The Wltoys / XKs 12402-A also known as the D7 Racing Truck is a great entry Level Hobby grade vehicle and well priced under the $100US price range (even cheaper with a coupon code listed in the description of the videos below)
It runs off a large 550 Brushed motor coupled to a ESC/Receiver combo and the battery provided is a 7.4v 1500mAH Lithium-Ion which on this truck is located underneath the chassis of the truck, so no body pins or body shell has to be removed every time swapping batteries over which is a plus!
You can easily use 2S lipos with the deans t-plug connector as you can see on my driving test review and speed test videos below also.
Overall i think its a great Basher vehicle, it is on the larger side of the 1/12th scale size of RC, and with a couple of simple mods like addition of oil filled shock or even a brushless upgrade will only make it even better.

Here are some of the Specs , Purchase link and coupon codes are in the description of all my videos.

Feature:
1. Four-wheel independent suspension system; high-performance suspension; adjustable trolley design for the whole vehicle;

2. The 550 high-power drive motor is more powerful, and the speed can get 45KM/H, which is faster than the same type of car;

3. High-performance natural rubber tires ensure that the remote control car has better grip performance on the road surface;

4. The sealed gear case and the electronic board with waterproof and dustproof function can drive as usual even in dusty or watery roads;

5. Full-vehicle high-speed globe bearing and steel drive shaft greatly enhance the service life of the remote control car.

6. The remote control is beautiful in appearance and generous; the remote control has forward acceleration, braking, reverse deceleration, and steering and throttle size adjustment functions;

7. Anti-explosive PVC color printing car shell, beautiful and resistant to collision.

Initial Overview and First Look

WLToys XKs 12402-A D7 Racing Truck Overview (17 min 5 sec)

On field Bash Test Review

WLtoys XKs D7 Racing 12402-A RC Truck Review (17 min 34 sec)

Max Speed Test on 2S Lipo

WLTOYS 12402-A D7 RACING TRUCK 2S LIPO SPEED RUN (4 min 34 sec)

Good stuff. Great reviews. Do you see this as being better than a 12428? The bell crank steering is a HUGE improvement. Is the independent suspension better for bashing than the solid axle? How about mods? Are the shocks any good? How about ground clearance? I run my buggies on grass and need some extra clearance.
If you turn the wheels by hand, is there any binding/ gear mesh problems? When we changed the 12428 plastic gears for metal, there was a problem with a genuine bind or at least tight mesh in both the front gearbox as well as the rear axle assembly. The only way to make things better was to install shims between where gearbox halves come together as well as leaving the screws loose in the rear. In the newer versions of the buggy, they give you metal gears right out of the box, BUT, they never fixed the gear mesh problem. Do you see signs of that needing to be addressed here as well?

Does anybody else, who actually own this buggy, have any remarks? I think this is easily the replacement for the 12428. It addresses many of the problems. Anybody out there? I'd like to hear from owners before I buy one of these.

Hello yes I also own the 12428 and this D7 Racing truck is far better in the handling and speed department overall than the rock racer 12428 and is a better off road basher in my opinion. The gear mesh in the diff's is fine and smooth. Thanks for tuning into my videos ��

I think I’m beginning to understand what’s going on here. I thought this was a new buggy, when in fact, it’s been around as long as the 12428. While many of us struggled with problems with the 12428, WLToys saw what we were doing to try to fix their shortcomings and put the fixes in this one, without letting anybody know what they were up to. Now, Banggood and a lot of other places have tons of these and other vehicles sitting around not getting sold. To boost sales, they’ve given the vehicles and even upgrade parts to guys to do videos. Everybody thinks these are all new when, in fact, they’re old and gathering dust. If they want to get rid of them, all they have to do is lower the price.

ThIs truck isn't old like the ancient 12428 rock racers from 2016/17, it only got released last year and BTW, I picked this one out myself cause I thought it looked like it would be a good truck. I choose everything I decide to share on my channel. This truck is nothing like the 12428 buddy, the whole chassis layout, motor spec and ESC are different!

