Deutz-Fahr Agrotron 135: a comfortable tractor whose repairs can be costly
A mechanic at the Polish workshop Agro-Mechanika described a used Deutz-Fahr Agrotron 135 tractor that turned out to have serious faults in its front axle suspension and ZF 7200 transmission. He rates its ergonomics and visibility highly but says technical condition should decide any purchase.
The Polish agricultural machinery site farmer.pl has published mechanic Mariusz Zdanowski's account of a used Deutz-Fahr Agrotron 135 tractor brought to the Agro-Mechanika workshop. The case is useful for anyone considering an older model like this, because some of the damage only emerged during the repair.
The owner had recently bought the tractor and its history was unknown. It was clear from the start that the gearbox needed work, but diagnostics revealed more problems, including with the hydraulics.
Front axle suspension
One of the biggest surprises was the front axle suspension. At first the hydraulic suspension control was faulty and the system could not build proper pressure. The mechanics restored the hydraulics, but then found the axle had serious play from worn mounting components, and the suspension pins were missing altogether. Zdanowski believes the mechanical part of the suspension needs full regeneration. In this design the whole rigid axle is suspended on a central pivot arm, and seized, corroded pins are extremely hard to remove. The fact that the hydraulics raise and lower the axle does not mean the suspension is mechanically sound.
ZF 7200 transmission
The second major problem was the transmission: two of the three double clutch packs were damaged. The gearbox had been repaired before, and the damage pointed to errors in the earlier assembly. A new double pack costs 8,000–10,000 zloty according to the mechanic, but this time used parts were found for about 4,500 zloty each. ZF 7200 series gearboxes came in many variants, so parts must be checked down to the tooth count of the gears.
The mechanical repair is finished, but the tractor is not ready: the Agrotron 135 MK3 has an older control system and needs calibration, so the workshop had to call in an external specialist.
Assessment
The mechanic rates the design highly: the sharply sloping bonnet gives good forward visibility, and the cab controls are laid out logically. When buying a used unit, buyers should check not only the hydraulics but also the pins, bushings and axle play, as well as the transmission and earlier repairs. The decision, he says, should rest on technical condition rather than looks or an attractive price.
