Kawasaki Forums - Help!! 08 3010 Trans Diesel Severe Decel / Engine Braking

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Help!! 08 3010 Trans Diesel Severe Decel / Engine Braking

Newb here, so any help would be greatly appreciated.
We have a 2008 4x4 Trans Diesel that has been great up until now.

While driving, any time you release your foot off of the accelerator pedal it will decel to the point of almost locking the rear wheels up and will basically use the unit as an engine brake. The slower you go the less noticable it is but regardless of your speed it is fairly violent, literally like downshifting a manual transmission car at 50mph and dropping it from 3rd gear to first and dumping the clutch. The Mule will do this in high/low and is something that is new. If anyone has any pointers please throw them my way.

not that it matters but I have a lift kit and SS rims and larger tires on the unit. Only other mods are an amp and speakers.

the first thing i would check is the rear brakes they could be locked up im not sure on the governor assembly on the diesels but the gas motor set up uses the governor the keep the throttle high enough to keep the drive clutch engaged to allow for engine braking you may want to check to make sure the governor is working correctly aswell

Hi ,
Need to Get the mule off the ground, ( all four's )
Take the " Drive Converter Cover Off , Watch The engine Clutch If If " jumps In "
Or There Is Alot Of DIRT . Need To clean Inside

It was the bushing that goes in the drive or driven pulley, whichever one is all the way in the rear. Had to pull both off and install the new bushing, fixed the problem.

Dear OKCMULE,
I have the exact same problem with my 4010 Diesel Mule. Here's a link to the schematic for the driven pulley:-

https://www.kawasaki.com/Parts/Parts...2009/KAF950F9F

Any chance you could help me by being a little more specific in describing what solved your problem? When this issue arose with my Mule I removed and rebuilt both the drives and replaced the drive belt too and it didn't fix it. I replaced the bushings in the driven pulley but I am concerned (after reading your solution) I may have overlooked something. Any help is appreciated as this rapid deceleration thing is driving me insane.

Regards,
Brian.
Australia.

On the driven converter we replaced 92139-1078 bushings and turned 49048-1097 shoes to the new side.
Cleaned everything up really well and that was that.
I had a kawi tech buddy help take the converter apart for me and re assemble as that was a royal pain in the ass. Not sure if mine was the same as the 3010 had two options and I cannot remember which one I had. If it was just that bushing really causing all of the problems I would imagine that the drive pully bushing could possibly cause the same issues.

Thanks for taking the time to reply.

You have given me something to go on.

As stated, I completely overhauled both drives on mine and fitted a new belt when this started happening and it didn't solve it. I also replaced the two bushings you quoted and I installed three new plastic shoes too as well as the main spring. I am sure I rotated it when I put it all back together too.

I rebuilt the convertor completely, and that included placing some welds where the weights were hitting the body, and machining the welds flat in a mill.

I must have missed something. I set up everything according to the 4010 Diesel Mule Workshop Manual. I have ordered new springs, bushings and plastic shoes for the driven clutch, so I'll have another go, but this time concentrating on what you have said.

The convertors are tricky but I just manufactured all the tooling required myself. I had to buy the bolt to remove it. You are lucky that you had your Kawi Tech buddy to help. I've contacted three Dealers here and all have either recognised or known of this issue. Next they all become vague and won't offer a fix or change the subject. I have written to Kawasaki here asking if this is a known problem. If I found a Dealer here who appeared competant then I'd remove both drives and pay to have them look at them.

Most forums suggest using a dry Moly lubricant on these CVT's and I didn't do that. I will this time.

Thanks again for taking the time to help me.

Kind Regards,
Brian.
Australia.

I've found a little more information regarding this problem on another Forum:-

"Apparently it is a known fault that should have got a recall from Kawasaki, but didn't.

Early 4010 Diesels were fitted with rear pulleys that had been badly machined. The sliding surface wasn't smooth enough and wears the bushes in the centre of the sheaves rapidly. A local Kawasaki dealer put us right and sold us a reconditioned rear pulley set, already built up. Once the belt is removed, you can check your rear pulley for wear by winding the sheaves in opposite directions, this takes spring pressure off and you can feel the play in the bushes."

