This is a how to weld a diff for a nissan 240sx. ( this is just a guideline for people to use if they want to know how to do it. functiontheory.com is not responsible for you not doing this right)
ANYWAY. lets begin, we had an extra non abs diff laying around and since most of you know im starting to build a drift car. i decided to get cracking on welding up the diff. i know there is MANY mixed opinions about welding a diff… we here at FUNCTIONTHEORY.COM have personal experience on a few of our cars that we build. we have had no problems at all, for years on our drift cars with diff blowing up, or failing. so that is why u decided to weld it. besides i know most of you do it even if you talk crap on forums about it.
so the way we think we have made it so successful for us is we take A LOT of care doing it. i would say its easily a two hour job. and its super messy. the key is making sure you shield the ring gear with a towel so that any slag flying around wont get stuck on it. also you must THOROUGHLY wash all excess slag COMPLETELY out of the diff. this is the messy part. we used lots of wd40, and motor oil.
here are the steps
tools.
1/2 breaker bar with small 1/2 inch extension
14mm socket
ratchet
flat head screw driver
pen magnet
rags
oil
1. drain the oil out of the diff using the drain plug at the bottom of the diff cover.
2. reinstall the drain plug and them remove the 14mm bolts to take the diff cover off
3. take a rag and get most of the oil off as much of the spider gears as possible.
4. use carb cleaner or something similar to take the rest of the oil off the spider gears so you have a clean area to make a good weld on
5. COVER THE RING GEAR WITH A TOWEL BEFORE WELDING ANYTHING. the towel is going to have to come out ch time you have to move the gears to weld the other side.
6. make sure the spider gears are clean and dry. then tack all four corners of them on both sides
7. no go back to the first side you did and start welding the crap out of each cornermake sure the heat is up on the welder to get good penetration. do this to both sides ( DO NOT weld the ring or pinion gear)
8. allow to cool. we just let it air cool. we didnt want to make the metal contract to fast and possibly mess up somthing in the diff.
9. now here is the patient part. it is going to be a little hard to turn because slag might have gotten in the pinion and ring gear. so go very slow and DON’T force it. this is where you are going to use the flat head screw driver and break off all the slag pieces so they don’t come off and BLOW UP your diff while your driving.
10. after you have gave it plenty of oil baths turning the gears while it is full of oil to make sure to get all the lose pieces of slag out you can use the pen magnet to get what ever else out you can.
11. making sure all the oil is back out and the diff turns with ease NO BINDING due to slag. if there is you will have to give it more oil baths and reach your finger in and try to feel for any pieces of slag. now you can re assemble. we just used some RTV gasket maker. and tightened up all the 14mm bolts on the cover. fill it with gear oil and your good to go.
to wrap it up. yes it does look a bit ugly but you really need to lay alot of weld on to be sure that nothing breaks off and wrecks the diff. again this is just the way that we do it that has shown great success for us. we are aware that there are other ways. but we choose to use whats best for us. below are a few pics.
CLICK HERE FOR THE FULL STEP BY STEP PHOTOS
