Experts Needed - Husqvarna 445 - Run 3/8" x .50 Chain with Sprocket & Drive Change?

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KCOLC

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Help! I was recently given a stock Husky 445 (.325 x 50). Have already have a Husqvarna 266 (20" bar) with which runs 3/8 x .50 chain. It has a stock 7T sprocket. I have so many chains for 266 that I would like to run the same chain on the 445 too so I can keep life simple and avoid confusion. I realize, IF THIS IS POSSIBLE, that I will need to change the 445's sprocket, bar and possibly the clutch too. Has anyone here done this? I'd be very grateful if someone can tell me what needs to be done and what parts are needed and who has them? My dealer, who has carried Husqvarna for a very long time was clueless. Put a call in to Bailey's on Friday morning but they have not returned my call. My guess is the knowledge I need exists here! Not worried about stressing the 445. It won't be used to cut anything larger than about 6 to 8" I'm over 6' and the 20" bar is easier on the back. Many thanks!
 
The 266 is a whole lot more saw than the 445. The issues in bar-ing up your 445 to use the same chains as the 20" 266 include changing to a 3/8 drive sprocket on the 445 and a 3/8 pitch 20" bar with the small tail for the 445. I'm guessing that your 20" 266 takes 72 links. The link count might be different for the 20" bar on the 445. The link count would have to be the same to use your existing chains on both saws.
 
The 445 just isn't strong enough for that - you better forget it!

Thanks everyone...I respect your advice...the saw will be used just for limbing and other light work. With the saw's health in mind the setup isn't intended to be used at anywhere close to the 20" bar's full capacity. My desire to use matching chains on both saws is because I have nearly a dozen chains for the 266, and don't want the aggravation of trying to keep seperate same length chains. I'll use a 20" in bar on both saws. Because of my height a longer bar is easier to work with. Galde, yes...my 266 3/8 x .050 chains are 72 links. Sorry I forgot to mention that.
 
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Thanks everyone...I respect your advice...

I'm not sure if you meant you respect it but will do otherwise, or you respect it and will follow the suggestion. My advice is to do as ST suggested and run .325 on the 445. It really doesn't have the power to pull 3/8" chain. You shouldn't need more than a couple of loops which really doesn't present much of a management issue. This is even more true if you plan to run a longer bar (20") on the 445. I'm 6'4" and I wouldn't even begin to consider a 3/8" 20" bar set-up on that saw. Even a saw like the 346 which has .9hp more is better suited to a .325 chain.
 
I meant I respect ALL the advice. I'm learning from those who are telling me it's not enough saw as well as from those that know it's not enough saw but "if you want to take that road here is how to do it". MUCH more knowledge here than I have. So...what I'm getting is that using 3/8 x 50 isn't a good idea on the 445 because of the saw's lack of power BUT it seems it can be done. I'm going to see if I can come up with a sprocket & bar combo that will work on the 445 with 3/8 x 50 x 72T and see what the cost is of making the change and then make a decision from that point. The saw was a freebie. It's beat up but runs great and has just a needles width under 180lbs compression. Not sure what a new one has. From the way it looks it has seen a lot of use (maybe just abused) and came to me with a 20" bar & a .325 chain but the bar is not straight and the sprocket is trashed so both need to be replaced. May end up just putting an 18" setup on the saw, selling it and trying to find the lightest used Husky I can find that will use the same 3/8 x .050 x 72 chain as my 266.
 
Thanks everyone...I respect your advice...the saw will be used just for limbing and other light work. With the saw's health in mind the setup isn't intended to be used at anywhere close to the 20" bar's full capacity. My desire to use matching chains on both saws is because I have nearly a dozen chains for the 266, and don't want the aggravation of trying to keep seperate same length chains. I'll use a 20" in bar on both saws. Because of my height a longer bar is easier to work with. Galde, yes...my 266 3/8 x .050 chains are 72 links. Sorry I forgot to mention that.

It will likely do that - but I never had any aggravation from keeping same length chains that don't interchange around - you just need some system...
 
Here's an update. Starting with the advice I received here on the Oregon 108565X (3/8 x 50) rim sprocket as a possibility, it appears I can add a matching Oregon ORF11893 bearing and the 2000RNDK095 Power Match bar ( 20" x 3/8 x .050 x 72DL, small tail ) and I'm where I want to be. A caution that many here advised me of and that I'll repeat for the benefit of those that may read this thread in the future: This is NOT the optimal setup for this saw. If you intend to use the saw at the bar's full capacity and your saw's health is a concern stick with .325 chain and go easy with any bar over 18". Thanks very much to everyone who contributed. Unless I've missed something I think I'm going to give this a try. Will add an update in the future.
 
Baileys has some good deals on Carlton bars. Just do a search on their bar selector for a Husqvarna 50 with 3/8 pitch, 20 inch. For example, they have CPU 20 CJ58, Carlton bar. However, it's .058 and you probably want .050. They had some inexpensive combos on the last flyer they sent out, and they have the sprocket rim that you need.
 
Well.....Ordered a ORF 108565X Oregon Drum and matching 3/8 x 7 rim from Bailey's. Large Spline. While all other dimensions are a good match to the stock drum the teeth on the drum that engage the black plastic "socket" on the oil pump drive are too large and won't fit. There is enough unneeded metal on the drum that I can take it to a machine ship and have it customized. Is there an off the shelf solution? Bailey's couldn't find one. Neither could Oregon.
 
