Pacific coast Datsun Posted May 2, 2007 Report Share Posted May 2, 2007 Ok guys, with help from Kevin [bleach] & Ryan i was able to buy a 82 Z car 5 speed transmission which i will swap into my 71 521. I measured both tranny's already & the stock 4 speed short tail in the 71 is roughly 26 inches long & the Z tranny is roughly 31 1/2 long. I know i have to shorten the front shaft which i can do myself but i need to know by how much, & Kevin tells me that the tranny mounts swap easily & it will bolt right in.Also i was told to use the throwout bearing thats in the stock 4 speed instead of the 82 Z unit. I was wondering if anybody who has done this swap can post pics & or give me advice or tip me off to any possible problems they ran into. Quote Link to comment
slodat Posted May 2, 2007 Report Share Posted May 2, 2007 The clutch, t/o bearing, collar, etc are all associated together. The trans does not affect them. What Kevin is saying, is correct. You will have to relocate the shifter hole back some. To measure the drive line, wait until it's in the truck. Quote Link to comment
tangent Posted May 2, 2007 Report Share Posted May 2, 2007 Do you have the stock motor, or an L20 in your 521? Quote Link to comment
]2eDeYe Posted May 2, 2007 Report Share Posted May 2, 2007 Not much to add, but tell Ryan I said hi and to give me a call...or at least PM me ;) Quote Link to comment
Pacific coast Datsun Posted May 2, 2007 Author Report Share Posted May 2, 2007 Ok it's the stock L 16 w/ short tail 4 speed. Good idea on installing it 1st then measuring the front shaft. Steve Ill probably see him tomorrow night & ill tell him to hit you up. Ill be degreasing it before it goes in so i still have a few more days. Quote Link to comment
Bleach Posted May 2, 2007 Report Share Posted May 2, 2007 Keep that Z throwout bearing. Mark it "Z 225mm" so if you go with an L20b later in a Datsun you'll know you can use that with a Z 225mm clutch kit. take the weird tranny mount bracket off the tranny. The 4-speed crossmember and tranny mount will bolt to the Z trans. Quote Link to comment
datzenmike Posted May 3, 2007 Report Share Posted May 3, 2007 Could you not measure the two transmissions and subtract to get the difference? Quote Link to comment
Pacific coast Datsun Posted May 6, 2007 Author Report Share Posted May 6, 2007 Ok i got into the teardown/removal of the 4 speed & i noticed that the 521 trans. has a flange on the end of it & the shaft bolts up right there. The Z tranny driveshaft simply "slid" right in. My question is... is there a way to use the 521 front shaft on the Z trans.? Or, should i go back to the yard & snag the shaft out of the Z & use the front of it & mate it w/ the 521 shaft? Oh & does anybody have any tips to get the trans. to slide back to remove it? Im doing it w/ engine in, all bolts are off, exhaust is out of the way & I can only get it back from the engine about an inch! Quote Link to comment
datsunaholic Posted May 6, 2007 Report Share Posted May 6, 2007 Well, I unbolted the cab and jacked it up on my 720, which has the long transmission. That gave me the necessary room. Quote Link to comment
Icehouse Posted May 6, 2007 Report Share Posted May 6, 2007 I'm way to much of a wuss to do a tranny swap without pulling the engine.... I'm not good at hanging out under my rig. Plus my guns aren't big enough to hold a 4 speed up let alone a zx 5 speed :D So the tranny mount points are in the same spot? I put a dogleg in a 521 and I had to modify the tranny mount. I think you could find a short bed 620 DL that would work, as long as the 620 has a long tail trans the front half of the DL should be the perfect length. When I swapped the dogleg in the 521 I just used the 521 DL without the stupid big nut (haha Big nut) the 521 has a slip yoke I think thats why the bolt the DL to the trans, I have never had a problem not having the bolt in though. Quote Link to comment
Pacific coast Datsun Posted May 7, 2007 Author Report Share Posted May 7, 2007 Ok well for sure i know that i can simply swap the tranny mounts on the trans.so it will bolt to the 521 frame. And after talking with a few people yesterday i was told that i can unbolt the large bolt at the end of the trans. & then slide in a reg slip yoke shaft. But...the hole where the bolt was will have to be plugged or I can just weld the hole up to stop any fluid leaks. I think im going to just pull the motor & seperate the 2 then, & im sure ill have to use a 620 or the Z shaft & cut/weld them back up. Ill snap a few pics & post in a bit. the stock 521 front shaft... rear of the 4 speed, big ole 21 or 22 mm bolt & flange.. & the 82 Zx trans... Quote Link to comment
