# Bad news for the big Jake.



## MasterMech (Sep 24, 2017)

Bad news for the big Jake. 

I mentioned in the verticutter conversion thread that I had a bearing knock in the engine on my GK526A. Well, so I thought. While playing around with both machines last weekend, I noticed the clutch on the 526 "wobbled" when it was engaged. Like, a lot. So that explains the vibration I was feeling. So I figured that the engine and driveshaft were misaligned or perhaps the bearing in the clutch was sloppy. I took her apart proper this weekend, and my heart sank. It's that bearing alright. That $10 bearing siezed up and ruined the hub of the clutch. $500 for a replacement. Yeeoch.





This mower has always had a bit of a knock at idle, so I'm guessing the clutch has been like this for a long time. Technically I could mow with it like this for quite a while yet and just limit the idle time. But it will bug me to no end. I wanted to replace the traction axle on this machine this year due to the belt cover bearings seizing and wearing a similar grove in the traction axle. That only affects it when the transport wheels are mounted so I guess it'll have to wait.


----------



## Gilley11 (Nov 3, 2019)

Know anyone with a lathe? Maybe weld over the old area and retrue?


----------



## MasterMech (Sep 24, 2017)

Gilley11 said:


> Know anyone with a lathe? Maybe weld over the old area and retrue?


Funny because I work in a company that has a whole floor full of machine tools and I'm quite capable of using them and doing the welding. But that's strictly not allowed.


----------



## Vtx531 (Jul 1, 2019)

Bummer. At least the part is still available. Maybe even a cheaper used one on ebay? Or consider buying a spare parts unit?


----------



## MasterMech (Sep 24, 2017)

Vtx531 said:


> Bummer. At least the part is still available. Maybe even a cheaper used one on ebay? Or consider buying a spare parts unit?


EBay, how could I forget that one? But no luck unfortunately. Keeping a spares carcass around is rather unattractive for me since garage space is at a high premium and having been in the equipment repair biz previously, I am very adverse to having dead equipment around. But you have sparked my memory a bit. :thumbup: Going to call a couple used golf equipment guys I know tomorrow.

One of the benefits of buying a greensmower, be it Toro, JD, Jake, even Baroness, is that spares can usually be purchased even long after the production of a model has ceased. Jake still builds the GreensKing 500 series to this day, and this centrifugal clutch is the current configuration of these models. Unfortunately, that means 9 out of 10 machines on the market that I'd consider spares donors, are going to have the older style disc clutches. I consider the newer centrifugal clutch units a big advantage for a machine used on a home lawn. I was really hoping that the clutch itself would hold some clue as to who the original supplier was. As is sometimes the case, I got my answer, just not the one I wanted. :lol: The clutch has only "Jacobsen" and Jake part numbers stamped into it. So the only sources are Jake themselves (4135990 $537.91 + Freight) and R&R ($464.80 + Freight, but that's awful close to the $500 free shipping threshold). Jake is running 10% off on parts until 2/15/2020 via their POWEROFORANGE promo. But R&R is probably the route I'm going to go (assuming I can't locate a used unit) as I need a bunch of their stuff for the verticutter conversion of my other Jacobsen, a 522A.


----------



## MasterMech (Sep 24, 2017)

I guess this post is a bit of a PSA to those who might own a newer style Jake to check those clutch bearings at least annually. It's pretty easy to get to it and dirt cheap to replace vs. the consequences of it failing in this manner. Or be one more thing to add to the list when checking out a potential purchase.

Unfortunately, my 526A has been an example of what issues might be hidden in a 10 year old machine (used daily) that while it runs and cuts just fine, has these hidden issues that are expensive to fix. The traction axle issue is largely superficial to the home user, just irritating to me. That said, this class of machine carries the benefit of being a very high quality build and that once I fix the problem, it stays fixed! Slowly it's undergoing a mechanical restoration of sorts.


----------



## MasterMech (Sep 24, 2017)

Just a quick update on the big Jake, I did replace the clutch with R&R's replacement clutch. Unfortunately, while trying to scalp the lawn, this mower just doesn't have the power needed to cut at .250" in my Bermuda. I tried stepping the HoC down, and it just wasn't getting it done. So I tried the 522a I picked up earlier this year, and it ate through the mess and asked for more. Maybe the big Jake's engine really is getting tired. Sigh. It will likely mow just fine. But it will need addressed before next spring for sure as the 522 will be a verticutter here shortly.


----------



## 95mmrenegade (Jul 31, 2017)

Interesting thread. Maybe you can answer a question on a Jake 526a. I was over @ Micahs house and his is starting to act up. As soon as you engage the traction unit the machine starts moving. Ground speed is controlled by engine speed at idle it is a slight slow walk. A couple things we noticed. The clutch you pictured has a wicked wobble at idle and knocks. What could be causing the problem? Could the clutch on the motor be the problem or something inside the traction control unit. Thanks for the help. @Micah_gear


----------



## MasterMech (Sep 24, 2017)

@95mmrenegade

I'd go ahead and unbolt the engine mount plate, and pull the clutch apart. It will be very obvious if you have a similar issue. In my PM with @Micah_gear I did throw out some ideas on what could be happening. In his photo, the clutch looks dark just like mine did. I now believe that at some point the clutch was severely overheated and cooked the bearing.



