Replacing an Oil Pump in a Husqvarna/Poulan/Craftsman/Johnsered Chainsaw

It was the middle of winter, the nights were cold and we needed some firewood for our little combustion heater.  Out I went with my 2 times hand-me-down Husqvarna 136 chainsaw to cut some wood up. After only a minute of cutting the blade began to smoke. Despite the cold I thought “That ain’t right” and quickly stopped the saw to investigate.

I did the usual checks. I checked the saw had enough oil – it did. I checked the blade was sharp.. it wasn’t any more – though it was when I started only minutes before. I then checked that oil was getting to the bar and the chain. Ah, that’s the problem.

The chain was bone dry!  I checked the bar. There was some dirt in the bar but not enough to prevent oil getting on to it. Finally I checked where the oil is meant to come out on the chainsaw – Nothing was coming out.

A little digging and I found that the oil pump cover had a slice in it. How it got there I’ve no idea. The fact it was there proved to be the problem. The oil pump cover performs two jobs. It creates a seal so suction can build up for the pump and acts as a dirt cover.

I began to pull the chainsaw apart to check the state of the oil pump. Pulling the saw apart started off quite easily. Off with the steel outer cover, remove the rubber insulator.. then I hit a road block. The oil pump was actually under the main drive socket/chainsaw clutch. It was held in by two screws that I had no chance of getting into. Hence the drive socket/clutch had to be removed.

The drive socket/clutch is actually a reverse thread screw type setup attached directly to the main crackshaft of the engine.
Every attempt I did to unscrew this piece simply turned the cylinder.  I gave up for the night in frustration.

Google is a friend and I soon found the reason I couldn’t undo the part.  In the official repair manual, a special ‘cylinder lock tool’‘ is required to brace the cylinder in position and a special ‘drive socket/clutch release tool’ is used to grip the clutch. These tools allow the clutch/drive socket to be unscrewed and hence the oil pump removed. A quick inquiry – $58 for both! No way was I going to pay that for tools I’d only use once. I was at a loss.

Luckily I eventually found the following forum post. In the post the person mentions using an old nylon rope as a cylinder lock – Ironically they mention the official tool often pokes a hole in the cylinder! Anyway back to the shed I went to give it a go. Nylon rope in cylinder, vice grips as release tool – It worked! The drive socket/clutch released and I was able to access the oil pump.

With the oil pump removed it was clear the part needed replacing. The oil pump in the chainsaw is driven by a worm thread on the main drive shaft. This worm thread turns a plastic gear which causes a half cylindrical piece of metal to rotate. As it rotates it creates suction. This suction draws the oil from the oil tank, through an oil filter into the oil pump. The oil pump passes the oil from one side of the pump to the other and out via plastic channels to the bar/chain. In my case the plastic gear on the oil pump was stripped in one place. It looks like the slice on the pump cover allowed dirt to get in. The dirt jammed the plastic gear and the metal worm thread did a nice job of stripping the gear.

After downloading the parts list for the 136/141 from the Husqvarna website (Note: IPL = Illustrated Parts list) I was soon able to work out what part I needed – it was part 530014410 (apparently also the same as: 530029838, 530029834, 530029835, and 530029912, 545036801). A trip to the local chainsaw shop had the part listed at $32. A quick trip to eBay and I found the part for less than $10 delivered! (Thanks to user/ebay store Mowers4u)

I ordered the part and waited for it to arrive.

A few weeks later (it was an international trip) the part arrived and after giving the chainsaw an extremely good clean using degreaser, petrol and a wirebrush; I set about putting the chainsaw back together. At each stage I checked that the pump was working. Turns out the model of pump I got (as stated in the eBay ad) was actually an enhancement to the original part with better dirt protection – looking at the part this modification was clearly visible.

Eventually I finished putting the entire chainsaw back together and test it out – it worked! Oil now flowed nicely on to the chain again. A fine line of oil was now clearly visible when spinning the chain next to an object. So for the cost of a couple weeks worth of waiting, a couple hours of my time and less than $10, my trusty Husqvarna 136 Chainsaw was back in action and ready to finally cut that much needed firewood! (The backup stock was getting really low 🙂

One final side note to anyone wanting to replace the oil pump; the part I used is actually is able to be used by many chainsaw makes an models. Taking direct from the Mowers4U eBay Add:

“This is an oil pump assembly Poulan, Husqvarna, Jonsered, and Craftsman chainsaws. The oil pump is part number 545036801, which is the latest version and supercedes part numbers 530014410, 530029838, 530029834, 530029835, and 530029912. The pump fits a large number of models including Poulan and Poulan Pro 2200, 2500, 2600, 2750, 2775, 2900, 3050, PP255, PP295, PP310, PP315, PP4620, and Husqvarna models 36, 41, 136, 141, 137, and 142. This is a genuine Poulan part, not an aftermarket part”

Installing The New Oil Pump on The Husky