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What is a Welded Diff?

What is a Welded Diff

If you are into your drifting, you will fully understand the purpose of a welded diff. It is a modification to the differential that will allow you to oversteer more easily, which of course is ideal for those learning to drift their car.

So what is a welded diff? In short, it allows for both the back wheels to remain spinning at the same speed. With an unmodified differential, the outside wheel spins faster than the inner wheel to turn a corner. However, a welded diff will mean both wheels will spin at the same speed, which causes the inner wheel to lose traction.

For cheap drift cars such as a Nissan 240SX, Miata, BMW (E36/E46) and many others, welding the differential is a cheap solution. However, when it comes to daily driving, the weld in your differential may cause some issues as discussed below.

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What To Consider Before Welding

Welding the differential will put a lot more strain on the drivetrain and if it’s not in great condition, you may want to fix it. You will want to check everything starting from your clutch and all the way back to the rear axles.

If you are knew to welding, you may want to take some trial runs beforehand. It is essential that the weld on the diff is done properly because the last thing you want is shards of metal inside the differential.

How to Weld a Diff

The hardest part of welding the differential can often be removing it from the car in the first place. If it is your first time welding the diff, it may be advised that you purchase a used differential incase things go wrong or you decide to return to an open differential.

welded differential

After you have removed or have a spare differential, you will want to drain any oil and remove the housing. Before you begin any sort of welding, you will want to completely clean the diff. If there are any tough bits of dirt, you may want to use a brake cleaner.

Once fully clean, you are then ready to begin welding. Many people have their own methods of welding but most people begin with the corners where the spider gears meet together. This allows for more steel to be connected and making it a more solid weld. Others may simply weld where the gears meet and that is the weld complete.

Before installing the differential back into your car, you will want to ensure it’s completely cleaned up. You will not want anything to get in the way of the moving components inside of your differential.

Welded Diff

Benefits of a Welded Diff

People that weld their differentials are interested in one thing, which of course is drifting. As mentioned earlier in the article, it makes both wheels spin at the same speed, which causes the inner wheel to lose traction.

Compared with an LSD diff (Limited Slip Differential), they are far cheaper and allow you to drift more easily. You can still easily drift with an LSD diff but most will only lock up under a certain amount of torque, which can be difficult in low powered cars.

The Downside

The welded diff is known to be the cheapest solution to easy drifting but it does come with drawbacks. The main being the effect that it has on daily driving as you may have to adjust your driving style. At slow speeds during tight turns, you can expect your wheels to hop and a variety of unusual noises. Your worst enemy will now be parking lots and three point turns.

However, for situations such as these, you can drive the racing line as opposed to tight or wide turns. This will avoid any awkward turns and it will be the straightest line through a corner, which is a tactic used by many racing drivers.


To many, a welded diff may seem dangerous and a complete waste of time. However, if you have a cheap rear wheel drive car that you want to take drifting, it’s the best option. Using a LSD differential does make daily driving easier but you will still require a bit more skill to get it sideways for drifting.

If you have welded your differential correctly, they can be long lasting. With regards to daily driving with a welded diff, it does take time to get used too but eventually it will just become the norm.

procarreviews author

Written By Dan

About the Author

Dan is an automotive journalist and owner of over 10 cars ranging from supercars, tuned cars, classics and your good old beater cars. He always likes to get his hands dirty with nut and bolt restorations or detailing sessions using the best products on the market.

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