Tools for hub nuts

[Dalamar]

I'm looking check my rear hub nuts for tightness and would like to check that the following torque wrench is suitable:

Norbar push-through torque wrench 60-340Nm

https://www.norbar.com/products/view/product/categ...

Covers the Nm range needed and the push-through style is required for tightening up the left hand thread.

Unfortunately, I couldn't find a similar type in 3/4" or at a sensible price with other brands so would stick with 1/2". Plan to get a 1/2" 41mm socket too.

Does that torque wrench sound ok?

[bobfather]

Word of warning, when applying this high torque to the hub you risk damage to the LSD. I speak from experience, having done a torque up using the opposite wheel/tyre on the road to resist rotation. My very next job was to drop and swap the damaged diff. You need to set up something to resist rotation of the hub that you are working on. SH Bible covers this and suggests a solution

[phillpot]

Personally I wouldn't mess with them. To my mind they are a locking nut whacked up tight and never heard of one coming loose.

" if it ain't broke don't fix it! "


But if you must, yes that Torque Wrench looks suitable.

Edited by phillpot on Wednesday 17th August 19:03

[QBee]

I will get shot for this, but sometimes it is better to take it to an expert.
This sounds like one such time.
Yes, I know this is a forum for people who like to do these things themselves.

[Classic Chim]

QBee said:

I will get shot for this, but sometimes it is better to take it to an expert.
This sounds like one such time.
Yes, I know this is a forum for people who like to do these things themselves.

Four good grunts on the wrench should do it
What can possibly go wrong
I’m in the camp of if it’s not broke don’t fix it.

[Belle427]

The Halfords advanced torque wrenches used to be made by norbar so worth keeping in mind if they are cheaper there.

[Dalamar]

Thanks everyone for the info so far. I'm looking into this as a TVR parts supplier suggested this as a possible, albeit less likely, cause of some drivetrain clunking from the rear.

Some more background:
I have been slowly improving the drivetrain to remove or reduce the clunking on my 1995 Chimaera. Before when I went on or off the throttle when cruising on A roads or the motorway I would get a clunk that was somewhere from the back of the gearbox through to the diff region.

Since the car is a rolling restoration, I've gradually changed the following:

New clutch - the clutch plate cushion springs were shot.
Propshaft - UJs are fine and regreased.
Gearbox support bracket has new rubbers.
Diff - refurbed by Grantura Engineering 18 mths ago
Driveshafts - reconditioned by a local engineering firm and new UJs fitted by me from Dave Macc. I needed some help as the end of the splines were damaged by a previous owner hitting the ends with a hammer.
Rear shocks, springs and bushes are new.
Rear drop link bushes changed.
Diff bushes were checked by John when I took the diff up for refurb and were deemed OK. The top diff bush on the chassis was in the same condition when I had the diff off. So hopefully OK.
Diff hanger bracket was reattached with some loctite and torqued up.
Last winter I went around and checked all the usual diff and driveshaft bolts to make sure they hadn't loosened off after a few months of driving. All OK so far.
Checked the exhaust isn't hitting anything or close to and it has new isolation bushes.

So now, take up from standing is fine, into second is fine and so on. On and off the throttle is fine in first and second but on and off in third at decent revs can induce a clunk. It comes more from the middle to nearside of the rear of the car as far as I can tell. More torque more clunk. The fact it's fine on/off throttle in first and second suggests to me the backlash in the diff is OK and the noise I think isn't diff related.

Part of me thinks it's just the nature of the car with a fibreglass body so just enjoy driving it. However, next time I have the car off the road or changing wheels I'm trying to put a plan together to check for possible problem areas.

So I'm going to check:

Diff mounts again with a prybar in case anything has loosened.
All the usual bolts associated with the diff, prop and driveshafts.
Wishbone bushes - I know these are old, crusty and probably shot in places. They are the metalastic ones. Will check for movement in all directions with a prybar and also by feeling for movement with the wheel attached.
Drop link brackets - these have been fine each time I've removed the anti roll bar.
Wheel bearing tightness - hence my question previously. I appreciate it is doubtful but an excuse to treat myself to a decent torque wrench! Would also be handy for the crankshaft bolt.

Anything else I've missed? It's not a big issue but I just want to see if I can eliminate or reduced that last little bit of clunk.

[bobfather]

For wheel bearing wear to be bad enough to clunk, I'd expect there to be other signs. Clunking is usually UJs, CV's, diff or diff mounts

[Peter Thompson]

Could the clunk be coming from the limited slip mechanism in the diff?

[Steve_D]

phillpot said:

.......... a locking nut whacked up tight and never heard of one coming loose..........

