take it apart when you reassemble.
 
#9 ·
All makes sense,exactly what I did,and worked great.And as you mentioned,once the nut is seated hand tight,you get around an eigth to a quarter turn.After that,it becomes obvious that there's no need to go any farther.Funny how that works.I believe that both axle nuts are tightened the same and are not going anywhere,and most importantly,the bearing spins freely.For anyone doing this,here are a couple of tips;flatten the tabs(except for the two that face down)before slipping it onto the axle.Put the nut on hand tight,and then take a thin putty knife and tap it under all of the tabs raising them slightly to get them off of the metal shield of the bearing(or else they'll rub when tightening the nut).That shield is soft and will distort easily,thus the putty knife.After tightening the nut and lining it up with a tab,use the putty knife and a small tool(chisel)to raise the tab while preventing it from touching the bearing shield.I then used a punch to finish setting the locking tab tightly in place.Rick,AFA marking positions,always a good idea.In this case,each axle was way different,so this procedure will make em' the same.
 

Attachments

#11 ·
aamatruda:
I disagree on the installation detailed. To begin the nut as shown on the pic is upside down. There is no need to flatten the tabs during the assembly. There are two sets of tabs on these washers, one inside and seven on the OD. The internal tab should slide into a groove in the shaft with the external tabs facing up towards the nut. The nut has a beveled side that should be facing the washer, the outer tabs will be away from the bearing, after tightening the nut one of the washer outer tabs will line-up with one of the nut slots to be bent to lock it. Enrique.
 
#13 ·
Tom,Thanks for the compliment,but the tools' teeth need to be ground or shortened in such a way as to not interfere with the pre-bent tabs(see last photo),not a big deal but was the reason I had to flatten the seven tabs.(The Highwood Alfa photo shows the tab washer as supplied new,all pre-bent tabs.It is for a 105 series axle). As Enrique points out,flattening the tabs is not necessary,honestly,neither is the tool I made! Let me try to clarify this post.The pictures below show the order and orientation of the parts as they were installed on "my" four axles.The bearing was pressed on the axle with lettering and numbers up.Next,the tab washer,with the two tabs facing down(inside the bearing)and the seven bent tabs facing up.The nut goes on next,with markings up.Hope this helps and I apologize for any misinformation.If any of this is still incorrect,let me know,critique welcome.I still stand by using a putty knife to protect the bearing shield when bending any tab up or down.Phil D.
 

Attachments

#14 ·
I replaced my rear wheel bearings a while ago and used a technique very similar to that described by Phil above.

My tightening tool was also made to fit though my tab bender was a small sharp(ish) screwdriver and a blunt punch.

A couple of observations -

The bearings are normally a snug fit and can be seated perfectly with careful use of a press. Writing side in or out does not effect function but makes it easier to identify the bearing when it next needs replacement - pretty much standard mechanical practice for fitting anything.

The castellated nut was torqued to the first tab/indent alignment after initial finger tightening.

The castellated nut is bevelled on both sides.

Regards,
Chris
 
#19 ·
New forum member, old thread! I'd like to service the bearings on a couple of axles, and their ring nuts seem to be on too tight for a punch-and-hammer approach to removal. Is their an available substitute for the A.5.0120 tool? Phil's homebrew tool looks great; will I have to make my own version of it?

Kevin
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top