Work on my rear end, DIY or sub-out?

So it turns out the CSPish Miata has a bent rear sub-frame/cradle. It prevents me from getting a proper alignment and locates the left rear wheel almost 2" forward. I've sourced a new unbent one and have it ready to go.

So how big a job is it? My friend who owns/operates a local shop (who did my alignment and is a solid guy) offered to do it on a Saturday for "significantly less" than the usual price of $750. I can't get him to commit to an actual number though.

I'm fairly handy and have jackstands, impact tools, etc. I replaced the rear diff already so it looks like some of the same steps. I'm feeling like 500-600 dollars is a lot of cash for something I technically CAN do but I'd hate to get it ripped apart to find out that I'm over my head.

Any sage advice? Warnings?

DIY, both for the money savings and so that you know what else is going on under there (oh look, a nearly worn through brake line!). I would bet that taking the whole rear subframe out is barely any more difficult than the diff swap you've already done, if not easier.

You can drop the whole subframe and suspension out as one piece. You will have to disconnect the brake lines - when I did it, I left the parking brake cables connected and unbolted the brake calipers, which meant disconnecting the soft lines to both calipers at the body end. The subframe is 4 bolts and 2 nuts, all of which are pretty easily accessible.

If you're doing it on jackstands, the easy way to do it is probably to drop the diff (remove driveshaft and exhaust, unbolt/pull axles depending on which ones you have) then take the control arms off, just so you're not trying to drop out a big heavy chunk all at once. Then drop just the subframe. Assembly is the reverse of disassembly, as they say. It will take a while just because of the number of things connected, but none of it is difficult.

Isn't the painful part disconnecting the PPF?

Seriously? 4 hours in and no comments about DIY rear end work? I'm cancelling my subscription.

Duke wrote: Seriously? 4 hours in and no comments about DIY rear end work? I'm cancelling my subscription.

I came here to post something, uh... similar.

I am also dissapoint.

Duke wrote: Seriously? 4 hours in and no comments about DIY rear end work? I'm cancelling my subscription.

I know, it was slow pitch softball time. I mean Miata, rear-end work, etc. How much easier can I make the setup?

I don't really know about the specifics of the Miata - but it's an IRS and usually they connect to the chassis in only a couple points. I drop the rear out of an E36 by disconnecting the exhaust, driveshaft, the top of the dampers, control arm buckets and 4 bolts in the subframe. It then rolls out from under the car with a skateboard under the diff. Less than an hour to get here:

Once it's out - everything is easy even if it's rusty or stubborn because you aren't laying on your back and the torch won't ignite the gas tank :)

I have nothing to add except the original post said the left rear wheel is 2 feet forward. I can see how that could be an alignment problem. I loled

This thread is a disappointment. Just when I think I have you guys figured out, you go and throw me for a loop.

In reply to Antihero: Ha! Oops, I fixed

Work with/for your friend at his shop, to help drive the "significantly less" cost down even further, and to provide you with the tech support and tools you might need. His shop is a whole lot better than your driveway.

Bring beverages and lunch, and you might even get it done for free.

In reply to KyAllroad:

Rust would be the deciding factor on whether I'd pay ~$500(or even the full $750) for someone else to do that job.

petegossett wrote: In reply to KyAllroad: Rust would be the deciding factor on whether I'd pay ~$500(or even the full $750) for someone else to do that job.

This. All of this.

If you know your car is rust free, I'd say do it at home. But if you have the slightest doubt of rusty hardware, the shop will probably be worth every penny.

If you can get the lower control arm long bolt out without bashing the threads to bits with a (large) hammer, the rest of it is probably safe.

I disagree about the rust. Get the car on stands days before you are going to actually work on it, PB blast everything you're going to touch- daily if you can leave it there. An impact gun should make short work of everything after that.

No appreciable rust. My rear end is clean

See, it's not that difficult to make these jokes! You guys are slipping....

In that case, you'll have a line of Miata guys willing to help with you clean rear end with a thread title like that.

So it seems that as long as you use lots of lube and be careful when pulling out the long bolts (may need to rock them in and out a little) you should have no problems with DIY work on your rear end.

I just dropped a rear end out if a Miata last weekend- it took me less than 20 minutes. I have a lift, but still...

Do it yourself. Change all the bushings while you are in there, and change the fluid. Swap out the diff mounts for poly ones (you will thank me). Clean everything, and paint. 2 weekends, and it will be perfect- you will feel great about yourself.

And just think how many rear end jokes you will gain by the time you lube that thing and stick it in the rear- priceless!

Well, are you the type that prefers the self gratification of hammering your own rear end, or do you take pleasure in having someone else hammering it?

So tonight after work I pulled it apart, got the old subframe out and the new one in. Tomorrow night I'll bolt everything back together and get it out to the shop for an alignment next week.

I did manage to dump ALL of the diff oil out on the driveway.