Yuchai steering clutch brake bands

Bob Rooks · Jan 17, 2012

Steering clutch brake bands, and my postulation for modifying the existing lining (including replacing the aluminum rivets with brass), or completely relining with segments from new friction material instead of the "fire hose" type OEM lining.

The light colored band has the worst rivet job I've ever seen some rivets are not even countersunk. The dark colored band is the second worse job some rivets have separated and bulged the lining. Even the end clip is randomly riveted (which is not really a concern).

MRTOES · Sep 3, 2023

Bob
I contacted you some time ago about Farm Pro Yuchai steering clutches being stuck regarding your expertise. As I discussed, I filled my chamber with Marvel oil and it took no time to free up the steering clutch by driving the dozer. I will have to tear it back down, however to replace the brake band. After seeing this post I was wondering if you had any suggestions as to possibly using a material that would allow running the clutch and brake in a wet solution of say transmission fluid or some other light oil? Not sure there would be enough friction on the drum but just throwing this out. Your advice would be appreciated. Thanks BobC

Bob Rooks · Sep 3, 2023

MRTOES said:
Bob
I contacted you some time ago about Farm Pro Yuchai steering clutches being stuck regarding your expertise. As I discussed, I filled my chamber with Marvel oil and it took no time to free up the steering clutch by driving the dozer. I will have to tear it back down, however to replace the brake band. After seeing this post I was wondering if you had any suggestions as to possibly using a material that would allow running the clutch and brake in a wet solution of say transmission fluid or some other light oil? Not sure there would be enough friction on the drum but just throwing this out. Your advice would be appreciated. Thanks BobC

Hi Bob,
Good suggestion, and not a bad idea. There are obvious benefits to running wet steering clutches, but in this case there are a few issues that need to be addressed. Here's my take on it.
Sealing the compartment to prevent cross contamination of oils in the transmission and final drive compartments.
1) The lip seals as installed are to keep oils IN their respective compartments, not to keep other oils out. You would have to devise a double-opposing lip seal to prevent cross contamination and dilution of the other oils. Such a seal may already be available but size may be a hurdle.

2) The clutch discs are sintered bronze, and would have no problem running wet. They are virtually the same as found in Paragon and Borg Warner marine and fork lift transmissions.

3) Brake bands. Here lies a real challenge, but doable in my opinion. The bands would need a segmented sintered bronze arced lining equivalent in thickness to the friction material, and about one-and-a-half to two inches long. They cannot be riveted - must be bonded, so I don't see this as a DYI process (at least not for me). Back in the day Cat and others used wet clutches quite well for a long time.

ultrarunner · Sep 3, 2023

I switched from riveted to bonded in the antique cars.

The woven lining is called Scandinavian...at least with the old cars...

When the D3 needed bands I found Peterson Tractor a CAT dealer was faster and NOT more expensive...

Bob Rooks · Sep 3, 2023

ultrarunner said:
I switched from riveted to bonded in the antique cars.

Yep, did that myself.

ultrarunner said:
The woven lining is called Scandinavian...at least with the old cars...

When the D3 needed bands I found Peterson Tractor a CAT dealer was faster and NOT more expensive...

That was with much heavier viscosity oil. The sintered bronze steering clutch pack here won't like that.

MRTOES · Sep 11, 2023

Bob Rooks said:
Hi Bob,
Good suggestion, and not a bad idea. There are obvious benefits to running wet steering clutches, but in this case there are a few issues that need to be addressed. Here's my take on it.
Sealing the compartment to prevent cross contamination of oils in the transmission and final drive compartments.
1) The lip seals as installed are to keep oils IN their respective compartments, not to keep other oils out. You would have to devise a double-opposing lip seal to prevent cross contamination and dilution of the other oils. Such a seal may already be available but size may be a hurdle.

2) The clutch discs are sintered bronze, and would have no problem running wet. They are virtually the same as found in Paragon and Borg Warner marine and fork lift transmissions.

3) Brake bands. Here lies a real challenge, but doable in my opinion. The bands would need a segmented sintered bronze arced lining equivalent in thickness to the friction material, and about one-and-a-half to two inches long. They cannot be riveted - must be bonded, so I don't see this as a DYI process (at least not for me). Back in the day Cat and others used wet clutches quite well for a long time.

Thanks Bob for your reply. I have been looking around for bonding prices. They are quite expensive but doable. I won't be tearing down again until this winter. I considered doing "same fluid" on both sides but haven't ran that thought all the way through yet.
Will see how it goes.

Bob Rooks · Sep 11, 2023

MRTOES said:
Thanks Bob for your reply. I have been looking around for bonding prices. They are quite expensive but doable. I won't be tearing down again until this winter. I considered doing "same fluid" on both sides but haven't ran that thought all the way through yet.
Will see how it goes.

Same oils will not work. The transmission/bevel gear case uses SAE 80W-90 gear oil (anything heavier will be difficult shifting). The final drives use SAE 140 or SAE 240 gear oil. The sintered bronze components will not work satisfactory, if at all, with those lubricants. Too viscous.

Bob Rooks · Sep 15, 2023

Here's one for ya. Years ago I thought about making the dozer full hydraulic by gutting the clutch, transmission, bevel gear, and steering clutch/brakes. and installing skid steer pumps, valves, and drive motors.

MRTOES · Sep 15, 2023

Bob Rooks said:
Same oils will not work. The transmission/bevel gear case uses SAE 80W-90 gear oil (anything heavier will be difficult shifting). The final drives use SAE 140 or SAE 240 gear oil. The sintered bronze components will not work satisfactory, if at all, with those lubricants. Too viscous.

Thanks Bob. Speaking of shifting I am going to say this about the regular transmissions in the dozers. I assume they are the same ones as in the 30 hp Jinma tractor. I like those tractors and have one, sold a few. One nightmare problem I have seen twice. Shifter fork breaks. Falls into gears. If you do not stop IMMEDIATELY gear teeth break off. This requires a break down of complete transmission AND rear end. On a dozer this will be a night mare. So if you ever feel this happen STOP IMMEDIATELY AND TAKE TOP PLATE OFF.