Ford 6640 sle 16x16 quad mod gearbox walkaround

Ford 6640 sle 16x16 quad mod gearbox lost drive and is undergoing a repair job.

[@bojanivanovic5498]

greetings, can you somehow show where the tractor speed sensor is located

[@kmann1430]

Im looking at a 1994 6640 that will not travel foreward or reverse in both 2wd and 4wd the pto does work and the clutch feels like its working,think its the same problem?

[@rcbatti500]

Does the gearbox oil pressure warning light glow (red) when you try to engage gear, but stop when you press the clutch?

[@kmann1430]

No,the gearbox pressure light is not illuminating at all

[@rcbatti500]

@@kmann1430 Probably not a hydraulic problem for you(assuming your warning light is in working order). You better look for electrical or mecanical issues.

[@michaelliviola5717]

@@rcbatti500 Mine did this but has stopped now. 96 Ford 8240 Mod Quad. All pressures are good until tractor is put in gear. We lose pressure on the low pressure circuit and the tractor will not move. We also lose the rear lift arms when the clutch is release and in gear. The clutches in gear read low but if we switch them to the other 2 clutches C2 and C4 they read exactly opposite but still low. If not in gear the arms work perfect. All solenoid valves seem to be in good working order. We are now suspecting the control valve. Any suggestions?

[@rcbatti500]

​@@michaelliviola5717 remove control valve! Mine had a broken snap ring (97608S), witch caused the Hydraulic spool(F0NN7R222AA) and plug (F0NN7N394AA) to fall out into the gearbox . allso gasket( 82012862) was broken Link to parts catalogue: www.mycnhistore.com/us/en/newhollandag/tractors/agricultural/naba01agr07740series/4-cyl-ag-tractor-40-series/transmission/transmission-top-shaft-rear-half-16-x-16/cn/71070EC9-B8BF-E111-9FCE-005056875BD6/13F9724F-E6BE-E111-9FCE-005056875BD6

[@blixtkrig]

Any common fault on these?im in to buying an -98 whit about 5000h on the clock.

[@rcbatti500]

Minor things like the gearbox cable connector , and degrading old rubber parts. Old tractors are old and needs maintaining. I wish you good luck with your tractor

[@blixtkrig]

Did not buy that one.but have found an 96 sle now whit 8000 on the clock.is it to mutch h.should i whait for an sl to come for sale.im a bit afraid of the clutchkit in the gearbox on the sle

[@antoniohermida6906]

What was the breakdown?

[@rcbatti500]

A snapring that kept the plug for c3/c4 lubrication selector spool in place. Easy to repair but reqired a lot of deassemble.

[@antoniohermida6906]

How much is the repair?

[@rcbatti500]

Changed parts worth of about 3000€ on the whole tractor, took the whole winter in the workshop. I did the labour myself.