Jump to content
aclwalker

Can we clarify VR6 hub nut torque then sticky please?

Recommended Posts

I'm soon going to replace a front wheel bearing as the noise is becoming intolerable now.

 

On this forum there's a lot of confusion about the hub nut torque for a VR6.

 

Some people mistakenly say it should be 265Nm. This is clearly wrong as this is for the non-VR6 models which have a 6 point nut rather than a 12 point nut like the VR6 has.

 

Bentley says 90Nm + 45 degrees.

 

Some on this forum say that Bentley is wrong for certain late VR6s and that it should be 50Nm + 30 degrees, after first tightening to 200Nm then loosening. Supercharged and Yandards have both said this, if I'm not mistaken.

 

Some questions that I can't find the answer to, however:

 

1 How is "late VR6" defined? I can see no changes in ETKA in this area on the VR6, which suggests that they are all the same. How do you choose between 90Nm or 50Nm?

 

2 Does "late VR6" simply mean that VW realised after a few years that 90Nm was too tight? If so, that would suggest that ALL should now be set to 50Nm, not just "late VR6s".

 

3 Where have Supercharged and Yandards got this information from? I'd like to see the reasoning behind changing from 90Nm to 50Nm as 50Nm seems very low for such a critical component. (I'm not saying they're lying but it would be good to see the original source for this!)

 

4 VR6s of that era (Golf, Passat) seem to all have identical part numbers in relation to wheel bearing housing and the bearing itself. Any other forums/posts about VR6 based cars from that era seem to say 90Nm. Why is the Corrado apparently different?

 

For what it's worth, when I did my CV joints on one side, the hub nut did feel about 90Nm when I loosened it. It was definitely NOT in the hundreds. I didn't replace the bearing then, even though it was starting to go, because it was an emergency CV joint repair and the weather was really bad. I did tighten it up to 90Nm and it seems a bit 'stiffer' (i.e. in terms of rotating the wheel) these days than it was before. It is definitely more difficult to rotate than the other side. So, either I have tightened it too tight at 90Nm, or it's just a natural progression of it failing from when I did the CV joint, as it was making noise even then before I undid it for the CV joint.

 

Please can Supercharged or Yandards clarify the reasoning behind the apparent change from 90Nm to 50Nm? Could they please also give some guidance as to how you decide between the two or if, indeed, all VR6s should now be 50Nm? After all, there is only ONE bearing and ONE housing listed for ALL VR6 Corrados (and, it seems, all VR6 VWs of that era), so I can't see why some would be 90Nm and some 50Nm.

 

Perhaps a final clarification or definitive answer could be stickied and/or put in the knowledge base, as I know it's an often asked question but unfortunately confusion still remains between 90Nm and 50Nm.

Share this post


Link to post
Share on other sites

Interestingly, I've just done a Google for "vr6 hub nut 50nm 30 degrees" and come up with two interesting PDFs:

 

http://www.veedubz.co.za/tech/VW%20Haynes%20Mk3/TRANSMISSION%20REMOVAL%20&%20INSTALLATION.pdf

and

http://album.seehere.org/albums/userpics/10001/Mitchell_Repair_Information_Company_-_VW_Golf_3_Repairing_Handbook.pdf

 

Both seem to originate from a "Mitchell Repair Company".

 

The first one is a South African link and confirms the three possible torques: 265Nm, 90Nm + 45 degrees and 50Nm + 30 degrees (after putting to 200Nm then backing off one full turn).

 

It says that 265 is for "Without Plus Suspension".

90Nm is for "With Plus Suspension, except Passat".

50Nm is for "With Plus Suspension, Passat".

 

Not exactly very helpful. And what is "Plus Suspension"?

 

The second PDF is quite interesting though. It's a massive almost 1000 page document. It also confirms the three possible hub nut torques above, but gives a different explanation as to when they are used:

 

In addition to the Passat bit above, it says:

 

With Tripod-Type Joint 265Nm.

With Bonded Axle Shaft Splines 90Nm + 45 degrees.

