Torquing Up Hub Nut

[Bazza-c 0]

Having just put a new driveshaft on my 205 gti MI16 which was originally the 1.6 gti and still has the original gearbox. I've seen that the hub nut should be 260NM but my torque wrench only goes upto 210NM. The hub nut is currently torques to 210 sitting on the drive till I can finish the job. Does anyone know a formula of how to get the last 50NM. I don't know anyone with a suitable torque wrench and the car I'd kept off the road and is only trailered to tracks for playtime, so getting the car to a garage is very expensive and time consuming.

I'm guessing that as the thread gauge is a constant that once a specific torque has been reached ie. 210 then an specific amount or turn (degrees) should achieve 260.

Does any one have such a formula?

 

Many thanks

Barry

[Tom Fenton 1,542]

Some may disagree but driveshaft nuts are something I do not worry too much about the torque. You know it is already at 210 so give it another good "grunt" with the power bar and call it a day. Once you are at that kind of torque level, e.g. the nut is now loading the shaft end, it takes very very little extra angular movement for a huge increase in torque. More important to me is making sure the securing method be it r-clip or stake nut is in good order to ensure once tight it will stay put.

[Bazza-c 0]

Thanks Tom for your reply. Of course that makes sense since a small degree of turn will, at these torque levels, produce a sizable increase of torque, probably not easily measurable by degrees of turn. Is my understanding correct or am i mistaken.

[Tom Fenton 1,542]

Hi Baz, yes that is correct, however it is not a simple job to calculate angle required as there is friction on the nut threads and face to take into account as well as thread form and angle.

 

To be honest these days I rattle the nuts up with my Dewalt impact gun until they won't go up any more and call it a day. Been doing it like this for the past 7 years on my trackday car and no issues yet, if that sets your mind at ease.

[Bazza-c 0]

Thanks Tom for your reply. Of course that makes sense since a small degree of turn will, at these torque levels, produce a sizable increase of torque, probably not easily measurable by degrees of turn. Is my understanding correct or am i mistaken.

[swordfish210 20]

I do the same, just wind it up on the wrench as far as it wil go and then give it a good British Standard Nip and leave it at that, no issues so far

[Kev-G 1]

Big bar + a good tug ;-)

 

Will get flamed for this, but never bothered with the retaining clips on my track cars....

[welshpug 1,657]

no retaining clips is not a clever idea, no matter how tight you do the nuts up, its also an MOT fail (if they can see them)

 

have had shafts come loose on a rally car where another mechanic had left them off, luckily our service vehicle was a Berlingo so we could borrow the R clips and castellated covers!

 

the driver did a few stages complaining the brakes kept going, finding the pedal would be VERY long on initial press then coming back if pumped, this was the play in the wheel bearings from the loose nuts pushing the pads back in the calipers!!

 

I use the same method as Tom and Mark.

 

 

 

Wheelnuts however a different story, torque wrench every time.

Edited March 13, 2011 by welshpug

[HERMAN 33]

4 white knuckles and a grunt

[Alastairh 47]

Good sized bar and once FT just make 2 little clicks in your mouth to similate a torque wrench and your done!

[oli-pug 6 2 Cars]

Also agree with the others, FT is enough

[large 33]

just get a 1 foot long power bar and 13st 10 on the end of it. That will give you a little more than 260 N/M but not a lot.

 

260 N/M is not that tight at the end of the day.

[pug_ham 244 3 Cars]

no retaining clips is not a clever idea, no matter how tight you do the nuts up, its also an MOT fail (if they can see them)

1.6 GTi's never had clips though, thay are staked into the driveshaft end, just like the base models.

 

1.9's were the only GTI model that had the clips.

 

Graham.

[Cameron 16]

My torque wrench only goes up to 220Nm so I do it up til it clicks, then give a quick bounce on the end of the bar to budge it round another degree or so. As Tom said at this kind of torque you're talking a degree or two between 200Nm and 250Nm.

[Simes 248 2 Cars]

1.6 GTi's never had clips though, thay are staked into the driveshaft end, just like the base models.

 

1.9's were the only GTI model that had the clips.

 

Graham.

 

+

I've had 1.9 shafts before that have had no hole for a retaining clip.

[pug_ham 244 3 Cars]

Not all 309 GTI driveshafts had the clip either afaik but never seen an original 1.9 driveshaft without one iirc.

 

Graham.

[welshpug 1,657]

Indeed thanks for pointing that out, I forgot all about it! even though my 1.9 205 has one of each type

 

still, always stake or clip

[lagonda 42]

If you really want to be sure of being in the right area, a free alternative to another torque wrench is to use a set of common or garden bathroom scales. Place a block of wood between your bar handle & push or pull until you get the correct weight. You will need to measure the bar. If it's 2 feet, halve the weight for lb/ft, you can always extend your bar with a piece of tube, gaining extra leverage, & a more useable length for your calculation.

[large 33]

Or you could look at my post above that gives the amount of weight you need on a 1 foot bar. foot pound if you like.

[Jamal 2]

I uses this formula:

XNm=Your weight(kg)*10*the bar length(in metre)

 

Example

260Nm=75*10*m

m=260/750

m=0,346

 

So you have to stand 0,346m from the nut on the bar to get the hub torqued up to 260Nm.

 

Hope it helps.

[davepug205 7]

I torque mine up to 4 dg's youll hear the airgun goin dgdgdgdg = job done

[allye 530 3 Cars]

As above, I find it best to drag the air line out, plug in the impact gun and sqeeeezzzee

 

Sorry, thats not much help.

[SurGie 54]

Im surprised with the amount of replies in this thread

 

I use the bigger type of torque wrench for the larger torqued hubs, my smaller torque wrench is for everything else.

[hothatch 2]

borrow a torque wrench that does 260 NM !! i always torque nuts an bolts up, torque settings are there for a reason!

 

Although the reason im so fussy is probely do it in habbit of always working on other peoples veihcles , last thing you want is a customer coming back with a loose hub nut lol. I suppose you got no one to answer to but yourself lol. I just think torquing's good practice.

[EdCherry 34 1 Cars]

Personally torque these kind of things. To tight/lose and its not exactly helping the longevity otherwise is it.