RTV 4wd issue

[ego260]

Hi guys, new to the forum and joined just recently due to issues with my RTV 900 4wd.

I bought the machine used back in November, 4wd worked great then and it handled steep hills in Buffalo County while my dad used it on his hunting property. However, I recently ran into issues with it a few weeks ago while cutting firewood.

It does not seem like the 4wd is fully engaging. I get the light on the dash indicating it is engaged, but when the front wheels come under load or there is any resistance I get a grinding noise that sounds like it is coming from up front and the wheels skip as if 4wd isn't actually fully engaged. If I let off the gas, then ease back on the gas the grinding stops and the machine continues forward.

Later, I ended up getting the back wheels hung up on a log and the front wheels would not engage at all. After about ten minutes of engaging and disengaging 4wd, I disengaged the rear lock differential and then 4wd finally engaged and pulled me of the log with no problems.

It is also stored covered outside, and the temperatures were below zero and never above freezing during the days that I was using it, and extremely cold during the weeks leading up to it being used, so I am wondering if its possible something had gotten frozen up.

I am not super mechanically knowledgeable, but I live in Wisconsin and work in Louisiana, so when I am home I need the machine to work flawlessly. I get home in a week and would like some pointers on to begin looking where to trouble shoot before I take it in to the dealership, any help would be greatly appreciated.

I have looked at the CV boots and there are no rips or tears, but other than that I have not done anything or looked at anything yet.

 

[ego260]

Hopefully someone has some suggestions

 

[WoodDuck]

Well, there's a few possibilities here I'd say. While I'm not familiar with Kubota RTVs specifically, I've spent a fair amount of time working on other brands of UTVs and SxSs. You've either got an electrical issue with the electric solenoid not fully engaging the 4wd in the transfer case, or a mechanical issue in the drivetrain between the transmission and the front wheels. Can you tell where the noise is coming from for sure? If not, you may put the whole machine up on a lift or jack stands, and see if it will make the same racket with the 4wd engaged and the tires turning in the air. If it does, have someone run the machine for you and lay down beside it to determine the location of the noise. When located, pull it apart and see what's up. Could be damaged gears, defective solenoid, something bent, binding, etc. The source of the noise you're hearing is where I would investigate first anyway. Good luck!

 

[ruffdog]

I believe 4x4 is lever operated through a cable to the trans-axle. If it is not fully going into 4x4, it could be a froze up cable, not adjusted correctly, rusty linkage, worn gear dogs. If the trans-axle is successfully being shifted into 4x4, look for a damaged spline on either end of the front driveshaft, damaged front diff, stripped splines at a front axle/wheel hub.

 

[ego260]

Thanks for the info, I did order a couple of CV axles today in case this is the issue. I'm really hoping its not the front differential. I'll be changing the oil in it when I get home to look for any metal shaving in the oil.

 

[ovrszd]

I'm with ruffdog.

First place to start is the cable and it's adjustment.

After you are sure the lever at the trans is engaged all the way and it still doesn't work, then look for deeper mechanical issues. To check the cable adjustment, engage the lever, then go to the trans and unhook the cable, then see if the lever can be moved farther. If so the cable is out of adjustment.

Start simple. Don't start by spending money. Maintenance first.

Rare for the front axles to fail. Also rare for the front differential to fail.

All of this is said assuming your Dad didn't get stuck and thrash the pants off it.....

 

[WoodDuck]

I believe 4x4 is lever operated through a cable to the trans-axle. If it is not fully going into 4x4, it could be a froze up cable, not adjusted correctly, rusty linkage, worn gear dogs. If the trans-axle is successfully being shifted into 4x4, look for a damaged spline on either end of the front driveshaft, damaged front diff, stripped splines at a front axle/wheel hub.

Thanks for the correction Ruffdog!, as I'm not familiar with the Kubotas, I didn't realize they had a mechanical 4wd mechanism. Most everything I've worked on in recent years has had electronic push button 4wd. You're right though, I'd pull it apart systematically to find the root cause of the issue before I started spending any money on parts. Cheers!

 

[Industrial Toys]

The first thing I would do is jack up the whole machine and see how things feel, look, work and sound.

