Mike Phillips Posted September 8, 2008 Report Share Posted September 8, 2008 New guy, first post... I'm looking for a 1975 or older Datsun truck and many of these seem to have 4-speeds and I need to have an automatic. So does anyone know which auto trannys will swap into a 4-speed model? I found a 1974 Datsun truck here in SoCal for sale and that's the deal with it right now, it has a 4-speed and if I buy it I'll need to convert it to an automatic. I'm pretty mechanically inclined as I did a similar swap like this already this year when I converted a 1975 GMC Jimmy with a 4-Speed manual transmission to a 700R4 automatic and it took about 3-4 weeks to get it all done and dialed in. Here's the thread on that conversion. It would be easier to buy one that came with an automatic already and I'm looking for one of these models but sometimes you just have to go with what you can get. Mike Quote Link to comment
cici Posted September 8, 2008 Report Share Posted September 8, 2008 there is a 74 here in wash for 300 has a good auto and need a water pump and fan and is good to go maybe its a idea Quote Link to comment
Z-train Posted September 8, 2008 Report Share Posted September 8, 2008 Be warned:Any 620 with a slushbox will be a complete dog and gas mileage will suffer to the point of being equal to some fullsize trucks.:mellow: Quote Link to comment
Llittle_Llama Posted September 9, 2008 Report Share Posted September 9, 2008 can you swap in an auto tranny from a 280z? been wondering about this for awhile..... Quote Link to comment
datzenmike Posted September 9, 2008 Report Share Posted September 9, 2008 If you get the '72 1/2-'73 620 the short tail 3N71B auto from a 510 will fit right in. If you get a '74-'79 620, you will need a long tail 3N71B auto from a 620 of those years, a auto 280z/zx from '77-'83 (maybe older but '77 for sure) or an auto from the 810/Maxima up to around '83. Now be careful here... around '83-'84 a 4 spd auto was used with monster over drive ratio... you don't want that. The '82-'83 3N71B had a locking torque converter. Your choice on that. The locking torque converter drive plate will look like the one on the left (engine side shown) It had a deeper bulge for the converter. A reg auto is almost flat http://i138.photobucket.com/albums/q251/datzenmike/autostdflywheel001.jpg[/img]"] For a long tail truck, ('74-'79) the auto tranny must be from an L series engine, and has to measure about 31.5" long in order to fit where the 4 (or 5spd) was. Quote Link to comment
Mike Phillips Posted September 9, 2008 Author Report Share Posted September 9, 2008 Good info... There's a couple of the older Datsun trucks parked in yards around here that look like they could be had, from your Truck Photos area here, I've seen at least one 320 and a couple of 520/521's I'll check them out and see what the story is on them, maybe take a picture or two... :) Quote Link to comment
datzenmike Posted September 9, 2008 Report Share Posted September 9, 2008 The 520/521s didn't have automatics I believe. Quote Link to comment
Llittle_Llama Posted September 9, 2008 Report Share Posted September 9, 2008 so what will i need to control it? is there an ecu or anything? Quote Link to comment
datzenmike Posted September 9, 2008 Report Share Posted September 9, 2008 The L series tranys had no electronic engine controlls. Plug 'n play. Quote Link to comment
zerow Posted September 9, 2008 Report Share Posted September 9, 2008 The locking torque converter drive plate will look like the one on the left (engine side shown) It had a deeper bulge for the converter. A reg auto is almost flat http://i138.photobucket.com/albums/q251/datzenmike/autostdflywheel001.jpg[/img]"] datzenmike, I got a converter like the one on the left when I picked up my L4N71B at the j/y. I thought it was shaped that way because it was bolted to an L20A, not because it was locking. The tranny case and everything on it points to it being a "regular" 3 speed w/ od. :confused::confused: Quote Link to comment
Llittle_Llama Posted September 9, 2008 Report Share Posted September 9, 2008 so basically i can get a 280z auto tranny and just bolt and go huh? what would be the downfall to this? are they 4 speeds? Quote Link to comment
