No, you do not need to remove the two bolts. But, you do need to get all the air out of the system or it air locks and will warp a head or two, and the temperature light will never turn on as it has no hot water circulating in the thermostat housing to trigger the switch.

Take a look at the parts diagrams for the radiator, and you will see the problem child. The design of the pipes that carry coolant to the radiator put them in a configuration that works like a drain trap and traps air in the system on the engine side of the thermostat right at the head where the housing resides. That keeps the thermostat from opening and it will overheat the cylinder heads.

My guys, who do hundreds of these in a year, just about stand them at 45 degrees with the radiator cap side of the radiator up and open, after they fill everything. Takes them about 3 minutes, but time is money in the shop! Do not rush at home, just fill both fillers and the reservoir, go have a coffee and watch a football game, then come back and fill it full again, then cap the caps on the engine side and the reservoir. Do not run it yet.

Leave the radiator cap off. Jack the left front corner up as far as you can safely get it, then fill everything again and take another extended break.

Once it takes no more coolant after setting, let it run while checking to see that the coolant on the outflow side of the engine is actually starting to warm (it will start to warm in seconds because there is a bleed hole in the thermostat once there is coolant to that level). If it is warming, watch the radiator coolant level as it burps out the trapped air. Then let it run until the thermostat opens and you will feel hot water in the radiator.

If it is not warming on the outlet side of the engine almost immediately, shut it off and remove the temperature sensor from the water jacket on the head, and fill the radiator filler until a solid stream of coolant runs out the temperature sensor hole. Refer to the cylinder head parts diagram for its location, and to the Generator parts slide if you are not quite sure what component you are looking for. That will burp one side and usually allows the water pump to prime and the water to flow to the thermostat housing. Once it is full button up the temperature sensor, leave the radiator cap off, and start it again once you are sure the radiator is full.

It will burp at least one more time and need coolant, then be good to go.

The key is do not rush!

 

Couple quick questions: You said, Leave the radiator cap off, jack up the left front corner even higher, fill everything, take another break.. then, once it takes no more coolant, let it run... Should I still have it jacked up? Should I run it with the radiator cap off? (You mentioned it will blurp out the trapped air)
And lastly, how do you know when you have succeeded? Just when the thermostat opens or can that happen and still have air in the system that causes a problem... especially with the new heater being installed.
Thanks so much for the help!!!
Joe

 

Missed getting back to you sooner.

We leave the radiator cap off after the second or third round of filling after it sets and bleeds by gravity. Then run it with the front corner raised and the cap off.

Once it needs no more coolant, the cap goes on, everything checked one more time, and then it is lowered and run for a test run.

If the cooling system pipes from and to the engine are hot to the touch it will be circulating coolant. It will not air lock if the coolant is fully circulating.

 

You don't HAVE to jack the front end up, although it does make it easier and less time consuming-which is important in a repair shop atmosphere. But it's also important to turn out good work.

Sometimes we don't have a way to raise the front end up that high at home.

What I usually do is take both caps off. Front radiator and center cap.
Remove the air bleed screw in the intake manifold (2510 only...3010 is on the upper metal line near the engine).
Fill the center filler until coolant runs out of the engine bleed screw. Leave the engine OFF for now. Once coolant comes out of the manifold, reinstall the screw.
Then fill the center filler until coolant comes out of the radiator cap, in front. Once it starts coming out, reinstall the radiator cap.
Now...start the engine. Idle only.
Continue to fill the center filler until no more air is seen circulating. With a heater, it takes time. The coolant will also get hot so be careful. As the thermostat opens you will see hot coolant circulating. As the level drops, refill it slowly. It helps to find a funnel that fits tight in the filler neck...as this allows that to be the highest point in the system and lets air escape easier.
Let the engine cool off completely. Refill the system after it cools down. Reinstall the cap. Fill the reservoir HALF full (not halfway to teh full line, fill it up halfway to the top). Start and run the engine until the fan comes on, then kill it, let it cool off completely. Watch the reservoir and refill if necessary.

 

Thanks guys for all the help. I have the heater completely installed. I am trying to do the bleeding now. I can not locate the air bleed screw in the manifold. How do I identify it?
The system is definitely not circulating.
Thanks!
Joe

 

I found the air bleed screw on the Manifold. Opened it and let the fluid run out. Just going to keep refilling and let sit for a while. Thanks again. I will give an update soon.

