Cub Cadet RZT50 - Hydrogear

[kasedian]

Ive got a good one for you guys. I have a RZT50. Had it for about 5 years now, with 250 hours. After the first year I had it, the left side transmission went out. Had it replaced under warranty. Well, anyways, I got to looking at it a year later, and the hydrostat that they put in was a little different than the other one. The only thing I noticed, was that the replaced one had a vent tube coming out of the top, down the side oabout 6 inches. The original side hydro has a hose going up under the seat to a fluid resevoir. Well, I retrofitted the fitting, got rid of the vent tube, and ran it up to the resevoir.
I dont know about your machines, but do most of them have these fluid resevoirs? I see warnings not to power wash them, and was wondering if that only pertained to the ones with vents. Thanks

 

[JTKub]

I believe some of the Hydro-Gear EZT drive equipped machines have a common bottle, with both drives plumbed to it. Others are just vented like your 'new' drive. The main thing is the drive is vented properly so condensation can't build-up in it. If you bump-up a model to the ZT-2800 drives or above, they all share a common bottle. I know on mine, it looks empty when the machine is cold and fills up about a 1/4 of the way when hot.

Joel

 

[LeftTurn]

I had to replace both transmissions last year on a 3 year-old RZT50.

The dealer disconnected the oil reservoir (under the seat), telling me that the new transmissions "are sealed". I sure hope that he's right!

 

[kasedian]

Hmmmm. I took the breather tube fitting out of the top of the transmission, and replaced it with a fitting that attached to the hose that went to the resevoir. I dont know what it will hurt doing that, but so far it seems to be running fine. Ill take pictures later this week when it stops raining and post.
Anyone else see a problem with retro-fitting a "sealed" transmission with a breather, to one that connects to a resevoir?

 

[JTKub]

It will still "breathe". That's the main thing. I'm thinking they might have left it segregated so there could be no cross-contamination with the other drive. Just a guess.

I like the idea of having the breathers run to a bottle. That way you could atleast get sort of a visual idea if you've got moisture in the oil or whatnot. They say not to add oil to the bottle because it's only meant as an expansion tank, but a little 15w40 in there won't hurt. Like I say, it stays empty on my ZT-2800 equipped Z-Force, but fills up 1/4way when hot.

Joel

 

[LeftTurn]

My only concern is how long the things will last. I got just over 200 hours on the first set of transmissions. At a $1500 to replace both, I feel like I "rented" them for about $7 per hour!

 

[JTKub]

My only concern is how long the things will last. I got just over 200 hours on the first set of transmissions. At a $1500 to replace both, I feel like I "rented" them for about $7 per hour!

I feel for you. I don't know that we've ever come to a conclusion as to why the failures occur other than;

1) Some had severe condensation contamination of the oil. Suspected cause was water wicking it's way down the input shaft and into the case, in conjunction w/ poor case venting. Supposedly a better shaft seal was designed, but I'd do all I could to keep the mechanicals dry on these machines. Any sign of weakness from a drive and immediately pull it and do an oil change.

2) Something along the lines of internal thrust washer failure, or something rubbing/wearing into the case causing excessive heat and failure. I have read of 1-2x where owners tore into it and fixed this themselves.

Why it's the left drive that primarily fails is a mystery to me. Their both identical aside from layout.

Joel

 

[LeftTurn]

I've wondered about that deck wash system, where you are supposed to hook up a garden hose to the port on the deck. It seems like spraying that much water on the underside could cause some to get into the transmissions. I don't use that anymore, but I did a few times prior to the transmission failures.

 

[wdchyd]

I've seen these hydrogear hydrostats fail at the main bearing/swash plate assy on the rotating group internally.......IMHO these units are being pushed to their max limit as far as durability.......the oil reservoirs are way undersized and they run way too hot for my comfort......if you have a failure on one side then take off corresponding wheel motor, open up, clean, reseal to remove contaminates internally......if you don't rinse out the wheel motor you risk the likely chance of repeated failures on the same side....

The only thing I can suggest is double up on your oil/filter changes and if the oil looks dark, do double flushes and be proactive with oil cleanliness BEFORE they get damaged from heat and wear.....

 

[JTKub]

The only thing I can suggest is double up on your oil/filter changes and if the oil looks dark, do double flushes and be proactive with oil cleanliness BEFORE they get damaged from heat and wear.....

Problem is, on the Hydro-Gear EZT series, the only way to drain the units or even look at the oil is to remove them from the machine and invert them, plus there's no replaceable filter.

 

[wdchyd]

Ahhhh, Sorry....I've seen these on Dixiechoppers and Exmarks with filters and reservoirs.....that just adds to my observations of these pumps being pushed to their limits......they should have some kind of fresh oil replenishment of sorts.....:confused2:

 

[JTKub]

Ahhhh, Sorry....I've seen these on Dixiechoppers and Exmarks with filters and reservoirs.....

They do, but you have to bump up to the 2800's at a minimum to get filters and a reservoir. Check the "single axle transaxles" on the Hydro-Gear's website. For 2011, they list the 2100 as the lowest-end model, then the 2200 as the EZT, then the 2800's: Hydro-Gear - Products

Joel

 

[LeftTurn]

They do, but you have to bump up to the 2800's at a minimum to get filters and a reservoir. Check the "single axle transaxles" on the Hydro-Gear's website. For 2011, they list the 2100 as the lowest-end model, then the 2200 as the EZT, then the 2800's: Hydro-Gear - Products

Joel

I have to laugh at the FAQ answers in the learning center section of Hydro's web site. Talk about non-answers! Why have a FAQ section at all?

 

[JTKub]

I have to laugh at the FAQ answers in the learning center section of Hydro's web site. Talk about non-answers! Why have a FAQ section at all?

Yep, even though H-G did some nice updating to their website, that FAQ section is pretty weak!

My only direct dealings with HG was back in 2005 when I was researching what exactly "Cub Cadet Drive System Fluid Plus" oil was at the time. That was a positive experience for me.

I emailed back/forth with an Engineering, Tech Support fella who was a great help. He gave me direct contact info, faxed me product data sheets, etc.

Hydro-Gear has got to making money hand over fist. I still can't figure out why they're the ONLY ONES in the market with integrated ZTR drives. I can't figure out why Tufftorq/Kanzaki or some Chinese company doesn't jump on the bandwagon? They ALL want this type of drive now.

Joel

 

[LeftTurn]

I sure hope that the new transmissions last longer than the old one.

It seems odd to me that the "breather tube" is open to the air, while the old transmissions were connected to an oil reservoir. The open tube would seem to invite moisture and dust.

The new ones have a fan, which I don't remember seeing on the old ones. Maybe more cooling will help.

I got only 2 seasons out of the originals. Anything over that is a win, I guess. It's a shame, given how well the engine runs and other parts are holding up.

 

[OldMachinist]

JTKub I recently got a hold of the MSDS for the Cub Cadet drive system plus fluid and its Shell TTF-SB.
I uploaded the msds here drivesystemfluidplus.pdf

On the Hydrogear transmission stuff I've got 518 hours on my Z-Force 50 transmissions. I've had them both off and opened up once to clean the internal filter and replaced original vents with ones for a hydraulic tank. I put Castrol 20w50 in them and have had no problems.

 

[JTKub]

JTKub I recently got a hold of the MSDS for the Cub Cadet drive system plus fluid and its Shell TTF-SB.

Yes, that's exactly the info I got 6yrs ago. I can't find my original posts on it assuming it's been too long. Here's the data sheets HG gave me from back then: http://www.tractorbynet.com/forums/cub-cadet-l-g/116864-2166-alternative-drive-fluid.html

Joel