i cant decide if i want to weld the rear diff on my 78 subaru brat. it has a 4 inch lift, and i run 27-29 inch tires on it. i primarily use it off-road, but it does see occasional highway driving and around town. if i weld the rear diff, i know it will help a lot off-road, but im afraid that when i drive in on pavement i will break axles or the diff itself. i know some people weld the diff, then remove an axle for street driving... but that sounds like a pain to do all the time. what are your experiences with welded diffs? should i do it?

Weld it,Over inflate your rear tires for street driving,drive it fast around turns so there is less force on each axle,finally when turning from a stop turn as wide as you can to again minimize the stress on rear axles.I will say though that actually blowing a rear axle or the diff on the street is rare unless you pull the front axles for RWD shenanigans...

 

However,it is not advised to weld it with a 110 welder,unless you can heat the spiders to a dull red  with a torch to get more penetration.

 

also when your driving on a slow curvy paved road (sub 35 MPH) it can help if you intentionally drop one of the rear tires into the dirt.

Edited June 12, 201411 yr by Uberoo

i appreciate the input so its not that big of a deal on pavement around town? i have access to a 220 mig welder, that should do the trick right? also, im going to be running some deep tread tires, does that make a difference?

real light rig Ive done it, don't carry a big load in the back ,

other than tire noise its not a problem because the rear axle is just dragged through corners without power being sent to it.

Alright awesome! I will weld it asap! Thanks guys

I picked up a spare rear diff to weld so if I screwed up and it breaks, I could plug in the original.

Edited June 16, 201411 yr by ironworkerboomer

i'd like to do that if i can find one on the cheap

i'd like to do that if i can find one on the cheap

I have a 3.9 diff laying around in Missouri... I could have a friend ship it if you're interested

im actually thinking about ditching the brat project.. but i will let you know if i change my mind, thanks