HizAndHerz Posted April 30, 2006 Share Posted April 30, 2006 Can anyone provide the measurements for the JTR crossmember so I can see if it will work for the Maxima auto tranny? I've looked at lots of pics of off the shelf and fabbed transmisssion mounts on the forum, but haven't come to a conclusion on how to handle a Maxima 4-speed auto in my 280Z. I'd like to avoid having to re-route the exhaust, and it looks like the JTR crossmember may be the easiest option. The Maxima has the mount about 6" behind where the 5-speed has them, so I cut the original brackets out of the tunnel. The tunnel is oddly shaped back there and it would be difficult to make new brackets that bolt or weld up to the tunnel like the originals. I've also looked at using the front differential crossmember, and I can make the work around the exhaust, but it hangs pretty low and is a bit kludgy. I don't weld so I'd like something that could bolt in. Any thoughts? Quote Link to comment Share on other sites More sharing options...
Darrel Posted April 30, 2006 Share Posted April 30, 2006 The zx tunnel isn't as flat as you think it is. Go ahead and make the brackets with 2x3 square channel with one side cut out. Use which ever crossmember, straight or curved that will match closer to the tunnel. You can always shim it out. For the interior you will have matching plates to thru bolt to. The straight or curved brace is proably about the best bet to use. The joys of modification. Quote Link to comment Share on other sites More sharing options...
HizAndHerz Posted April 30, 2006 Author Share Posted April 30, 2006 Darrel, that's what I'm going to do. You know how it is, can't help but keep second guessing Quote Link to comment Share on other sites More sharing options...
HizAndHerz Posted May 1, 2006 Author Share Posted May 1, 2006 Darrel, it looks like I'm doing a combination of things. I've been trying to avoid the hassle and expense of having the exhaust re-routed. Using the original crossmember and putting new brackets on the tunnel would get in the way of the exhaust. The second approach was to use a differential crossmember which has the bend for the exhaust pipe. I was going to try to extend the corssmember by bolting on "wings" and then bolt it all to the floorboard with reinforcement. What I'm doing now is cutting the differential corssmember so that it fits up into the tunnel. Then I'm going to make new brackets out of 1/4" thick angle iron (the only place I could get supplies from on a Sunday didn't have square channel). I'm going to butt two pieces of angle iron together with two or three big bolts through each to make the bracket. I cut a flange out of the exhaust pipe since it was right in the way. For now, I'm going to put a sleeve on and then have it welded up right when I'm all done. Here's what I have so far: Here's a bottom view. Note that there's plenty of room before the yoke bottoms out on the tranny case. Another thing. The tranny mount is in pretty bad shape, the rubber is about to let go. I'm probably going to rig up the crossmember so that I can use a GM-style transmission mount like this one: Please tell me what you think. Thanks! Quote Link to comment Share on other sites More sharing options...
Darrel Posted May 1, 2006 Share Posted May 1, 2006 Ya just gotta build a better mouse trap dontcha? When I went to Utah to pick up my transmission from Twheel, I checked out how he did his swap. About the only thing I made different were the brackets. Everything else was pretty much the same. What did it look like with the other cross members? With the orignal cross members they do turn up to allow for the exhaust. Quote Link to comment Share on other sites More sharing options...
HizAndHerz Posted May 1, 2006 Author Share Posted May 1, 2006 Ya just gotta build a better mouse trap dontcha? Well, I tend to obsess over stuff. I just thought it was cool how well the hump for the exhaust pipe worked out. What did it look like with the other cross members? With the orignal cross members they do turn up to allow for the exhaust.The original just didn't turn up enough to get out of the way of the exhaust. It also hit the passenger side of the tunnel so I'd either need to bash in the tunnel a bit or drill another hole in the crossmember so that the mount could be a little off-center. I really appreciate you giving me all the great info and allowing me to bounce ideas off you. I'm taking off of work tomorrow to try to finish this thing off. We could have 280Z #2 back on the road tomorrow! Of course, that will leave room in the garage for Z #1 to have the Maxima N-47 head swap. It never ends, does it? Quote Link to comment Share on other sites More sharing options...
Darrel Posted May 1, 2006 Share Posted May 1, 2006 When I did mine, I knew i was going to have new exhaust. I made sure the driveline angle was correct (although I'm not convinced of that now). Then I had the exhaust done in 3". When you get it done, I'm sure your wife will love it. Quote Link to comment Share on other sites More sharing options...
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