A-arm pins

How To Replace Differential – Losi Baja Rey

Does your Losi Baja Rey need the front differential case replaced? Do you want to know how to replace differential on the Losi Baja Rey? In this article, I am going to show you just that.

Once you replace the diff case the Baja Rey will be good as new and stronger than ever. Check out my previous post on the symptoms of the front diff case.Losi Baja Rey

Getting Started – Things You Will Need For The Repair

The first thing you will need is, of course, the upgraded aluminum front differential case.

Exotek 1803 gun alloy you can purchase from amazon.com for $39.63

Some (diff) grease

A tool set

And a large work area to set the truck and work in. That is all you need to replace the front diff case.

I am going to break down the way I changed my front diff. “I” found to be the quickest. So Let’s get to it!

The Steps To Removing The DifferentialBaja Rey Hood






1. The first thing you need to do is to remove the front body clip. Take out the 4 screws on top of the hood, Then the 2 screws on the front edge of the doors on each side. Lift the body section up and off and set it aside.

2. Remove the front bumper. There are 4 screws on the bottom that need to be removed, Then remove the 2 screws on top, That hold the bumper brace to the diff and then the 2 screws that hold it to the roll cage, 1 on each side.

Now slide the bumper forwards and off. Set it aside.removing baja rey bumper






3. Now we need to remove the sway bar. The ends just snap on and off. Pop off the ends, Then remove the 2 screws holding the cover plate on.

You may have to use a small flat blade screwdriver and put it behind the cover and pry a little to get the cover plate to come off. Pull the cover plate off and then the sway bar.losi






4. Next, you need to remove the lower A-arms. Do this by pulling the bracket that sits on the front of the diff and arms. Leave the c-clips on the pins and you can pull the bracket and both pins

A-arm pinstogether. You may have to compress the suspension up and down to get the pins to slide out. Then set it aside.

Once the pins are out, Pull the lower arms outward so the axles slide out of the hub on diff.

5. Then remove the upper shock bolts. Slide the top of the shocks of the mount bolts and let them hang off to the sides.baja rey shock mount







6. Here you need to remove the upper shock mount. Remove the 4 screws and lift the mount up. The shock mount and upper A-arms are removed together.

Let them hang down under the front of the truck. The steering links are still attached so be careful.baja rey front end removed






7. OK, Now we can remove the front differential. I was able to sneak the diff out by taking out the 5 screws on the upper chassis plate.

This allows you to be able to lift up the plate a little, Just enough to sneak the diff out. You may need to wriggle the diff and lift up slightly and then pull it forward and out, All while lifting up on the chassis plate slightly.

Careful not to bend the plate.losi differential







I know there is another way to get the front diff out. This is the way I found to be a little quicker and with the least amount of parts needing to be removed.

Changing The Differential Case – Aluminum Upgrade

Take the 2 screws out of the diff case, and carefully separate the two halves. Once you get the case split (make note of how the gears are set in the case) take the gears out and wipe them off with a clean lint-free cloth.

Carefully inspect them for any chipped or missing teeth. “If” the teeth are OK, Then you can reuse them. Clean off all the old grease and any debris.

Now take the new aluminum case and install the gears as they were when removed from the old case. Install the new bearing that came with the aluminum case. Make sure the bearing is fully seated in the case.

Add some fresh clean diff fluid or silicone transmission oil to the gears. Then set the other half of case on and bolt them together. The diff case is now ready to be put back in.baja rey aluminum differential

When I did my diff, I put enough gear oil in that it filled the case about half-way. “I” know this is way more diff fluid than what is needed. “I” did this to ensure the case had plenty of lubrication to keep the gears lubed, As I run and bash very hard. This has worked out great for me, No noise and seems to keep the diff cooler as well. The fluid does seep out from around the axles, So I clean the front end of my truck more frequently.

Diff Install – The Upgraded Differential

So now you’re ready to put the diff back in and get your truck back out bashing, So Let’s finish up!

1. Gently lift up and hold the upper plate and slide the diff in. Make sure to line up the driveshaft.losi diff install


so it goes back in the diff hub. Then put the 5 screws back in the upper plate and snug them down.


2. Take the upper A-arms and shock mount and set it back on the top of the diff. Install the 4 screws that were previously removed and snug them down.

baja rey shock mount







3. Now slide both the front axles in the diff and put the lower arms in place. Slide the pins and bracket through the arms and diff case.A-arm pins






4. Put the shocks back on the mount and install the 2 nuts that were removed earlier and snug them up.

baja rey shock mount







5. Put the sway bar back in place and snap the links back on the lower A-arms.

6. Install the cover plate, Making sure the sway bar stays in place. Put the cover in place and tighten the 2 screws back down.








7. Grab the bumper and put it back on. install the 2 screws on top, Then the 4 screws on the bottom and finally the 2 screws for the roll cage (1 on each side)losi front body removed







8. You can now put the front body section back on. Install the 4 top screws and then the 4 side screws (2 on each side).

You are now done. That is how to replace differential on Losi Baja Rey.

Complete Repair – The Final Step

Now that you got your differential fixed up, It is time to see it in action. Grab a charged battery and your transmitter. Take it out and have some fun.losi baja rey







“I” really hope you have enjoyed this article and it has helped you learn how to repair your Losi. Doing your own repairs will allow you more runtime with your RC’s.

Most hobby shops will repair them for you, However, they usually want you to drop them off and in a day or two they will call you to say it is done and you can come to pick it up.

Who wants to wait a day or two? Most any RC repair is easy enough to do on your own, So you can have it back up and running relatively quickly.

“If” you like this article or have any questions, Leave me a comment. “I” will get back to you right away.

4 thoughts on “How To Replace Differential – Losi Baja Rey

  1. Hi
    Thanks for your the clear instruction on how to replace the front diff of Losi Baja Rey 1/10. I’m very keen in replacing the diff. Can you tell me what weight diff silicone oil I need to put in for the Front and Center and back? What weight oil, it comes in stock, for all 3 diffs?


    1. Hi Jana,
      I used 10k silicone oil in the center diff. This provides a better climbing capability. In the front and rear diff I used plain diff grease to lubricate the gears.


  2. Hey there, somehow I ended on your site and started reading the article about Losi Baja Rey, How To Replace Differential. I have to admit that I don’t know anything about Losi Baja Rey and the differential replacement but I did learn a lot from reading your step by step. It is very well explained! Thanks for sharing!


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