With Compressed Hub Splines 50Nm + 30 degrees (after going to 200Nm then backing off one turn).

 

So, I think we're finally getting somewhere. The tripod-style joint refers to the inner CV joint on non-VR6 cars. The inner CV joint on the VR6 is a ball-bearing joint like the outer (but obviously without an axle).

 

The difference between 90Nm and 50Nm seems to rely on whether you use bonded axle shaft splines or compressed hub splines.

 

I remember reading some people saying that the hub splines should be bonded with some sort of loctite. However, mine were GREASED when I took them off before, with what looked like copper grease.

 

So, the VR6 torque would now seem to rely not on the bearing or housing, but instead on the hub and outer CV joint (which the axle shaft is a part of). I'm just going to check ETKA again and see if there was a change in hub or CV joint...

 

OK, this is getting interesting. ETKA lists only one part for the hub for the VR6, but crucially, it's got a "B" on the end, which means it's the second revision. This suggests that all replacement hubs are probably going to be the second version, which would suggest that they should be 50Nm + 30 degrees (after 200Nm and backing off one full turn), given that Supercharged and Yandards mentioned that "late VR6s" are the lower torque. ETKA only seems to list one outer CV joint for the VR6.

 

I've checked my third party replacement hubs and they say they replace the VW part number with the "B" on it. I've not got my other spare CV joint here to check its OEM replacement number.

 

So, to summarise, it looks like if your hub is already the "B" version or if you are replacing your hub and the new one is the "B" version, then use the 50Nm + 30 degree (after going to 200Nm and backing off one full turn). If you have original hubs, which are not the "B" version and you are reassembling everything (e.g. after CV boot replacement but still using original hubs), then use the 90Nm + 45 degree setting, plus a locking compound.

 

And never use 265Nm for a VR6!!!

 

I would hazard a guess that the change was to save the hassle of using a locking compound, which probably only really works on new, unrusted cars. Clearly it's much easier to just torque and be done with it, rather than messing around with locking compounds.

 

Does my investigation and its conclusions make sense?

Share this post


Link to post
Share on other sites
I get a really big bar and jump on it...torqued up f-tight!

 

autodata says...

Excellent, your attachment just confirms my second post. 50Nm is for compressed splines, which is probably the "B" version of the hubs. Finally the confusion seems to be over!

 

BTW, What is "autodata"? That looks quite good. Is it a website or something?

Share this post


Link to post
Share on other sites

Look for autodata on the net,its used in the automotive trade for technical information.

 

Its not free and you need to purchase the fully licenced and working one for lots of money like i have........... :wink:

Share this post


Link to post
Share on other sites

Hi Alan, sorry hardly been on here recently and only just got your PM's...

 

The info me and Yan posted was from the proper VW Workshop manual for Corrado Running Gear - this gets updated with TSB's so is always more reliable than the Bentley etc...

 

Good to see autodata actually have the correct torque info for once too although there is a bit more of a procedure to it which I think we have posted in a thread.

 

I think as you've found it depends on what's actually on the car but the procedures are critical for the longevity of the new bearings.

Share this post


Link to post
Share on other sites

Hallo,

 

Just to confirm what you have already worked out, it's the splines on the CV joints that are different and any new cv joints fitted will have the compressed splines.

 

The other thing to note is that the VAG ammendment to the workshop manual states that when rebuilding the hub assembly and until torqued the vehicle weight should be off the wheels to prevent damage to the bearings. Whilst it is a pain in the bum to try to torque up with the vehicle on axle stands a friend with a foot on the brake pedal should do it.

Share this post


Link to post
Share on other sites

Thanks guys, it all makes sense now.

 

As for not putting the weight on the car until torqued up, I was aware of this. Once you get the thing apart you can see why this is the case. The axle part of the CV joint actually takes the weight of the car alongside the bearing and hub. If it is not fitted, or loose, then the bearing and hub takes the full weight which could easily make the bearing collapse.

 

Also, it should be possible to lock the disc with a screwdriver in the disc vents and pressing against the caliper. This would make it a one-person job.