 

The heater is not getting hot. Looks like the thermostat is opening and the water is circulating, however, the heater lines are not getting hot. I pulled the heater line off the engine side by the shut-off valve, filled it with coolant, it came out where I pulled it off without a problem. I re-installed the line and started it. For some reason, the lines/ heater are not getting hot. I was going to just let it cool down, top it off if necessary and try again. Any suggestions?

 

Ok, Got it! The heater is working fine. Has a very low buzz when the fan goes on. Almost like a bearing sound. Hope that is normal!
Thanks for all the help!!

 

Might need a drop of turbine oil on the motor's bushings. You can get the oil at a pellet stove dealer, it is same stuff used for pellet stove motors.

Glad to see you got it. I am out of the country again, and not always able to log into the site.

If you get a radiator flush kit from one of the auto parts stores, about $5, they have a "T" that will fit in the top heater hose and allow you to prime and bleed the heater quite easily if this comes up again.

 

Great advice. I will purchase the kit and install the "T" during the next coolant change.
Now that the heater is working, the engine is staying pretty cool. Seems as though my thermostat is barely opening. I was running it up and down the road tonight, it is about 42 degrees Fahrenheit out. The thermostat did not open. Heater was cranking, the passenger side steel line (thermostat side) was finally hot (it seems like it stayed cold for a while, not sure that is right), but still even when if finally got hot, the radiator and the steel coolant return line was cold. I checked the temp of the heads with my IR heater gun, and they were about 140 degrees F, Think they might have gone up to about 152 at one point. Finally the radiator and the return line got hot. But then, about 10 minutes later, the return line was cold again. I am just assuming that the engine stays cool enough and does not need to circulate the coolant and everything is fine. I just want to put it out there and make sure I am not missing something and accidentally do some damage. I hope it is all working as it should. The service manual says that the thermostat should open between the range of about 145 and 153 degrees. I hope as long as it opens it means it is working correctly.
Thanks again for the help!
Joe
*Edit: Just ran it again for a couple HOURS, still 42 F outside.. I don't think that thermostat even opened once! Think the heads got to about 158 at one point but my IR Thermometer has a 4 degree accuracy range. Heater working great and maybe the reason it has not opened the thermostat? Is that ok? I'm a little concerned.
Thanks.

 

I am not sure where you plumbed your heater, but if you put the pressure line before the thermostat and the return line after, it will run cool as the coolant circulates through the heater with the thermostat closed.

If you have cold running engine symptoms, it may be necessary to install a valve in the heater line and shut it down until the engine warms. Usually that is not a problem.

 

I don't really notice any cold running engine symptoms. if I didnt feel the lines, and check the temp, I don't know that I would ever have noticed anything. But it's still relatively nice here weather wise. Not sure what is going to happen when it gets down to 18 degrees.
I did plumb it as you said above.. from the temp sensor by the thermostat and a "Y" adapter into the return line. The heater came with a shut off valve, but it is kind of a pain to use. We'll see what happens. If it has a problem when it gets really cold, I will resort to closing the valve.
Hopefully the way I have it set up is ok and will not hurt the motor.
The one problem I am having that does seem to get worse with cold weather is the loud banging sound I hear from my front end. As I start to speed up, it sounds like something is loose in the front end. Had the problem last year, but it seemed to not be so bad and would go away after the machine warmed up. Didnt get to loud this summer, I assumed it was a U-joint going bad so I ordered new u-joints and was going to tackle that next. With the weather getting colder, the sound has really magnified and I feel like I am going to do more damage if I don't fix it. But now I am guessing that it might be the bearing in the front gear box (front drive shaft) where it attaches to the drive shaft (propeller). How do I figure this out? It is difficult to pull of the drive shaft propeller and then the bearing? I am looking at the parts diagram and the bearing appears to have a series of spacers, washers and a seal held on by a nut. If I get the drive shaft propeller off, it looks like i can pull of the nut and change the bearing and seal. Do I just need to pull off the rings in the U-joint to take out the drive shaft propeller? Not really explained in the service manual.
Thanks again for the help! Hope it's ok to ask another question in the same thread!!
Joe

 

Running a bit cold will not hurt a thing unless it stays too cold and requires excessive choking to keep the engine running when it is being run, then that washes oil from the cylinder walls. You will definitely know if that is the problem.

