Springs are made of strip spring steel (T-profile) grade 60C2
Spring sheets are subjected to heat treatment (hardening, tempering) to the hardness NVZ6Z-444
For all springs, the sheets in the center are tightened with a center bolt.
So that the sheets of springs do not diverge to the sides, they are pulled together with clamps.
The ears of the clamps are tightened with bolts.
The front suspension arrangement is shown in fig. 1.
The front springs are installed on special platforms of the front axle beam and attached to it with stepladders made of 40X steel
The front spring is attached to the frame by means of a removable patch lug 3, which is connected to the main sheet with a special stepped pin 17, and with the spring bracket with a spring pin.
To prevent turning and longitudinal movement of the finger, flats are made in the bracket at its ends, one of which includes a bolt that tightens the split part of the bracket.
There is a gap of 0.3 - 1.25 mm between the head of the stepped pin for fastening the false eyelet and the root leaf, which is necessary for moving the root leaf in the longitudinal direction when the spring is operating.
The rear end of the patch eyelet is attached with a stepladder 16 and an overlay 14 attached to the end of the fourth sheet.
In order to protect the rear spring bracket from intense wear due to the sliding of the spring ends along the supporting surface and side walls, replaceable protective liners are attached to its inner surface.
The main rear spring 1 and additional 2 of the MAZ-54322 car (Fig. 2) are attached with stepladders 4 to the rear axle beam.
An additional spring is placed on top of the main one, and spacers are installed between them.
The front and rear ends of the main rear spring are attached to the frame in the same way as the front spring.
Auxiliary rear spring has straight ends and is supported by sliding supports of the frame brackets. Pushing forces from the rear axle to the frame are transmitted by the front end of the main spring.
During manufacture, the springs are divided into two groups depending on the sag and, when installed on a car, they are selected so that the difference in the sag for the left and right springs does not exceed 8 mm.
The rear suspension of the MAZ-54322 is equipped with an anti-roll bar, which increases the vehicle's stability when driving on roads with a side slope and when cornering.
A torsion shaft 10 serves as an elastic element of the stabilizer.
The rear suspension of the MAZ-64227 car (Fig. 3) is of the balancing type. The ends of the springs 3 rest freely on special supports that protect the drive axle beams from wear.
The middle of the springs are attached by ladders 2 to the balancers 4, which can swing on the axles 8 of the balancer suspension.
Axles 8 are pressed into brackets 9, which are bolted to the vehicle frame.
Both drive axles are pivotally connected to the frame by means of a system consisting of six torque rods that absorb forces from the reaction and braking torques and transmit pushing forces.
Maintenance of springs
Maintenance of the springs consists of lubricating the spring mounting pins in the brackets, checking the mounting of the springs, lubricating the leaf springs and checking the fastening of the inserts of the rear spring brackets.
Longitudinal mutual shift of the sheets may indicate shearing of the center bolt, so it is necessary to check the relative position of the sheets of springs in a timely manner.
In order to avoid shearing of the central bolts, the spring ladders should be tightened, and they are tightened only when the springs are straightened.
The moment of tightening the nuts of the stepladders of the front springs is 40 - 45 kgcm, rear (MAZ-54322) - 60 - 64 kgcm.
When a squeak appears, the springs must be lubricated with graphite grease. for this, the car is lifted by the frame, the springs are released and the sheets diverge.
Graphite grease is introduced into the gaps formed between the sheets.
Maintenance of the rear suspension of the MAZ-64227 car comes down to checking the tightening of all bolted connections.
It is especially necessary to monitor the fastening of the brackets 11 (see Fig. 3) to the vehicle frame and the tightening of the stepladders, as well as the connection of the hinges of the torque rods and the nuts 10 of the fastening of the coupler 12.
The nuts of the rear spring ladders should be tightened at no load car, tightening torque 70 - 80 kgfm.
The tightening torque of the nuts 10 is 32 - 40 kgcm, and the bolts for fastening the brackets of the torque rods 18 - 20 kgcm.
For seasonal maintenance, you need to change the oil in the balancer crankcase, for which you need to remove the balancer cover, drain the oil, rinse the cover and reinstall it.
