Fulcrum shaft lubrication

[Philippe-J.]

At the moment I am rebuilding the rear suspension of my 67 OTS.
I can see that the lubrication of the fulcrum shaft bearing tube wrt to the bearings is made by a grease nipple. Perfect.
But how about its inner face? It surrounds the shaft itself, with no insurance it won't rotate around it. The only grease this interface can get it the one you put when assembling them.
Would it be a solution to dig one or two small holes in the tube for the grease, injected through the nipple, to go down to the shaft?
Thanks for your comments.

[Philippe-J.]

Forget it, the tube is of so a tough steel that it is impossible to drill a hone in it.
I tried on an old and worn one, the drill bit could not even bite the metal.
Maybe a good idea, but unworkable.

[mgcjag]

Just grease as you assemble...there isn't much movement so won't be an issue.....Steve

[Philippe-J.]

That's good news, as I had no way to drill that hole!
Thanks Steve.

[Philippe-J.]

The story staring the fulcrum shaft bearing tubes was not over for me.
I had to buy two of them as they were badly worn on one side of the IRS. I then ordered them to one usual, received them and installed them. Well, I tried to, and failed
The assembling of the first side, with original tubes, proved to be a bit fiddly, I had to tap strongly on the shaft to let it in. When I saw that the shaft was stuck in the outer side of the second wishbone, I though it was the same story. So I taped again, more and more strongly . What a mistake that was! It was hopeless, it would not get in.
Nor out either ! I was stuck.

The only way out was to use huge force, which destroyed one bearing and one threaded end of the shaft.
At least I could get the tubes out and discovered that one of them had too small an ID, by few thous. Which is worse in one sense, is that the other one was OK.
Lesson learnt: never trust even reputable provider and always check their parts prior to integrate them in your car...

[mgcjag]

Hi Phillipe.....you fitted a new diff I think?....have you shimmed the diff mount brackets correctly to the diff and ensured that the fulcrum shaft slides through irs cage page K15 service manual .....not doing this makes the shaft very difficult to fit....Steve

[Philippe-J.]

Hi Steve,

yes I did. You're right, the alignment is tight, and this shimming is mandatory.
But my problem was actually the ID of one tube. Having extracted it and the shaft, I saw that it was stuck on it. I had to heat it to slid it out of the shaft. Some rotating sand paper allowed me to increase the ID just enough. Now the rear suspension elements are assembled, problem solved.
How few thous in excess can ruin your life is amazing ...

[angelw]

Philippe-

Hello Phillippe,
I assume we're talking about the rear wishbone inner fulcrum. That being so, with regards to drilling holes in the bearing tube to get lubrication to the bearings; that is not necessary. There are two Drawn Cup, Needle Roller bearings per inner lug of the wishbone, with a significant gap between the inner faces of the two bearings, with the grease nipple positioned mid way in the gap. Accordingly, grease is available to both bearings, and because they are Needle Roller Bearings, there is sufficient air space between the contact of the Roller and the Bearing Tube for grease to enter via pressure applied by a grease gun.

If you are hell bent on drilling a hole in the tube, then a Solid Carbide drill will drill the hardened Tube material.

The bigger issue that most seem to be oblivious to, is that the width of the two inner lugs that house the bearings of each wishbone are different by circa 0.6mm (0.024"). The inner Yoke is ambidextrous, and doesn't become handed until its assembled with the other components that make up Right and Left Hand wishbones. Accordingly, the matching width of the different width lugs is diagonal. That is, if the thinner width lug is at the front of the Left Hand wishbone, the thinner lug of the Right Hand wishbone will be at the rear.

The length of the Bearing Tube is rather important. If it is shorter than the width of the lug the bearings are housed in, plus the thickness of two Thrust Washers, the Bearing Tube won't be clamped so that it stays stationary with the Fulcrum Shaft, and clamping force will be applied to the side faces of the lugs that house the bearings. If the bearing tubes are too long, fore/aft end float of the rear wishbone will exist.

Drawn Cup, Needle Roller Bearings can be bought as a set consisting of the Needle Roller Bearing and a correct tolerance Bearing Journal Tube. My experience is that the Bearing Journal bought through a reputable bearing distributor is better quality, in terms of dimensions, than those being supplied by the Jaguar Parts suppliers. Unfortunately, correct length Bearing Journals aren't available from bearing suppliers. Accordingly, I purchase a length that I can make two from its length with minimal waste, and it allows me to make two different, correct lengths, to accommodate the circa 0.6mm variation in lug width of the rear wishbone.

Regards,

Bill

[angelw]

With regards to assembling the rear wishbone with the differential mounting brackets, once the brackets have been correctly shimmed, so the the Fulcrum Shaft will pass through the bores in the IRS Cross Member and the bores in the diff mounting brackets with minimal effort, I do the following:

1. offer up the rear wishbone complete with all associated washers and seals held in alignment with two short mandrels (slightly shorter than the combined width of the lug and washers. The Thrust Washers and Seals are held in place with grease.

2. Leaving out the Spacer Tube that locates between the lugs of the diff bracket, I drive a longer mandrel from each side of the IRS Cross Member, through the bore of the IRS Cross Member, the Needle Roller Bearing, and the lug of the diff bracket. In doing so, the short mandrels are expelled leaving the lugs of the wishbone, the diff brackets, and the bores of the IRS Cross Member correctly aligned.

3. One of the longer mandrels is now drifted towards the centre of the IRS Cross Member until flush with the face of the Cross Member, and then continued using the Fulcrum Shaft as the Drift until the mandrel is expelled into the area where the spacer tube will locate.

4. The Spacer Tube is now placed in position and the Fulcrum Shaft drifted all the way home, and in the process, expels the other long mandrel.

The Fulcrum Shaft and Wishbone Assembly are now assembled correctly and await the nuts to be applied to the outer ends of the Fulcrum Shaft. The above is achieved with minimal effort and grief.

Regards,

Bill

[Philippe-J.]

Thank you Bill for such a detailed presentation. Indeed you were encyclopedic !
Philippe