Rear Hub Nuts

[GordonW]

Please tell me there is an alternative (and cheaper) source of these than the £16 odd quid per nut  Caterham require????

 

[SM25T]

Try Redline, Ford or car spares shop. Or reuse original with thread sealant.

[GordonW]

Anyone tried those from KitCarDirect? Seem remarkably good value almost on the too good to be true scale....

[David_Long]

I did once source cheaper nuts for drive shafts I use in the Mini racing we do. OME where a similar price to the Caterham Item.  After a few failures with cheap ones (failing to stay tight) we just started reusing old ones, or fitting new OE quality, which proved more reliable. After a bearing failure, or two, they don't seem so expensive.

[GordonW]

David, point well made, not sure why I pursue the money saving mission over critical items like this, Redline saved me a few quid and hopefully assured quality.

[Geoff Brown]

Hub nuts £8.40 + VAT each from Redline.

You can re use Nylocs as long as they pass the turn down check. Turn the nut down the respective thread by hand until it stops.  Do not force - just finger tight. If the top of the nut nut is no more than flush with the end of the shaft/bolt it will be OK to re use.

BUT as the drive shaft nut is a 'Jesus Nut' I would replace with new. I always do.

The reason for the name? Because when it comes loose or falls off that is the only exclamation to be heard!

'Jesus Nut' was common slang for the nut that held helicopter rotor heads to the drive shaft. I wonder why?

 

[GordonW]

Geoff, I agree with you on the renewal point. Inflation must be rife, they're now £10.40 + each but still way better than Caterham.
 

[Geoff Brown]

Mine were £8.40 +VAT in October last year = £10.08 so not too much of a price rise.

[GordonW]

I'm not complaining but it was £10.40 plus vat.

[Guy Lowe]

John (ex Redline) once told me that you can re use, simply place the nut on a flat surface and then place a lump of flat steel on top of the nut and give the steel a whack with a hammer. Apparently it compresses the nylon where it has been cut by the thread IYSWIM & can be done to any nyloc. Personally I always replace them. 

[Geoff Brown]

That is a large price rise.
The reason for the rise is demand from the many Seven owners dropping their BMW/Titan diffs for overhaul!

[Tony Whitley]

Guy, how many times had Trevor used that trick on the TRE nut that came undone at Keevil? 

[ScottR400D]

#11 No need to touch those when removing the diff, Geoff!

Fortunately, or it would have cost me a fortune fitting new ones each time! 

[Guy Lowe]

Why would you need to replace the hub nuts when changing a diff Geoff?

Edit: I was actually replying to post number 11 but this software seems unable to deal with something as simple as that. 

[Geoff Brown]

Guy - The reason I change the hub nuts when dropping a diff? Because although popular I do not personally advocate the short cut way of removing the complete hubs even though it probably has a 100% success rate.

I am a creature of habit as after 43 years as an aircraft engineer the only way to dismantle & assemble something is the piece part way, removing, inspecting, cleaning & replacing if required. In aviation engineering there are no short cuts unless they are sanctioned by an approved written procedure.  

For the extra half hour per side with no pressures I think complete dismantling is the way - IMO

 

 

[ChrisC]

Love the reminder of "Jesus Nuts".  I flow RC helicopters where the head was attached to the main shaft with a "Jesus Bolt" and that was always replaced after every crash.  

The original ford part numbers are 6133688 and 6133689 which have lots of alternatives

https://7zap.com/en/part/FORD/6133689/  

Ranging from £1.89 to £18 (for a genuine Ford item), admittedly the £1.89 versions are from Europe suppliers, so some are not shipping to UK at the moment. 

Recently a CC mechanic did tell me about a batch which stripped before they reached 270Nm, makes me glad to have genuine Ford items for now, even if one nut is 1mm bigger than the other :-(.   

[GordonW]

Chris, many thanks useful stuff, I passed on the £1.89 option......

[ChrisC]

I think the difficulty is avoiding the £1.89 items sold with a 1000% markup :-)  

[ScottR400D]

#15. Geoff, that presumably means you dismantle and inspect the drive shaft joints? 

Do you have a source, other than CC who seem a little random, for joints, boots, clips etc and especially the compensating spring, which Caterham don’t offer at all?

That last item in particular seems to carry risk but is the one thing that can’t easily be got  

 

[Geoff Brown]

ScottR400D - that is far too deep unless necessary. There would have to be a major problem with the CV joints or boots revealed by visual inspection & manipulation. 

Therefore cannot help with internal spares procurement. Surely the manufacturer can supply the parts. I do believe that there has ben a thread on TT about joint overhaul?

