Subframe Bracing

[supra90turbo]

Well, I'm bringing my subframe to get welded today!
While it's there, I'm gonna have them strengthen it too.
Someone want to show me where the braces need to go?
I've never seen a broken one, so I don't know what the weak points are.





thanks!

 

[IJ.]

Kurt: See the U cutout for the Diff nose?

This is a good place to start bracing (only failed ones I've seen have all been around there)

Once I start on my 9" install I plan to do the bracing thing as well so will have a better idea what's involved then!

More detailed pics from different angles and I could make suggestions but as I've never had mine out I'm flying a little blind here.

 

[bgrieger]

Look to reinforce around these areas (one badly cracked one...pics from a post on SF, but my parts car looked similar). I would box in the U shaped section at the driveshaft end, reinforce the bolt holes and strap across the top of the subframe where it crosses the back of the diff.

 

[IJ.]

bgrieger: Thanks for the post!

 

[supra90turbo]

WOW!!! Yes thank you very much!!!!!

 

[supra90turbo]

Just noticed I put this in 7M technical... D'OH!

 

[mkIIIman089]

Whoa! I didn't realize thats the kind of stuff people were talking about with these cracks, much more serious then I thought.

 

[IJ.]

There's a theory that if any of the bolts are loose at all it stresses the others and rips them apart!

A few of mine weren't as tight as when I fitted the Torsen so this could be true! (good argument for loctite)

 

[supra90turbo]

Mine were all wicked tight, so that could be why my subframe was mint.

For anyone in my area...
www.dentsport.com

I highly recommend them to anyone who wants any work done. They are top notch. Very cool guys.

 

[mkIIIman089]

Ugh... with the DS fiasco I just had I might want to check those bolts too then. I torqued them all to spec but I didn't use thread locker or anything.

 

[IJ.]

My Subframe is good but I didn't expect it to be damaged as the car was an NA so wouldn't have had enough power to break it!

 

[drjonez]

the key is the diff nose mount area....all other damage you see is caused by motion of the diff (typically after the nose mount cracks, the diff starts flopping up/down...damaging other parts). the '89+ braces are KEY and it is probably worth welding in extra bracing as well. nashman did some GREAT work, see if you can find pix of what he did.

personally, i added 20 lbs of steel to my subframe...

 

[johnathan1]

I know this thread is really old, but are you saying the 89+ subframes are much stronger than the pre-89 ones, jonez?

This is what I discovered today, after looking for the cause of the "squeaking" sounds I have been hearing for the last couple of weeks:

Does this look like it was caused by loose mounting bolts? Should I try to tighten the other three bolts to make it last a little bit longer, while I find a replacement?

 

[drjonez]

I know this thread is really old, but are you saying the 89+ subframes are much stronger than the pre-89 ones, jonez?

This is what I discovered today, after looking for the cause of the "squeaking" sounds I have been hearing for the last couple of weeks:

Does this look like it was caused by loose mounting bolts? Should I try to tighten the other three bolts to make it last a little bit longer, while I find a replacement?

nope, i'm not saying that @ all. the only diff between the yrs is the addition of the braces on the '89+ ones....and that doesn't even help.

yup, i think the diff being slightly loose is a contributing factor to the beating death of your subframe. yours looks pretty bad, time for a new one...