jakeshoe Posted September 5, 2006 Share Posted September 5, 2006 I'm playing the trans swap game again in the Z car. I have yet to really drive it, but long story short, I pulled the initially installed TH350 out to rob the converter for another project. I then installed a 200-4R in the Z, but I got a serious offer on the 2004-R, so I sold it, and now am re-installing the Th350. I really do not like the way the JTR crossmember fits, and it appears to elevate the transmission too high causing odd driveline angles. I would have to space the crossmember down from the car to get a more idea driveline angle. I'll probably just fab up a different crossmember after looking at it tonight. I need to actually measure the driveline angles but I can look at it visually and tell the engine and trans are tilted upwards in the rear instead of downwards or even level as they should be. Any other experiences? Quote Link to comment Share on other sites More sharing options...
bjhines Posted September 5, 2006 Share Posted September 5, 2006 damn heavy piece... Quote Link to comment Share on other sites More sharing options...
jakeshoe Posted September 5, 2006 Author Share Posted September 5, 2006 damn heavy piece... Yah, It's plenty stout enough, the floorboards will give out before the crossmember does. It doesn't seem to fit real good or give the correct driveline angles. My car is a early styel 260, so I'm wondering if the crossmember is more oriented to the 280 cars... Quote Link to comment Share on other sites More sharing options...
BWRex Posted September 5, 2006 Share Posted September 5, 2006 I don't care for it too much either.The mounting to the floorpan is,o, I don't know,somewhat cheesy.On the other hand,it wouldn't be in the manual if it didn't work.There are a few members here that fabbed their own trans mounts for various transmissions,that IMO,are stronger looking,prettier,and more accomodating for things like dual exaust.Try searching,members galleries,etc.The information you seek is here,it sometimes takes alittle while to dig it up.Good luck,and post the trans mount you decide to go with! Quote Link to comment Share on other sites More sharing options...
280zwitha383 Posted September 5, 2006 Share Posted September 5, 2006 Look at JTR's transmission mount for the ZX, it is a three piece VERY adjustable mount that bolts onto the tunnel and everything is slotted. I have seen a mount that is just 4 bolts into the tunnel, two on each side welded together so that it's just one piece. The 4 bolt one is very simple and I would guess it would work fine. Quote Link to comment Share on other sites More sharing options...
Lason Posted September 5, 2006 Share Posted September 5, 2006 I talked to the guy at JCI when I went in to pick up my LS1 stuff about the tranny crossmember because I dont like the floor mount thing myself. He said they offer two of them. On is a JTR style mount but it comes with re-inforcing plates to go on the interior to keep the bolt from pulling out of the floor which is a VERY good idea IMO. The other they offer is for late 260/280Z's that attaches to the subframes. The late 260/280 subframe extends further back as it knife edges than the 240/early 260 so that is why they have two. Personally Im putting in frame connectors out of 2x3 tubing and will attach my home made x-member there. Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted September 5, 2006 Share Posted September 5, 2006 I am planning to do my mounts something like original - braces on the sides of the tunnel and a bracket from there under the tranny. Quote Link to comment Share on other sites More sharing options...
jakeshoe Posted September 5, 2006 Author Share Posted September 5, 2006 I made some brace plates to spread the load on the floor from 6x6" steel 1/8" thick metal. Should really help as far as that goes. MY main concern is not so much the mounting as just the geometry. It seems way off to me. The trans is angled upward. I'll have to get under it with an angle finder and check all the geometry but it seems it would be WAY off just looking at it visually. Quote Link to comment Share on other sites More sharing options...
jbk240z Posted September 5, 2006 Share Posted September 5, 2006 I think it is good for a mild street car, but I do agree that it seems to angle the trans up a bit. Quote Link to comment Share on other sites More sharing options...
a6t8vw Posted September 5, 2006 Share Posted September 5, 2006 whats most important is the output shaft of the trans and the pinion angles are parallel despite the diffrence in height. This cancels out the vibes Quote Link to comment Share on other sites More sharing options...