Share this post


Link to post
Share on other sites
Thanks guys, it all makes sense now.

 

As for not putting the weight on the car until torqued up, I was aware of this. Once you get the thing apart you can see why this is the case. The axle part of the CV joint actually takes the weight of the car alongside the bearing and hub. If it is not fitted, or loose, then the bearing and hub takes the full weight which could easily make the bearing collapse.

 

Also, it should be possible to lock the disc with a screwdriver in the disc vents and pressing against the caliper. This would make it a one-person job.

 

Another option for disc locking is to fit 2 wheel bolts and then put an bar between them and rotate the disc until the other end of the bar sits on an axle stand.

Share this post


Link to post
Share on other sites

Don't see what the big deal is.

 

90K ago I had some new front bearings put in and the 12 sided nuts were air gunned on good and tight. Replaced the bearings again a few weeks ago as part of a chassis refresh and they were fine.

Share this post


Link to post
Share on other sites
as a mechanic i rarely use the torque settings unless it was a head job or something,i just gun it up well tight ! :tongue:

 

 

 

yyyeeeeeeeehhhhhaaaaaaaa!!!! :lol:

Share this post


Link to post
Share on other sites
as a mechanic i rarely use the torque settings unless it was a head job or something,i just gun it up well tight ! :tongue:

 

If it's your day job then I bet you can be pretty accurately 'feel' the torque for most sizes of nuts and bolts, it's not like most torque wrenches are accurately calibrated anyway, particularly the lower ranges.

I do like to use the torque wrench when I'm doing my own stuff, mainly because I have a history of under tightening or massively over tightening nut and bolts :lol:

 

My best ever was loosing 3 out of 4 wheel bolts on one front wheel on my mk1, I pulled over when it started wobbling really badly :epicfail:

Share this post


Link to post
Share on other sites

I am just fitting a new GKN CV joint & new hub to my VR, I've just checked that they go together ok and found that the CV only slides into the hub by about 20mm then stops - is this what's meant as compressed splines? The thread of the CV comes through about 12mm which I guess is enough to put the nut on and tighten and pull it through- is this right though? can't see any damage to splines on either part. Are the Cv splines tapered or something?

 

Cheers,

Share this post


Link to post
Share on other sites
I am just fitting a new GKN CV joint & new hub to my VR, I've just checked that they go together ok and found that the CV only slides into the hub by about 20mm then stops - is this what's meant as compressed splines? The thread of the CV comes through about 12mm which I guess is enough to put the nut on and tighten and pull it through- is this right though? can't see any damage to splines on either part. Are the Cv splines tapered or something?

 

Cheers,

 

It went together fine :) I noticed that the splines on the new hub have flats ground on the first 25-30mm so you can slide the CV in easily, then when you put the hub nut on it tightens up and pulls the CV joint through.

 

Followed the procedure for Torqueing, Even 200Nm doesnt seem very tight initially, then backing off and 50Nm + 30deg seems very low. I guess that alot of that 200Nm still 'holds' when you back off the nut, because the of the interference between splines & hub, so its probably alot tighter than it seems.

 

I couldnt resist tightening it up a bit more though, didn't go overboard just tightened until it seemed about 'right'

Share this post


Link to post
Share on other sites
On 2/21/2009 at 8:08 AM, aclwalker said:

Interestingly, I've just done a Google for "vr6 hub nut 50nm 30 degrees" and come up with two interesting PDFs:

 

http://www.veedubz.co.za/tech/VW%20Haynes%20Mk3/TRANSMISSION%20REMOVAL%20&%20INSTALLATION.pdf

and

http://album.seehere.org/albums/userpics/10001/Mitchell_Repair_Information_Company_-_VW_Golf_3_Repairing_Handbook.pdf

 

Both seem to originate from a "Mitchell Repair Company".

 

The first one is a South African link and confirms the three possible torques: 265Nm, 90Nm + 45 degrees and 50Nm + 30 degrees (after putting to 200Nm then backing off one full turn).

 

It says that 265 is for "Without Plus Suspension".