With a bit of reverse engineering, I think the 108215X will work. The 345 takes the 108308X spur sprocket and the 108215X rim system. The 445 shows the 108308X spur system. This is from the Oregon look up system. Since they take the same spur sprockets, maybe the oil drive gear is the same. I had the 353 and 345 apart recently and I can't remember if the pump drive was the same. There is a statement that other parts may be required, so perhaps you need a different oil pump gear.

I looked it up and the 445 takes the 503931801 oil pump gear. The same gear is used on many 340, 345, 350, 445, and 450 saws with the spur sprocket.

The 503892103 oil pump gear fits the 346xp and 353 using the rim system. I bet this gear will work on your saw but I'm not willing to tear my 346xp down to tell you for certain. Maybe someone will come along that has both systems apart.


Baileys summed it up:
Oregon Power Mate Rim & Drum for (.325" x 7) Husqvarna & Jonsered 345, 346, 350, 351, 353
This professional drive system includes a splined drum (clutch cup) with a replaceable rim. The rim floats freely on the spline, allowing the saw chain to align with the groove of the bar. Comes complete with .325" x 7 tooth spline. Drive sprocket bearing sold separately.

Note Requires a special clutch tool 31118 to replace. If you are converting a Husqvarna 346, 351 or 353 from a spur sprocket you need to purchase #503 89 21 02 oil pump drive gear as well. If you are converting a Husqvarna 357 or 359 from a spur system you need to purchase #503 91 27 03 oil pump drive gear. This rim & drum system has a small 7 spline and uses RSS rims. If you would like to run larger RSD rims, use part number ORF 108565.


Q. I have a 350 and am replacing the spur set up with a rim sprocket. Do I need a new oil pump drive pinion? I purchaced the 503892103 rim drive pinion but it is to large (15mm) to fit the crankshaft (13mm). The spur oil pump drive pinion is smaller (13mm) and rides nicely on the crankshaft. It seems that the rim clutch drum will drive the spur drive pinion but its a pretty loose interconnect.
A.
On the 350, no oil pump is needed. With this rim and drum system it should catch the oil pump as you don't need a different pump.
 
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From Cassadaga Edge and Engine,"

* The complete sprocket system includes a clutch cup with spline and a replaceable rim sprocket.
* The rim floats freely on the spline, maximizing chain-bar alignment and the rim is replaceable which extends the life and increases the value of the sprocket system.
* The system provides smoother cutting and less chain jumping and wear.
* Does not include bearing (Part number ORE 11893)
* Includes one .325" pitch, 7 tooth rim sprocket
* Hub size: Small, 7 spline

Fits the following saws previously equipped with rim sprockets (additional parts may be needed if converting from spur sprocket):
Husqvarna: 346, 346XP, 351, 353, 357

Jonsered: 2145, 2149, 2159
Additional Information
Part Number 108215X
Brand Oregon

"

The rim should be: small 7 spline 3/8 Oregon 18720
 
Update 3

Dsell, Thanks for that. Will give it a try. Ordered the 108215X sprocket (small spline) and the 18720 rim ( 7 x 3/8) . Let's see what happens. If it works as is great. If not, perhaps it will require less machining.
 
Getting There

With a bit of reverse engineering, I think the 108215X will work. The 345 takes the 108308X spur sprocket and the 108215X rim system. The 445 shows the 108308X spur system. This is from the Oregon look up system. Since they take the same spur sprockets, maybe the oil drive gear is the same. I had the 353 and 345 apart recently and I can't remember if the pump drive was the same. There is a statement that other parts may be required, so perhaps you need a different oil pump gear.

I looked it up and the 445 takes the 503931801 oil pump gear. The same gear is used on many 340, 345, 350, 445, and 450 saws with the spur sprocket.

The 503892103 oil pump gear fits the 346xp and 353 using the rim system. I bet this gear will work on your saw but I'm not willing to tear my 346xp down to tell you for certain. Maybe someone will come along that has both systems apart.


The 108215X sprocket (small spline) and 18720 (3/8 x 7) rim arrived. The good news: This combination almost gets me where I want to be. 3/8 x .050 x 72DL with a 20" narrow tail bar. The bad news: As dsell warned, it seems another oil pump gear is needed. The teeth on the spline are a too small for the oil pump pinion gear as we suspected. It works and the saw oils fine but I worry that since there is so much play in the fit that reliability may be a problem. Have the 503892103 gear ordered. If that fits the saw and fits the spline we're in business!

View attachment 239023
 
May end up just putting an 18" setup on the saw, selling it and trying to find the lightest used Husky I can find that will use the same 3/8 x .050 x 72 chain as my 266.

Sounds like a plan to me...not sure which model, but good luckski!
 
It will likely do that - but I never had any aggravation from keeping same length chains that don't interchange around - you just need some system...

I use freezer bags with yellow and green index cards (semi vs safety chains, easy to spot). Big number for chain length and the saws # on the flip side.

My 3 saws (5 bars) and the electric pole saw do not mix. It is NOT a pain unless I get lazy.
 

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