rude_day Posted April 29, 2015 Report Share Posted April 29, 2015 Hello Ratsuners! I would first like to say that I've been on this forum for quite sometime now & would like to say that A LOT of this information has been VERY helpful! So thank you to all Ratsun Members! I just wanted to talk to you guys about the 720 4x4 transmission but before I do that I would like for you guys to check out my truck from owning it for 2 years & some months now. (This will be my proper introductions even though I've been on her for a while) WARNING: Pictures Were Taken With Cell Phone Camera, So Please Excuse Some of the Qualities & Enjoy! When I first got her :w00t: New Wheels: 2004 Nissan Titan 17x7.5 +30 225/45 1/2 inch Spacers up Front & 1 inch Spacer in the Rear Lowered torsion bolts all the way, 4 inch blocks, 1 leaf removed & flipped the overload ^^^^^ Even height only because I had a bed full of records & a table ^^^^^ New Wheels Again: Enkei 15x8.5 -34 195/50 ZERO SPACERS!! Lowered S'more: Torsions bolts max with only 1 nut & removed the other nut & washer (if you know your datsun you should know what iam talking about). Reindex 2 Splines & Ford Pinto shocks up front. Rear stil has 4 inch blocks, 1 leaf pulled & overload flipped but also has 3 leafs cut that act like a block to go even lower. (will post a picture soon.) Engine Shots & Last picture with my friends 620 KC So thats my truck Daisy. What it has: L18 with W53 Peanut Head & DATSUN 1600 valve cover 32/36 DGEV Weber Carb Glass Fuel Filter 240z Alt KA24E Oil Pump Champion Radiator with E-Fan "Grey Goose" Coolant Reservoir Front & Rear Markers Deleted & Japanese Style Markers Added 3 Quote Link to comment
rude_day Posted April 29, 2015 Author Report Share Posted April 29, 2015 Okay so on with the topic haha So a while back I picked up a 1985 720 4x4 transmission for my 5 speed swap, BUT the big mistake was when I finally got home & cleaned it up I ran into this problem. There's the speedo slot but no hole :confused: So I looked up the trucks vin that I took the trans off of & it said it was a 2WD but it was clearly converted to a 4x4 because it had the 4x4 set up. It totally slipped my mind because the trans was sooo easy to get to since someone already took the motor. (It was only hanging on 1 bolt from the exhaust :lol:) ANYWAYS now I know that 2WD short trans has the speedo slot open & the 4x4 shot trans does not because the speedo is attached to the transfer case :no: So I then asked a Ratsun member if he thinks that there's a speedo drive gear on the main shaft even though is not opened. He had said no because there's not point in putting it, if it doesn't get use, which i thought made total since. Then I asked if it's even possible to put a speedo drive gear on the shaft & he said he doesn't think so. He just said try looking for a 2wd 720 short trans. So after all that I was pretty bummed but then I thought to myself, what if I just take off a speedo drive gear from a transmission I have & then drill out the hole & BOOM I have a trans with a speedo now right? What do you guys think? For the people that don't know what iam talking about it's the plastic gear on the main shaft to the far right in the picture below: Also Iam sorry for not saying the correct term but I now call it the Speedo Drive Gear :lol: 1 Quote Link to comment
kelowg Posted April 29, 2015 Report Share Posted April 29, 2015 gps speedometer,no Connection to trans. I was sick of not being able to see guage cluster. Installed custom guages with said gps speedo. 1 Quote Link to comment
datzenmike Posted April 29, 2015 Report Share Posted April 29, 2015 Machining that hole must be precise so that the plastic gears mesh but don't crush. Unlikely the mainshaft gear will be on there also so you would need one. It's held on with a C clip. Earlier ones used a metal gear later were plastic. I would find a proper tail stock. 1 Quote Link to comment
uberkevin Posted April 29, 2015 Report Share Posted April 29, 2015 Sweet truck!! Good luck! 1 Quote Link to comment
]2eDeYe Posted April 29, 2015 Report Share Posted April 29, 2015 I would take the tail housing off and see if there is a provision for running the speedo gear on the shaft and then go from there. Once you have the housing off and verify you have a gear or the provisions to run one, it wouldn't take much $ to have the local machine shop put the hole in the right place. 1 Quote Link to comment
