2006 SLT1554 Transmission Issue
 

2006 Cub Cadet SLT1554, 2 cyl Kholer engine, Hydro-Gear transmission, 550+ hours

Last summer, during the hottest days of mowing, I noticed that once the transmission heats up, my tractor's trans seems to lose momentum and slip when I climb grades and it's slower even on level ground. With the age/hours on this tractor, I believe the transmission is wearing out. I contacted Cub Cadet to try to purchase a new Hydro-Gear transmission but was told they are no longer available. My Cub Cadet service center apparently doesn't rebuild them either. While I've tried to maintain my tractor well over the years, I've never serviced the transmission and my owner's manual doesn't list anything about how to change the fluid, the type/weight of fluid to use, or the quantity to refill.

I recently watched a YouTube video (Taryl Fixes All) which showed how to replace the fluid and filter on a late 90's Hydro-Gear transmission. He gave some tips on using a thicker oil (10w40 or 15w50 full syn engine oil) with up to 20% Lucas Hydraulic Oil Booster to prolong the life of worn hydraulic transmissions. Examining my trans, I've located the drain plug, but my transmission has no filter. It does appear to have a plastic fluid reservoir, but I can't determine the oil level or how to fill it (no signs of the trans leaking). I'm thinking I either have to drop the transmission or remove the seat, bodywork and fuel tank... either way that's going to be a fair amount of work for a "Hail Mary" attempt on fixing my issue.

Any advice or suggestions? I purchased a new 48" tractor last fall, but the old SLT1554 works so well, other than the transmission, I'd hate to scrap it. It's always nice to have a backup machine.

Thanks in advance.

It looks like it has an internal filter. It has drain and fill plugs and an expansion tank. I've never worked on one.

I have experience repairing these Hydro Gear's, so here's my 2.5 cents....

A. Changing the oil and filter will do you little to no improvement, and if any, it will be temporary.

B. Changing the filter will require complete removal and disassembly of the transmission.

C. If you are determined to go that far, the cause of your problem is worn parts,
specifically those named "center section" and "block assemblies", so those need to be replaced along with the filter.

D. Purchasing parts will take you north of 200 dollars.
(i.e. block assemblies, center section, filter, seal kit, oil)

Hope that helps.

2006 SLT1554 Transmission Issue
 

Thank you Ironman and Sam Mac. I found the drain plug. So that silver plastic reservoir looking thing is an expansion tank. Makes sense.

I just spent about 1.5 hours taking off the rear tires and looking at linkage and springs on the trans. I didn't see a fill plug, but I really wasn't looking for one today. As far as I can tell everything looks okay there. Then I tried to see what would be involved in removing the rear fenders/body and fuel tank. I learned you'd pretty much have to disassemble the entire tractor to go that route. Dropping the trans out the bottom would be easier (but not exactly easy). To try changing the fluid and adding the Lucas additive would be a fair amount of work with no guaranties and the cost of the synthetic oil and additive could run around $35-$40. probably not worth the time or money w/out rebuilding the trans. I just hate throwing a way a machine that could be fixed, but sometimes it's time to say goodbye.

A couple of years ago I pulled the engine and transmission out of my 2002/200,000 mile pickup truck and totally rebuilt them both at a cost of around $4,000 in parts and machining. At least with the prices on used trucks, thanks to inflation and lack of supply, that work turned out to be a good investment IMO. In the 7 years I've owned that truck I think I've fixed/replaced every mechanical part and system, but I bought it for almost nothing as a non-runner.

The full plug is on the top. Under the the edge of the fan.
Removing the trans is not very difficult. 4 bolts, direction rod, brake rod and reverse Switch wire harness. And the belt of coarse.

I replaced one in 2020 with a brand new trans from cub cadet. I can't imagine they don't still make them as they are a common trans used until pretty recently.

As for rebuilding it I've researched it to be about $300 in parts and fluid. If your not doing it yourself it runs about $600 with labor.
The new trans was just over $600 with shipping.

2006 SLT1554 Transmission issue
 

guyina4x4 -

I spend about a week last fall looking on-line for a new replacement trans for my 2006 SLT1554. Everyone I spoke to (including Cub Cadet) told me the same thing. Discontinued and no remaining stock. I even tried looking for a rebuild kit with no success. I couldn't even find a way to contact/speak to anyone at Hydro-Gear. Only transmissions I found were used on eBay (probably no better than my old trans). My authorized Cub Cadet service center told me they don't rebuild/repair Hydro-Gear transmissions. They just replace them. Anyway, as I already purchased a new tractor, I'm not willing to put $300, or more, into 16-year-old lawn tractor with over 550 hours on it. I'll just use the Cub Cadet on the rougher, flatter areas of my property, until it dies. Now that I know where drain and fill plugs are located, maybe I'll just try some thicker Walmart oil in the trans to see if that helps. When the outside temp is cool out (50's to low 60's) the tractor still works fine.

Yes, Cub Cadet has stated for years most of their hydros are not serviceable. Which isn't really true, they aren't worth paying somebody to service.

As for hydro gear https://www.hydro-gear.com/contact-us/

And yes I'd never spend the money either, i replaced one for a customer that loved his cub.

They used the same trans in most of the 1000 series LT, LTX, SLT, and SLTX series tractors for about 15 years.
I swap a lot of them used.
That trans was too weak for the 1500 series.