Swapping out front subframe on jack stands?

[Tatsu333]

I picked up a used 2018 tS front subframe and flexible draw stiffeners from the member classifieds here that I'm going to swap onto my 2020 BRZ as I continue with my build.

A local shop quoted me 6.5 hours @ $130 CAD for labour to do the swap, so I'm *thinking* about tackling it myself in my garage on jack stands since I'd much rather spend that money on something else...LOL.

This YouTube video on the swap makes me think it's more like a couple of hours' work, tops, so I'm really having trouble swallowing that cost, but the idea of having to support the motor while I'm under it kind of freaks me out a bit, and I know it will be a PITA for access to some things without a lift.

Anyone have any thoughts / feedback on the feasibility of doing this swap on jack stands and/or any advice on how best to do it?

[NoHaveMSG]

I’d try to rent/borrow an engine hoist.

[Stang70Fastback]

I've never done it, and I'm sure an engine hoist or something would help, but... as someone who has swapped engine mounts by simply jacking the engine up by the oil pan... wouldn't this just be the same process? You gotta disconnect the other bits and bobs first (steering rack, front LCA, etc...) but once you slightly jack up the engine... that front crossmember isn't doing anything, right? In theory couldn't you just unbolt it, swap over your engine mounts, and bolt the new one back on?

[Tatsu333]

Originally Posted by Stang70Fastback

I've never done it, and I'm sure an engine hoist or something would help, but... as someone who has swapped engine mounts by simply jacking the engine up by the oil pan... wouldn't this just be the same process? You gotta disconnect the other bits and bobs first (steering rack, front LCA, etc...) but once you slightly jack up the engine... that front crossmember isn't doing anything, right? In theory couldn't you just unbolt it, swap over your engine mounts, and bolt the new one back on?

Basically, this looks like what the guy in the video has done, but with the car on a lift. I'm just a bit worried about a) supporting the entire weight of the motor by the oil pan (though I suppose if the transmission mount is still connected, it's also doing a bit) and b) having it be balanced enough that it's not going to somehow flop over / off the jack while I'm under the car (which is probably not something that's possible, but hey - I have no idea...).

Originally Posted by NoHaveMSG

I’d try to rent/borrow an engine hoist.

This presumes I would know how to hook it up properly...LOL. While I've wrenched on my cars plenty, that's one thing I've never done. It looks simple enough in principle, but I don't know exactly where on the motor to hook it up. That said, I would definitely be more comfortable with this option than jacking it up by the oil pan, and it *looks* like I could rent one locally for about $60 per day...

Hmm...definitely worth looking into further to save $800+ in labour...

Thanks for the feedback, folks!

[Tatsu333]

The other thing that is tricky is that I likely won't have room under the car to properly torque any bolts that go in horizontally (like the control arms, etc.) - just not enough room to turn my 3' torque wrench.

Could be that prying out the control arms from the subframe would also be challenging because of the space.

I'll have to think on this a bit more...

[Stang70Fastback]

Originally Posted by Tatsu333

The other thing that is tricky is that I likely won't have room under the car to properly torque any bolts that go in horizontally (like the control arms, etc.) - just not enough room to turn my 3' torque wrench.

Could be that prying out the control arms from the subframe would also be challenging because of the space.

I'll have to think on this a bit more...

Meh, I just replaced literally everything up front EXCEPT the subframe with only a set of jackstands. The only bolts with over a 100 ft-lb torque spec are the two bolts securing the knuckle to the strut, which you won't be loosening or tightening from under the car. Having said that, an electric impact is your friend.

[dragoontwo]

I did this by supporting the transmission with the car on jackstands.

[Tatsu333]

Originally Posted by Stang70Fastback

Meh, I just replaced literally everything up front EXCEPT the subframe with only a set of jackstands. The only bolts with over a 100 ft-lb torque spec are the two bolts securing the knuckle to the strut, which you won't be loosening or tightening from under the car. Having said that, an electric impact is your friend.

I *LOVE* my electric impact gun - one of the best tool purchases I ever made for something so inexpensive...LOL.