'78 Hilux Sunrader Build Thread - 3RZ W55 Swap

Discussion in '1976-1983 Build-Up/Project Threads' started by RG113, Mar 12, 2023.

  1. RG113

    RG113 Member

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    Well, it wasn't easy, but its in...roughly.

    As it stands, the engine is mounted in it's final resting place. The short hood of the hilux made dropping the engine with trans as one unit very very difficult and id advise against it for people who are scared of scratching the paint. The transmission is currently being held up by a jack as these motors don’t have pitch stop mounts like the subaru i am more used to. Driveshaft slotted in beautifully on install, that was way better that i expected, lets hope it is correct because i really don't want to pull that out.

    Next up is to test fit, cut, tap, and mount the transmission cross member to accept the w55 trans. Although i have a '78 and the transmission knowledge thread i shared before is supposedly for a '78 Chinook, our trans crossmembers look completely different. I don’t know if min is and early '78 or a late '78 or if it was unique to the dual rear axle trucks but they don’t look the same at all despite us sharing the same L43 trans to start. I'll post some pictures tomorrow and get that cut and mounted up so i can move onto the electrical and the cooling system.

    While im doing that, i have a friend who is gonna take care of the nightmare rust situation where the battery usually fits as well as making an exhaust that will go down and cross under the trans to mate to the existing exhaust system so that takes some time consuming stuff of my hands. I do have to pay for it but at least it will speed up the process for me.

    The wiring in this rv, both front and back, is downright appalling and i both hate and suck at wiring so chasing down where all these wires go with be a bummer but it has to get done. I plan to just make the vehicle run and drive and then while my gf does the rear RV part of the build, i can handle taking the dash out, cleaning up the 45 year old wiring harness of everything i don’t need, and fixing my turn signals which just shut off when i hit the brakes.

    Here is a pic of the rv with the new engine and the hood fitting!

    IMG_3679.jpg

    IMG_3676.jpg
     
    Last edited: May 14, 2023
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  2. jetas

    jetas Grand Toyotaholic

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    I do have to say that they put next to no effort into making that engine look any kind of good:lol:
     
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  3. RG113

    RG113 Member

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    right? Like “it’s a truck engine, it’s fine.” There’s also vacuum line galore at the back of the intake manifold
     
  4. Liquidhandwash

    Liquidhandwash Enthusiast

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    The mod would not be legal in most places, there is a fair bit of stress on the centre link and failure of a weld would be catastrophic at any speed, so if you're going to do it, get an engineer to weld it for you, they might say no.
    An alternative is to cut up the sump and use the bottom half of the 18r sump, I would tig or gas weld it as mig welding almost always results in an oil leak.
     
    Last edited: May 15, 2023
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  5. jetas

    jetas Grand Toyotaholic

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    All they care about in the US is emissions, you can have the most unsafe POS on the road tho
     
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  6. RG113

    RG113 Member

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    Exactly what Jetas said above, and because it is a 1978, we don’t even have emissions for it in the state of Connecticut where it will be titled. As long as it is a solid weld (my friend is a professional welder so it will be done right), i don't think i need to worry about it too much. i would have to notch the pan so much that it would most likely hit the oil pick up so it is prohibitively not the greatest situation but this is an unusual combination of parts so i just need to make it work
     
  7. RG113

    RG113 Member

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    Update:

    Yesterday we went through the process of modifying the transmission crossmember and it didn't go as simply as the following thread describes nor does that transmission cross member look anything like mine...despite being the same year supposedly...thanks toyota (i figured out why this is, read a couple posts down to see the reason).

    The thread im talking about: https://toyotamotorhome.org/forums/...-l43-to-w50-and-w50-to-w55-transmission-swap/

    That being said, i had to make some adjustments and modify the transmission crossmember a little more than just notching it.

    I started by cutting off (just the part that is welded onto the trans crossmember) where the trans mount sits into, the piece with a circle you see below.

    IMG_3688.jpg

    Next, i cut off the piece to the left which is the spring loaded mounting point for the e-brake cable and grinded down the trans cross member to as if those pieces were never there to clean it up.

    When i test fit it without either of those mounts in, i was able to fit the cross member back into it's factory location. I then noticed i could flip the trans mounting piece i had just cut off upside down and reweld it back onto the trans cross member while adjusting for the 4in gap that the new trans mount location was off compared to the original trans. See below:

    IMG_3695.jpg

    Now i know those welds look terrible, the other side looks better but im not a welder and have only some minor experience with an argon mig but its good enough for mock up. I plan to weld on supports on either side to withstand the overhang but currently the trans is mounted in the car, bolted to the trans crossmember and holding itself up, so its fine for now.

    I will have to weld on the ebrake cable piece again as well as cut a bigger hole in the floor because right now, if i hit a big bump, the shift mech would most likely hit the top of the trans tunnel, see below:

    IMG_3689.jpg

    I plan to reweld on the front section i cut out and then build some sort of sheet metal surround that is higher than the exiting trans tunnel to clean it up. I will then put new carpet down with the shifter boot and that will make it look nice again but this is how it will stay for now until i cut a little more out of it.

