Rear Subframe Differential Support Pictures

[rao]

A lot of people have discussed various solutions to the diff bolt problem. I decided to go with the solution offered by vendor mike radowski. It puts the bolt in double shear, makes a lot of sense to me and has held up to decent power numbers. It is also pretty darn cheap :)

Here is a typical thread discussing it http://forums.bimmerforums.com/forum/showthread.php?t=499460

I have never seen good pics of this solution in the subframe and since I had my freshly powder coated subframe ready for installation of new bushings I decided to try to get some good pics of this part in its home. I put the busings in the freezer overnight and that with a small 12 ton press made short work of installing them. Once I have the RTAB's in hand the rear suspension will be going on the car.

Enjoy.

http://img225.imageshack.us/img225/7425/42807diffandcrossmemberxb6.jpg

http://img96.imageshack.us/img96/1231/42807diffandcrossmemberej9.jpg

http://img179.imageshack.us/img179/8559/42807diffandcrossmemberlk1.jpg

http://img80.imageshack.us/img80/2567/42807diffandcrossmemberfv0.jpg

http://img171.imageshack.us/img171/6408/42807diffandcrossmemberlu5.jpg

http://img96.imageshack.us/img96/4831/42807diffandcrossmemberyb2.jpg


The rear subframe is now tucked back into place, which means the I have officially started butting the car back together !!! :buttrock

I also welded up the part of the RTAB mounting points that was not welded as recommended by Turner Motorsports. No pics, just imagine them welded up :)

[promp3]

interesting, that looks tig welded...but the case is cast iron? am I missing somthing...
cast iron welding is a misterious thing to me, it does exsist, but I am pretty sure you can't just use mild steel filler rod. I have heard of people welding up cracks with mild steel but never a load bearing weld.

[rao]

The case is cast iron and cast iron can be TIG welded.

That support and the joint are strong enough to support the whole car and then some. Time will tell though.

[dynamowhum]

Thanks for sharing RAO

[GMW364i]

Rob,

We tried that setup on a car, it had cracked after ~2500 miles with an LS1. It was properly tig welded as well. Hopefully you have better luck. Other issues are going to cause problems with your differential, I wish I saw your post before you powder coated as your subframe is going to twist up.

Paul

[rao]

I know - the 36 reinforcements that are needed.

Get them in a CAD file so that I can use them when mine breaks. :)

[mike radowski]

Thanks for the pics Rob!

At first I TIG welded mine on with a nickel rod and a mild preheat. I saw a small crack forming one day while the car was on the lift. I then MIG welded it at the highest amperage setting. It's bombproof now. I haven't had an issue with any brackets that I have installed here with my MIG.