








⚙️ Drive smoother, last longer — the synthetic edge your gears deserve!
Lucas Oil LUC10121 SAE 75W-140 Synthetic Transmission and Differential Lube is a premium synthetic gear oil engineered for heavy-duty and high-performance vehicles. It features a specialized additive package that reduces gear noise, extends bearing life, and withstands high temperatures without losing lubricity. Ideal for limited slip differentials, this 1-quart synthetic lubricant ensures reliable, long-lasting protection and smoother operation.

| ASIN | B000BCKWVE |
| Assembly Required | No |
| Brand | Lucas Oil |
| Colour | Multi |
| Customer Reviews | 4.8 4.8 out of 5 stars (723) |
| Date First Available | 7 August 2012 |
| Exterior | Machined |
| Generic Name | gear oil |
| Global Trade Identification Number | 00049807101213 |
| Item Dimensions LxWxH | 8.4 x 8.4 x 29.8 Centimeters |
| Item Form | Oil |
| Item Weight | 880 g |
| Item model number | LUC10121 |
| Liquid Volume | 1 Quarts |
| Manufacturer | Lucas Oil |
| Manufacturer Part Number | LUCA10121 |
| Material | Synthetic |
| Model | Lucas Oil 10121 Synthetic SAE 75W-140 Gear Oil - 1 Quart |
| Net Quantity | 946.35 Milliliters |
| Number of Items | 1 |
| OEM Part Number | 10121 |
| Package Information | Bottle |
| Product Dimensions | 8.38 x 8.38 x 29.85 cm; 880 g |
| Recommended Uses For Product | auto racing |
| SAE J300 Viscosity Grade | 75W-140 |
| Size | Others |
| Specific Uses For Product | Vehicle |
| UPC | 049807801212 049807401214 |
| Upper Temperature Rating | 1 Kelvin |
| Viscosity | 75W-140 |
| Volume | 1632 Cubic Inches |
N**1
I needed to do a fluid change on the rear diff of my 2002 F150 with factory limited slip. I have never used any Lucas product before, only seen their oil additives (and I don't use additives at all, Lucas or other brands). I have read some bad reviews of Lucas gear oils, but most seem to be complaining of issues in transmissions or transfer cases, not differentials, so I figured why not try it. It meets all the specs and is cheaper than other synthetic fluids of the same viscosity (even cheaper than Supertech 75w-140 synthetic from Walmart). I did notice this fluid does not have as strong a foul odor like some gear oils do. It still smelled, but not as bad as others I have used before. I changed the fluid with no major issues and it seems to work just fine. I did add the Motorcraft XL-3 Friction Modifier to the differential. The Lucas fluid is supposed to contain Friction Modifier and it says no need to add more, but I have heard of many people having rear end chatter with the OEM Ford LS no matter what fluid is used unless the Ford friction modifier is added too, so I did it. I was having some chattering from the rear end when doing sharp turns from a stop before I changed the fluid, no issues at all after the change. I only gave it 4 stars for now since I don't know long term how this fluid holds up. If it is still good in a year, I will change it to 5 stars. As of right now, I would not hesitate to use it again. Edit 7/10/15: Well, it is a year later and nothing to report except truck is still running fine with no noise or leaks from the rear end. Seems like a solid choice for gear oil for me. Will be on the top of my list if I need more. 5 star rating now. another edit 9/16/16: well, no more updates on this fluid. I had to drain my rear diff (had to replace the anchor plate for the passenger side brake caliper, which requires removing the axle shaft and draining the fluid). I debated re-using the fluid, but decided not too. The fluid came out looking almost like it went in. Only had 10,000 miles or so on it though. I did not use more Lucas fluid for the refill, I just went with some Supertech gear oil from Walmart instead. Seems the price of the Lucas has gone up and cost as much as other name brand fluids, loosing its biggest advantage for me (low cost).
C**E
Todo correcto. Producto y envío ok. Volveré a comprar seguro. Contacto con el vendedor ok.
M**D
Did not solve my problem, noise is increasing and now I can feel hard acceleration.
A**E
Use Lucas products for many years. They always do what they made for.
R**N
Good product
Trustpilot
4 days ago
1 month ago