Rear 260 bumper removal / shock compression

[The Wingnut]

The Z is going into the body shop in a few weeks and I'm trying to get all the critical stuff out of the way before it happens. I'd like to get the rear bumper off before she goes in. How much of a pain is this? I'd consult an FSM if I had one.

I figure while I'm at it, I'll pull off the extra rubber and collapse the shocks.

...I've used the search option and come up with 280 bumper coversions / shock collapse, but didn't find anything on doing this to 260s. I haven't seena fill screw on the 260 shocks. Do I need to drill a hole in order to do this?

[The Wingnut]

The bumper is off. Four bolts and it's done. Rubber pieces are off as well.

Nearly 40 views and no input? I realize a lot of people here are safety conscious and frown on bumper mods. I'm assuming the risks associated with collapsing the shocks.

Anyone?

[The Wingnut]

I found the screws for the air side of the shocks. The left side collapsed without even taking the screw out, but the right side won't collapse even with the screw completely out and the air drained.

I would really appreciate some help with this.

[Arne]

A.J., I think part of the problem here is that I've never heard anyone talk about collapsing their Z's bumper shocks here. Collapsing the bumper shocks on a 2002, or 320i? Sure. But on a Z? Haven't heard about it. So I fear there isn't much knowledge on this here.

[Go240Zags]

A.J., I think part of the problem here is that I've never heard anyone talk about collapsing their Z's bumper shocks here. Collapsing the bumper shocks on a 2002, or 320i? Sure. But on a Z? Haven't heard about it. So I fear there isn't much knowledge on this here.

I found these threads with a quick search (the second thread is one you started Arne 'Newbie needs pre-purch advice'):

1. http://www.pronto.it/elenco/query.php

2. http://www.classiczcars.com/forums/showthread.php?t=18300&highlight=collapse+shocks

3. http://www.classiczcars.com/forums/showthread.php?t=12091&highlight=collapse+shocks

[redneckz II]

If you crawl under it and look at the mounts, you will see that it can be removed by taking out the three bolts that are holding the shock to the car. On one side it is easy to do. But the other side, you will need to lower the gas tank a small amount. You only have to drop it far enough to get your hand up and into the space above the tank. After use a rachet to get the three bolts out from above the gas tank. Then you can move the shock out or in to the area above the gas tank. It may take some turning to help get it out, just keep working at it. After that you can either add a 240Z rear bumper to it, or put it back on after the paint job. Good Luck with it, Rich.

[The Wingnut]

I managed to compress the passenger side shock. Both are now compressed and the next step is to find a stainless carriage bolt to go through the mounting holes in lieu of the large rubber bumpers.

It seems to be hit or miss with these shocks. One simply required loosening a screw and letting all of the gas out, the other would not compress until I'd let the gas out and drilled 3 different holes. Having done so, I would recommend letting out the gas using the screw in the end of the shock between the holes in the mounting bracket, and drilling a hole in the outer cylinder, not the inner. Drilling the inner will result in a large amount of oil / hydraulic fluid everywhere. If you drill into the outer cylinder near the flange where it tapers outward, it should release the gas in the outer cylinder and allow you to compress the shock. Do this before you drill the inner cylinder, which should be a last resort. Wear gloves and eye protection!

If you want to guard against low speed impacts, don't do this! Anything above 5 mph will likely damage the car beyond the protection that the bumpers can afford, but if you are still concerned with being hit, there is no going back once you've collapsed them.

[KDMatt]

I'm glad it worked out, and if you took any pictures during this process those might be neat to see.

I often dream about removing the fugly 5 mph bumpers that they slapped on the otherwise, flawless S30 body... I want to drive around bumperless I think... crazy as it sounds.

[zcarnut]

I did this on both the front and rear bumpers on my 260Z, Wingnut.

Once the shocks have been compressed you will need to secure them in the compressed position. I just drilled through both the inner and outer tube and used a bolt and nut. Once the rear bumper is compressed the bumper ends no longer line up with the 260Z rubber mounts. I used 240Z bumper end pieces (with the 260Z center piece) and these lined up with the holes on the 260Z body.

[The Wingnut]

Steve, when you say the rubber mounts don't line up, are you referring to the smaller pieces bolted into the recesses on the 1/4 panels and the inside of the bumper? I disposed of the larger piece farthest forward as it was in bad shape, but I kept the smaller ones that are completely hidden by the bumper itself..

My assumption was that these pieces prevented the bumper ends from 'wobbling' and hitting the bodywork. Maybe something could be fabricated to replace them.

[zcarnut]

Steve, when you say the rubber mounts don't line up, are you referring to the smaller pieces bolted into the recesses on the 1/4 panels and the inside of the bumper?....

I think so. It’s the rubber mount that bolts to the bumper end (with two bolts) and the body. They seem to break easily which is another reason to loose them.

My assumption was that these pieces prevented the bumper ends from 'wobbling' and hitting the bodywork. Maybe something could be fabricated to replace them.

I’m sure you could make something. I just thought it was easier to replace the bumper ends with 240Z ones and mount them to the body just like the 240Z did. The hole in the 260Z body lines right up with the 240Z bumper ends.

[The Wingnut]

I examined my bumper last night, you're right, they did tear off. It may be possible to rig a bracket of some sort with materials from a hardware store. I'd rather not have to go through the bother of tracking down and swapping in 240 bumper ends.

I kept the pieces...I'll look at them and try to come up with a solution.