troyt Posted October 21, 2010 Report Share Posted October 21, 2010 Which Datsun 5 speed trans came with the '81 720 truck? ratios, shift pattern, etc Thanks Quote Link to comment
datzenmike Posted October 21, 2010 Report Share Posted October 21, 2010 Which Datsun 5 speed trans came with the '81 720 truck? FS5W71B ratios, 2wd Z22 motor reg, long wheelbase and KC. 1st... 3.321 2nd... 2.077 3rd... 1.308 4th... 1.000 5th... 0.833 2wd SD22 motor reg, long wheelbase and King Cab. 1st... 3.592 2nd... 2.246 3rd... 1.415 4th... 1.000 5th... 0.813 4wd Z22 motor King cab only 1st... 3.592 2nd... 2.246 3rd... 1.415 4th... 1.000 5th... 0.813 shift pattern, 1..3..5 2..4..R etcThanks The 4X4 and diesel gears are identical but the speedometer is driven off the transfer case in the 4X4 so the tailstock of the 4X4 will not have the hole for the speedo drive pinion. The diesel starter is on the driver's side so the transmission will not bolt to the gas motors. Generally the transmissions are 31.5" long but there are short 26" 5 speeds, I have one from a 4X4. The shortness is all in the tailstock. Front and rear case halves will swap as well as internal gears (in sets). An L series front case can be swapped onto any of the '81 5 speeds from a 720. Quote Link to comment
troyt Posted October 21, 2010 Author Report Share Posted October 21, 2010 Thanks Mike. Got info on the mod to fit with an L, that's where I was headed next. Troy Quote Link to comment
datzenmike Posted October 21, 2010 Report Share Posted October 21, 2010 If swapping an L front onto one of those use the 2wd tranny. The others are too low in first and too much rpm drop between shifts. Quote Link to comment
jrock4224 Posted October 22, 2010 Report Share Posted October 22, 2010 mike you know everything your posts super impress me... you should start your own datsun website... Quote Link to comment
datzenmike Posted October 22, 2010 Report Share Posted October 22, 2010 Well it's from a few years of seeing the same questions asked, and usually answered, sometimes correctly. So I started writing stuff down, specially transmissions and started a collection of transmission info, charts, ratios, identification and exceptions... there is always exceptions to everything. Every so often it all becomes so cluttered with scribblings that I get a new note book and condense everything down..... again. I try to cross reference info when possible to check accuracy. Some books copy other's errors. I have a 280z 5 speed, an '80 200sx 5 speed, a 720 Diesel 5 speed, a shorty 720 4X4 5speed, an '85 CA18ET 5 speed, 2 620 3 spd automatics, a 280zx turbo auto and a 4 speed auto from a Maxima. I sold or traded the bell from the diesel and the CA but kept the gears and the 280zx turbo auto is in pieces.... how else to see how it works????. Most recently I found out where the long doglegs come from. Been looking for 4-5 years since I first saw a picture of one. . Quote Link to comment
troyt Posted October 22, 2010 Author Report Share Posted October 22, 2010 I love the coffee stains ;-) Quote Link to comment
izzo Posted October 22, 2010 Report Share Posted October 22, 2010 Well it's from a few years of seeing the same questions asked, and usually answered, sometimes correctly. So I started writing stuff down, specially transmissions and started a collection of transmission info, charts, ratios, identification and exceptions... there is always exceptions to everything. Every so often it all becomes so cluttered with scribblings that I get a new note book and condense everything down..... again. I try to cross reference info when possible to check accuracy. Some books copy other's errors. I have a 280z 5 speed, an '80 200sx 5 speed, a 720 Diesel 5 speed, a shorty 720 4X4 5speed, an '85 CA18ET 5 speed, 2 620 3 spd automatics, a 280zx turbo auto and a 4 speed auto from a Maxima. I sold or traded the bell from the diesel and the CA but kept the gears and the 280zx turbo auto is in pieces.... how else to see how it works????. Most recently I found out where the long doglegs come from. Been looking for 4-5 years since I first saw a picture of one. . Where do the long doglegs come from? I have one in 80 L powered 720. Quote Link to comment