datzenmike Posted September 9, 2008 Report Share Posted September 9, 2008 Yes bolt up 'n go. You would need coolant lines to the front and an aftermarket tranny cooler. Strap it to the rad so the fan can draw air through it. I don't like the stock rad tranny coolers, have you ever cut one open??? All there is is a copper tube about 8" long joining the in and out tube... pathetic. Get an aftermarket trailer towing tranny cooler, the biggest you can afford. No I don't think the 280s had the L4N71B 4 speed, they may have had converter lock up around '82, ask Bleach. Quote Link to comment
Mike Phillips Posted September 10, 2008 Author Report Share Posted September 10, 2008 Is there an automatic tranny that will bolt up to this truck's engine? 71" Datsun 521/1600 pick up - $800 Found another 1971 and a 1974 both with 4-speeds. :rolleyes: Quote Link to comment
datzenmike Posted September 10, 2008 Report Share Posted September 10, 2008 Absolutely. Any L series auto will bolt to it but you will need a 5 bolt drive plate/starter gear. L16 and l18 have 5 bolt cranks, anything from an L20B up have 6 bolt. The 521 should have a short tail tranny (26.3") so a 510 automatic should be just right for length. An L18 will have the 5 bolt drive plate but if from a 620 it may be to long. Maybe get the auto and the shorter drive shaft and swap them both into your 521. Quote Link to comment
Mike Phillips Posted September 10, 2008 Author Report Share Posted September 10, 2008 ***Update*** Okay, I found a 1974 Datsun Truck with a factory automatic that runs, drives and brakes. The owner says he purchased it from an Estate sale and it appears to have been well taken care of. He bought it to hotrod with a small block Chevy because the body and interior are still in good shape. He thinks the water pump needs to be replaced and of course all the hoses, belts, oil change, etc as it's been sitting for a few years but it does fire up run and drive. Price: $1000.00 I'm waiting on some pictures and if the pictures look good I'm thinking about buying it. It's $200 miles from my house so I'll hook my car trailer and fetch it with my truck. What do you Datsun Connoisseurs think? Also, if the engine ends up needing replaced, instead of replacing it I would be open to buying a used/running engine and just swapping it out. What engine should a stock 1974 Datsun Truck have in it? What engines will bolt in? For example from a newer Datsun? Thanks! Mike Quote Link to comment
Mike Phillips Posted September 10, 2008 Author Report Share Posted September 10, 2008 Just talked to the owner, he's sending me some pictures right now. He said he checked the oil and at the bottom of the dipstick it looks kind of like chocolate milk which can be a sign of a blown head gasket. Is that a known issue for the engines that come inside of these trucks and is it a complicated job to have the head rebuilt as far as putting it back on and adjusting the valves etc. I'm pretty good with Chevy engines so I'm no Newbie to wrenching but I've never take apart a Datsun engine. Mike Quote Link to comment
Mike Phillips Posted September 10, 2008 Author Report Share Posted September 10, 2008 Here some pictures... 1974 Datsun Truck Quote Link to comment
datzenmike Posted September 11, 2008 Report Share Posted September 11, 2008 ***Update*** He thinks the water pump needs to be replaced and of course all the hoses, belts, oil change, etc as it's been sitting for a few years but it does fire up run and drive. Price: $1000.00 I'm waiting on some pictures and if the pictures look good I'm thinking about buying it. It's $200 miles from my house so I'll hook my car trailer and fetch it with my truck. Also, if the engine ends up needing replaced, instead of replacing it I would be open to buying a used/running engine and just swapping it out. What engine should a stock 1974 Datsun Truck have in it? What engines will bolt in? For example from a newer Datsun? Thanks! Mike So, it (engine?) runs but water pump may be bad. Oil is iffy so maybe a HG needs replacing. Been sitting for a couple of years. You are basically buying a good looking body, at least on the outside, unless you can drive this truck to get a better idea of what work needs doing to it. For a thousand bucks you should be driving IT home. Everything should work. Quote Link to comment
