• Husqvarna Motorcycles Made In Sweden - About 1988 and older

  • Hi everyone,

    As you all know, Coffee (Dean) passed away a couple of years ago. I am Dean's ex-wife's husband and happen to have spent my career in tech. Over the years, I occasionally helped Dean with various tech issues.

    When he passed, I worked with his kids to gather the necessary credentials to keep this site running. Since then (and for however long they worked with Coffee), Woodschick and Dirtdame have been maintaining the site and covering the costs. Without their hard work and financial support, CafeHusky would have been lost.

    Over the past couple of weeks, I’ve been working to migrate the site to a free cloud compute instance so that Woodschick and Dirtdame no longer have to fund it. At the same time, I’ve updated the site to a current version of XenForo (the discussion software it runs on). The previous version was outdated and no longer supported.

    Unfortunately, the new software version doesn’t support importing the old site’s styles, so for now, you’ll see the XenForo default style. This may change over time.

    Coffee didn’t document the work he did on the site, so I’ve been digging through the old setup to understand how everything was running. There may still be things I’ve missed. One known issue is that email functionality is not yet working on the new site, but I hope to resolve this over time.

    Thanks for your patience and support!

Crank End Float

H

Husky390

Husqvarna
AA Class
Hi all,
I am currently assembling my 390 78 engine and looking through the workshop manual I can't see an end float measurement for the crank. The assembled crank wheels are pressed to 52mm wide as per manual and the big end has 0.85mm side clearance but the end float appears to be zero!!
I have used a new crank case gasket and the main bearings are pressed to the full depths.
I expect end float to be important. Has anyone else found zero end float?
I am worried she will fail.
Thanks
Russ
 
I'm just building my first husky 2T and from what I can see that is right due to the nature of the bearings and the way it all presses together I'm not expecting any end float. I think this is right but it would be good to have it confirmed. I'm not used to the pressing of the crank to the pin length either and then shimming the small end.
 
I haven't worked on that era stuff but this might be of some intrest. I am pretty sure the manual would have you do it different. I put the drive side bearings, in your case I believe there is one double row one, all the way in tight against the plate near the drive gear. Then I get the timing side bearing in it's bore so that there isn't binding. If it were put flush on the inside there sure would be binding. I can't see how any end float would be anything but in the bearings and new ones especially the double row ones don't have much at all. The crank should pretty much turn as easy when the cases are close to contact as when fully assembled. Spinning the crank with the cases just short of the locating pins can be a way to tell how bad out of true something is as they can kind of move around.

fran
 
On my 360 that I just put together the crankshaft is stepped on the primary side so the crank will seat up to the primary bearing race. On the flywheel side there is a thrust washer placed on the crank because it is the same dimension along it's length. there is some clearance no doubt but it cannot be felt due to the fact that the crank is an interference fit to the bearings. That is the way I see it but someone else can chime in on it.
 
I agree with dkwkid. The bearings on both sides are an interference fit. You should need a puller, to pull the two halfs together. The crank won't move when the cases are closed with new bearings.
Husky's have a piston steered rod. That's why they spacer rings on each side of the wrist pin bearing.
 
Best is to press crank cheeks flush with the pin. Measure across the crank to where the stubs make contact with the bearings w/spacer on ign side. Then measure from bearing to case center edge add them together then add thickness of gasket should be greater than width of crank.
After assembly of the cases always pull crank to the ign side there is quite a bit of clearence but if crank is pulled to the clutch side ign can rub.
Later George
 
Huskydoggg said:
The crankshaft's lateral location in the cases is important. The bearings must be seated and the crank should be drawn up against the ignition side bearing with the correct spacer/washer in between. To allow for manufacturing tolerances and gasket crush, there is a small amount of clearance on the primary side. There is no measureable float unless your bearings are toast.
Pulling the cases together can create lateral "preload" on the crank bearings. You may notice this as slight drag as you turn the crank by hand. A tap on the end of the crank (ignition side) with a deadblow mallet can release that preload and let the crank spin freely.
Click to expand...
spot on dogg.... i get this on every engine i build of all makes.... sort of a party trick when i say look how stiff this crank is ...then one quick tap with the old hide hammer and its a sewing machine smooth action !
 
Thanks for your responses everyone. I can see now that end float is impossible with this design. This is my first Husky rebuild and I like the design more and more as I go on. I was surprised to note the main bearings got a bit tighter to spin once they were home in the cases so that set me worrying. No end float, tight bearings...
Great to have the help from others with first hand experience.
Now for the top end.
 
Does pulling the crank into the ignition side bearing, also center the rod under the piston in the bore?
With the spacing washers on either side of the wrist pin bearing, the rod would need to be centered in the piston. Right??
Here's the tool I made for pulling the crank in. Had to make adapters for each side (and find a left-hand tap), but it works pretty smooth.
Ron

Husky Crank Puller 001.jpg

Husky Crank Puller 003.jpg
 
Nice work Ron!
Ok So I have her all together and the piston to go on. The distance spacers don't look quite right. When I put the pin in the piston with ring / needle bearing / ring, the rings stop the bearing moving side to side but the con rod slides over the rings! That sure doesn't look right to me. Shouldn't the inside diameter of the ring be close fit on the pin and the outside diameter similar to the con rod diameter?
If this is the case, what should I be making the rings out of?
Thanks for sticking with me.
Russ
 
The spacer rings just keep the wrist-pin from floating out of the rod. They are approximately the same diameter as the wrist-pin cage and appear to be aluminum.
 
The 2 alloy rings is what I have. I can't see what controls the whole con rod from moving sideways. The common story is that the con rod BIG end movement is controlled by the SMALL end shim washers. With the SMALL end of the rod able to float over the shims, The smallest clearance is the BIG end, which measures 0.85mm (0.033 inches)TOTAL . Conventionally, way too much for well tuned engine. Someone brighter than me must have the answer.
 
Russ,

I seem to recall on my 250CR the spacers were more like washers and are a larger diameter than the
wrist-pin cage, I wish I had it apart to verify.

I checked the parts lists for the 79 250 and 390. Both use the same wrist-pin bearing part number,
but the part numbers for the distance rings are different.

I used a Wossner piston in my 390 and that piston does not have enough room to fit the distance washers.

However, without the washers, I felt the stock wrist-pin bearing was to narrow (.830") and the bearing would move out of the rod to much. I found a wider bearing (.890") which left me with the same clearance (.080" total) as a Mahle piston with the distance rings.

Truthfully, I didn't think about which end was controlling the rod side to side (maybe I should)?
I think you'll be okay, since that's the way it came apart. But I'd like to hear from someone brighter than me too.

BTW, I also used a Wossner piston in my 250 and that piston had room for the washers, go figure?
 
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