Tipps & Tricks  Claas

Claas front axle drive shafts

Warning, danger to life!!!

In the first cut of the 2022 season, a steep slope had to be harvested. The machine was chopping downhill when, for no apparent reason, it suddenly picked up ground speed rapidly. The reflexive stepping on the brake pedal only caused the machine to yaw to the left, but there was no noticeable braking deceleration despite the all-wheel drive being switched on. As a last resort, the driver quickly turned the steering wheel to the left in order to bring the machine, which fortunately stopped despite the relatively high speed, to a halt across the slope. At the time in question, the tractor with trailer was to the right of the chopper, otherwise a collision would have happened here as well. The reason for this behavior: A broken right drive shaft on the front axle!

Therefore, the urgent advice to all owners of such a Claas axle is to check the drive shafts in your own interest with a "crack detection spray"!

All Mengele SF 6 and SF 7, Claas 690 to Jaguar 800 (Type 490), all Claas Dominator/ Mega and the Case "CF" machines are affected!

This list does not claim to be complete!


Loss of power due to intercooler

At some point in a Jaguar 850 it became apparent that the engine was no longer producing as much power as it had previously done. Especially when driving into the corn crop or the grass swath, the machine was always pretty powerless at first.

After driving about 50 meters, the engine power suddenly increased noticeably again, but without reaching its original level.

This effect was more pronounced the higher the outside temperature was.

The cause: After 6,000 hours of operation, the intercooler was so clogged and sludged internally that, on the one hand, it could only supply the required air at a reduced rate and, above all, it could no longer cool this reduced amount of air sufficiently.

After replacing the intercooler, the machine ran like new again!

Chute rotation Typ 498

Apparently it has often happened that the bracket for the worm of the turret rotation has broken off on the Type 498. It is therefore recommended to reinforce the weld seams for the bearing tube of the auger bracket or, if possible, to weld in reinforcement plates. Alternatively, in the event of damage, it is also possible to convert the tower to rotate using a type 502 spur gear, which, however, entails considerable costs.

Drive upper intake rollers 600 series

At Claas, the upper feed rollers are traditionally driven by means of a PTO shaft coming from the left, which is attached to a stub shaft of the right-hand gearbox of the upper feed rollers.

This stub is provided with external teeth, which transmits the torque to the gear wheel in the gearbox, which is provided with corresponding internal teeth.

Since the sealing against moisture is quite poor, especially with the 600 series, a lot of rust forms on this toothing over the years. This rusting increases the wear of this toothing quite dramatically, so that both the stub and the gear wheel in the gearbox have to be replaced at some point.

These spare parts are no longer available for the 600 series.

Although the sealing on the 800 and 900 machines is improved from the outside of the transmission, moisture can still penetrate here from the PTO shaft side.

The occasional regreasing of this toothing could possibly represent a permanent remedy for this problem.

General engine problems

Since the Mercedes engines of the Claas machines up to and including the first 800s are largely identical in construction to the units installed in the Mengele, the known problems are not listed again here.

In this regard, please refer to the “Mengele” section.

Venting fuel tank

With a Jaguar 970, built in 2018, it was noticeable that after a short while after the supposedly full refueling, there was suddenly another 20 to 30 liters of diesel to fill in the tank.

This phenomenon was even more evident in the case of particularly powerful refuel systems.

The reason for this phenomenon turned out to be the tank ventilation, which slowly clogs over the course of the season and the air cannot escape from the tank quickly enough.

The problem can be avoided by cleaning this vent socket with compressed air or a cloth once or twice a season.

Bracket exhaust silencer Jaguar 970

On a Jaguar 970, built in 2018, both retaining straps for the exhaust silencer have already torn off: the front at approx. 1,600 operating hours, the rear at approx. 2,400 operating hours.

Above all, the fact that the main drive runs below these straps is dangerous. If the main drive catches one of these retaining straps while working, expensive consequential damage cannot be ruled out.

It is therefore advisable to reinforce these straps as a precaution!

Steering cylinder Jaguar type 489 deformed

A 1994 Jaguar 860 got so deep in the mud while chopping corn that the rear axle almost touched the ground. In this driving condition, the steering wheel was then moved, whether accidentally or intentionally.

The consequence of these steering movements can be seen in the photo below.

Steering movements with wheels that cannot move freely must be avoided!

A different piston rod was used in the steering cylinder purchased as a replacement for the above-mentioned machine in order to reliably prevent such damage in the future: The original piston rod had a diameter of 24mm, the reinforced one now has 30mm. Furthermore, the drivers of the machine were explicitly instructed to only carry out steering movements when the wheels were turning freely.

Bearing upper intake rollers Jaguar 690

On the older Jaguar 690, the upper intake rollers are not supported by roller bearings, but only by cheap brass bushings (see red arrow in the picture on the left).

Even if these brass bushings are reasonably generous in length and can also be relubricated, this type of bearing is completely unsuitable for the forces that occur at this point.

The result: Both the bushings and the shaft are subject to a certain amount of wear, which increases rapidly due to the inevitable ingress of dust!

In order to permanently solve this latent problem, an affected machine was converted from rolling bearings.

For this purpose, the rollers were opened on both sides and a carrier disk with a bearing seat were welded in.

A disc with eight threads was then welded flush with the roller, onto which a cover disc was screwed, with which the bearing was fixed.

This bearing is still lubricated via the grease nipple that is already present for the brass bushing.