datzenmike Posted October 22, 2010 Report Share Posted October 22, 2010 They never came on any cars to N America. They were on the JDM 610 SSS known as the 180B in Oz and the 810SSS outside Oz. (think I got that right or close) The transmissions were bolted to import JDM motors and found their way into use here. SHORT LONG Quote Link to comment
FricFrac Posted October 30, 2010 Report Share Posted October 30, 2010 FS5W71B 2wd Z22 motor reg, long wheelbase and KC. 1st... 3.321 2nd... 2.077 3rd... 1.308 4th... 1.000 5th... 0.833 2wd SD22 motor reg, long wheelbase and King Cab. 1st... 3.592 2nd... 2.246 3rd... 1.415 4th... 1.000 5th... 0.813 4wd Z22 motor King cab only 1st... 3.592 2nd... 2.246 3rd... 1.415 4th... 1.000 5th... 0.813 1..3..5 2..4..R The 4X4 and diesel gears are identical but the speedometer is driven off the transfer case in the 4X4 so the tailstock of the 4X4 will not have the hole for the speedo drive pinion. The diesel starter is on the driver's side so the transmission will not bolt to the gas motors. Generally the transmissions are 31.5" long but there are short 26" 5 speeds, I have one from a 4X4. The shortness is all in the tailstock. Front and rear case halves will swap as well as internal gears (in sets). An L series front case can be swapped onto any of the '81 5 speeds from a 720. FS5W71B as in the 280ZX 5 speed? If that's the case is it an easy swap for an '81 720 4X4 with a 4 speed to a 280ZX tranny? And since the 240SX S13 ('89-96) can be swaped into a 240Z-280ZX by machining the belhousing for the front bearing has anyone done the 240SX five speed swap? Quote Link to comment
datzenmike Posted October 30, 2010 Report Share Posted October 30, 2010 First... The Z series and the KA motors sit more vertically upright than an Lseries motor. the L is leaning slightly to the pass side. Second... L, Z and KA motors have the same transmission bolt pattern but the different 'tilt' of the motor requires that this bolt pattern be rotated slightly so that the shifter is vertical inside the car. Third... Imagine sitting in a car with a right hand leaning L series motor and tranny. Now imagine swapping in a left leaning (or just more vertical) Z or KA series motor. The L tranny would have to twist to the left to bolt up. This will cause two things. The shifter will now be leaning over into your side or hitting your drivers seat. Also the tranny will not sit level on the transmission mount. Basically you cannot swap L trannys with Z or KA trannys without this problem. However you can swap the front cases (with the rotated bolt patterns) to make it fit. The 280zx and 720 5 speeds to '85 have a 56mm front counter bearings. A 720 Z series front case is a direct swap onto a 280sx tranny. The 240sx tranny will bolt directly to any Z series motor but will be longer and the rear mount and shifter hole will need mods. Quote Link to comment
FricFrac Posted October 30, 2010 Report Share Posted October 30, 2010 ............. The 240sx tranny will bolt directly to any Z series motor but will be longer and the rear mount and shifter hole will need mods. I though you just needed to machine the bearing on the front of the ZX housing when you swap in the SX. Would it be the same mod to the Z engine transmision housing as well if that's the case? http://atlanticz.ca/...tall/index.html Quote Link to comment
datzenmike Posted October 30, 2010 Report Share Posted October 30, 2010 You can machine the zx case for the larger 62mm bearing on the 240sx transmission.... or just pull it off and substitute the 56mm bearing from a zx transmission. Might be easier. The FS5W71C from the 240sx will have a larger 1st/2nd shift rod that pokes through the front case so the ZX case will need the 14mm shift rod hole increased to 16mm for it to fit. Use the zx front cover plate if using the 56mm bearing. There is no reason to modify or even use a Z series front case on an FS5W71C 240sx transmission. They both fit engines with the same upright posture or 'tilt'. Only the L series is leaning to the right. But just for argument sake yes you would have to make the same bearing swap or machine the case. OR get the front case from an '85 and up Z tranny as they switched to the larger 62mm bearing. NOTE in all cases if putting an L or Z case onto an FS5W71C from a 240sx or D-21 Hardbody the inside surface of the case around the counter bearing hole must be machined for the wider gear clearance. It should be machined here and remove about 0.13" or just remove the lower boss: Quote Link to comment