Today I was stripping a chassis and needed to undo those nuts. Did not know the size so grabbed a fist full of sockets from toolbox. Whilst going through them to find the right one the nut just unscrewed as I slipped the socket on. The other side took a 3/4 drive impact gun to shift.

PS Wedge 280i so Jag shaft/bearings but the same principle.

Steve

[Dalamar]

Peter Thompson said:

Could the clunk be coming from the limited slip mechanism in the diff?

I don’t know enough about how they work to say but I do know John had to rebuild those LSD plates and he took multiple readings on them for how much torque could be applied before they start to slip. Mine were slipping way too soon he said. I think there are springs in between the plates that age and need to be swapped.

[phillpot]

Steve_D said:

Today I was stripping a chassis and needed to undo those nuts. Did not know the size so grabbed a fist full of sockets from toolbox. Whilst going through them to find the right one the nut just unscrewed as I slipped the socket on. The other side took a 3/4 drive impact gun to shift.

I hadn't allowed for some muppet not putting it together correctly previously


PS . . . . 41mm

[Steve_D]

phillpot said:

Steve_D said:

Today I was stripping a chassis and needed to undo those nuts. Did not know the size so grabbed a fist full of sockets from toolbox. Whilst going through them to find the right one the nut just unscrewed as I slipped the socket on. The other side took a 3/4 drive impact gun to shift.

I hadn't allowed for some muppet not putting it together correctly previously


PS . . . . 41mm

38mm on the Wedge.

Steve

[EddyP]

Just get someone to put their foot hard on the brakes whilst you're torquing them, then it won't put the load into the diff.

[gavgavgav]

Dalamar said:

Thanks everyone for the info so far. I'm looking into this as a TVR parts supplier suggested this as a possible, albeit less likely, cause of some drivetrain clunking from the rear.

Some more background:
I have been slowly improving the drivetrain to remove or reduce the clunking on my 1995 Chimaera. Before when I went on or off the throttle when cruising on A roads or the motorway I would get a clunk that was somewhere from the back of the gearbox through to the diff region.

Since the car is a rolling restoration, I've gradually changed the following:

New clutch - the clutch plate cushion springs were shot.
Propshaft - UJs are fine and regreased.
Gearbox support bracket has new rubbers.
Diff - refurbed by Grantura Engineering 18 mths ago
Driveshafts - reconditioned by a local engineering firm and new UJs fitted by me from Dave Macc. I needed some help as the end of the splines were damaged by a previous owner hitting the ends with a hammer.
Rear shocks, springs and bushes are new.
Rear drop link bushes changed.
Diff bushes were checked by John when I took the diff up for refurb and were deemed OK. The top diff bush on the chassis was in the same condition when I had the diff off. So hopefully OK.
Diff hanger bracket was reattached with some loctite and torqued up.
Last winter I went around and checked all the usual diff and driveshaft bolts to make sure they hadn't loosened off after a few months of driving. All OK so far.
Checked the exhaust isn't hitting anything or close to and it has new isolation bushes.

So now, take up from standing is fine, into second is fine and so on. On and off the throttle is fine in first and second but on and off in third at decent revs can induce a clunk. It comes more from the middle to nearside of the rear of the car as far as I can tell. More torque more clunk. The fact it's fine on/off throttle in first and second suggests to me the backlash in the diff is OK and the noise I think isn't diff related.

Part of me thinks it's just the nature of the car with a fibreglass body so just enjoy driving it. However, next time I have the car off the road or changing wheels I'm trying to put a plan together to check for possible problem areas.

So I'm going to check:

Diff mounts again with a prybar in case anything has loosened.
All the usual bolts associated with the diff, prop and driveshafts.
Wishbone bushes - I know these are old, crusty and probably shot in places. They are the metalastic ones. Will check for movement in all directions with a prybar and also by feeling for movement with the wheel attached.
Drop link brackets - these have been fine each time I've removed the anti roll bar.
Wheel bearing tightness - hence my question previously. I appreciate it is doubtful but an excuse to treat myself to a decent torque wrench! Would also be handy for the crankshaft bolt.

Anything else I've missed? It's not a big issue but I just want to see if I can eliminate or reduced that last little bit of clunk.

Roll bar bushes, and the tightness of the mounting plates (think there are little 10mm nuts from memory), one of those little plates moving a little bit can make a clunk.

[Oldred_V8S]

EddyP said:

Just get someone to put their foot hard on the brakes whilst you're torquing them, then it won't put the load into the diff.

Or put the space-saver wheel on and lower the car to the ground The SS wheel allows the 41mm socket to reach the nut.

[Dalamar]

Roll bar bushes, and the tightness of the mounting plates (think there are little 10mm nuts from memory), one of those little plates moving a little bit can make a clunk.

[/quote]

Thanks, the plates were nice and tight but the ARB rubbers were worn. Next thing to get sorted.