Front Lower Fulcrum Block

[265bhp]

Hi

Help please

Part C15088

I am currently assembling the suspension and am having trouble with the installation of the original torsion bars

I haven’t given up hope of cleaning out the last microns of paint in the splines, but it is all a bit tight...Getting the torsion bars to slide into this front block....and looking at the angles of the bars relative to the front and rear mounting plates, I am wondering if these front fulcrum blocks are not symmetrical and need to be placed in a certain way

I am convinced ...more hoping...that this is not the case....but thought I would ask

Thanks
Jonathan

[mgcjag]

Hi Jonathan...Im assuming you have a setting link in place...try removeing it and letting the lower wishbone drop down a bit.....then try to slide in the torsion bar...once in replace setting link and connect rear connector....if not in the right position repeat as above untill you find the correct spline positions....hope that makes sense....Steve

[265bhp]

Hi Steve

Thanks...good to hear I am not doing something fundamentally wrong at least...
Yes...have a setting bar and have been trying that...both moving it upwards and down...so then I am happy to keep persevering ..!

Best
Jonathan

[mgcjag]

A small thin triangular file to clean out the splines....you should be able to get them to slid in/out fairly easily...just dont get tempted to hammer them in...slight tapping with a mallet will be ok.....Steve

[abowie]

The fulcrum blocks are the pieces that holds the rubber bush for the fulcrum shaft front and rear. They are not handed. AFAIK the axis of the fulcrum shaft is at right angles to the machined base of the fulcrum block.

The front TB spline goes into the Front Lower Wishbone Arm. Like the TBs themselves these are handed L and R, and it is possible to assemble them incorrectly. Check that you have them correct. C15373 and C15374.

They can also suffer accident damage; there is a diagram with correct measurements in the Service Manual if you want to check them, although as long as they seem to be a mirror image of each other on the bench you're probably alright.

Next, the splines on both the TBs, the wishbone and the rear TB teardrop need to be scrupulously clean.

If you can't get them to slide in easily by hand, take them off the car and bead blast all the splined surfaces until they slide in easily. The teardrop must also be able to slide into the hole in the engine frame easily. If not you will need to file the hole until it does.

To adjust the TBs.

Fit the setting link.

Lubricate the splines with Never Seize.

Slide the teardrop onto the TB past the splines until it is able to rotate freely on the shaft past the splines.

Slide the front of the correct side's TB into the spines in the front wishbone arm. Then engage the teardrop on the rear splines and slide it back toward the hole, attempting to line it up with the 2 holes for the bolts that secure it. At this point you don't need to be able to slide the teardrop all the way back; you just need to be able to line the bolt holes up and slide bolts into them.

When it doesn't line up, slide the teardrop forward onto the shaft again, slide the front spline out and then experiment by rotating the bar one spline at the front until when positioned properly the teardrop bolt holes line up.

Then you can tap the teardrop back into the hole in the engine frame and secure with the bolts. If you struggle excessively here you can now remove the setting link and move the wishbone up or down to allow the teardrop to go into the hole. Once it's in you can then move the wishbone back until the holes line up.

Finally tap the TB back or forward until the locking bolts will fit at the front and install them.

Good luck!

[265bhp]

Thanks Andrew
Will return to the garage on Saturday and have a fresh look at it all...thanks for the post...appreciate the guidance....
Best
Jonathan

[peters3103]

Good advice Andrew as I’ll be doing this soon too, once my parts are painted and re-bushed. I’ve done it by the book before but tips from someone who’s done it probably dozens of times is invaluable. Good luck with yours Jonathan.

Cheers,
Pete

[AshM]

Jonathan

All great advice from Andrew (as always). I did not have the luxury of bead blasting so just cleaned up all of my splines on the TB with a circular wire wheel in a drill.

Then a smear of copper grease and everything moved nicely for the adjustments that Andrew describes.

Hope it helps.

cheers
Ash

[Polse7317]

Thank's Andrew for your explanations ….Very Very Very appreciated

[265bhp]

Ok....so a small update....right hand side is now in....after about a 4 hour session..!

