Transmission Fluid Change Interval


New member
Good Morning,
I'm creating a service interval reminder/log for all our vehicles, tractor and RTV. I just completed the 200 hour maintenance on the X1100C and noticed that the change interval for the transmission fluid is at 400 hours but the hydraulic fluid that I changed is for 200 hours. Both use Super UDT2 so I'm curious as to why there is such a longer interval recommendation on the transmission in comparison to the hydraulic tank fluid. I've noted on past posts on this forum that some of you responsibly recommend to others to also pay attention to the length of time between changes and not just the hours. I put 200 hours on our RTV last year and will probably be in that same range for years to come. My question to you is would you recommend changing the transmission fluid tank sooner than the 400 hours which would be about every 2 years for me? Also, if someone could explain how the RTV uses the SUDT2 in the hydraulic tank vs. the transmission tank.

Thanks for any input.



Well-known member
Site Supporter
The manuals should be changed to read as follows
The oil should be changed at xxx hours or yearly,whichever occurs first.


Site Supporter
There are two hydraulic reservoirs in the RTV X series. The "hydraulic tank" holds the fluid used by the power steering, dump bed and VHT (transmission.) It is filtered both on the suction side and on the input to the charge pump. When you change the filters, make certain you drain the tank first. It holds several gallons of fluid. The "transmission case" provides lubrication for the rear diff, range gears and 4x4. It is not filtered. I think it holds just shy of 2 gallons. I am rolling up on 200 hours but will start doing this service each fall, regardless of hours. The cost of the maintenance parts is nothing compared with a new tranny or case.


Active member
I just did my 50 hour service. I didn't drain the fluid when I did the filters change, but I did top off the tank after I was done as it was a quart or two low after changing the filters. I didn't have the issue other people have had with one of the filters being installed by Lou Ferrigno at the factory. All 3 filter came off fairly easy with a set of filter wrenches.

One question, there is a breather tube installed at the top of the transmission case that seems to blow the fluid all over the transmission. Anyone else have this issue with fluid being blown out? I have kept a watch on the transmission fluid level on the yellow plastic dipstick. Level has always remained filled to the top fill mark. I took a can of brake cleaner and washed all the excess fluid off of the transmission, so I can keep an eye on it to see if it is still being blown out.


Gold Site Supporter
Gold Site Supporter
My RTV had a stainless wire mesh piece that came oem and fit into the neck of my rubber breather tube both pieces were removeable . I never had any transmission oil splash out.


Active member
Chances are that the gearcase is just a little over full. Mine will do the same if filled to the top of the hash marks.
Good to know. I was hoping the trans case didnt have a hairline fracture somewhere. When I bought it new in September, the dealer service dept wiped excess grease from their grease gun all on the hydraulic fittings and I couldnt figure out what was spitting that much grease out everywhere. Not a good way to start a business relationship with a new customer. Ya just can't find good help anymore.