Sterckeman Axle. Dec '82. Rusted Flanges

[TowerAmulet]

UPDATE 15-08-16 - THIS IS STERCKEMAN ESCAPADE 400
Hi, I have an old axle made by ftf (71 Louhans France) in December 1982. The plate says axle type BT9628. 800kg. It is similar to modern AL-KO axles in that the vertical axle mounting flange bolts to a gap in the deepest part of the tapered, galvanized chassis rail effectively completing the chassis structure. Four bolts mount each flange, the lower two of which are in domed depressions that mate with corresponding dents in the chassis rail providing improved clamping location and chassis alignment. The axle tube is of circular cross section and has 4 grease nipples in total on the radius arm pivots, 2 per side (1 inboard and 1 outboard of the mounting flange each side). I anticipate that springing is by torsion bar and not rubber as in my experience rubber types have a non circular cross section axle tube to grip the rubber outer and no grease. The spring rate does not necessarily feel like rubber but I could be completely wrong. It has rusty flanges as the axle itself is not galvanized and I need to do some welding. Does anyone know the internal arrangement of the axle tube? If so then please let me know so that I don't hurt anything in there. I cannot see how the radius arms are retained axially in the tube or what locates the fixed end of the torsion bar if that's what it uses.
Can someone please enlighten me?
I have some pictures I can upload if needed once I sus this particular forum's method of doing so.
Furthermore I wonder if a more modern galvanized rubber sprung axle would retrofit straight in the slot? Are they standard with AL-KO ? I heard somewhere that ftf "became" AL-KO .
Thank you.

 

[Gagakev]

Sorry cant help with the axle, but folk on here do like a piccy.

How to post a piccy

Good luck and welcome.

 

[TowerAmulet]

Ok thank you Gagakev. That's a method I've not done before and eversoslightly long winded but I'm sure it will be easy once I've done it and come in handy elsewhere too.

 

[TowerAmulet]

I have looked at the rubber sprung AL-KO axles on the Nightstar and the domed depressions or dimples for the two lower flange bolts that locate the assembly are dished the other way. They bulge towards outboard on FTF chassis but towards inboard on the AL-KO chassis and so it seems that they are not retrofittable.

 

[DrZhivago]

folk on here do like a piccy.

How to post a piccy

Except you do not have to have a Photobucket account and link to a picture on it, as the above How-To link says. You can link to any picture on the web, such as one you have posted into your own hosting area

 

[TowerAmulet]

This is the axle installed. The bit bolted to the lower chassis rail flange is a non-standard strengthening brace.
You can see rust holes in the bit of the flange showing in the chassis window.
https://postimg.org/image/kbwssnk2h/
This is the grease nipple for the radius arm pivot. There is another inboard of the chassis rail. The radius arm is hollow rectangular tube with through-welded pivot shaft and stub axle. There is some sort of bolt radially through the pivot shaft inside the radius arm. Does this attach to torsion bar?
https://postimg.org/image/3pf8jkr4p/

The axle is now removed for repair. The axle tube will get red hot when welding. I need to know the materials and layout of the components therein. I can deal with grease but I need to know if there are delicate bearings or bushes in there and their extent in the tube. The weld zone is between the two grease nipples so that could be a gap between bearings or it could be the edge of a heat-treated bearing or it clould be a nylon spacer or other vulnerable component. Someone else must have done one of these at some point in the past.
I really need an exploded assembly diagram of this axle type. There must surely be one somewhere.
Thank you.

 

[TowerAmulet]

Hi I have modified the thread title to define the make/model as discovered under paint on the roof panel/lid this morning. So It is a Sterckeman Escapade 400 folding caravan from 1982 (ish). The chassis is 373cm length crossmember -to-crossmember. The A-frame is separate and quite long. All galvanized which is why the axle condition was overlooked i guess. Does anyone else have one of these?
Thank you.

 

[TowerAmulet]

Feedback: I have bitten the bullet and dismantled this axle now.
The arrangement is one radius arm at each end of a common torsion bar that is constrained at the axle midpoint by a square window. There are 2 separate pivot shaft bushes inside each end of the axle beam each fed by one grease nipple. They can be scraped with a screwdriver and are non-metallic as far as I can see. They are more like a dark chestnut brown plastic material that is fawn/light brown when scratched. The hollow radius arm pivot shaft has a circular bore initially and then a square section bore at the closed end for about 2" of length in the vicinity of the grub screw. The torsion forces are taken care of by the square-in-square and the axial load is taken by the grubscrew (and wall friction).
The M14 grub screw has a conical pointed tip that mates with a conical crater in the torsion bar (photo)

https://postimg.org/image/qpswx4sih/
The torsion bar is about 25 mm square and made from two rectangular leaves. Two stacked shims about 6" long are between the ends of the leaves. There are two more shims at the midpoint but the rest of the torsion bar length is shimless. TX