Bleach Posted May 7, 2007 Report Share Posted May 7, 2007 The whole time you were pulling that tranny I had thought it was going in your '74 620. :) Get a late 620 center driveshaft as mentioned. Hopefully one with decent rubber around the bearing. Make sure it is a standard cab short bed. It might fit as is... but even if it needs to be shortened you will have the correct shaft to go into the 5-speed. Quote Link to comment
Pacific coast Datsun Posted May 8, 2007 Author Report Share Posted May 8, 2007 Thanks Bleach. I found the 1 piece driveshaft that came out of my 69 521 & it fits into the Z trans....:D the nice thing is they're the same length... I have 2 options, run the 1 piece shaft or mate the front of the J 13 shaft to the 521 front shaft & keep it a 2 piece. Either way it'll have to be shortened. I should be pulling it all out tomorrow. Quote Link to comment
Icehouse Posted May 8, 2007 Report Share Posted May 8, 2007 Mine didn't leak that I know of. Quote Link to comment
Bleach Posted May 9, 2007 Report Share Posted May 9, 2007 wow Mark. Your shaft is even longer than mine! :eek: Quote Link to comment
datzenmike Posted May 9, 2007 Report Share Posted May 9, 2007 I think the one piece won't clear the cross frame that the carrier bearing and the torsion bars mount to. Or will hit it during suspension travel. Quote Link to comment
Bleach Posted May 9, 2007 Report Share Posted May 9, 2007 I think the one piece won't clear the cross frame that the carrier bearing and the torsion bars mount to. Or will hit it during suspension travel. cut cut cut Quote Link to comment
datzenmike Posted May 9, 2007 Report Share Posted May 9, 2007 I did this... a 4" section of 12" water pipe, cut, cut, cut... weld. Quote Link to comment
Icehouse Posted May 9, 2007 Report Share Posted May 9, 2007 Why did they stop doing a 1 piece? I heard that they made a law they could only be like 70 some inches or something??? Quote Link to comment
Pacific coast Datsun Posted May 9, 2007 Author Report Share Posted May 9, 2007 Allright, i got the motor pulled & the 4 speed off & the 5 speed mated to the block. I swapped throw out bearings as instructed by Bleach :D And as i was told by the PO the clutch looks new.... in hand is the Z TO bearing... & the Z trans mount removed, same exact mount as on the 4 speed except its farther back so ill have to fab a new trans. mount... And now i dropped it back in & lined up the motor mounts but i think the trans. is touching the floor of the cab..:confused: Ill get some better pics tomorrow. Quote Link to comment
Bleach Posted May 9, 2007 Report Share Posted May 9, 2007 The 620 has provisions in the frame to mount the rear crossmember in two locations like it was made (even in 1973) for a short or long tail. Hopefully you just drill a couple holes to mount the rear crossmember in there. Quote Link to comment
datsunaholic Posted May 9, 2007 Report Share Posted May 9, 2007 Well, even in '72 you could get a longtail tranmission in a 620... it was an automatic, though. That's why the 2 sets of mounting holes. They didn't change the chassis in '74 because the J-series 620s (Mexico-South America, Australia, UK, Africa, etc) still used the shorttail tranny through the late 70s. Quote Link to comment
Icehouse Posted May 9, 2007 Report Share Posted May 9, 2007 I had to fab a new mount for the dogleg trans. I basically cut 2 1/4" out of the stock mount and welded it back together. Quote Link to comment
Pacific coast Datsun Posted May 10, 2007 Author Report Share Posted May 10, 2007 Thanks guys,remember this is going in my 71 521. I may do this later on the 620. Huge progress today...got the motor bolted back in, modified the 521 trans.mount , & cut & re welded the front shaft.... the factory trans. mount is way too long, i cut 2 inches out of it... i welded it back together...thats Ryans middle finger..HaHa & it bolts right up perfectly! the 4 speed flange slided right into the 5 speed so i can bolt the front shaft back up after i shorten it... front shaft bolted to flange, you can see how far its off... I had to cut 4 1/2 inches out of the shaft then welded it back up. I test fit it afterwards & i need to drill out the holes on the carrier bearing bracket a little Quote Link to comment
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