MasterMech msg_id=25568 said:


> If the mower will not stop the reel and/or traction drive when you let go of the handle then the clutch is still engaged. There are a few possible reasons why:
> 
> 1: The engine idle speed is set too high. Disengage the traction clutch and the reel clutch. Start the engine and let it warm. Push the - side of the speed control lever all the way forward. Then set your minimum idle speed.
> 
> ...


----------



## 95mmrenegade (Jul 31, 2017)

@MasterMech

So whats the process, basically unbolt the engine and slide sideways to free the clutch


----------



## MasterMech (Sep 24, 2017)

95mmrenegade said:


> @MasterMech
> 
> So whats the process, basically unbolt the engine and slide sideways to free the clutch


Three screws on the face of the clutch that attach the driveshaft and then the four bolts holding the engine plate down. You should be able to maneuver it enough at that point to see what's going on. Don't lose the shims/washers that are under the front of the plate. When you go to pull the clutch off, don't forget the two set screws that hold it's position on the crankshaft.


----------



## Micah_gear (Jul 11, 2018)

@95mmrenegade

Thanks for your expertise!

I pulled the motor and jack shaft to get to clutch. Low and behold, the barring is shot. Not sure if clutch is ok.

What should I do next?


----------



## MasterMech (Sep 24, 2017)

I can see your hub has taken a bunch of wear from that seized bearing. Your options,

1.) Replace the clutch with a new part. $460 from R&R, might as well pick out another $40 worth of stuff to get the free shipping. The clutch is awful close to $600 through Jacobsen. I can give you the numbers off of my clutch that I bought from R&R if you want to try and source it elsewhere.

2.) Find a good used clutch. These machines aren't hard to find for less than The $500 a new clutch will run you. These fail rarely enough that I'd be comfortable with buying a "salvage" machine and robbing it of its clutch. Any 518/522/526 will do as long as it has the InCommand controls. I'd also swap the bearing out on the good clutch just because.

3.) Repair the old clutch. As suggested above, it might be possible to repair the worn hub via welding it up and machining it back down. I don't know the material exactly but it does appear to be a cast part so welding may or may not be so easy. You might try machining the hub down and pressing a sleeve onto it to return it to the proper dimensions. You'd need a local machine shop willing to try! If the hub was successfully repaired, then all you have left to do is replace the failed bearing.

Keep us updated on how it's going!


----------



## Micah_gear (Jul 11, 2018)

Thanks!!

https://www.rrproducts.com/?k=4135990
Is this the part you ordered? Does it come with the bearing or do I order that separately? Is there anything else I need to order to complete this project?

Not too many used Jacobsens in my area. Will probably have to order the new part. Replaced reel/bedknife last year and motor is strong. Probably worth putting the money in it.

Can't beat the cut and look of the 526a


----------



## MasterMech (Sep 24, 2017)

That's the same clutch I bought. The bearing is included. I had to file the key down a bit to get it installed, no biggie. I didn't need any additional parts but I would check your machine over. Bearing in the belt cover for the transport axle ok? Transport hub bearings? You could always throw a bedknife (don't forget the screws!) on the order and call it good.


----------



## g-man (Jun 15, 2017)

@MasterMech I'm curious. What was happening during the scalp? Stalling or slipping on the clutch?


----------



## MasterMech (Sep 24, 2017)

g-man said:


> @MasterMech I'm curious. What was happening during the scalp? Stalling or slipping on the clutch?


The engine is getting dragged down to the point of slipping the centrifugal clutch. I do need to re-check the rpm settings on the engine. But I did reach down and hold the governor wide open and she didn't have any more to give.


----------



## Micah_gear (Jul 11, 2018)

@MasterMech

Question: the torque clutch is the same as the centrifugal clutch right? I ordered same part number as you did and just want to make sure before I open it.

Thanks!


----------



## MasterMech (Sep 24, 2017)

@Micah_gear same function!


----------



## Micah_gear (Jul 11, 2018)

@MasterMech 
@95mmrenegade

Thanks!

Got new clutch installed. Long story, but it's installed and works great.

Throttle cables still need adjusted. Mower still moves unless I turn throttle to the full negative. Maybe springs are too tight? Which spring in your opinion do I need to adjust?

I check handle and that seems ok.

Really appreciate all of your help


----------



## MasterMech (Sep 24, 2017)

Micah_gear said:


> Throttle cables still need adjusted. Mower still moves unless I turn throttle to the full negative.


Without squeezing the bail bar to the handle, moving the throttle control affects engine speed? Or not?

The mower should not move at all unless the bail bar is squeezed to the handle, regardless of where the speed control is positioned. Once you do squeeze the bar, the mower may not Start moving with the speed control at full -, but should start moving with just a bit more + on the the speed control.


----------

