Front O/S torsion bar adjustment. Update !

[Cyprusnoddycar]

Greetings from Cyprus,
My R4 is running well, although it handles really badly due to the front O/S (driver side) torsion bar needing adjustment. I did the correct measurements and it is 3 cm lower than the N/S ! So I have ordered the correct adjusting tool from De Marco in Italy. Although I am not sure if I have the fixed non adjustable type of torsion bar ? It's not very clear in the Haynes manual. Thanks Kevin

 

[JdeW]

Since the production from 1961 every front and rear torsion bar (left and or right) is adjustable, there are NO fixed non adjustable versions.

On the first generations of 4L, the torsion bars are adjusted using a lever attached to the rear end of the bar, which has 4 or 5 possible tightening positions on the chassis. The end of the bars (where the lever or the axle is attached) is hexagonal. This adjustment system is not very precise, but still adjustable.

From the end of 1968 (1969 models) and until 1978, the ends of the bars are no longer hexagonal but notched. The height under the body is achieved by modifying the notching of the bars in the axle and the anchoring lever and the "fine" adjustment is achieved using a cam pressing more or less on the anchoring lever of the torsion bar.

Finally, models since October 1978 have a fixed anchor bearing at the chassis level. The adjustment is therefore made only from the notching at the end of the bars, this thanks to an improvement in the production and control of the bar calibration. This system is optimal (for an R4 of course), a shift of one notch modifies the height under the hull by a fixed value.

 

[Cyprusnoddycar]

Since the production from 1961 every front and rear torsion bar (left and or right) is adjustable, there are NO fixed non adjustable versions.

On the first generations of 4L, the torsion bars are adjusted using a lever attached to the rear end of the bar, which has 4 or 5 possible tightening positions on the chassis. The end of the bars (where the lever or the axle is attached) is hexagonal. This adjustment system is not very precise, but still adjustable.

From the end of 1968 (1969 models) and until 1978, the ends of the bars are no longer hexagonal but notched. The height under the body is achieved by modifying the notching of the bars in the axle and the anchoring lever and the "fine" adjustment is achieved using a cam pressing more or less on the anchoring lever of the torsion bar.

Finally, models since October 1978 have a fixed anchor bearing at the chassis level. The adjustment is therefore made only from the notching at the end of the bars, this thanks to an improvement in the production and control of the bar calibration. This system is optimal (for an R4 of course), a shift of one notch modifies the height under the hull by a fixed value.

Okay many thanks for all this information, so it looks like I have the post October 1978 set-up with the fixed anchor on the chassis. So I will have to reposition the torsion bar after marking the original spline position. I guess moving 1 spline must make the car 1cm higher ? I have been working on cars for 55 years, although never done this job before. I have also found a Youtube video as well in French, to guide me. Thanks again Kevin

 

[angel]

Some years ago I had posted a tutorial here: https://www.renault4.co.uk/forum/threads/how-to-set-front-ride-heights.5693/#post-33719
It's a more involved job than you think. Besides the anchor lever spanner, you will need a long (~1m) pipe for leverage, and space uder the car for this, so you have to work on a lift.
Before making any measurements take the front ant roll bar out completely and fit it again only after you have completed the adjustment.

 

[Cyprusnoddycar]

Some years ago I had posted a tutorial here: https://www.renault4.co.uk/forum/threads/how-to-set-front-ride-heights.5693/#post-33719
It's a more involved job than you think. Besides the anchor lever spanner, you will need a long (~1m) pipe for leverage, and space uder the car for this, so you have to work on a lift.
Before making any measurements take the front ant roll bar out completely and fit it again only after you have completed the adjustment.

Thanks for the info Angelos, the French guy in the Youtube video used a shorter lever about 33 cm long with a hydraulic jack which worked well to release the torque on the torsion bar, and reload it again after adjustment. I printed off the instructions from your 2012 post to follow.

 

[Cyprusnoddycar]

Update: I am having big problems adjusting the O/S (Driver) torsion bar to the correct ride height, and think either the torsion bar is weak, or someone else has fixed the bar in the wrong position in the front end ? I spent 2 hours trying to remove torsion bar from the splines yesterday, but it just won't budge And I can see someone else has been bashing around the flange before trying to remove it. I even tried heating it up with a blow torch to try and remove it but all to no avail. So I have decided to dismantle and remove the lower front suspension wishbone today complete with the torsion bar. It's great fun, although not so easy when you are 73 ! But then I hate having nothing to do.

 

[Q plate]

Fwiw Try as I might I couldn't budge my rear torsion bars with 'normal' heat had to enlist a friend who's got a portable ish oxy acetalyne set & even then it took some doing. Not always an option I know but it was the only way in the end I could get it to budge. Good luck with it keep us posted the front seems a lot more involved

 

[Cyprusnoddycar]

Fwiw Try as I might I couldn't budge my rear torsion bars with 'normal' heat had to enlist a friend who's got a portable ish oxy acetalyne set & even then it took some doing. Not always an option I know but it was the only way in the end I could get it to budge. Good luck with it keep us posted the front seems a lot more involved

Thanks ! I have never had splines stuck like this in 55 years working on cars. It's like they are welded in ! Bloody Renault's !

 

[Cornish4]

Once you disassemble the front suspension and leave the lower wishbone hanging, unbolt the rear anchor bracket. The torsion bar should simply pull free from the wishbone.
With regard to the rear torsion bars, once the shock absorber has been removed, and the
swinging arm supported with a jack, and the bar sprayed with penetrating oil, it should come loose with the help of a suitable bar and lump hammer.