Height Drop at Front Series 3 V12

[Paddy]

Learned Collective, thoughts please on my series3 1971 full restoration nearing completion.

4 weeks ago I hired in the JD43 tool and managed after a few attempts to set my ride height to 6 3/4”. Having pushed up and down on the frame numerous times over the weeks to ensure the ride height returned, it now has dropped to 5 1/2 “.
I deliberately left the height higher than the manual as I had not put in the coolant or oil, oil went in two weeks ago and no drop, coolant in today and now it appears to have shifted down.
I am at a loss as I would not have expected such a drop even considering the additional weight of the fluids added.
I set the cams to their furthest point so I could adjust the ride height if the ride height stayed as set, now it has dropped I can not use this as a means of getting out of jail.

Your thoughts on why this happened would be appreciated, I have gone through the forum over time and read a number of post related to torsion bars unwinding due to age etc, etc.
I am somewhat deflated this afternoon that this has happened knowing this has now halted my project plans for a live run in September, it has taken 5 years to get here .

Also, another niggle on parts, a brand new fan switch t housing which I acquired some time ago from one of the main suppliers let me down, 7 litres in with coolant and a fault in the aluminium casing caused me to halt operation, there was a pin hole in it New one ordered in on overnight delivery.

All in all a depressing couple of days.

Thoughts most welcome
Paddy

[mgcjag]

Have you moved the car since initial setting and now find it low.......did you use slip plates under the front wheels...or roll the car forwards/backwards after setting your ride height...just pushing up/down isn't really going to settle the suspension.....Steve

[madjack4]

Hi just jack up under suspension arm mark torsion bar splines remove move round one spline rebuild i removed all my front suspension rebuilt it and set it u don't need no special tool just a bit of brain power

[bitsobrits]

Paddy,

The nuts that hold the top and bottom A arm pivot bushings in place need to be loosened when you are setting suspension height. Just to the point where you can spin the washer with your fingers will do. Then after you have set the height and fully settled the suspension, preferably by going for a brief drive (a few hundred feet will suffice, but at least dozens of feet) you can tighten up those nuts. The height will not then change. Many people get this part wrong then end up chasing their tail. Torsion bars do not instantaneously weaken or drop or unwind. Most all of the myths about T bars changing settings are due to tightening those A arm nuts prematurely or not loosening them at all during the setting process.

[Paddy]

Thanks for all the responses, yes the car was pushed up and down the drive a few times to settle it in over a couple of weeks as well as applying a downward pressure. I thought I was being smart and allowing for a little further settlement once the engine was fired !!

Back to the drawing board and the basics

Many thanks all.

[Bob.]

Hi Paddy,

Are the TBs original to the car? If so are they fitted to the same sides as when removed? They are stamped LH and RH with, originally, a red band on the RH and blue band on the LH, but someone in the past may have refitted them to the wrong sides which would have resulted in the original directional scragging process carried out during/post manufacture, having been reversed and now if fitted to the correct sides this would have to "sort itself out" for the new direction of rotation.

If the TBs are new (the original size is unavailable AFAIK), are they marked RH and LH? Some have beeen marketed as non handed but this implies they have not been through the scragging process so settlement would follow as the microstructure adjusts.

Bob