Talk Morgan Forums Morgan Sports Cars Morgan Plus Four, Supersport & Plus Six (CX & CXV Generation Vehicles) Plus Fours suspension

Any competent engineer will tell you grease is not a substitute for poor tolerances. If, as you all seem to be saying this is a recurring issue may I suggest a strong letter to the factory signed by all affected. It is not reasonable to have purchased a product not fit for purpose.
I have a 1990 +4/4 with wire wheels and have never had issues, I also have a 2021 plus four, with alloys.

is it only the wirewheels that cause the clonking noise?

As far as I am aware, yes.

Yes only wires. The holes on the adapter plate are bigger than the bolts leading to slop. Mmc should really pay this. I seem to remember they did at the time under warranty. Maybe someone on here can comment

I thought it was the actual splines mismatched in fitting tolerance ? Hence the bung the gap with grease temporary cure ?

If it's just the bolt holes oversized then they can be bored and sleeved quite easily by a proper engineering co

Anyone got a pic of the adaptor plate / drive thingy

Maybe I'm wrong John but that is how I understood it for pre my22 cx cars. Maybe slop on the hub causes excessive spline wear

Two separate issues, both known about. The issue I mention is, I suspect, excessive clearance between the splines of the hubs and the output shafts. MMC solution is to pack with graphite grease (shaft only) however, this quickly proves to be a temporary solution as I can testify, regular attention is required.

Interestingly, I have undertaken quite a bit of research since originally raising this issue. It seems that vintage and classic racers use high temperature molybdenum infused grease on splined shafts / hubs. It is considered a better solution for heavy loads and higher temperatures. I sourced such a grease and spoke to the technical department of the manufacturer. Indeed they conclude that for the problem I have experienced a
molybdenum based grease is a better solution. I procured some and removed the rear wheels (fourth time this season) and treated hubs and drive shafts with it. I will be undertaking a 250 mile trip next week and will report back. One thing I did notice on wheel removal and inspection (grease manufacturer instructed me to thoroughly clean all traces of graphite grease off hub and shaft prior to application of new grease) was evidence of galling between the back of the shaft and the outer radius of the hub. This suggests to me that a thin of grease is required between the two surfaces, which they now have.

Forgive me for joining in but.....

ANY looseness on the hub must damage splines, wheels and hubs. In the happiest of worlds, both should be replaced.

The cures are, rated by desirability are, IMHO,

1. new hubs and wheels without such looseness

2. CooperMan's solution above. But then what is the current condition of the splines, wheel and hubs, on the car?

3. Loctite makes a product for such issues. It is called Loctite 660, a cream that fills in gaps, specifically made for lose round holes and parts. The Jaguar and other communities speak well of it..but a precise method of how to use it is needed. I am sure Loctite will oblige.

4. We forget that this company has new Management since 2019. That ended the Pickersleigh "hard times" from 2003 to 2019. It was bought over by a multi-billionaire Londoner who very honourably stepped up and pumped in 3 times his entire purchase price to cover Plus Four and Plus Six design/component issues made by the former owners he bought from. Why not politely approach him? Gentlemen can still surprise.

L

Having read the data sheet on Loctite 660 there is no way I would use it on a splined drive shaft. I suspect it would be extremely difficult to remove the wheel once it had fully set.

I occasionally use Loctite 660 (as a stopgap) on stripped wheel bearing seats on motorbikes.

Important!
The Loctite instructions state:

Disassembly: As this is a high-strength bond, disassembly is usually only possible later by applying targeted heat (to approx. 250°C).