mike Posted September 11, 2008 Report Share Posted September 11, 2008 ??? if youre not against swapping everything out and dont mind stuff that is not 100% bolt in, find a good body and a newer ka24 or ca18 or something rwd with an auto and get the best of both. By the way, nice k5. Gotta love the full vert 2nd gens. Quote Link to comment
ppeters914 Posted September 11, 2008 Report Share Posted September 11, 2008 So, it (engine?) runs but water pump may be bad. Oil is iffy so maybe a HG needs replacing. Been sitting for a couple of years. You are basically buying a good looking body, at least on the outside, unless you can drive this truck to get a better idea of what work needs doing to it. For a thousand bucks you should be driving IT home. Everything should work. I'm still learning, but I gotta agree with Mike on this one. If you can't drive it home, $500 tops, and that's only because the body looks in such great shape. But nada until you see and touch it live. Quote Link to comment
Mike Phillips Posted September 11, 2008 Author Report Share Posted September 11, 2008 Well it's in my driveway now, $600.00 It has the L18 1770cc engine in it and I've already located a L20B engine to go into it. The L20B has a manual transmission behind it so I'm going to need the correct flywheel to mate the engine to the transmission. The engine will come out this Saturday and the entire truck will get an extreme makeover. I looked and called on numerous Datsun trucks and everything I found was a manual transmission model and I know that getting one that was a factory automatic would be the best and easiest way to go, so for me, this was a good deal because I want to get something 'now' and start getting it on the road. This isn't going to be a show car but a daily driver to go back and forth to work and run errands. Quote Link to comment
datzenmike Posted September 11, 2008 Report Share Posted September 11, 2008 If and when you swap motors DO NOT forget to install the spacer between the drive plate and the end of the crank shaft too. All automatics need this spacer or the starter will not engage properly with the ring gear. You will need a six bolt hole one. Quote Link to comment
Mike Phillips Posted September 13, 2008 Author Report Share Posted September 13, 2008 ***Update*** Tomorrow the old engine is coming out and the engine compartment is getting an extreme makeover. Have made a deal on a L20B engine and located the correct flex plate for the conversion. Will hopefully pick both of those items up next Thursday and then next Saturday install the engine. Will finish buffing out the old, oxidized paint as all it needs is a little polishing and waxing to restore the gloss and shine. Here's some pictures, after tomorrow I'll start a dedicated thread for this project. Most of the paint inside the bed is still there, that is it's not all scratched up and rusty so I'm going to buff the inside of the bed out as well as all the paint on the outside, inside the cab and the engine compartment... I had this truck for about 12 years and called it Big Blue... 1971 3/4 Ton Chevrolet 4x4 Long Bed 402 Big Block Chevy Turbo 400 Short Shaft 2-Ton Military Transfercase 4:11 Corporate Rear with Detroit Lockers 4:11 Dana 44 Front Axel with Detroit Lockers H-Beam Rear Bumper 4" Driveline Tubing Roll Bar Full Convertible with Custom Half Cab Convertible Top 44" Super Swampers on 16.5 Aluminum Slotted Mags Me with my front axle buried in mud, think I broke the stubby in this picture... My friend Eric pulling me out... Eric's truck, this truck is street legal in Oregon... (I know, I've driven down I-5) Same truck a few years later with a paint job... I guess the Datsun is now, Little Blue... :) Quote Link to comment
datzenmike Posted September 13, 2008 Report Share Posted September 13, 2008 ***Update*** Tomorrow the old engine is coming out and the engine compartment is getting an extreme makeover. Have made a deal on a L20B engine and located the correct flex plate for the conversion. Will hopefully pick both of those items up next Thursday and then next Saturday install the engine. :) Don't forget a pair of these spacers!!! http://i138.photobucket.com/albums/q251/datzenmike/transautodriveplatespacer.jpg[/img]"] Quote Link to comment
lynchfourtwenty Posted September 13, 2008 Report Share Posted September 13, 2008 nice find man.. Quote Link to comment
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