Found this but I do not think it mentions sourcing new internals: 2012_06_03_Driveshaft.pdf (lotus7.club)

[john hooper]

Im just about to start my bmw diff removal, what is the recommended way to remove drive shafts. Do you just remove 4 bolts holding the hubs to the ears. Sorry if this seems a stupid question but am new to caterham maintenance and welcome any advice from more experienced owners  

[ScottR400D]

Many of us do just that. Geoff recommends dismantling the hub but I'm not aware of anyone having issues by not doing that. I guess it's worth doing if you have any doubts about the condition of the hub bearing but, again, not aware of anyone who has.

This is my method, gleaned from a marathon session of stripping and rebuilding last year and also as used by others on here:

PREPARATION

Loosen rear wheel nuts, jack car and support on axle stands, with front wheels chocked. Not too high but high enough to allow diff, possibly on the jack platform, to come out under the de dion.

REMOVAL 

Remove rear wheels.

Select 1st gear, handbrake on and undo the 4 prop bolts. (If removing the prop, drain gearbox oil or have a tray to collect spill from tail shaft housing.)

Undo callipers, 2 bolts each, don’t lose the spacers! Carefully lift callipers clear of disc and cable tie to damper spring. Pipes will give easily enough.

Disconnect speed sensor and roll bar links from brackets both sides. Tape sensor to chassis out of harms way.

Suck oil from diff. If you have .8L in it won’t leak, if you have 1.2L in it will! (BMW)

Remove the 2 bolts and the nuts on the other 2 bolts, on each side, that fasten the ear to the end of the de Dion. No need to loosen the two bolts in the ears that don’t go into the de Dion.

Remove each drive shaft c/w disc/hub/ear. 

Remove the A frame. Note how many washers each side at front.

Remove the ARB.

BMW, if removing carrier and diff together:

Remove cable ties and whatever arrangements holds the handbrake cable to the chassis bars. Push handbrake cable up from the two locating brackets just above diff; pull cable through on RH side till inner allows cable to come out of bracket on Side of diff carrier.

Slacken long 1/2” bolt and two short bolts of diff.

Jack up under diff, on jig.

Remove all bolts.

Lower down.

 

BMW, if removing diff from carrier :

If removing diff without carrier, no need to mess around with handbrake cable, other than to disconnect from chassis for ease of access, the cable can then be moved about more easily, and remove the long bolt and short bolts holding the diff to the carrier.

Note: Removing the parcel shelf makes access and vision easier, you can look down and see things more clearly and even put a strap around diff to lower it with, if you wish. I actually removed the alloy shelf bar too. Carefully drill out the existing pop rivets

 

REFITTING

Replace propshaft if it has been removed.

Lift differential into position and loosely fit from short bolts. raise rear into position and fit long bolt. (Refer to CC manual for detailed instructions on centring etc.) Retorque according to CC manual, using thread locker.

Refit ARB.

Refit A Frame, with same number of washer each side at front as removed, check it’s central. Replace plastic ‘race’ washers on rear A Frame bolt, the old ones will be worn. They can be obtained from CC.

Replace drive shafts on each side, to correct torque, according to CC manual. 

Reconnect the ARB to brackets on De Dion ear. Reconnect the speed sensor.

Reposition the brake callipers, fit bolts through spacers and torque to CC manual recommendation.

Reconnect all handbrake cable cable ties etc. 

Replace bolts in propshaft, torque as per manual, threadlocker. Need to put handbrake on, 1st gear, whilst torquing prop, release and rotated 90 deg between each bolt.

Mark all refitted and torqued bolts with marker paint for visual check later.

Replace wheels.

Replace and pop rivet shelf bar; put wooden part of shelf in place whilst putting first two rivets in to make sure of location. Replace shelfs.

 

Note: Clean and inspect all components on removal, change nuts and bolts if in any doubt.

 

[john hooper]

Thanks for the guide. That's how I was hoping to do it but was a bit worried by the mention of hub nuts. The new diff has come in a cage so will probably remove old diff with cage. I was thinking of removing the alloy shelf bar and packing it up a bit as it is in contact with the diff. 

[ScottR400D]

Re the shelf bar, I would fit the new diff in its bracket and then check if you still need to pack it up at all. I didn't and It shouldn't really need it but who knows?

 

 

[aerobod - near CYYC]

In terms of the shelf bar and diff contact, the car configuration and variability between cars and specific models will determine if modifications need to be made. On my car the diff cover when delivered was the old design that didn't have the long bolt passing through the top of the cover. With the new cover that was re-designed to stop deDion to cover contact, the top of the cover was higher, causing contact between the fuel feed pipe that runs under the boot floor on my car and the top of the cover.

I needed to either re-route the fuel pipe, lift the boot floor or relieve the top of the cover where there was excess material. I decided to relieve the top of the cover above where the long bolt passes through to attach the carrier:

The old cover design: