Tuesday, December 29, 2015

Axle, Subaxle, and Stub Axle Reassembly

Once you've completed the prep work it's time to reassemble.

Kingpins:  Let's start with kingpins. The kingpins come as a set; kingpins and a set of lower and upper bushings. You need to insert the bushings into the subaxle- the top bushing is inserted from underneath and the bottom one is inserted from the top. After they've been pressed into place they need to be reamed out to accept the kingpins. If you don't have a bearing press or experince using a reamer you may find it easier to take it to the machine shop and have them do it.

The kingpins are assembled with a spacer placed under the axle, between the axle and lower part of the subaxle. The spacer takes up the vertical slack in the assembly. The spacer is about 2mm thick. If you need a new spacer you can use a valve spring shim from an old American car. I got the ones pictured below from my local auto parts store. The kingpins are around 15mm in diameter, which is about 5/8".
Heinkel Cars and cabin scooters
Valce shims make good spacers
Once you put this together you need to secure the kingpin into the axle with the locating pin. The assembly also has a tabbed washer you must bend in two places; once against the axle to keep it washer steady, and once over the head of the pin to keep it from loosening. 

The completed assembly should like this:

Heinkel Kabine
Assembled axle and subaxle

Heinkel Cars and Cabin Scooters
Kingpin with locator pin and folded tab washer

Shock Installation: The next step is to insert the shocks into the towers. Take the spring and insert it small end down into the tower. Put a shock retainer collar on each side of the spring so the shock can slide down and fit totally into the spring. If you put the spring in the tube incorrectly the shock collars will not fit.

Heinkel Cars and Cabin Scooters
Spring in the tube- incorrectly. The large side must be up
Heinkel Cars and Cabin Scooters
Shock collars fit in the spring, and the shock fits into the collars

The shock retainer plate (the piece that caps the shock tower) is next. There's a rubber cap that protects the top of the shock itself, Stick the small end into the shock tower as shown below.
Rubber collar protects the top of the shock
The shock piston rod sticks up through the top, goes through a thick gasket  (pink in the picture) and and is capped with a gasket.
Heinkel Cars and Cabin Scooters
Partially assembled Heinkel shock retainer plate
 Here's a good picture of the assembly:
Heinkel Cars and Cabin Scooters
Assembly should look like this 
Heinkel Cars and Kabines
Use clamps to compress the spring and complete the assembly

The entire assembly is held together with two fine threaded 8mm nuts.
Heinkel Cars and Cabin Scooters
Completed shock tube assembly
Axle Crank: This is where it all starts to come together. Inserting the axle crank secures the axle and shock assembly.

Heinkel Kabines
NOS Heinkel axle roller bearings
The first step is to grease the caged roller bearings and gently insert them into the subaxle. You need to be careful here; the roller bearings will fall out of the cages. 

Heinkel Kabines
Gently pressing roller bearings into the subaxle
The bearing is sealed with a rubber gasket that resembles a thick rubber band. You may not even be aware that these were present originally, as they have often disintegrated.
Heinkel Cars and Cabin Scooters
Rubber seal around the subaxle bearing race
You need to cap each end of the assembly with a bronze bushing. These are not reproduced to my knowledge, hence my reuse of some rather beat up originals.
Heinkel Kabines
Bronze end caps- don't throw your originals away!
Now insert the stub axle into subaxle and shock assembly. If you use the English Club's shock bushings you will need and extra spacer on the outside of the shock shaft.
Heinkel Cars and Cabin Scooters
Note extra spacer on the outside of the shock shaft

Heinkels and Trojans
Assembled
I secure these with Nyloc nuts rather than the original castle nuts and cotter pins. Nyloc nuts are easier to torque correctly and you eliminate the risk of distoring the threads on the subaxle from overtightening.

Stub Axle Reassembly: You can now attach the ncessary items to the stub axle. Attach the wheel brake cylinders first.

I use new replacement cylinders. They are made by Bendix for the German Club. I blew out a seal on my rebuilt original cylinders a few years ago (resulting in a complete loss of braking power and paint damage from brake fluid) so now I only use new.

You must modify the backing plate to attach the cylinders. The holes are spaced about 1.6mm futher apart than the originals You can elongate the holes using a dremel tool.
Heinkel Cars and Cabin Scooters
Replacement cylinder mounting holes are further apart. Backing plate must be modified

Heinkel Cars and Cabin Scooters
Brakeside view of mounted replacement cylinders

Heinkel Kabines
Installed wheel cylinder with bleed and flathead screws
Now place the spacer on the axle. This keeps the hub assembly the proper distance from the backing plate.
Heinkel Cars and Cabin Scooters
Spacer ring for main axle

Heinkel Cars and Cabin Scooters
Installed spacer ring
You are now ready to install the brakes- a topic for another time. The completed axle assembly looks like this:

Heinkel Cars an Trojan Bubbles
Completed suspension assembly




1 comment:

  1. Although it's more fiddly to fit, King Pin Spacer Washer ought really to be fitted at the TOP, rather than the Bottom. Otherwise the weight of the vehicle when stood back on it's Wheels, with Steering use, will quickly wear the Washer, giving more Vertical slop in the set up...

    ReplyDelete