Early R4 rear axle interchangeability.

[Simon.AU]

My poor R4 van (1963 R2104) has been hanging round too long, I must get it going again. The reason it was laid up was because the rear suspension outer bushes deteriorated. Having done these before on my R4L I know how horrible they are to do, which was the reason it was put to one side. So I'm looking for alternatives, or an easy way of changing them, then resetting the ride height with the old anchor lever adjusters.

I know the later (1967 onwards) splined rear torsion bar and trailing arms should fit, and would appear to have a much easier way of setting up the ride height. Is this the case? Also how interchangeable is a very late GTL rear axle with an early chassis (from looking at the pics of Clemntines rear trailing arm mount, they still seem to have the three mounting bolt fitting). Oh, and I guess I'd also have to change the rear brakes too to the later drums, as I guess the early small drum back plates wouldn't fit the later trailing arms, which means that I would also likely need the matching bigger drums on the front, which then would likely require new stub axle carriers, this is getting more complex :-)

Then there is the problem of finding the rear axle I need, the only cars sold here had the anchor lever adjustment and private imports of later models are rare. Hmm, perhaps one of the Japanese import places can help with a trashed GTL from Japan.....

Oh, if someone has the Sus, 311 & 312 special tools or the Sus 25-01 kit that they want to get rid of let us know too.

 

[Liam4R4SPARES]

If you pay the postage i will let you have a GTL rear axle with all the brakes etc for the price of a curry [£20].
Regards Liam

 

[malcolm]

The mounting points for the early and late axles are the same (I used pre-'70 dimensions to make my jig). On older cars the top of the rear centre chassis legs dip down a bit near the rear suspension mounting - the top of the rails are straight on the GTL, but I don't know whether this would cause a problem.

I've not looked into it, but I'm hoping the brake backplates are interchangeable between earlier and later axles. The GTL drums have a handbrake that could get in the way.

 

[Simon.AU]

Many thanks for the info! Liam, I'm currently following the trail of a potential donor that has popped up here, so before I bug you on postage prices I'll check that out first. Thanks again!

 

[angel]

The three 8mm holes for the trailing arm bush carriers are the same so any arm will fit. But you will also need to fit the torsion bar anchor levers.On '67-'77 cars you should fit the adjusting cam (possibly by drilling the chassis),'77 and later cars have fixed anchor levers retained by 3 bolts (again chassis drilling).I have never done it (in theory it should not be too difficult...).The problem is not the backing plates, there were three different stub axle diameters (drums,bearings,seals are different).These for the front-handbraked R4s,later GTLs had 180mm rear drums with rear wheel handbrake and as you noticed,you are going to be in too much of a hassle...
As far as adjusting,you are right,'67-77 R4s have cams,and ride height adjustment is as easy as turning a 19mm spanner (nearly...).Then Renault changed to fixed anchor levers,to adjust the ride height you have to remove the bar and rotate it on the splines.Not fun if the bars have rusted on the splines (most of cases).
Why don't you try the method used on the later R4s for removing the tension from the bar? Take a M10 threaded rod 350mm long,make up a fitting to imitate the shock absorber front mounting and fit it on one end of the rod. Remove the shock absorber and fit the tool in place of it. Screw a nut on the end of the rod (rear shock absorber mounting).By tightening this nut, you force the suspension arm downwards,taking the strain off the torsion bar. If you have loosened the anchor lever bolt,you will notice when it is not under tension,then you can remove it and by tightening or loosening the tool you can move the lever to the desired hole. I hope you did not get bored by reading all this!!!

 

[Simon.AU]

Thanks for the detailed explanation. I've since found that the post early 1970 rear stub axles have a larger diameter requiring the matching backing plates too.