1978 390 Auto build

Ok, so here is dumb question? So how long will all this work last, with rebuild?
I have run across some of these automatics sitting round that were hardly rode.
Just curious on some feed back.

the 60million squillion dollar question.....goes up there with "how longs a piece of string"

I think a lot of the original purchasers of the auto's didn't realise just how much time and money they take to keep running. The oil was probably an issue, as it is quite expensive. If they used an unsuitable oil it would quickly wear the box. I know there are several oils out there that do the job, but having witnessed the 'blueing' inside mine I will stick to what husky suggested in the first place. I think a lot of the people that had trouble just parked them at the back of the workshop and forgot about them.

The new 1st gear hub arrived the other day, and is now assembled with the shoes. It is nearly all ready to button up, but before I do that I am making a holding tool to remove the 1st gear crank nut, and a puller to remover the 1st gear hub. I also made a spring guard out of some scrap 1.2mm stainless sheet.

The only thing I don't have at the moment is a torque wrench that goes up to 90Nm. Mine stops at 70 !

Pictures of recent progress will follow soon.

Good progress if it was foot lbs, all you needed was 10 guys with two feet!

Keep er going!

Did you get the later hub? I have a suitable torque wrench but your a bit far away to just drop it round!

Thanks Steve, but no, I replaced it like for like as all the rest of 1st gear was good.
Are you going to the AMCA AGM on 29th ??

I don't think so.

Great work grouty! She's lookin' good.

When is the first ride?

PS. The AE500 (&430) first gear clutch hub has to tightened to 120NM, thats a lot of feet in the old language

You need a truck one!

Wayne, what size thread is on the crank on the later Auto's ?
My 390 has a 14x1.00 Torque is in the book as 90Nm. I seem to remember they increased it for later models. Did they have the same crank thread or were they bigger ?
Is it worth tightening mine a wee bit more ?

The 500 thread is 18mm (give or take with out my calipers on it).
No I wouldn't over tighten it, just lap the hub to the shaft, then add some locktite to the thread. (and enjoy)

Suprize - the 1/2" Supacheap Auto torque wrench does the job nicely. I now have a 1/4", 3/8" & 1/2" T/wrenches to cover everything on my 84 to 2013 collection.

excellent! I will invest....

I have never had any nut problems at 90 Nm

Cool. I will go for that and some Loctite.

Grouty,
We better see a go pro vid of a ride when you get her going!

Just to show that I have not been too idle lately ....

I made the spring guard/cover roughly to Michel's sketch. I found I had to increase the O.D. a bit to 76mm to cover the springs. The hole in the centre was drilled to 14.1mm for the 14mm thread. Woodruf key in place and tightened down to 70Nm at the moment.

I hate putting stuff together only to find out that I have to bodge it to get it apart again. I already had a natty little tool for holding flywheels and clutches, so I modded a couple of M10 bolts and turned them down to 6.2mm for about 15mm at the end. This fits perfectly in the holding holes in the shoes.






I must be sad .... it made me very happy !




I also needed to be able to remove the first gear clutch from the taper. I bought this iron 3 slot puller from ebay and milled out the 3 slots a bit further.
A 6.5 end mill was all that was needed as the thread in the hub is M6x1.00
I tested it tonight and it works perfectly.






The two M8 bolts sticking up are to jam a bar into to stop it turning.

Nice work, clever tools

Nice work Grouty! It will pay off in the end!

What is worse that can happen! You just start it and push it around!

Nah, you close!

I went to the workshop tonight with a cup of tea to escape the kids for 1/2 hour. Sitting and thinking time (as opposed to just sitting !).
The reason is, that I want a cable operated rear brake to work alongside the footbrake. It would be nice to have a rear brake on the handlebars. I don't really fancy having bits of cable and pulley's etc hanging down underneath the engine.

Let me run my idea past you ..... I intend to make a bracket that fixes to the chain tensioner bolt in the swingarm and the right lower shock bolt to secure the outer of the cable. The inner would, I think pass through the small fork in the rear brake arm and affix to the end of the brake rod/adjuster pin. The only real downside is that the free play on the inner cable would tighten up as the swingarm passes through the "inline" position where the spindles all line up, and then slacken off as the arm continues it's movement. I measured this difference tonight at about 5mm. I think that would be "live-able" with as far as the handlebar lever movement goes (I will be using Magura levers). This way everything is fairly well up out of the way. I have worked out a way of stopping the outer cable from jumping out of the swingarm bracket as the footbrake is used. I have a bit of spare 1.2mm stainless sheet left over from the 1st gear spring guard, so maybe I will make a test bracket using that.

Or am I barking up the wrong lamp post .......