Banging noise from the front end can be a number of things. I generally want one up on jack stands and securely stabilized when I start looking for sources. It can be the propeller shaft, the carrier bearing, either of the front drive shafts, the clutch plates in the front differential, or even a cracked or broken spider gear.

I would suspect the clutch plates are locking and then snapping if the noise is more noticeable as you turn corners and the outside wheel has to speed up to compensate. If that is the case, new lube and a good friction modifier would be in order for the front differential. If it is just popping and cracking along when driving in a straight line, then I would suspect the front drive line CV joints.

The Spicer style universal joints it uses are pretty easy to diagnose by just rolling the propeller shaft and feeling and listening. Same for the carrier bearing (a lot of people forget to grease it from the top, and it will pop when it is worn out). If you are replacing them, be sure the replacements have grease zerks. They do not take a lot of grease, but because they last for so many years the grease will dry out long before the bearings wear and then the universal joint will fail.

If it turns out to be the carrier bearing, it is sold as a unit at Kawasaki. But, on the 2510 it is assembled with three bolts on each side of the main assembly and the bearing is readily available from most commercial bearing supply houses, just take the old bearing in with you.

The 2510 still uses C clips on the universal joint trunnions on the propeller shaft. So once you remove the circlip on the front side of the carrier bearing it is pretty easy to get the universal joints out for repair. It is still sometimes necessary to remove the front differential bolts and move it forward and down to pull the shaft if there is significant crud or rust in the main spline at the carrier bearing that prevents it from compressing and releasing the front spline from the differential so you can pull the shaft.

The CV joints in the front driveshafts will snap and pop when they are dry or worn out. They are like the CV joints on cars, and can be serviced much the same way. Kawasaki sells an inside joint kit and boots, but not the outside joint. Most shops just replace the entire assembly when those joints are bad because the parts and labor to repair exceeds the cost of the entire assembly. Each assembly runs about $530 each, so it can be more economical for the do-it-yourself owner to disassemble and repack or replace the bearings if they have the time. The real cost and effort is in the labor pulling them out and re-installing them. So once out they can usually be serviced by a drive line shop pretty inexpensively if you do not know how to pop the joints apart for service, and it can be a bit of a messy job.

The other thing that sometimes pops and snaps is the spline between the front hub and the end of the front drive shaft if one has been neglected. If you see looseness in that spline, along with rust, that could be the source too. It will make a crunching noise when you listen to it roll. Unfortunately, when those start popping it is usually time to replace both hubs and drive shafts. It is critical to keep them lubed so they do not rust away, and the nut on the end of the axle properly torqued. If you use anti-seize on any splines, be sure you do not use the products with the microscopic glass balls, those eat the splines away. I prefer the same stuff used by the marine industry to coat stern drive to motor shaft splines, it is rust resistant and really sticks.

 

I just replaced the front axles and hub bearings, so I'm pretty sure it is not that.
Seems funny to me that the noise seems to get quieter as i drive it for a little. Can it be as simple as changing the diff. lub? I just bought some so I am going to do that right away.
When I get under my Mule to check the front U-joint for play, it seems pretty solid but the rod that comes out of the front diif has about a 1/4 inch of play each way (right, left, up down etc). That is why I am assuming it is the "bearing roller" (92116-1006).
I am going to put it up on jack stands and check it again. I will try to take a video so I can post it and see if you think that is the problem.
RCW, thanks so much for your help and time! If you are ever in CT, you have credit for a sick dinner on me.
Thanks.
Joe

 

There should be zero play on the pinion shaft.

With that much play, drain the oil in the differential and you will find grindings.

 

Thanks RCW. If that is the case, then can I replace the bearing roller and the oil in the diff and be ok. Or do you think I am going to have to open up the diff and do more repair... or replace the whole diff? Obviously, I hope it does not come to that.
THanks.

