Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Splined shaft lubrication

Afternoon all.

I have a CX with wire wheels, hence splined output shafts. I have to regularly remove the rear wheels to relubricate the drive shafts with graphite grease to prevent drive shaft knocking (seriously irritating). I currently use Castrol graphite grease.

Over the last four years I have noticed the problem rears its ugly head after driving in very hot weather. After a return trip to Malvern on Tuesday when I saw a temperature of 33.5C, the drive shafts started knocking on the way home.

It suggests the grease is thinning due to high ambient temperatures.

Is any one aware of, or using, a high temperature alternative graphite grease that holds out longer and hence requires less attention?

Cheers, Andrew

There is a high temp version, sure its Castrol?

Sorry, just to confirm.... it's the hub splines you are talking about?

I keep an old note from a proper auto engineer, it's quite lengthy regarding spinners & spline drive wheels, but the basics are...

Don't use anything containing molybenum disulphide (moly) or PTFE, don't use ordinary oil or grease

He preference was lead based additive in high temp grease (probably can't get that now)

Second choice was copper based which apparently had the benefit of anti-galling and good shear stress meaning it stopped overtightening of the spinner threads

(sorry but graphite isn't mentioned)

Hi Andy,
If I have read your question properly.
As far as I am aware in many years of cars with wire wheels, you do NOT grease the inner bevels on the wheel or hub or the outer bevel on the wheel, just the splines. The bevel is where the drive concentrates not on the splines. If you have greased the bevels (inner and outer) then the wheel will definitely knock (the splines taking all the torque) and will also ruin the splines over time.
On one particular 1936 Riley Kestrel we owned I had to rebuild the wheels and also slightly shorten the front wheel knock off thread to allow the wheel to press up hard onto the hub bevels which stopped the knocking. If I have read the question all wrong then swear once and disregard all.
Happy Miles.

I know this issue with wire wheel CX Plus Fours has been mentioned before. I understand the suspension system was designed to accept aluminium bolt on wheels. To pander to trad style centre lock wire wheel demand MMC introduced adaptors, but it appears the hub splines on some/all of these don't accurately match those on wheels causing rattling if not regularly greased. Happy to be corrected but doesn't this make such adaptors unfit for purpose

From an engineering point of view the hub bevel locates the wheel when the centre nut/spinner is fully tightened in both lateral and vertical planes. The splines providing further location in vertical plane as well as transmitting radial force for driven and braking force for undriven front wheels. Final location from centre lock nut. I think it important therefore that both splines and hub bevel are greased to ensure most accurate location when tightening centre lock. Indeed if you accept the need to grease splines, excess will be pushed onto bevel as wheel is re-fitted making it impossible to leave it dry. If there is knocking the splines are worn or a poor fit from new, although in the latter case it seems fresh grease can hide it for a while.

Concur with Richard V6…I also recall that it was found that the early wire wheel adaptors were a poor fit; I thought it was sloppy holes where they are bolted on? There were threads on TM about it.

Cant quite understand Kiwi100 comments. I have always greased the splines and bevels annually, and approaching 60k miles have no issues at all. Indeed, I cannot see how practically, the splines can be greased without getting grease on the inner bevels when the wheel is slid into place?

In the past I have simply used the same grease as that used on king pins, but in recent years have changed to copper grease which doesn’t get flung out on the inside of the hub.

I also recall the adaptors having poorly sized stud holes Doug. However the temporary "cure" of greasing splines suggests an issue there as well.

Like you have had no issues greasing the whole hub, wheel and nut on my Classic, but not after every wheel removal, and never considered the type critical. Only grease I get on inner part of front wheels is after greasing kingpins. Despite cleaning off old grease expelled, further working of front suspension always pushes out a liitle more which drops onto wheels.

It's just under 6 months and 1800 miles since my P4 automatic was serviced by Malvern and recentyl I can feel and hear my splines and the take up between reverse and forward...clearly there is an issue.......I'll talk to Malvern today to see what they recommend and see if there has been any change in the quaity of the spline adaptors. If it becomes an issue I'll just convert the car to studded wheels, as repacking grease is not the long term solution. I hope its just a more regular maintence issue as I enjoy the spoked wheel look, but I wont let this spoil my enjoyment of an otherwise very good car.

A little annoying, but there are some nice alloys out there that may just tickle the fancy. I'm in a really good mood today and very forgiving of Morgan (at the moment) as my Battistinin Harley is being delivered today, so something else to play with, just as a week or so of rain is forecast for here. Oh well such is life.