Old Magnet D6-c Direct Drive Clutch Brake

Hey Old Magnet,

My 14-a needs to warm up 15-20 minutes before it shifts good, do you think it just needed to warm up?

Hi Glen,

The trans brake does have an adjustment (may be shot also). It's very much like the 9U brake on the oil clutch model.

As I understand it, there is no hydraulic control tank, just the diverter valve coming off the pump. As far as capacity there would be plenty if the setup was for hydraulic power controlled winch on a direct drive tractor and the hydraulic tilt feature. What's the issue with the winch?

15-20 minute warm-up seems reasonable. What are you running for lube oil?

Hey Old Magnet,

We only gave it about 8 minutes run time. Jess suggested draining the 30 weight and running ATF.

In the photo from link, it shows the cover broken where the hyd line hook up to the winch. They are capped off at the winch and capped off at the diverter valve. Jess spotted that some of the nuts holding the winch are fresh, it hasn't been on the Cat too long. The winch is a gamble, the rest of the Cat runs fair. That old cat will sure out last the job for the summer.-glen

Don't put ATF in the direct drive gearbox,fix the clutch brake, if it is not worn out, the most common cause of problems here is the brake being adjusted too tightly, so you can't get the clutch linkage to go forward far enough to release properly.

I should have said check the most obvious, is there any debris in the belly pan which prevents the linkage going down far enough to release properly?

Try this. Idle engine down as low as it will go and still run. Pump both steering clutches at the same time with left arm several times...have right hand on gear shift and when you pull them for the last time, attempt to put in gear.

Used to work on older D6's, D7's that had the long levers and no CCU on the back. It was easy to tell if it was working or not on the older machines. The steering booster ran off the top shaft of the transmission and when you couldn't pull the levers back easily...it was time to stick it in gear.

ETA: Once you get it in gear and you need to shift...hold foot brake and SHIFT!!! After a few minutes and the oil gets hot in clutch it shouldn't be much trouble for the rest of the day.

Speaking of oil clutches and the oil being cold, back when I was a young one (I am almost 70 now) and driving our two D7's (yes, one at a time), one of then had the oil clutch. In the winter here in Arizona (it never got really COLD like it does where you guys know is gets in the snow country - b-r-r-r-r) but anyway, the oil was so sluggish that in the morning I could not get the clutch to stop spinning in order to put the transmisson in gear.

I finally figured out the clutch brake would not work because the front seal on the transmissin or the rear seal on the clutch was slightly leaky.

Unfortunately my father was one of those the never really quite fixed most things. Anyway, the cluch brake was usless because it was covered with oil.

Being as young as I was (near 20 at the time) I had no say so about fixng anything.

It would take a good half hour of the engine running (in the morning) to get the clutch oil "thin" enough that you could put the transmissin in gear. That D7 had a Be-Ge hydraulic pump on the rear so I finally figured out that I could pull on it's lever and that effort of it trying to pump would cause the main oil clutch to slip so I could put the transmissinon in gear. Worked like a champ.

After a half hour of working, the clutch oil was OK and the rest of the day was good. Incidentally in the summer all was always OK.

Many years later, after I was NOT working on our ranch any longer, I learned that the employees that were driving that D7 finally ruined the transmission. It was probably that they were "grinding" the transmission into gear in the cold mornings.

It still makes me cringe to even think about it.


That D7, I was told by one of my cousins, had ended up in the scrap yard becasue his father (mine had already passed away) had disassembled the transmission and much of the gears and everything became lost. ANOTHER GREAT BIG CRINGE HERE!

Fortunately, the other D7 had the older mechanical clutch and it was still around when I was supposed to get it but I had no resources to move it to my house (this was about 10 - 15 years ago) and the land it was sitting on was sold by my last remaining Aunt and so that D7 went away.

It still upsets me to no end to this day.

The part that is not so good about having the winch plumbing disconnected is that the winch housing acts as the hydraulic sump with it's suction strainer. Just running the pump and hydraulic tilt cylinder makes for a pretty short circuit, limited heat transfer and no reserve oil capacity. I'd also want to check if the high pressure filter still services the circuit (if it has a filter)

All hyster 'D' series winchs have there own seperate hyd pump and run off there own circuit, ie winch case oil.
Do Not try to run it off the tractors hyds. Usual winch pump position on a D6 is off the back of the transmission pump.
You need a special drive adapter and pump and coupling from hyster. Although i have seen belt driven pumps fitted at the front of some D6s; this wasn,t standard.
Specs for a D6D pump are 11gpm. Runs at 230 psi. winch relief valve is in the winch control valve on LH side of case.
Series 3 30 was original winch oil spec; i just use 30 wgt TDT oil for mine. Some people run atf, but this was usually in the later 'W' series winchs with paper clutch plates.
Incidently most dd tractors had sliding gear winchs and ps always had ps winchs; but a ps winch was sometimes fitted to dd tractors.
Hope this helps Merv