At times I found myself laughing out loud ..lying on my back under the car...as the back and forth of setting and adjusting the torsion bar splines Alignment was therapeutic and charmingly old fashioned

I certainly had a sore neck for a while this morning after all that wriggling around...

However I have to confess that the only way to get the torsion bar to slide in easily was to undo the 2 bolts holding the rear lower fulcrum shaft casting...this allowed me to Wiggle the whole lower wishbone assembly that then allowed me to slide the torsion bar in more easily....and once the rear pigs ear bracket was installed correctly I then eased this rear casting into alignment and drifted in the 2 bolts


Left hand side should be a lot simpler as I now know what I am doing

Hopefully the fact that I had to loosen this rear bracket doesn’t ring any alarm bells in any way

All the best
Jonathan

[265bhp]

As an update to this post, both sides are installed...the near side being slightly easier, probably as I knew what to do

However I do have a slight concern

I have double checked everything and am sure I have the components installed correctly, and the setting tool was corrected to be 45.9cm from upper damper bolt to lower wishbone bolt.....but the lower wishbone is pointing down at quite some angle....





And when I jack up the lower wishbone to install the damper, the damper is absolutely on its maximum extent in order to install it...and by which time I have lifted the car off the front axle stand support ( the manual suggests that the car shouldn’t be lifted if I have read it correctly)

So I am still hoping for some reassurance from one of you friendly knowledgable types...that I have done all this correctly..!

Thanks for looking

[mgcjag]

Hi Jonathan...why have you extender the setting link longer than spec....however its only slight....your dont have the extra weight of the bonnet yet...and i assume when you jack up you get to the point where your almost about to lift the car.....the shocks should then fit which i think you say tbey are doing....what shocks are you useing..some have different fully extended center lengths.....so basically i think you are doing ok....Steve

[Simonpfhc]

Hi Jonathan,

This is a picture of mine after setting via factory instructions:

[mgcjag]

You shouldnt really be letting those hubs hang on full drop without the shocks fitted.....upper ball joints can be damage(so the manual says)....Steve

[Simonpfhc]

Doubtful - hardly any weight.

However, only been about 5k mikes so far.......wheels haven’t fallen off though

[abowie]

That looks ok to me. Once you have the hub installed and the bonnet back on you'll be able to reinstall the shocks. They are usually at full stretch when you put them in.

[265bhp]

Hi guys

Thanks for the replies...appreciate that...I will now be able to keep going this weekend with a better sense of confidence

Steve
I bought the setting link off ebay a few years ago, thinking it would be perfect...but weirdly it was not made according to the Jaguar dimensions....so that’s why I had to extend

It is now the Correct 45.9cm dimension

I did come across this image a while back



Which perhaps is what it was made too....slightly shorter.....

Why this would be published is a mystery to me as I assume there should only be one dimension

The dampers I have are old stock Girlings....sold to me by a trader ....said to be same as the original...but from the late 60’s or 70’s



Thanks again
Jonathan

[mgcjag]

Hi Jonathan..the diagram you have above is from the 3.8 section of the service manual...different models have different lengths also detailed in service manual....is your 45.9 the centers between your holes..it's larger than the 45.24 in the diagram....Steve

[265bhp]

Hi Steve
Am certain my manual is the 3.8 type..see these photos from it





And as you can see the 45.9 is the centre to centre..hence my confusion



So I think that initial image must be for a later car

What do you think..?

Best
Jonathan

[mgcjag]

Hi Jonathan...here is mine and the page from the 3.8 section...the 4.2 sections have other measurements...Exactly the same as the one in the Knowledge base section and showing the same measuremrnts....So i have no idea whos measurements are correct.....does your manual have different sections for the other models..mine has a whole manual for 3.8 then supplement pages for changes to other models....Just also worth checking fully open length of your shocks...from an old post by Heuer.. Girling confirmed, 15 3/4" (400mm) ..... Steve