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MG MGB Technical - Is it necessary to lube input shaft?

Soaked the new spigot bushing in engine oil for a few days. Ready to mate gearbox to engine. Does the input shaft (or spigot bushing) need further lubrication like a thing coating of grease or such?

Thanks, Tom
Tom Custer

Tom. An interesting topic. I am sure that several methods will be presented, all by people who have used them and found them to work.

First, the input shaft (first motion shaft) should not touch the spigot bushing (pilot bushing) if everything is working correctly. Hence, no need to lubricate the end of the shaft and no requirement in the workshop manual to do so. But, some people do so and I have never seen a problem associated with doing so.

The clutch plate (driven plate) should be checked to ensure it slides freely on the splined input shaft. Not all of them do and minor fitting is, sometimes, required for smooth operation. Again, the workshop manual does not address the subject of lubricating the splined section of the first motion shaft. Movement of the driven plate is minimal. Only release of the pressure applied by the pressure plate is required to disassociate the flywheel and driven plate. But, some people feel that a slight bit (very slight) of grease on the input shaft splines is worthwhile. Again, no problems I have seen associated with a very light trace of grease.

Myself, I have assembled them dry with no problems, and long use life. So, I do not believe that lubrication is necessary and suggest that, if lubrication is applied, it be a very light coating of grease.

Les
Les Bengtson

The bush is Oilite, which is why you soak it, so it is lubricated for life.
The splines should have a light coating of hi temp grease. I use Lubriplate. Without lubrication, you get fretting corrosion on the splines with long use, and rust with no or little use - like most cars that get stored a lot. Those of you in NM or AZ wouldn't know about such! Up here you can watch water condense on parts when a warm front comes into a cold shop in the morning.

FRM
FR Millmore

Ditto FR Millmore.

I smear a thin coating of Lubricate on the input shaft snout as
well as the splines. Been doing it that way for decades with
no problems.
Daniel Wong

New clutches should come with a tube of grease, I put this on the splines of the friction plate and first-motion shaft, the end of the shaft that goes in the spigot bearing, and the pivots of the release bearing. I think the chances of the end of the first motion shaft *not* touching the spigot bearing are minimal, given the tolerances of this era plus wear i.e. movement in bearings on crank and gearbox. Having said that the two are moving relative to one another when the clutch is partially or fully disengaged.
Paul Hunt

Thanks for the info gents. I saw a reference in Lindsay Porter's book about using Copper Ease on the input shaft and splines. I'll look through my chemicals and see if I have a suitable lubricant.

Tom
Tom Custer

Well, I'm embarrassed. My Borg and Beck clutch kit did have a small tube of hi-temp grease and the instructions said to use it on the splines and shaft. And just last week a friend of ours said that talking to me was like talking to a deaf mule. Then she called me an idiot.

She may be on to something.

Tom
Tom Custer

But you heard her, and you agree at least that she may have a point, so that invalidates her whole deal! Slippery business, this.

FRM
FR Millmore

"Experience is recognising a mistake you have made before"
Paul Hunt

Tom -

Sorry to prolong this thread, but I have to ask. Which end of the deaf mule did she think she was talking to, the intake or the exhaust?

Terrence
Terrence Goodell

For years this input shaft/spig-bush consideration has bounced around in the background during rebuild. Thanx all for the detail and common sense, specially FRM!. If input floats around inside spig, then what is the initial clear? I vaquely recall 10 thou. somewhere in the grey matter/ashes...VEM
vem myers

This thread was discussed between 28/10/2009 and 18/11/2009

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