Rear Axle Questions

[John Dolphin]

A few questions for the forum concerning the Jupiter rear axle:

1) What should the diameter of the rear damper lower pivot be? I had some new pins made a good while ago now and they have a 5/8" diameter for the damper pivot. Should these be 1/2" as the securing nut is 1/2"?

2) Any tips for installing the panhard rod? I have the chassis on a dolly at the moment and the rear axle is in the full droop position. It looks like it would be easier to install the panhard rod with the car on its wheels and some weight on the rear.

3) Does anyone know the thread for the axle halfshafts? I need to run a die down one of the threads as I think it has been slightly damaged when the halfshaft was pulled to replace the wheel bearing. Also I could do with getting some new slotted nuts to replace the original ones.

4) I have read in the handbook that there should be gaskets either side of the hub bearing retaining plates but there are no gaskets listed in the parts book. What do other people do? Is it ok to use a gasket compound like Hylomar?

[Srenner]

Off the top of my head, I think the rear axle thread is 20 TPI and the major diameter on the thread is either 3/4" or 13'16". Rather unusual. You might obtain a thread file and carefully chase any crushed threads.

The panhard rod seems to be easier to install if the tires or axle are under load and put the suspension close to proper alignment. If you can mark the chassis centerline, you will have a better idea of how "snug/loose" you need to make the nuts in order to place the axle in the centerline of the chassis.

Hylomar does not set up and vibrations can cause it to migrate over time. Any good silicone sealant applied evenly and sparingly will work. I don't recall that my cars had any paper gaskets and I'm pretty sure they were never apart.

Good luck.
Scott

[John Dolphin]

Scott,

Thanks for the reply.

I'll have a go at dressing the half shaft threads with a thread files as you suggest.

I have noticed that the thread lengths on either end the panhard rod are different. Should the longer threaded end be on the chassis end?

Regarding the rear damper lower pivot pin diameter, the sectioned diagram in the workshop manual shows that the damper pin is the same diameter as the trailing arm section of the pin. My remanufactured pins are like this so I guess I'll have to change the my damper bushes to suit.

[Drummond Black]

John, following on from Scott's post, I had the rear brake drums off the Jupiter this afternoon and I remembered your request regarding the thread on the half shaft. Yes, it is 20 TPI and the O/D is 7/8 " ( 0.875 inches ). A very fine thread for a large diameter. I had to do a small ammount of dressing with a thread file to return the thread to a smooth condition.

A point worth noting when you refit the brake drum is to remove the key from the half-shaft before fitting the brake drum. Fit the drum lightly on the half shaft taper and then line up the keyways. Slide the key into the keyways with the chamfered end facing inwards and towards the half-shaft. The key will then sit at the outer face of the brake drum. If the drum if fitted with the key in position it can, in some instances be forced up the half-shaft and ride up the ramp at the bottom of the keyway slot giving a false sense of a fit. When you then fit and tighten the half-shaft nut you run the risk of cracking the oil seal area on the brake drum. You may think all is well as the drum has now found the taper, however the oil seal will soon be torn allowing grease to ingress into the brake shoe areas.

Obviously the same applies to the Javelin axle as well.

Over the years I have found a few axles with this fault.

See you at Daventry.

Drummond

[John Dolphin]

Drummond,

Thanks for the tip regarding the rear axle key. I am just getting to the stage of fitting the drums back on so your timing is spot on.