question Zetor 4712 - can't select gears!

[Dennis]

Hi Renze, all,

I succeeded at last - on Saturday I bought an aged, rusty Zetor 4712 that has languished for 5-6 years in a roofless barn!

Got it started tonight (flushed the fuel system, unblocked the filters, fitted a new battery & filled the coolant system with hot water - fired up after 15-20 turns!)

The PTO works, the clutch feels 'normal' (although I never tried a Zetor clutch before) but the gear lever is very loose and no matter what, I cannot get it in gear. Tried high & low box (again, the selector feels fine) but nothing.

So, what have I missed? My guess would be a gearbox selector lever stuck, but I don't know this gearbox at all - any help out there?

 

[markku]

First, check the low/high lever! Specially the spin that lock the lever on its shaft. It can be broken and gearbox is in N position!

 

[Dennis]

Thanks Markku, I'll recheck that tonight - it fels like the hi-lo selector is moving, but I'll take the detent plug & spring out and see if the rod moves!
My problem might be lack of knowledge - I don't have an operators manual and the markings are all corroded off the labels. I assumed the gear lever just moves up & down in the slot, but do you have to twist it to locate gears? I have the repair manual and it looks like there are multiple selector levers, so just moving the lever up & down would not be enough!

 

[Renze]

It's a five speed with reverse.

Just try to push the knob on the lever forward and you will see that it twists into gear. knob will move about 2 to 4 cm, depending on gear. (4th and 5th gear have a smaller lever stroke because they are constant mesh, while the others are slifing mesh)

 

[Dennis]

Renze, that was what I needed! Started it up tonight and got it into all gears, but the left hand wheel is locked solid. Right hand moves fine; the handbrake 'collar' is loose so I guess the brake shoes are frozen onto the drum.

Tried rocking in forward & reverse, low box, for about 45 minutes but it still won't come free. I'll have to split the casing when I have time.

thanks again, I'll send some pic's when I have a chance.

 

[Renze]

Brakes stick within 2 months. Dont think you'll fix the brakes when you need them after two months, because they are stuck then. Our 5245 also has a sticking brake sometimes.

 

[basil]

Success at last! I loosened the bolts around the casing and rocked the beast forward and back for 10 minutes with no luck; my foot slipped off the clutch and BANG!, the wheel moved.

Moved the tractor back to the house (in the dark, lot's of nice sparks from the exhaust!) ready to start a rebuild. 1st job - free up all the controls, change the filters & fluids and see what does/does not work. 2nd job, renew the brake system.

 

[Renze]

If the brakes are frequently used, they will work good.
But these old drum brakes had a nasty tendency to stick if not used every month. Last winter i had two leaking master cylinders on our 5245, i didn't have time to replace them. After two month when i needed it for road transport (to do spring work on a piece of land 3 km from home) i replaced the brake cylinder but found the drum sticking....


If it has been standing still for 6 years, i can imagine the sparks... All coal and tar in the head is oxidised into white foggy lumps that burn (oxygen and Co) quite well.