rude_day Posted April 30, 2015 Author Report Share Posted April 30, 2015 gps speedometer,no Connection to trans. I was sick of not being able to see guage cluster. Installed custom guages with said gps speedo. yea that would work but i would like a working speedometer Machining that hole must be precise so that the plastic gears mesh but don't crush. Unlikely the mainshaft gear will be on there also so you would need one. It's held on with a C clip. Earlier ones used a metal gear later were plastic. I would find a proper tail stock. yea I've seen it when i took it apart & i have good news!! IT HAS ONE!!!! &&&& ITS METAL!! :w00t: :thumbup: B) :frantics: :rolleyes: :lol: :D :) :sweat: :hyper: :fu: Sweet truck!! Good luck! thank you, thank you! I would take the tail housing off and see if there is a provision for running the speedo gear on the shaft and then go from there. Once you have the housing off and verify you have a gear or the provisions to run one, it wouldn't take much $ to have the local machine shop put the hole in the right place. well I got overly excited & started drilling since i found out that it has the gear on the mainshaft so to late for that :hmm: 2 Quote Link to comment
rude_day Posted April 30, 2015 Author Report Share Posted April 30, 2015 With this tool (Not sure of the name but i call it a stepper?) 2 Quote Link to comment
rude_day Posted April 30, 2015 Author Report Share Posted April 30, 2015 ALSO i found out its not a true 85 because it does not have the upgraded bearing but oh well at least i'll have a 5 speed. .... or I at least hope so haha. 1 Quote Link to comment
oldskoolvws Posted April 30, 2015 Report Share Posted April 30, 2015 Well, for ME personally, I dislike the Titan / New 17" or 18" look. Your Enkei's made the whole truck look 100x better. I don't think the new OEM wheels match the lines of the old truck. Just me though. What happened to the bed? Great thread! 2 Quote Link to comment
datzenmike Posted April 30, 2015 Report Share Posted April 30, 2015 You can't just run a drill throught there. It has to be at a precice angle that just intersects the worm gear. This is like brain surgery with an egg beater. 2 Quote Link to comment
rude_day Posted May 7, 2015 Author Report Share Posted May 7, 2015 Well, for ME personally, I dislike the Titan / New 17" or 18" look. Your Enkei's made the whole truck look 100x better. I don't think the new OEM wheels match the lines of the old truck. Just me though. What happened to the bed? Great thread! haha yea it was a phase when i got the titan wheels haha, they're sold already. & the bed, previous one had holes & a bad hit on the driver rear so i then picked up this one local for $50 bucks & the bed LOOKS worst then what it really is. & thanks! You can't just run a drill throught there. It has to be at a precice angle that just intersects the worm gear. This is like brain surgery with an egg beater. After reading your post i won't even bother to install the transmission then. So i'll just have to look for another short tail trans with the speedo slot open. BUT, once i get the trans i will proceed with this write up & at least people know now that it does have that gear for the speedo. 1 Quote Link to comment
rude_day Posted May 7, 2015 Author Report Share Posted May 7, 2015 PS: All my friends are saying to do my discs brakes first, because since i'll have another gear i'll want to go even faster :D So this post might be delayed some. Sorry everyone :hmm: 1 Quote Link to comment
datzenmike Posted May 7, 2015 Report Share Posted May 7, 2015 Fifth isn't for going faster only dropping revs slightly for mileage. It will be making enough power to cruise at highway speeds but make more in 4th at top speed. Likely it will go faster in 4th. 1 Quote Link to comment
nis720 Posted May 8, 2015 Report Share Posted May 8, 2015 Nice truck.... I have the transmission you need. 2 Quote Link to comment
rude_day Posted May 9, 2015 Author Report Share Posted May 9, 2015 Nice truck.... I have the transmission you need. 2 questions: 1st everything is fine with it? 2nd is it for sale? 1 Quote Link to comment
rude_day Posted May 9, 2015 Author Report Share Posted May 9, 2015 Fifth isn't for going faster only dropping revs slightly for mileage. It will be making enough power to cruise at highway speeds but make more in 4th at top speed. Likely it will go faster in 4th. true because 5th gear is now overdrive but technically i'll go faster cause i have another gear before over drive & also my friends just told me that because i have a bit of a heavy foot 1 Quote Link to comment