 

[JOHNTHOMAS]

Actually the transmission and operation is hydraulic and manually manipulated into gear selections. Had a RTV1140 for 8 years and now have a RTV500 and RTVXT1140. Mashing brake releases pressure for changing/selecting drive and in and out of 4wd. They can't be changed or shouldn't be changed while moving, suppose to stop, push brake and then select. Usually doesn't go in smooth and easy but with experience it becomes easier. Stop, mash brake, try selecting, sort of blip throttle is change isn't made and firm pressure on selector and mash brake and blip throttle and it will usually slide in. Some times driving while holding firm pressure of 4wd selector will cause the proper engagement or drive, stop and brake and try again and some times a bit or reverse can help. Asdk your Dad how he manipulated it or if he ever did or just put it in 2wd all the time and drove straight driving. Give it more time before going radical and always let the engine and hydro fluid warm up 3 to 5 minutes before moving after starting the machine, ALWAYS!!!

 

[ovrszd]

My RTV900 is an 07 model. Your cable system may vary. Don't remember you saying what year yours is?

John's advice above is very good in regards to gear selection. The applied brake relieves hydraulic pressure within the HVT.

The 4wd system is not hydraulic. It's completely mechanical. Selection is made using a lever/cable system. The cable length is adjustable on both ends.



This first pic is taken standing in front of the machine, hood open. I'm pointing at the 4wd cable. You can clearly see the cable adjuster. Adjustment is made by the two nuts clamping the cable housing to the frame mount. Moving the cable housing toward or away from the cable end changes the effect.

This pic is taken with the bed raised, left side of machine, just in front of rear tire, looking inward. My finger is pointing at the 4wd lever/cable assembly on the side of the transaxle. Again you can clearly see the adjustable cable housing nuts.

 

[ego260]

My RTV900 is an 07 model. Your cable system may vary. Don't remember you saying what year yours is?

John's advice above is very good in regards to gear selection. The applied brake relieves hydraulic pressure within the HVT.

The 4wd system is not hydraulic. It's completely mechanical. Selection is made using a lever/cable system. The cable length is adjustable on both ends.



This first pic is taken standing in front of the machine, hood open. I'm pointing at the 4wd cable. You can clearly see the cable adjuster. Adjustment is made by the two nuts clamping the cable housing to the frame mount. Moving the cable housing toward or away from the cable end changes the effect.

View attachment 640234



This pic is taken with the bed raised, left side of machine, just in front of rear tire, looking inward. My finger is pointing at the 4wd lever/cable assembly on the side of the transaxle. Again you can clearly see the adjustable cable housing nuts.

View attachment 640235

Actually the transmission and operation is hydraulic and manually manipulated into gear selections. Had a RTV1140 for 8 years and now have a RTV500 and RTVXT1140. Mashing brake releases pressure for changing/selecting drive and in and out of 4wd. They can't be changed or shouldn't be changed while moving, suppose to stop, push brake and then select. Usually doesn't go in smooth and easy but with experience it becomes easier. Stop, mash brake, try selecting, sort of blip throttle is change isn't made and firm pressure on selector and mash brake and blip throttle and it will usually slide in. Some times driving while holding firm pressure of 4wd selector will cause the proper engagement or drive, stop and brake and try again and some times a bit or reverse can help. Asdk your Dad how he manipulated it or if he ever did or just put it in 2wd all the time and drove straight driving. Give it more time before going radical and always let the engine and hydro fluid warm up 3 to 5 minutes before moving after starting the machine, ALWAYS!!!

Come to think of it, I vaguely remember hoping on the machine after I'd thought I already had 4wd engaged, to find that it had disengaged. I am not home right now, but will be on the 12th, the cables are the first thing I will check. Thanks for the pictures, I doubt I would have looked for a second actuator after I found the first one had you not pointed them out.

Also, my machine is a 2015. How pronounced should the "clunk" be when the machine engages into 4wd? Mine is hardly noticeable and there seems to be very little, if any resistance when engaging the 4wd lever on machine.

 

[ovrszd]

I know the HVT case has changed since mine was built. My pics may not apply. The theory will though.

I often feel resistance engaging/disengaging. That's caused by load on the gear system. Something so simple as cramping the fronts left and right will often relieve that pressure.

Avoid forcing the lever. That can stretch the cable and require adjustment.