2 years ago:

WLtoys 12402 - Surprisingly Fun 4WD RC Monster Truck - TheRcSaylors (14 min 39 sec)

Great review DG_Soarer, maybe you can answer some of my basic questions, I just picked up this WLToys 12402-A and wanting to know which particular model 2S battery you recommend that fits, is the stock charger OK? Also looking at upgrading the motor to brushless something like Racerstar 3650 Sensorless Brushless Waterproof Motor 60A ESC For 1/10 Monster Truck Truggy Cars - 3900KV which apparently is a pretty straight swap over? Easiest way to boost it from stock?

Show Off you Rig!

From what I can gather the 12402-->12402-A had a similar change to the 12428-->12427. They went from plastic to metal gears (and changed body). Also the 12402-A changed the battery mounting to a bottom compartment. The 12402-A is similar to the 12409 with the placement of the battery. so 12401-12404 and 12409 have very similar chassis. 12402-A and 12409 have same battery compartment.

12402-A parts: https://www.wltoysrc.com/129-wltoys-12402-a-parts (see metal diff and pinion)

Originally Posted by airofu

Great review DG_Soarer, maybe you can answer some of my basic questions, I just picked up this WLToys 12402-A and wanting to know which particular model 2S battery you recommend that fits, is the stock charger OK? Also looking at upgrading the motor to brushless something like Racerstar 3650 Sensorless Brushless Waterproof Motor 60A ESC For 1/10 Monster Truck Truggy Cars - 3900KV which apparently is a pretty straight swap over? Easiest way to boost it from stock?

Well, you are gonna need a new ESC, servo, receiver and transmitter, but the motor should fit straight in?

I bough this car after seeing it mentioned. Here's what I've gathered. Some of the unverified are things I've read or inferred, but not seen proved.

Battery Upgrade:
1. 2S 30C 2200mAh http://www.valuehobby.com/30c-2200mah-2s-t.html (Fits perfect in LxW see photo in later post)
2. 3S 50C 2200mAh https://www.amazon.com/2200mAh-Airpl...1&rps=1&sr=8-8 (This is about the biggest you can get. See Post #111 for photo)

Shock Upgrades:
Stock shocks are 85mm hole to hole and 96mm tip to tip.
1. 85mm hole to hole from Hooshion for 1/10 RC Car Truck Parts Crawler Type Axial SCX10 TRX4 D90
2. ZD Racing 7358 92mm Shock (92mm tip to tip, 85mm hole to hole) Also on AliExpress
3. 85mm hole to hole shocks from Hobbypark for Redcat Shockwave Sandstorm Tornado
5. ZD Racing 7853 oil shocks 92mm from Banggood
6. TrackStar Aluminum Shock Absorber Set 85mm S160085

Motor/ESC/Pinion:
If you like torque and bashing, stay stock, or go brushed, or sensored. High KV sensorless motors will have cogging at startup unless you gear down. Better to just have the motor gear it down. 3600kV or less or change gearing. The car isnt designed for this power, so things will break.
1. Racestar 3650 Sensorless 3700KV with 60A ESC combo (Tomley RC)
3. GoolRC 60A ESC and 3900kV motor
4. https://www.amazon.com/Robinson-Raci.../dp/B0006O7TIQ 19T 32P Robinson Racing Metal Pinion Gear (me)

Servo:
Be carefull to trim the max throw of your servo or it may overpower the stock parts.
1. DSSERVO 25KG DS3225 (Tomley RC)
2. HSP Servo Saver Arm 02025
3. HSP Servo Saver Frame

Front Steering CVD:
1. 2-5mm copper shaft couplers
2. HSP Redcat Exceed #166015 (These dont work unless you cut them down to size and join with the shaft couplers above. Recomend OEM replacement)

Diff Upgrades:
1. Removal Instructions: https://www.rcgroups.com/forums/show...&postcount=155
2. Stiff Diff solution: Remove an o-ring or a washer from part# K949-70 to loosen.
3. Metal spider gears from Verata Twin Hammer will replace the plastic OEM ones:

Weak Body Posts:
1, 3D Print upgrade part by KeKe:
2. Aluminum bar upgrade by KodakJack: and this 2nd revision

Transmitter/Receiver/Gyro
1. https://www.ebay.com/sch/i.html?_fro...kw=DUMBORC-X6+ DUMBORC-X6

Wheels:
1. Stock Wheels
2. 15mm hub extenders You will need to drill these out slighlty with 3/16 to make them fit.
3. Staggered stud tires. REQUIRES 15mm exterders

Cosmetics:
1. Light Bar 3D Printed fixture


Alternate Bodies:
1. Monster Truck
2. Short Course
Truck

Misc Hardware:

Stock Spare Parts:
1. https://www.wltoysrc.com/129-wltoys-12402-a-parts
2. 12409 Parts (similar chassis)

Other Forum Posts about 12402-A
1. https://www.rcgroups.com/forums/show...h-Speed-45km-h

Video Reviews/Upgrades in addition to OP
0.