90Nm is for "With Plus Suspension, except Passat".

50Nm is for "With Plus Suspension, Passat".

 

Not exactly very helpful. And what is "Plus Suspension"?

 

The second PDF is quite interesting though. It's a massive almost 1000 page document. It also confirms the three possible hub nut torques above, but gives a different explanation as to when they are used:

 

In addition to the Passat bit above, it says:

 

With Tripod-Type Joint 265Nm.

With Bonded Axle Shaft Splines 90Nm + 45 degrees.

With Compressed Hub Splines 50Nm + 30 degrees (after going to 200Nm then backing off one turn).

 

So, I think we're finally getting somewhere. The tripod-style joint refers to the inner CV joint on non-VR6 cars. The inner CV joint on the VR6 is a ball-bearing joint like the outer (but obviously without an axle).

 

The difference between 90Nm and 50Nm seems to rely on whether you use bonded axle shaft splines or compressed hub splines.

 

I remember reading some people saying that the hub splines should be bonded with some sort of loctite. However, mine were GREASED when I took them off before, with what looked like copper grease.

 

So, the VR6 torque would now seem to rely not on the bearing or housing, but instead on the hub and outer CV joint (which the axle shaft is a part of). I'm just going to check ETKA again and see if there was a change in hub or CV joint...

 

OK, this is getting interesting. ETKA lists only one part for the hub for the VR6, but crucially, it's got a "B" on the end, which means it's the second revision. This suggests that all replacement hubs are probably going to be the second version, which would suggest that they should be 50Nm + 30 degrees (after 200Nm and backing off one full turn), given that Supercharged and Yandards mentioned that "late VR6s" are the lower torque. ETKA only seems to list one outer CV joint for the VR6.

 

I've checked my third party replacement hubs and they say they replace the VW part number with the "B" on it. I've not got my other spare CV joint here to check its OEM replacement number.

 

So, to summarise, it looks like if your hub is already the "B" version or if you are replacing your hub and the new one is the "B" version, then use the 50Nm + 30 degree (after going to 200Nm and backing off one full turn). If you have original hubs, which are not the "B" version and you are reassembling everything (e.g. after CV boot replacement but still using original hubs), then use the 90Nm + 45 degree setting, plus a locking compound.

 

And never use 265Nm for a VR6!!!

 

I would hazard a guess that the change was to save the hassle of using a locking compound, which probably only really works on new, unrusted cars. Clearly it's much easier to just torque and be done with it, rather than messing around with locking compounds.

 

Does my investigation and its conclusions make sense?

I was just reading this old post as I'm about to tight my axle nuts. 

This:

50Nm + 30 degree (after going to 200Nm and backing off one full turn). If you have original hubs, which are not the "B" version and you are reassembling everything (e.g. after CV boot replacement but still using original hubs), then use the 90Nm + 45 degree setting, plus a locking compound. 

What do you mates think and do? 

I'm thinking of doing the 90Nm + 45 but not with locking compound, thinking more of using copper grease. 

Thoughts? Cheers! 

 

Share this post


Link to post
Share on other sites
8 hours ago, 1xshaunx1 said:

I borrowed my step sons big  makita 18volt 1/2” impact gun. Little grease

So as tight you could do? 

See that's one thing I have in mind as well, the bearing, hub needs to be sandwiched between the axle bolt and the axle. To me, that needs to be real tight and an impact seems to be the right choice as well... But then why VW got so precise with torque? 

Share this post


Link to post
Share on other sites

There has been a few cases of the thread shearing off the end of the CV, but factor in OE and aftermarket parts, confusion over tightening sequences, age and fatigue as well as bearing failure (which came first chicken or egg?).

 

 

Share this post


Link to post
Share on other sites

Well that's it, seems like there's not one straightforward way to do this. I do have OEM axles and I'm replacing the outside & inside joints with Meyle's, OEM knuckle with FAG bearing, quite a mix! My gut feeling says 90Nm, 50Nm seems so low... I don't have an impact so one less option in the equation! 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...