PBM Solid Diff and Subframe mounts install
 

Hey guys new to the forum. I've been setting my car up as a drift/stance/inching towards show car. Currently sitting on BC BR extreme lows and have maxed out ride height in the rear. Being that low I've heard of people breaking axles, specifically breaking bearing casings and am going to order the subframe and diff risers this week. Any advice for dropping the subframe? Have done big jobs but never dropped a subframe before and was hoping someone here had some pointers or trouble spots on this job. Thanks guys!

One thing that does crop up is the risk of stripping the bolts if you are not careful when replacing them. Apparently they are easy to get cross threaded and if you wreck the threads in the body you're screwed. For example, if you check out the install video for MCA traction aids, which require removal and replacement of two of the main rear subframe bolts, they go to the trouble of wire brushing the bolt threads before carefully starting them back into the holes. They only use the power wrench after the bolts are well started by hand. I think Whiteline also has a good install video online for their bushing kit instal which requires removal and replacement of all the subframe bolts.

The subframe alignment is also a bit sloppy judging by how far off the factory delivered camber can be. Might be a two person job to get the subframe centred.

There is some slop in the subframe but it doesn't affect camber.

It can affect the difference between right and left camber, apparently, but I see your point. If all the suspension pick up points are on the subframe itself then supposing the subframe can be installed slightly out of alignment with the body it would affect the thrust angle of the rear axle but not any of the individual settings. My alignment guy suggested he needed crash bolts in the LCA to equalize the rear camber side to side.

Yea I saw the guy that stripped his bolts but"hand tightening" them and the wire brushing does make a lot of sense. And what do I need to do to ensure that everything is a aligned tj the best of my ability. I'm doing this to save my axles I wanna make sure I don't put them in another bind ya know ?

I wouldn't worry about it, outside off getting the bolts in. It's really a negligible amount of movement.

I just did the subframe inserts a couple of weeks ago and it didn't affect the alignment. Just be real careful with the bolts as they are easy to strip. Clean all the threads and make sure everything is lined up when putting them back in.

Looking at the subframe diagram more carefully I see that everything bolts up to that, diff included. It is not possible to misalign anything bolted to the subframe. If you are reasonably careful bolting the subframe up to the body everything should be automatically lined up perfectly. No doubt that's why the factory builds it this way.

Okay awesome info so far, one last question. If I'm dropping the subframe and throwing the diff and subframe risers in is there anything I should buy and throw in while I have the thug on the floor? Any preventive maintence things or cheap upgrades to make my time more worth it?