Also, I finally had a Kawasaki Dealer contact me. The Dealer was at a Field Day several month's ago. He was aware of the problem. His reply was:-

"The problem sounds like the bushings on the driven pulley are worn, causing the moveable sheave to pull in under deceleration which then grabs the belt and will cause the drive system to lock up and seem like an engine break effect."

I probably won't be able to dismantle mine until after Xmas now.

I removed the drive convertor, belt and driven convertor from my 4010 Diesel Mule.

The drive covers had done their job and the convertors were clean, except for some belt dust.

The drive convertor is in excellent shape.

The belt deflection was perfect, as was the belt. When I wound off the movable sheave on the driven clutch to relieve the spring tension, the sideways movement on the movable sheave was quite excessive. You can do this quite easily and you’ll notice the excessive sideways movement.

I pulled down the driven clutch. The spring was over it’s service limit both by length and by tension (observing the two tangs that hold the spring in place). The two bushes in the movable sheave were over their service limit too.

The two bushes and spring were replaced only a few years ago and they should have survived much longer than that. I am convinced that the shaft in the stationary sheave (that the two bushes slide on) is the culprit. I installed two new bushes and the movement in the sheave is still extremely excessive. My opinion is that this shaft hasn’t been machined properly from the factory.

What has convinced to bin this driven clutch and purchase a new one is the fact that the OEM Part number for the complete assembly has been amended – twice.

To me that says something in relation to improving and developing the driven clutch assembly.

I am assuming that, when the drive clutch places the belt under tension, the belt pulls in on the driven clutch sheaves. The belt tension overcomes the spring tension and the driven clutch sheaves part, allow the belt to slip down in between the driven clutch sheaves, thus making the Mule go faster.

However, when you lift the throttle, the movable sheave gets cocked sideways and will not release, because the bushes are worn. The shaft that the bushes slide is imperfect and that will not help at all. The spring tension is not enough to make the sheave slide.

So the belt gets trapped lower in between the driven clutch sheaves. What happens then is that CVT starts working back to front. The driven clutch starts driving the drive clutch via the inertia of the vehicle. The drive clutch cannot release because the centrifugal force from the driven clutch now won’t allow those sheaves to release either.

This is what is causing the engine braking or rapid deceleration.

Building up this shaft and machining it back down is not difficult, except that:-

1. It’s partially contained in the sheave and difficult to get to.
2. Setting it up in a lathe would be very time consuming.
3. I don’t know what measurement the shaft should be machined back to anyway.

The shaft appears to be on a thread and locked in place by three grub screws. It’s not available as a separate part. I’ll try and remove it but that’s a job for another day.

I will update once I obtain a new driven clutch assembly and hopefully once it is installed it will solve this blasted problem I am having.

A further update:-

I am now more confused than ever with this driven clutch.

I have it in pieces and I have installed new bushes. I will be purchasing a new driven clutch and installing that, but I had the new bushes anyway so I thought I’d install them out of curiosity.

I managed to remove the shaft that the movable sheave slides on, so I am able to measure it properly. This shaft is worn, and the diameter varies along the length of it. I do not have a factory specification so I don’t know what the measurement is actually supposed to be.

But…….the wear doesn’t appear to be too severe.

I measured the two new bushes that I installed into the movable sheave. According to The Factory Workshop Manual, these bushes are already at their service limit! They haven’t done anything!

It may be that the machining on the movable sheave that the bushes are pressed into is not accurate, and that’s the way it came out of the factory.
I am sure that this business of the wear between the bushes and the shaft in the driven clutch is causing the problem, but for anybody rebuilding a 4010 Diesel Mule driven clutch with a view to using it again, then my advice is to be careful.

Measure everything and then measure again if you rebuild it because there’s something not right with the one that I removed from my Mule.

I’ll get a new one.