pipedsun Posted January 6, 2011 Report Share Posted January 6, 2011 CAN ANYONE HELP ME.......I purchased an 81 Datun 720 diesel sd 2.2..And i would like to convert to 4x4....straight axle it...what transmission or half case would bolt on from a 4x4 in order to give me the transfer case I need to do so? Quote Link to comment
izzo Posted January 6, 2011 Report Share Posted January 6, 2011 use any 80-86 720 4x4 transfer case, its divorced, just make appropriate driveline... Quote Link to comment
Wide14u Posted January 6, 2011 Report Share Posted January 6, 2011 mike you amaze me all the time Quote Link to comment
84Datsun720 Posted June 1, 2011 Report Share Posted June 1, 2011 I have an 84' 720 2wd with the 3 speed automatic, I was wondering if I could swap a 4 speed automatic or 5 speed automatic into it and what models they would come from (i.e. D21, maxima, whatever). I know a 5 speed manual would be better, but the area I live in is not suitable for a manual. Thank you for your help Quote Link to comment
datzenmike Posted June 1, 2011 Report Share Posted June 1, 2011 The L4N71B from an auto Hardbody with Z24i to Aug '89 will work. This is a true 4 speed auto with a 0.696 ratio overdrive. It may be an inch longer than your automatic. The automatic behind the '90 and on KA24E might also be a 4 speed but you will have to research this. The KA and the Z24 share the same bolt pattern. Admittedly and automatic is easier to drive, but there's not really anywhere that a 5 speed can't be driven, just more work. Quote Link to comment
84Datsun720 Posted June 5, 2011 Report Share Posted June 5, 2011 The L4N71B from an auto Hardbody with Z24i to Aug '89 will work. This is a true 4 speed auto with a 0.696 ratio overdrive. It may be an inch longer than your automatic. The automatic behind the '90 and on KA24E might also be a 4 speed but you will have to research this. The KA and the Z24 share the same bolt pattern. Admittedly and automatic is easier to drive, but there's not really anywhere that a 5 speed can't be driven, just more work. Would I need to get a new drive shaft if I used the 4 speed because it is an inch longer Quote Link to comment
datzenmike Posted June 5, 2011 Report Share Posted June 5, 2011 Can't answer that. All one piece driveshafts have some slack so the rear end movement will allow the shaft to slide in and out as the suspension flexes. The worst thing would be for it to bottom out. I would think that if you can slide the spline in far enough to move the driveshaft forward enough to get the rear U joint on it might work. Quote Link to comment
84Datsun720 Posted June 11, 2011 Report Share Posted June 11, 2011 Can't answer that. All one piece driveshafts have some slack so the rear end movement will allow the shaft to slide in and out as the suspension flexes. The worst thing would be for it to bottom out. I would think that if you can slide the spline in far enough to move the driveshaft forward enough to get the rear U joint on it might work. I have a long bed and its a two piece drive shaft, do you think there would be enough adjustment in it? and thank you for your help Quote Link to comment
84Datsun720 Posted June 22, 2011 Report Share Posted June 22, 2011 I have a long bed and its a two piece drive shaft, do you think there would be enough adjustment in it? and thank you for your help I spoke with father who is a mechanic and he said it might be better to try and find a correct length drive shaft. Do you think the drive shaft out of a long bed with the transmission I want would work? Quote Link to comment
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