How To Weld An Open Differential

[Mlogue84]

This will be my first attempt at welding a diff and giving instructions regarding the steps i took.

I am going to start by assuming you already took the diff off of your 240.

1. Start by removing the 8 (14mm) bolts holding the diff casing on.



2. Remove the 4 (17mm) bolts holding the Ring gear/ Axle assembly down.



3. Next take a hammer and a block of wood and hit the axles out. Make sure to turn the axle after each hit to evenly take out the axle.



4. Pull the Axle/ Ring gear assembly out of the casing. There is a pressed on bearing that you need to reassemble when you put it back together. There is a spacer as well on the ring gear side. This is the way it goes.



5. Next step is to take off the ring gear. Use a prybar to generate the resistance needed to break the bolts loose.



6. Completely rid the spider gears of any trace of oil. My choice was a couple cans of carb cleaner.



7. Next cover the pressed on bearing with something durable, My choice was a pair of leather gloves.



8. It is important to heat up the metal to get a good penetration for the weld. Use your torch / plasma cutter to heat it up.



9. Commence welding. Some people prefer to use a bolt and jam it in there, But I didn't think that was good enough. I colpletely filled in the entire joint on all four sides and partially the middle *BE CAREFUL NOT TO RUIN THE THREADS THAT THE AXLES SLIDE INTO!* Turn it over and do the same thing to the other side of the joints.
Some of those as you could probably tell are during pictures.


10. You need to get rid of all the little splatters in the assembly so they don't break loose and get in your bearings or between gears and mess something up. I reccommend getting it sand blasted. This is what it looks like after sand blasting.



11. Assemble all of your parts, organize and clean them.



12. Follow the instruction backwards and put it all back together. You need to put medium grade loctite on your ring gear bolts and the 2 main bolts holding the assembly into place. Don't worry about lubing quite yet.


13. Follow the torque specs for putting it all back together. I called my local pepboys then went down and got a print out.


14. Make sure to stop by nissan and get a new gasket, and use your gasket sealer!


15. Finally, use 80-90 gear oil at least to refill your new welded diff. Everything is sealed and self lubricating so, fill and put the fill bolt back in and you're off!

[Zetto*]

Great write up, good details.
+rep

[opponheimer]

Nice job! Good info, great pics.

[thatdrifterguy]

i didnt have to take it all out. just took out the cover then got it welded

[Mlogue84]

Originally Posted by thatdrifterguy

i didnt have to take it all out. just took out the cover then got it welded

You mean you took it somewhere and someone else welded it?

[blu808]

Nice write up. That should hold a mildly powered car. We have welded over 240 diffs from all around the country, and not one of them has broken using our process.

I like how carefull you were with all the parts, and how you cleaned everything correctly.

More faq on welded diffs here.

http://www.sdp-online.com/wlfaq.php

[thatdrifterguy]

Originally Posted by Mlogue84

You mean you took it somewhere and someone else welded it?

something like that. my welder broke halfway through. k sorry. maybe they did take it apart.

[Mlogue84]

Originally Posted by thatdrifterguy

something like that. my welder broke halfway through. k sorry. maybe they did take it apart.

What a pain, I hate starting something and not being able to finish. How is it holding up?

[thatdrifterguy]

i'd say its doing real good. i havent checked on it since i got it. ive had mine since feb. and i dont notice anything wrong. it should hold up pretty long as long as you did the welds good. but i think it does some to the trans mounts. you know how the wheels hop on some corners, well, my tranny hops a little sometimes

[Jonnie Fraz]

Nice write up...and if Luke said you did an ok job you better believe it. I had to repair a botched weld job and I imitated Lukes weld lock 3. 400+hp and she is still holding.

[Mlogue84]

Thats what I like to hear... I'm bolting it up tomorrow night, I'll be sure to let you guys know how it goes.

[ECR33S14]

thats a fantastic write up. well informed.

[Enjin]

doing it tomorrow! great writeup!

[Mlogue84]

This is definetly the best upgrade yet... So predictable! I'm so stoked! The best part is that there's no "clunk" noise or "jerky" feel like most of the two ways i've felt and heard. It's super quiet and I love that! Feels so much better too!

['90RPS13]

Great writeup man. Soon I will be doing mine.

[gotta240]

I also had the gear welded to the carrier. I don't think it is necessary to remove the gears from the carrier either... to each his own.

[NemeGuero]

Originally Posted by blu808

Nice write up. That should hold a mildly powered car. We have welded over 240 diffs from all around the country, and not one of them has broken using our process.

I like how carefull you were with all the parts, and how you cleaned everything correctly.

More faq on welded diffs here.

http://www.sdp-online.com/wlfaq.php

lol @ plug

[ch1873857]

dude. did you say use a torch or plasma cutter to heat it up? excellent write up though. im trying to sell my kaaz 2 way so i can buy a welder and weld my own among other things. for future reference, a plasma cutter uses a tungsten electrode similar to that of a tig torch just smaller. once the arc is struck a highly pressurized gas gets turned into plasma. no heating just straight cutting.

[Irukandji]

I like how you sandblasted it... great attention to detail

[gotta240]

I also don't know about heating the diff up so much. My welder(by living) said that you dont want to heat it up TOO MUCH as it can warp the gears... Again, jmo.

[98koukile]

But the gears... they are welded together, aka they don't need to mesh because they are stuck in place

[Mlogue84]

Originally Posted by ch1873857

dude. did you say use a torch or plasma cutter to heat it up? excellent write up though. im trying to sell my kaaz 2 way so i can buy a welder and weld my own among other things. for future reference, a plasma cutter uses a tungsten electrode similar to that of a tig torch just smaller. once the arc is struck a highly pressurized gas gets turned into plasma. no heating just straight cutting.

Use your torch then. Thats what I used, I didn't know that about plasma cutters.

Originally Posted by gotta240

I also don't know about heating the diff up so much. My welder(by living) said that you dont want to heat it up TOO MUCH as it can warp the gears... Again, jmo.

If anything the heat would make them smaller, but not likely.... None the less, like 98koukile said, They're going to be welded together so why not especially because you want the best possible penetration for durability.

[babowc]

Originally Posted by Mlogue84

Use your torch then. Thats what I used, I didn't know that about plasma cutters.



If anything the heat would make them smaller, but not likely.... None the less, like 98koukile said, They're going to be welded together so why not especially because you want the best possible penetration for durability.

Heat EXPANDS objects.
Cold CONTRACTS things.

[ch1873857]

who cares, in a welded diff you are using your ring and pinion only. the ring isnt on the diff when hes heating it up therefor no harm was done.

[Mlogue84]

Originally Posted by babowc

Heat EXPANDS objects.
Cold CONTRACTS things.

You're right heat does expand things, but when metal cools it will be smaller than before.

[atutt]

Heating the gears is unnecessary unless they were made out of cast iron. Or, unless you have a lower amperage welder that runs on 120v or less. any 220v+ welder with at least 100 amps would be more than sufficient for this. Also, if you were to use flux-core or metal-core you would get much much better penetration than MIG w/ sheilding gas. Also heating it without knowing how to properly compensate for your settings will most likely create undercut. If you get undercut you will mostlikely snap the welds along with a gear tooth or two.

[ch1873857]

ahhh..his welds are great. you want real penetration, get some 5/32 7018 at about 150 amps and let it burn.

[atutt]

/\/\A little overkill don'tcha think? lol

[ch1873857]

never.

oolijdsfoa

[gotta240]

i wasn't implying warpage of the spider gears... I was talking about heat transfer to the ring and pinion.... Not dissing...just offering opinions.