datzenmike Posted May 9, 2015 Report Share Posted May 9, 2015 Not following.... All 4 and 5 speeds have the same 4th gear. In fact it isn't a gear at all, the transmission just drives straight through from the clutch to the driveshaft, one to one. This is the best gear for passing, climbing a hill or hauling a load if you have a 5 speed. There is way less loading on the bearings. Now the over drive, in this case a later 4x4, a 0.813 ratio. This gives one turn in from the engine and 1.187 turns out. Another way of looking at it is if your 60MPH RPMs are 3,000 in fourth gear they will drop 561 RPMs to about 2439. As you can see you are making less power 500 RPMs lower. At 4000 it's 748 RPMs lower, at 5000 it's 935 RPMs lower and at 85 or 90 MPH you won't have near the same power available to push through the air. There are limits to how fast a vehicle can go. It takes 4 times the power to go 80 as it does to go 40. 1 Quote Link to comment
nis720 Posted May 11, 2015 Report Share Posted May 11, 2015 2 questions: 1st everything is fine with it? 2nd is it for sale? Nothing wrong, just upgraded to a different trans that could handle the power my current setup is making. It was rebuilt a few months before I pulled it out. It is for sale.... Pm me. 1 Quote Link to comment
rude_day Posted May 16, 2015 Author Report Share Posted May 16, 2015 Not following.... All 4 and 5 speeds have the same 4th gear. In fact it isn't a gear at all, the transmission just drives straight through from the clutch to the driveshaft, one to one. This is the best gear for passing, climbing a hill or hauling a load if you have a 5 speed. There is way less loading on the bearings. Now the over drive, in this case a later 4x4, a 0.813 ratio. This gives one turn in from the engine and 1.187 turns out. Another way of looking at it is if your 60MPH RPMs are 3,000 in fourth gear they will drop 561 RPMs to about 2439. As you can see you are making less power 500 RPMs lower. At 4000 it's 748 RPMs lower, at 5000 it's 935 RPMs lower and at 85 or 90 MPH you won't have near the same power available to push through the air. There are limits to how fast a vehicle can go. It takes 4 times the power to go 80 as it does to go 40. it was mainly a joke between my friends and I because they know i will want to go faster & they think its dumb cause i haven't up graded my brakes yet haha. now get it? if not its okay. 1 Quote Link to comment
rude_day Posted May 16, 2015 Author Report Share Posted May 16, 2015 Okay so first i would like to say I have bad & good news Bad News: My tail light broke on Monday night. :bye: I was just driving straight down the road, which wasn't really bumpy at all, but its just fell off. But the good news is that Konig209 has sent a tail light my way :thumbup: So all you 521 owners make sure your tail lights are tight, specially if you are lowered because 521 tail lights are VERY hard to get ahold of!!! So now for the actual good news that I wanted to tell you people. Iam back in action for my 5 Speed swap & all thanks to nis720 !! New trans is on the RIGHT: FS5W71B (SHORT) from a 86 720 New trans with speedo Old trans that i tried making a speedo slot that probably would've worked if i took my time instead of rushing Old LEFT New RIGHT Measuring at 26" So all I need to do is swap out the bell housings, pull the old trans & mod the stock trans mount More pics to come so stay tuned! 1 Quote Link to comment
Charlie69 Posted May 16, 2015 Report Share Posted May 16, 2015 Looks like you will be back on the road in no time. Quote Link to comment
datzenmike Posted May 16, 2015 Report Share Posted May 16, 2015 This is the correct way to measure the transmission length. Most measure from engine mounting surface directly to the tail and the diagonal (or slope angle) will always be longer. Good going. 1 Quote Link to comment
rude_day Posted May 20, 2015 Author Report Share Posted May 20, 2015 So I finished my 5 speed swap!!!! Don't have TOO many pics but i'll take some more when I do my oil change but here are these for now. 5 Speed LEFT & 4 Speed RIGHT MOST 521's (including mine) came with a 4 Speed like this one. But what's a bit different with mine is that my friend had gave me his 520 driveshaft (single piece) & I then removed this tail end flange? to make the single piece slid right in. Tip: I highly recommend cutting the treads when using a single piece because the driveshaft will sit very very close to the trans & it is very hard to bolt on the rear. Well for me anyways probably because jam low Other then moding the trans bracket, swapping bell housings, pulling the motor forward to mate the trans, it was a fairly easy process. Everything bolted up just fine. Engine to trans, trans to driveshaft, & driveshaft to rear axle. Stick shift is still in the same spot but just tilted a bit closer to the bench & I did NOT need to cut the driveshaft to make the it fit, same exact size as the 4 Speed minus the FLANGE! 2 Quote Link to comment
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