Technical Hub nut

[Ralf S.]

Does anyone knoe how many torques I need to put on the front wheel hub nuts?

I've lately swapped the n/s front wheel bearing and did the nut up using the Ralf S. automated torquing tool (i.e. just guessed it)... but I've got mu hands on a torque wrench so I may as well check it.

It's something like a number "plus 60 degrees".


Ta.


Ralf S.

 

[Davren]

Does anyone knoe how many torques I need to put on the front wheel hub nuts?

I've lately swapped the n/s front wheel bearing and did the nut up using the Ralf S. automated torquing tool (i.e. just guessed it)... but I've got mu hands on a torque wrench so I may as well check it.

It's something like a number "plus 60 degrees".


Ta.


Ralf S.

7 daNm +62°
.

 

[Ralf S.]

62 degrees is interesting.

You'd think 60 degrees would do it.. but apparently not. Someone decided (somehow?) that it needed 62..



Ralf S.

 

[flyingdutch]

Ok quit the joking most of the times its 180 190 nm for fwd cars

 

[Ralf S.]

So.. it's not 70Nm?

I dunno if 70Nm is a lot or not. I thought wheel bolts were something like 20Nm torques, so 70Nm plus 62 degrees sounds like plenty.. but if it's not 70Nm, how many torques is it?

My new wheel bearing came with just a plain collar on the end, rather than with a castellated top (for a cotter pin) or any locking tabs. Is this a special type of nut? After I tightened it (to however many torques plus 62 degrees,) is there a way these are supposed to be locked?


Ralf S.

 

[Davren]

Can't remember the last time Fiat (or any mainstream manufacturer) used castellated nuts and cotter pins.

The nut with a collar is a stake nut. Don't reuse the old one, you need a new one each time it's been removed. Tighten it to 70 daNm +62°, then stake part of the collar into the groove in the CV joint spindle. I use a blunt cold chisel to do them.

70 daNm +62° is a lot.... You'll need someone standing on the brake pedal to stop the hub turning and a long bar for the socket. I use the sliding T bar from a ¾" drive socket set with about 4 foot of scaffold pole on it.

You'll need a 36mm socket for the hub nut, but most standard sockets are too big to fit into the hub flange, so you may need to grind the outer wall of one down to fit. As I did with the one below.
.

 

[chris3234]

So.. it's not 70Nm?

I dunno if 70Nm is a lot or not. I thought wheel bolts were something like 20Nm torques, so 70Nm plus 62 degrees sounds like plenty.. but if it's not 70Nm, how many torques is it?

My new wheel bearing came with just a plain collar on the end, rather than with a castellated top (for a cotter pin) or any locking tabs. Is this a special type of nut? After I tightened it (to however many torques plus 62 degrees,) is there a way these are supposed to be locked?


Ralf S.

Most wheel nuts) bolts around ,80-100nm

 

[Davren]

Had to take the front wheels and bumper off one of my Stilos today so took photos of the hub nuts I replaced a few years ago.

First picture is how eLEARN says to stake the nuts on the Stilo. However, having done the first one that way, I considered that by splitting the collar, there was more chance of the bent part breaking off in the groove.

Second and third pictures are how I did the other side. This is the way workshop manuals for every other Fiat I've seen say to stake the nuts.
.

 

[flyingdutch]

Well it doesnt really matter how you "stake the nut " as long as you can make it snug , it wont spin off what matter is to make the nut really tight cause dont forget that its making a preload on the wheel bearing , otherwise the lock on the nut is required only for braking , high torque aplications. You can leave it unlocked and it wont spin of if youre driving like a grandpa.

 

[Ralf S.]

Okey doeky.. 70NM (7 daNMs) plus 62deg it is then.

I did mine up as tight as I could using a regular breaker bar (maybe 40-50cm). Sometimes you can tell how tight something wants to be but bearings are a bit funny. It'll be interesting to see how many torques I put on it compared to the book settings.

I've got a special 36mm socket for the hub nuts since I've had to change both sides inner CV joint spiders and a driveshaft over the last 2-3 years. It's been manufactured like Davren's home-made one; there's a 1mm machined step in the lower part of the socket so that it fits just right inside the Stilo flange hub. On fleabay for aboot £7 if I remember right.

The stake thing sounds about right. The Fiat nuts have the little tabs like in Davren's first photo but they get deformed once you've folded them in and out once or twice. The new ones don't have a pre-cut stake but the collar material looks quite thin, so I did wonder about bashing a small dent into the collar, so that it fits into the grooves in the driveshaft. You've confirmed what I was thinking, ta.

I've got loads of hub nuts now.. one came with the new bearing and I also got one with new driveshaft. Obviously I was able to re-use the one that was on there, since I hadn't put any stakes in it.. but I will now.

Ralf S.

 

[Ralf S.]

Well it doesnt really matter how you "stake the nut " as long as you can make it snug , it wont spin off what matter is to make the nut really tight cause dont forget that its making a preload on the wheel bearing , otherwise the lock on the nut is required only for braking , high torque aplications. You can leave it unlocked and it wont spin of if youre driving like a grandpa.

The nut on my nearside was nice and tight but my wheel bearing failed really badly over just a few days... (one Wednesday it started making noises .. and I changed it on the Saturday, 10 days later).

By the time I changed it, the bearing had enough play in it so that the whole hub was able to move slightly on the driveshaft. This made the wheel nut slack... not because the nut was coming unscrewed but because the hub was moving away from it slightly.

When I removed the nut, it was just finger tight, so without the stake it would have been able to come unscrewed, which is what prompted my question.

Technically without the hub nut the hub can fall out of the hub carrier (so the wheel would fall off) but in reality the flange is pressed in to the wheel bearing and doesn't really want to come out... and while it's becoming loose it would make a racket and vibration that is impossible to ignore.... but still, loose nuts is probably not a good idea.


Ralf S.

 

[flyingdutch]

The thing about making it tight is tension preset for the back bearing collar that is the parts which gets loose most of the times and damaged trough the years of use , also you always have to check if you pressed the bearing correctly and the hub in it too , i usually do one more press fom inner side to make sure its snug fit