wheelman Posted September 5, 2006 Share Posted September 5, 2006 I don't like the JTR tranny crossmember either so I made hangers for the stock Datsun member and moved it back in the tunnel about 4-5 inches to match up with my T5. I slotted the stock Datsun tranny mount (bolts to the tranny and the crossmember), the crossmember and the hangers I made so everything is adjustable. I bolted the hangers through the tunnel wall with backing plates inside the car for reenforcement. I had to do a little widening in the tunnel but you can't tell from inside the car. The output shaft and pinion angles are about 2 degrees off, which is a little more than I wanted but I can raise the nose of the diff to bring it to 1 degree. Not sure it would be worth the effort though as I don't have any vibrations from the driveline. Wheelman Quote Link to comment Share on other sites More sharing options...
gexgexgexgex Posted September 6, 2006 Share Posted September 6, 2006 well i plan on using the JTR crossmmber for my LT1 4l60e swap into my 1973 240z. I still can not believe it just monts to the floor, but if so many people use it its got to work. Any other ideas for a 4l60e crossmember besides the JTR one? Quote Link to comment Share on other sites More sharing options...
Turbo Meister Posted September 6, 2006 Share Posted September 6, 2006 My TH400 trans mounts to the JTR crossmember quite well. The crossmember is bolted to the floorboard, as recommended, and to the inside of the trans tunnel via 1/4" plates welded to the crossmember. Quote Link to comment Share on other sites More sharing options...
jakeshoe Posted September 7, 2006 Author Share Posted September 7, 2006 Got the trans installed today, crossmember re-installed, and the rear diff/driveline all secured. The rear diff actually sits higher than the trans, so actually the angles don't look nearly as bad as I initially thought. Just opposite of what I'm used to looking at. Now I just need to have an exhaust installed, and get it tagged/inspected. Quote Link to comment Share on other sites More sharing options...
dead2me Posted September 7, 2006 Share Posted September 7, 2006 I purchased the JTR, but ended up making my own as it didn't line things up for me the way they needed to be... very little on my car on my car ever seems friendly though, quite female in fact.... Quote Link to comment Share on other sites More sharing options...
Forces Posted September 29, 2006 Share Posted September 29, 2006 The second I put that crossmember under my car, I think my first impression was "....they can't be serious." I haven't decided if I want to use it. A guy I talked to in portland said that the floor pans were ripped apart with the 3"x 6"x 1/4" plate that is recomended by JTR. Quote Link to comment Share on other sites More sharing options...
Dan Juday Posted September 29, 2006 Share Posted September 29, 2006 I've used the JTR mount in my 240 with a T5 tranny and in a 280 with a T56. On both I made backer plates for the inside and used the recommended stock GM motor and tranny rubber mounts. I had no problems getting the u-joint angles right and have had no vibrations with either car. I had to slot the tranny mount hole with the T56 and add washers to raise the tailshaft for proper alignment. That car has side pipes so exhaust clearance is NA. I run duel 2 1/4" pipes on my 240 and where they pass under the mount is not the lowest point in the exhaust system. The JTR piece has the advantage of being simple, easy to work with, and already made. My experiance after two swaps is positive. Zero tranny mount problems. Quote Link to comment Share on other sites More sharing options...
nullbound Posted September 29, 2006 Share Posted September 29, 2006 I've also had zero issues with this mount, running a 200-4r behind my 377. I used plates on the top side as mentioned above. I'll be using the same mount on my next car. Quote Link to comment Share on other sites More sharing options...
heavy85 Posted September 29, 2006 Share Posted September 29, 2006 whats most important is the output shaft of the trans and the pinion angles are parallel despite the diffrence in height. This cancels out the vibes Not quite. True the angles need to be the same but the input and output shafts dont have to be parallel. Cameron Quote Link to comment Share on other sites More sharing options...
silicone boy Posted September 29, 2006 Share Posted September 29, 2006 I didn't have problems with my shaft angle (that doesn't sound quite right, does it?) I didn't like just being bolted to the floorpan, so I also fashioned brackets to attatch it to the frame rails (which were made of 2x4 metal tubing. It's really solid now. Quote Link to comment Share on other sites More sharing options...
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