I'm thinking yours was on the edge of needing adjustment when you got it.

 

[s219]

Actually the transmission and operation is hydraulic and manually manipulated into gear selections. Had a RTV1140 for 8 years and now have a RTV500 and RTVXT1140. Mashing brake releases pressure for changing/selecting drive and in and out of 4wd. They can't be changed or shouldn't be changed while moving, suppose to stop, push brake and then select. Usually doesn't go in smooth and easy but with experience it becomes easier. Stop, mash brake, try selecting, sort of blip throttle is change isn't made and firm pressure on selector and mash brake and blip throttle and it will usually slide in. Some times driving while holding firm pressure of 4wd selector will cause the proper engagement or drive, stop and brake and try again and some times a bit or reverse can help. Asdk your Dad how he manipulated it or if he ever did or just put it in 2wd all the time and drove straight driving. Give it more time before going radical and always let the engine and hydro fluid warm up 3 to 5 minutes before moving after starting the machine, ALWAYS!!!

That's only for the gears -- 4WD is a separate mechanical system and unaffected by pressure in the HST or the brake's pressure release function.

 

[ruffdog]

That's only for the gears -- 4WD is a separate mechanical system and unaffected by pressure in the HST or the brake's pressure release function.

^^^agree.

 

[JOHNTHOMAS]

That's only for the gears -- 4WD is a separate mechanical system and unaffected by pressure in the HST or the brake's pressure release function.

^^^agree.

Never to old or to experienced to learn or at least think about the machine, systems and situation. Now thinking and believing you guys are right comcerning the 4wd system. Some times mine slides in slick and some times displays resistance and I just do it all, twist steering wheel, press brake, blip throttle and some times drive while applying pressure on lever and usually or always slides in with no grinding or noises.

 

[ovrszd]

I've got a WSM for my machine. If needed I can illustrate the adjustment procedure.

 

[ego260]

I've got a WSM for my machine. If needed I can illustrate the adjustment procedure.

Hey Richard, sorry I've been really busy the last few days. An illustration would be great, and very appreciated! I plan on tearing into the machine wednesday night when my plane lands back home in Wisconsin.

 

[ovrszd]

See if I'm smart enough to attach the pic from my WSM that talks about adjusting the 4wd shifter......


Well that didn't work..... Let's try a pic taken of the WSM page with my phone.

Basically, it says to loosen the two cable housing nuts at the trans releasing the cable housing from the adjuster plate. Then, allowing the cable housing to move, make sure the trans lever is in the 2wd position and that the lever is in the 2wd position, then retighten the cable housing nuts.

The trans lever is rearward when in 2wd, forward when in 4wd. So, I'd loosen the adjuster nuts so the cable housing can move. Then push the lever rearward as far as it will go. Check to make sure the cab lever is still in 2wd. Retighten the housing nuts.

 

[ego260]

See if I'm smart enough to attach the pic from my WSM that talks about adjusting the 4wd shifter......


Well that didn't work..... Let's try a pic taken of the WSM page with my phone.

Basically, it says to loosen the two cable housing nuts at the trans releasing the cable housing from the adjuster plate. Then, allowing the cable housing to move, make sure the trans lever is in the 2wd position and that the lever is in the 2wd position, then retighten the cable housing nuts.

The trans lever is rearward when in 2wd, forward when in 4wd. So, I'd loosen the adjuster nuts so the cable housing can move. Then push the lever rearward as far as it will go. Check to make sure the cab lever is still in 2wd. Retighten the housing nuts.



View attachment 641155

Hey Richard, thanks for the help. Unfortunately, when I started looking around the machine I found the front right cv axle was loose. There are no rips or tears in the boot, but after pulling it, I noticed the splines were stripped. Grease is leaking from the end of the boot, but otherwise I am not sure what would cause the splines to strip on the axle itself.

I ordered two axles from sixity, and although the box says Kubota, they are not the correct axle. I called sixity this morning, they said they had a shipment of axles come in that were kawasaki axles in Kubota boxes. They shipped out new axles today, and they will be here Saturday.

 

[ovrszd]

Can you post a pic of your stripped axle?? I've never saw that before. Worries me. Especially if you are talking about the end that goes into the front diff....