WLToys 12402-A (1 min 33 sec)

1.

Wltoys 12402-A 4WD 1/12 2.4G RC Car Dessert Baja (Not Stock 5800kv brushless 3s lipo) OMGRC (2 min 26 sec)

(Beyond Souped up, 5800kV and 3s)
2.

How to fully upgrade your RC Car! WLtoys 12402-A Brushless, Oil Shocks, Big Servo! (26 min 29 sec)

(Walk thru of 3900kV motor, 60A ESC, Servo, and shocks upgrade)
3.

HOW TO FIX WLTOYS 12401-12404 SPEED PIONEER OR SUPER CAR REAR DIFFERENTIAL GEAR (7 min 57 sec)

(Rear diff teardown of old 12402 with Plastic Diff)
4. https://youtu.be/mLcWOJrQeaQ?t=730 (Every Page of Manual)
5.

WLToys 12402-A 4wd truck video update! (5 min 33 sec)

(Similar video #2 less informative, but confirms)
6.

WLToys 12402-A 1/12th 4wd truck unboxing video (13 min 2 sec)

(Unbox)
7.

Well under $100! The NEW WLtoys 12402-A 4wd 1/12 RC Car. Best Kids RC? (6 min 56 sec)

(Unbox)
8. WLtoys Compare between 12409 and 12402 (NOT 12402-A but close)

Well, you'll have to let us know if it's better than the 12428, with all of its inherent problems. I know, for a fact, that Merch does tons of videos after getting freebies of all kinds. The Soucechef is the same. I'd like to hear YOUR review or at least remarks. I don't know why the one review shows the transmitter taken apart. I just read the most recent 144001 posts and those guys are having a heck of a time with gears and cups wearing. The 550 motor is only slightly bigger, but it may be more than these things can handle. That buggy comes with metal gears to begin with. In one post, a link is given for replacement gears and it specifies they are powdered metal = junk! ALL WLToys vehicles, except for the 1/18 scale ones, use the exact same gears, etc. They become a money pit and you can't keep them running long. I had hoped this one would be better. Only time will tell.
P.S. One thing I noticed in one of those videos was that the servo was a 5-wire. I thought the review distinctly said it used a Two-in-one = receiver and ESC. I thought it said you could upgrade the servo, meaning it should be a 3-wire servo, like you show, unless there are different versions of the 12402, but I doubt it.

Looking at videos it seems the Racestar 3650 3900kv with 60amp ESC is pretty much a straight swap over on the 12402-A? Can I just do this on it's own to boost the power from stock? Do I need a new servo or a new transmitter?

Also is the stock WLToys battery that comes with this NOT a 2S lipo? If so what particular model 2S Lipo is recommended that fits and gives more run time?

Anything electrical that does not involve replacing stock with more stock means the whole thing has to be changed over. If you watch YouTube videos of brushless conversions, you can see that you have to make sure you don't go too big. This thing has a wheelie setup that appears to do nothing for you. The thing needs to be flipped so the wheels keep the front from going so high. The only problem with that is it will cause the wheelie wheels to dig in when you're off road. A better ESC and servo will do you more good than a brushless set up. IMHO, WLToys vehicles can't take a brushless system when the gears can't handle the stock setup. The very latest vehicle I've seen from WLToys is the 144001. Have a look at their discussions and you'll see what I mean.
The video of the guy fixing the plastic gear in his rear end is useless without him giving the link as to where to get the gear. It is also a waste of time to replace the gear he replaced without changing all of the other gears along with it. Maybe this isn't an issue if they come with metal gears now. Even if they do, the "powdered metal" gears are useless as well.