Clean oil is poured up to the level of the filler hole. During operation, it is necessary to monitor the absence of lubricant leakage through the covers and the stuffing box seal of the balancer axle.
The elimination of leakage is carried out by replacing the seals, gaskets of the balancer covers and tightening the bolts of the covers.
Spring repair
Before proceeding with the removal of the spring, you need to slow down the car with a parking brake, set the stops under the wheels, loosen the wheel nuts and spring ladders.
The procedure for removing the front and rear (MAZ-54322) springs is as follows:
- - unload the wheel with a jack on the side of the spring being removed and install a stand under the frame side member;
- - remove the wheel, disconnect and remove the shock absorber (for the front suspension);
- - unscrew the nuts of the stepladders for fastening the spring, place linings under the drum and, lowering the jack, release the beam from the spring until the drum fits on the lining;
- - remove the wedge of the spring pin, knock out the pin, remove the lug from the front bracket and remove the spring.
To restore a broken spring, it must be sorted out in order to replace the broken leaf. When assembling the spring, the nuts of the step-ladder for fastening the false lug are tightened with a torque of 2-4 kgcm and punched out at two opposite points.
In the fastening of the front end of the spring, pins and bushings twitch most of the wear. Pins and bushings are replaced if the gap in the mating is more than 2 mm.
In the mounting of the rear end of the spring, the upper and side liners are subject to the greatest wear, which are changed as they wear. If they are not replaced in time, the walls of the brackets wear out.
If there is more than 2 mm of wear on the walls, the brackets must also be replaced.
You should pay attention to the uniformity of shrinkage of the right and left springs. If the difference between the shrinkage of the left and right springs on a loaded vehicle is more than 15 mm, then the spring with a greater shrinkage is replaced.
Spring brackets must be replaced if cracks or breaks are found (welding is not allowed), as well as in case of wear of the rivet holes.
If the holes for the rivets are slightly worn, it is allowed to temporarily fasten the brackets to the frame with bolts, the holes for the bolts are first expanded to the desired size.
The assembly of the spring is also carried out on a device with a screw or hydraulic clamp. Before assembly, the spring leaves must be lubricated with graphite grease, assemble and tighten the spring with a center bolt.
The springs are installed on the car in the reverse order of removal.
Repair of the rear suspension of the car MAZ-64227
The procedure for removing the rear suspension is as follows:
- - disconnect cardan shafts from the middle and rear axles;
- - disconnect the pipelines of the pneumatic system going to the bridges;
- - knock out the fingers of the upper jet rods 1 (see Fig. 3), after unscrewing the nuts, and remove the rods;
- - unscrew the bolts securing the brackets of the balancers 4 to the frame;
- - lift the rear part of the car by the frame with a lifting device and roll out the bridge truck from under the car frame.
The upper brackets of the torque rods on the crankcases of the axle gearboxes must be tied together with wire so that the axles do not tip over and come out from under the springs when the bogie rolls out;
- - put the back of the car frame on the goats.
Disassembly of the rear bogie should be done in the following order:
- - unscrew the nuts of ladders 2;
- - supporting the axle 8 of the balancers with a lifting device so that it does not fall, remove the spring ladders;
- - remove springs;
- - unscrew the nuts of the fingers of the lower reaction rods, knock out the fingers and remove the rods 13;
- - roll back the rear and middle bridges; remove the covers of the balancers, drain the oil, unscrew the nut 7, remove the lock washers 6 and lock washers 5, unscrew the ring nuts and remove the balancers complete with bushings and seals.
Cracked or broken leaf springs, broken center bolts and clamps must be replaced. Cracks on the clamps can be welded and cleaned flush with the main surface.
The first main sheets, having wear in thickness of more than 4 mm, are interchanged with the second sheets of springs.
Root sheets with wear in thickness of more than 6 mm are replaced with new ones. Sheets with residual deformation (sagging) straighten.
Spring mounting ladders that have cracks or stripped threads are replaced with new ones.
Spring sheets are lubricated with graphite grease before assembly, the spring is assembled and tightened with a center bolt
Sleeves and seals of balancers, Torque bars that are worn out during operation must be replaced.
Installing the rear suspension on the car is carried out in the reverse order of removal.