 

Ok, good news.. after looking a bit more carefully at what was moving and making the noise, I was able to confirm that it is NOT the pinion shaft. It is the part of the drive shaft that connects to the pinion shaft. I have new U-joints but after looking at the play, I'm not sure if that will do it. It almost seems that the little connection part of the drive shaft that the pinion shaft goes into is loose. I am hoping that it is not the splines on the pinion shaft. I have a very short video I am trying to post with this and maybe someone knows by looking if this is simply the u-joint. If so, I will replace it. To do that, is it best to remove the Propeller Shaft Bearing Housing,(under the seat) therefor giving me some room to pull the front drive shaft back a little to get it off?
I am really hoping this is not something major.
Thank for all the help!!
Hopefully you can see the video..

 

Yes, does look like the yoke is bad. Pull it, take it to Six States (if you have one handy), or any drive line shop and see if they can match you up with a correct yoke. Kawasaki sells it as a complete front shaft assembly, but the yoke is usually quite inexpensive through a specialty shop.

Now for the good news. These front yokes do not slide on the spline during operation. It is simply a connection for ease of assembly. The yoke is also softer than the pinion shaft, so tends to wear out before the shaft becomes loose in a new yoke.

However, if you get a new yoke and it remains a bit sloppy shoot me a message and I will pull the tube of stuff out of the shop and let you know what it is, and how it is to be used.

Replacement is a snap after what you have already done to the Mule, just follow the instructions in the repair manual, and if the center spline is loose enough it will give enough to allow the shaft to slide back once the carrier bearing is disconnected from the frame.

If the center spline is rusted to the point it will not slide back far enough you will need to loosen the differential and let it drop a bit for the play you need to pull the yoke from the spine.

 

However, if you get a new yoke and it remains a bit sloppy shoot me a message and I will pull the tube of stuff out of the shop and let you know what it is, and how it is to be used.

Looks like I have to resort to your tube! I am assuming it is some type of liquid steel?
I pulled the drive-shaft, unfortunately it appears that the splines on the yolk are fine and it is the pinion shaft that has some wear. Not much at all, I really thought I was going to see something more worn down. I still took the drive-shaft to the local drive line shop, they were not able to match it up and felt that it was not needed and the splines on the yolk were fine and very square. I explained my problem and that replacing the pinion shaft would lead to a great deal of parts, labor and money. He suggested that I drill and tap a 1/4" whole in the yolk and screw down a small bolt or something. I have the drill bit, die bit and a 1/4" set screw. Will that weaken the yolk? Will I need one or would I need one on each size or perhaps even three spread around to stop it from rocking back and forth? Will three weaken the yolk? Maybe this idea along with some liquid steel or something similar could work???
I have no idea what to do.. can't spring for a new differential (several hundred dollars) and i feel like kawasaki service will tell me it will cost less then pulling it apart, replacing the couple parts, all the labor, adjusting the shims and whatnot. I don't have the tools or experience to do all the shims and the backlash adjustments, so I would be at the mercy of Kawasaki service (not that they are bad at all, but I think it will be way to expensive).
Can I make it work by fabricating it with the 1/4" set screws and/or liquid steel?
Thanks for the help.. I am definitely feeling a little worried at this point.
Joe

 

I found someone that drilled a hole and used a set screw. Here is the pic:

Another idea could be to saw a grove down both sides of the yolk (just enough, not saw the yolk in half) and bolt on a clamp.
I'm just concerned about it holding up, as you can see in the video I posted, it really has some serious play.
Thanks for helping!
Joe

 

Need your input RCW. I want to reinstall the drive shaft. What do you think based on the info in the 2 posts above? tap a hole and put a set screw or something similar? A clamp? Your tube of stuff?? I would love to know that tube is.
Thanks SO much for your help.

 

There is a product from LocTite specifically made for this purpose. I have some in the tool box of the UTE, but will have to pull it tomorrow to get the part number when I get back to the shop.

 

I really appreciate it RCW. Hope not to much of a bother.
Joe

 

What you want is LocTite 660. Follow the instructions and let it cure for at least 24 hours before use.

When the time comes that you want to remove the universal yoke it will be necessary to heat the union over 300 degrees F, to get the LocTite to release.

I use this on 1,200 horse diesel generator drive splines when they open up from vibration. I have never needed to replace one of those splines after using this product, it is that good!

 

Thanks RCW. I will try and locate it right away.