How to remove subframe cross brace?

gshort24

Any ideas on how I can remove this cross brace on the rear subframe? I'm trying to remove it so I can weld some brackets onto the ends to then be able to mount a Nismo performance damper. I just want to pull the brace out without dropping the whole subframe. Is there a way to unbolt the 2 rear subframe bolts to remove this support bar or a way to support the subframe and hold it in place so it wont drop out while I remove this bar? I tried removing the subframe bolts while the car was sitting on the ground and the subframe started to drop and slide down the long bolts so I just ended up tightening the bolts again. I can find access to a lift, but was just hoping I could remove this piece in my garage. Would it help to jack up the rear by the diff to put upward pressure on the subrame while I loosen the 2 rear subframe bolts? Guessing my mechanic will probably charge me a couple hours of work to remove this which would be $300 so trying to avoid that if I can. I would still need to remove the piece, take it to a welder to weld on the brackets before re-installing while I'm sure my mechanic will also charge me for the time the car is sitting on the lift etc, so didn't want to turn this into a $500 labor fee etc. just to be able to weld some brackets on.

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SouthArk370Z

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husam2012

You can loosen the bolts and while it will drop a little, it wont drop all the way.

You can also jack up on the diff to keep it in place, but I've lowered the subframe at one end before with no effects.

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Rusty

Jack the rear of the car up. Use jack stands to hold it up. Then put your floor jack under the diff. Then knock your socks off.

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gshort24

I don't have any room to put the jack stands under the subframe itself because the piece I need to take out also needs to slide forward 3-4 inches so it can clear the area where the long curved and skinny bars connect to it in the center (think its called the K frame brace), so i would have to slide the piece I want to remove into the only area that I can see to put the jack stands under.

If I just support the diff and remove the 2 rear subframe bolts which hopefully the sub frame wont drop and come off the 2 rear bolts because I don't think I'd have a way to raise it back up, but if that all works out is there any way that removing the 2 rear subframe bolts causing it to drop an inch or 2 would stress the front 2 subframe bolts or bushings? If I loosen the bolts the subframe drops, I may end up having to remove the k frame brace as well etc, but is it possible or any risk that after I remove loosen the rear bolts and remove and replace some supports, that after I bolt everything back in place that the subframe can be misaligned or will throw off my rear alignment etc. I'm not touching any suspension arms or components etc, but can the whole rear subframe shift?

I'm not a very experienced mechanic, and trying to save a few bucks, so just trying to look at potential problems before I mess anything up. Thanks for the help.

JARblue

Use the jack stand points instead of the subframe itself. They are in front of the rear tires ... should be clear of any parts you're looking to move around. See where they have the rear load set on this lift:

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Rusty

You are over thinking this. Like Jar said. Put the jackstands in front of the rear tires. Place your floor jack on the diff to keep the sub-frame from dropping. Start unbolting.

Your alignment shouldn't change if the sub-frame doesn't move. As ALL of the suspension pieces bolt to it. The only bad thing that could happen is if the sub-frame dropped and you bent the front 2 studs.

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BettyZ

Hope you're an experienced welder; life could get real interesting real quick if one of those tabs broke off.

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Rusty

What tab?

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BettyZ

The brackets the OP wants to weld onto the subframe so he can attach a Nismo rear damper. Did you lose your reading glasses again

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Rusty

My brackets are bolted on. Two bolts on each side.

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gshort24

I can handle oil changes, but that's about it, so I appreciate everyone's advise and suggestions which gave me the confidence to do this myself with limited tools etc. Thanks for the help.

In order to remove the cross member support straight down instead of trying to slide it forward a couple inches to clear the attachment area in the center for the long curved round bar sub frame brace, I just removed 6 bolts that were easy to get to, and dropped that curved brace down a few inches which didn't take that long. I looked again and their was an area where I could support the subrame with jack stands or for more space savings I just used a 2 x 4. As I was loosening the rear subframe bolts to get to the piece i wanted to remove, the body started separating from the subframe which made me nervous during my first attempt, but it ended up that the subframe was not actually dropping down away from the body which I expected load to be put on the 2 x 4s I had under the subframe, but instead since the shocks were still connected to the the body, it seems like the bolts were pulling and sucking the body down onto the subframe. I removed the subframe bolts, twisted and finagled the crossbrace out and through the side of the car so I didn't have to remove the muffler.

I was able to get ahold of a crusty Nismo crossbrace to use as a template to create my own brackets which could be welded onto the piece I pulled out of my car. I'll take it to a professional welder, then should be good to go.

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JARblue

Glad you got it taken care of but still confused why you didn't just use the designated jack stand points in front of the rear wheels

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gshort24

I could do the work without needing to lift the car, and I was originally concerned with holding up the rear part of the subrame which I thought would sag down. Supporting the jack point area was not a bad idea especially if I lifted the car, but I didn't try that mainly because the jack point was closer to the front end of the subframe, and not directly under the area were the bolts were being removed.

gshort24

I got the brackets welded on etc, the location of the bracket and the bolt holes appear to be the same as the OEM sample part that I have which has the brackets. It sounds like you have a Nismo that came with these performance dampeners. Can you do me a favor and check the clearance between the performance damper bracket and the lower control arm?

Mine is not touching, but it's pretty close, I can't stick a finger tip in between the bracket and the suspension arm. Is this OK or do I need more clearance in case I hit a large bump etc. It's hard to get a clear pic of the gap because of the shadows and the camera has to be at the perfect angle etc.

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