RTV 4wd issue

   / RTV 4wd issue #1  

ego260

Member
Joined
Jan 30, 2020
Messages
33
Tractor
Kubota
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.
 
   / RTV 4wd issue
  • Thread Starter
#2  
Hopefully someone has some suggestions
 
   / RTV 4wd issue #3  
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!
 
   / RTV 4wd issue #4  
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.
 
   / RTV 4wd issue
  • Thread Starter
#5  
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.
 
   / RTV 4wd issue #6  
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.....
 
   / RTV 4wd issue #7  
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!
 
   / RTV 4wd issue #8  
The first thing I would do is jack up the whole machine and see how things feel, look, work and sound.
 
   / RTV 4wd issue #9  
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!!!
 
   / RTV 4wd issue #10  
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.

20200205_083436.jpg




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.

20200205_083458.jpg
 

Tractor & Equipment Auctions

2016 Ford Explorer AWD SUV (A50324)
2016 Ford Explorer...
12in Backhoe Bucket (A52128)
12in Backhoe...
UNUSED SWICT 66" QUICK ATTACH BUCKET (A51244)
UNUSED SWICT 66"...
2013 Ford F350 Service Truck (A50515)
2013 Ford F350...
Backhoe Bucket (A50515)
Backhoe Bucket...
Tandem Axle Silage Cart (A50774)
Tandem Axle Silage...
 
Top