Gear ratios of the gearbox of MAZ cars

All equipment questions.

For all those who do not know how to determine the number of their gearbox. The following is a method for accurately determining .

You can calculate the gear ratio by rotating the gearbox for the drive wheel and calculating the ratio between the number of revolutions made by the gearbox flange and the number of revolutions made by the wheel.
To do this, you need:
Go to the viewing hole
secure the car with a wheel chock
put the gearbox in neutral
raise the drive wheel (Attention! if the car two driving axles, it is better to calculate the gear ratio on the working axle), and put marks (with chalk) on the wheel and on the floor so that they match.
we go down to the inspection hole and make a similar mark on the flange and gearbox housing.
Attention! Both marks (on the wheel and on the gimbal) must match before the countdown starts.
The next step is done with an assistant (although if you mark the wheel from the inside (from the gearbox side), you can do without an assistant). One person turns the raised wheel (in any direction) and counts by ear the number of complete revolutions of the wheel made, .

and the second person at this moment also counts by ear the number of revolutions made by the cardan. If you keep counting without a helper, you will have to count wheel and gimbal revolutions yourself at the same time.

It is important to keep counting until both marks match as closely as possible (as was originally established). At this time, you need to stop the rotation of the wheel and remember / write down the calculated number of revolutions made by the wheel and the gearbox flange. The more accurately you can match the labels, the more accurate the calculation will be. You can be sure that on any car, these markings will sooner or later match as accurately as possible. The greatest probability of this occurs from the 16th to the 22nd revolution of the wheel.
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As a result, we got two numbers. 16 and 39, which will allow us to determine the gear ratio of this gearbox. Please note that the figures obtained are not the gear ratio or the number of teeth of the main pair of this gearbox, these are only calculated figures.
Attention!!! When calculating the number of revolutions of the wheel / flange, be as accurate and attentive as possible! The slightest mistake (in the number of revolutions counted) can lead to the purchase of an unsuitable gearbox! In case of doubt, it is better to repeat the calculation again.
The final calculation of the gear ratio according to the formula

Since the mechanics of the differential of any gearbox is such that when the wheel is rotated (as we did), its number of revolutions doubles, we will need to make an adjustment to the calculated numbers (revs).
We correct the number of revolutions of the wheel, for this we need to divide the number of revolutions of the resulting wheel by 2. Example: 16/2=8. As a result, we get two numbers 8 and 39.
To obtain the gear ratio of the gearbox, it is necessary to divide the number of revolutions of the cardan (higher number) by the number of revolutions made by the wheel (lower number)
Example: 39/8 = 4875
The resulting number 4875 is the ratio of your gearbox.

The variety of gear ratios of gearboxes on MAZ vehicles is due to a large number of modifications based on the vehicle and, accordingly, different requirements for traction and speed characteristics. Depending on the application, as well as the conditions in which the vehicle will be operated, the manufacturer sets the most suitable gearbox for a particular modification. During operation, the question of changing characteristics often arises. Changing the gear ratio implies both a decrease in the load on the internal combustion engine, an increase in speed, fuel economy, and a change in the traction characteristics of the car.

On cars of earlier modifications, "round" gearboxes were installed, with different gear ratios. They are identical in design, the difference is in the presence of a lock and different axle shafts, examples of moments and gear ratios are given below:

25*11 pcs - 7,79

25*12 pcs - 7,14

25*13 pcs - 6,59

24*15 pcs - 5,49

24*16 pieces - 5,14

24*17 pcs - 4,84

The smaller the frequency converter, the "faster" the gearbox, respectively, the larger the frequency converter, the greater the "high torque".

The length of the axle shaft is 1080, it has 2 crowns of 20 slots (for non-lockable cases, the left and right are the same) and 3 crowns of 20 slots (for a case with a lock, one with 2 crowns, the other, on the side of the lock with 3 crowns). Final drive mainly with 4 satellites (21*15*51)

On cars of the latest releases, gearboxes with an “oval banjo” are installed and on board with 5 satellites:

29*21 pcs - 5,08

29*23 pieces - 4,2

29*25 pieces - 3,86

29*27 pieces - 3,57

29*28 pieces - 3,45

24*15 pcs - 5,33 for Maz-54323
For younger brothers MAZ - 4370 (39 * 10 and 38 * 11)

What is the gearbox in the photo? An earlier or later release? And what's on board, can you tell me? On the central bridge, the suspension dangles 10 centimeters up and down! Do you think the blank or the gearbox itself fell apart?

