subframe questions

[solipsvs]

ok so got a spare set of subframes that i wanna make cherry. wondering if anyone has seen a DIY on replacing bushings...

if theres some part numbers for the bushings, how did you remove the old ones and install the new ones...

is anyone making their own bushings from pourable compounds or if you have seen any for sale on the aftermarket.

thanks for your help!

[diagnosticator]

ok so got a spare set of subframes that i wanna make cherry. wondering if anyone has seen a DIY on replacing bushings...

if theres some part numbers for the bushings, how did you remove the old ones and install the new ones...

is anyone making their own bushings from pourable compounds or if you have seen any for sale on the aftermarket.

thanks for your help!

The main thing with the front subframe and the rear too, is to weld up the seams in the subframe to avoid cracks and popping and clicking noises that will cause eventually. The welds should not be continuous, they should be about 2 inches long separated by 2 inches. The subframe should be powder coated after welding to prevent rust.

The subframe bushings do not wear much at all. Unless there is damage or evidence of wear, replacing these bushings won't make any noticeable difference with interior cabin NVH .

[solipsvs]

ok thats what i suspected. the bushings dont seem to be removeable... and i want to powdercoat or paint it... can i do that with bushings in? good info on the welding.

[Steve Bassen]

Yeah, just stitch weld the subframe and hit it with some good epoxy paint afterwards. As far as the bushings go, just clean them with a good solvent and fill them with window weld to firm them up.

[diagnosticator]

I agree with Steve, epoxy paint will be easier to apply. Just make sure the surface is prepped right for a good seal against rust.

[solipsvs]

ok cool thanks. i can safely have them blasted i assume

[Denio24]

ok cool thanks. i can safely have them blasted i assume

Blast it or sand it and it will rust fairly quickly. Here is the process. Best is to sand progressively to from coarse to ~180 (finish with scotchbrite aluminum oxide) grit or blast everything and use a zinc phosphate cleaner/conditioner before spraying with epoxy primer. Most good epoxy primers nowadays have uv inhibitors and corrosion inhibitors in them and can be pretty much applied over anything. People don't really use self-etching primers nowadays unless it's going over bare unsanded metal and you're to lazy to scuff it up before painting. Only thing with epoxy primers it must be sanded to roughly 180 grit to adhere properly. Give 2 coats of that within the flashtime and your coverage will be pretty good. You don't have to apply a topcoat the choice is all yours, but if you want to then a good rattlecan spray paint will do.

A good epoxy primer my buddy uses is PPG DPLF..edit Southern Polyurethanes, not PPG DPLF. LINK

A more readily available primer would also be the Eastwood Epoxy Primer, and has been shown that is can hold up fairly well on its own.

[solipsvs]

thanks you guys for the info.

what about the inside of my subframe? is there an effective way to coat that? or is this why the sanding recommendation instead of blasting?

[diagnosticator]

thanks you guys for the info.

what about the inside of my subframe? is there an effective way to coat that? or is this why the sanding recommendation instead of blasting?

The subframe is dip coated at the factory, and there is no access to the inside. So sanding will preserve the inside paint coating if it is still in good condition.

BTW, I think the RS4 subframes are stainless steel FYI.

[solipsvs]

b7 rs4? nice idea

[Steve Bassen]

The subframe is dip coated at the factory, and there is no access to the inside. So sanding will preserve the inside paint coating if it is still in good condition.

BTW, I think the RS4 subframes are stainless steel FYI.

You might be thinking of the RS6 subframe, which is aluminum (and compatible with the B5 through B7, although I don't think anyone's actually done the swap).

[solipsvs]

so c5 rs6 subframe(s) is/are compatible with b6 a4? 1.8t too? any adaption needed? i like a non-rusty subframe!

[diagnosticator]

You might be thinking of the RS6 subframe, which is aluminum (and compatible with the B5 through B7, although I don't think anyone's actually done the swap).

I am not sure about what RS has the stainless sub-frames. I read that they are definitely stainless steel though. I will try and confirm that info.

[solipsvs]

im more worried about fitment