Vladimir 48.ru, judging by the photo, a 3-bridge Maz with a rear stabilizer. The reducer in the photo is rear, round, the first outputs, put on 5 satellites with a plate, later ones. Well, early and late release, the name is conditional, so to speak, there are a lot of installation and configuration options. Regarding the suspension clearance, 10cm is certainly a lot, maybe 10mm? Most likely the bearings will need to be adjusted or replaced after such a long operation. It is better to remove the piglet for inspection. Here are examples of a round gear and an oval banjo:
1. Reducer "Round" 2. Reducer "Oval"

Yes, everything is correct as you described, here is a photo of the machine itself! Piglet has already bought, the cardan dangles a lot, that's exactly what 10 cm! I think that at least the middle gearbox remained intact! Photo of the middle bridge! I just bought a car, one of these days I will remove the barrel and disassemble the middle axle! The machine will turn into an agricultural dump truck and, of course, into capital! Can you tell me about the gearbox? On the Zilovsky bridges, let's say there is a platform with full gear ratios! Do I think that a fuel truck should have high-speed gearboxes?

- added: 14 Dec 2014 at 19:04 -

Yes, I forgot to say that when I bought MAZ, I immediately saw that the cardan was hanging, and the price collapsed! The seller told me that these three mazes are exactly the same, take it and take it out of any gearbox, I pulled a pig out of it, but they couldn’t remove the gearbox itself, since it interferes with the trunk with the main line and pipes (everything is under the central bridge). And when I pulled the suction cup on another ointment, I counted the teeth on the large gear (driven) along the holes, marked one tooth and rearranged the gearbox, and counted 29 teeth on it!

Vladimir 48.ru,

Is this where there were 29 teeth, on the driven gear of the gearbox or FASHION (pig)?

I counted 29 teeth on the driven gear, and in my opinion almost the same number on the pig (I forgot) I will definitely write about the pig tomorrow along with the photo!

- Added: Dec 15, 2014 14:32 pm -

Today I counted the gear teeth that are on the MOD shaft. I counted 28 teeth! (photo) And how much in the gear that in the gearbox (as I understand it, the drive gear is spinning) will show an autopsy!

Take a metal brush and brush it almost to a shine, and there will be both embossed numbers and faded ones.

Where exactly can you tell me? About where to clean it? Otherwise, it may be easier to open the gearbox and count the teeth than to clean the entire gearbox with pantyhose to a shine!

Marking of the bridge from above, to the right (in the direction of travel) near the gearbox, the gearbox itself is approximately nearby. Decided to open the gearbox anyway, all the numbers can be counted on the disassembled one.

Vote

Krazevich, is there just a batch number and some kind of release date? And the gear ratio on it beats?

On the old bridge, they stamped me: the model and catalog number (r / s can be found in the catalog), I did not look at the new one, because the filling is already different.

Something like this: 53366 240 10…….

I don't know for sure, nothing else is written in the manual. I think the IF GP has failed in the gearbox. But here is a table that might be helpful. Where it is marked in red - the number of teeth on the MOD and above - on the gears of the central gearbox.

I almost got it! Tomorrow I'll try to shoot through the barrel and then I'll dismantle the bridge! I’ll clarify with you, since I have never dealt with Mazov’s bridges!

Today I removed the MOD with the gearbox cover! Both bearings have collapsed (the first one is next to the flange, the second one is on the gearbox). The gear teeth (28 teeth), which are placed and rotate on the drive gear (shaft), have collapsed. I counted the teeth on the driven gear (torque), it turned out to be 25. Most likely, I think there is a gearbox with a gear ratio of 6,59. As for the gearbox itself, I still don’t know how I’m going to get it, so I’ll definitely take a picture! What speed will I have with a 6.59 gearbox? Rubber 320. Checkpoint YaMZ 238-8 gearbox 0,71! I'm thinking of replacing the gearbox with 24x17-P.Ch-4,84, what speed will be with such gearboxes? What do you think, if the machine is used as a grain carrier?

from 4.84 it will be difficult for the grain conveyor, the speed will be from about 105 to 1500 rpm. Put the box on 5.49 at 1500 rpm and you will go 90 and it will become a little easier. If necessary, I can adjust the gearbox at a reasonable price.

And I have a 6.33 gear on my Zila, a yamz engine, a 9-mortar box, -9 gear 0.81, and at 2100 rpm the maximum speed is 86 km per hour! Maybe you miscalculated a little? It seems to me that there will be no 90 km per hour at 1500 rpm with a box of 5.49!