    Here is another image of the moved trans mount on the crossmember, it looks a lot better from this angle lol:

    IMG_3694.jpg

    Next up is to cut the floor more, weld supports to the trans mount, get the wiring taken care of, and get the rest of the stuff missing from the engine bay put back in (radiator, new electric fan, battery, washer bottle, intake, etc.), and lastly, weld a loop on the steering center link and then cut out the center. Then, it should drive.

    Just the little things ya know?
     
    Last edited: May 17, 2023
  8. Liquidhandwash

    Liquidhandwash Enthusiast

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    Looks like you are making progress, it's all the little stuff that takes time, just another item for your list is the final drive ratio of the diff centre might be a problem I know you can swap the diff centre on most Hilux from 1970- into the 2000s but not sure about the Tacoma, might be worth having a look.
    here's a link to the diff codes, the numbers are on the build plate under the hood.
    http://winterpalace.customer.netspace.net.au/diffcodes.html
    There is a later model diff centre with a 3.7 ratio that will bolt into the "G" housing I think you have to grind a small amount off somewhere to get it to fit in the hole, It had a different code and metric ring gear measurement, I can't remember the code, possibly "A" which is different to the datasheet. On mine, I had to re-drill the drive shaft flange, four holes, everything else was the same.
    here is some more info.
    https://rsmotorsport.com.au/files/Identifying_Toyota_Hilux.pdf
     
    Last edited: May 17, 2023
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  9. RG113

    RG113 Member

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    Thanks for this info, i do need to find out what the diff ratio of the new dually rear end is that i will be installing.

    In terms of actual issues, i thought diff ratios only matter for matching them if you are running an AWD or 4WD set up? Because im RWD, do i need to worry about the ratios other than what the speed will be on the highway?

    Let me know because im pretty sure i don’t need to worry about it. Thanks!
     
  10. jetas

    jetas Grand Toyotaholic

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    5th gear on the W55 with 4.11s is not great. Not sure whats in the dually diffs but 70mph at 3000RPM is terrible.

    If you decide you want to change the shifter position, you can pull the shifter, base and shift selector deal inside the trans from another W5x trans. Just separate the case, remove the tail shaft housing and remove the selector and do everything in reverse order
     
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  11. RG113

    RG113 Member

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    Hmmm yeah at 3k rpm at 70, ill definitely be lacking torque. Maybe a turbo/supercharger will be necessary down the road but i am really shooting for fuel economy so that may not be good for acceleration or even maintaining speed but on flats, hopefully it will be ok. As for the shifter position, it doesn't particularly bother me enough to change though it could after living with it for awhile so i appreciate the information you shared. Im sure that will be helpful for others that may not like the position. Appreciate it Jetas!

    With that said, i figured out why the transmission cross member looks nothing like the thread that i had showing the 1978 Chinook. After some research, i've determined that my titled 1978 Toyota Sunrader is actually a 1977. This unfortunately makes sense due to the nature of how the rvs are usually titled a year newer than their original chassis' due to the length of time it takes them to build the rv section.

    That said, i have a RN28 Chassis, with an L43 trans. Im assuming the tail shaft of my L43 must be different which caused there to be a different trans mount used (mine had two bolts from the trans to the mount and two bolts from the mount to the crossmember while the thread i was using had 4 in both spots). Weird but it explains some compatibility issues with some of the parts i have in terms of clearancing of the oil pan and steering centerlink with the toyonlyswaps engine mounts.
     
  12. Liquidhandwash

    Liquidhandwash Enthusiast

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    It's about the RPMs you want to pull with your engine, at highway speed. The 18rc is a short stroke rev-happy engine, that may have been doing 4000rpm at 70mph, with a low diff and small wheels and tyres. Your new engine is probably going give your grief if your doing that all day it has a longer stroke so more torque less rpm, I would be aiming 2500 rpm at 70mph. I don't know much about the dually diffs, I've not seen one in Australia, or NZ so I can't help you with that. Apart from the noise and horrible fuel economy, engine wear and reliability can be an issue. If the diff centre from your Tacoma fits I would use it
     
  13. jetas

    jetas Grand Toyotaholic

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    Also have to mention my tire size is 205/40/17 so its about a 24" tall tire.
     
  14. RG113

    RG113 Member

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    i currently have 4.10s as far as I know, and with the 20r in 4th, I was sitting at like 3600rpms at 70mph. Don’t know if that works out properly.


    I have the original 14in wheels that are 185/65/14 (I know the first and last numbers are right, the 65 im not sure about)
     
  15. Liquidhandwash

    Liquidhandwash Enthusiast

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    The 5 speed will help, it would take the rpms down to about 3300 rpms, you could also go for bigger wheels and tyres if you can get them to fit under that camper tub. I got 16s on mine from a Falcon, which is a similar vehicle to the ford crown vic. With the 16s you get a much better choice of tyres too.
    I found this doc that states the Tacoma diff will not fit the Hilux, so no joy there.
    I will be interested in your dually diff set-up if you decide to use it.
    https://lcengineering.com/differential-information/
    Look at your photos again, I can see it is a 20r engine, which we don't get many of here in Oz The 20r has a longer stroke than the 18rc so more torque less, rpms, which explains the diff centre of 4.1 Hilux over here get a 4.3 or 4.8 with the 18rc engine.
    That said, be on the lookout for a 3.7 diff centre, especially if you have to run small-diameter wheels and tyres.
    https://lcengineering.com/differential-information/
     
  16. RG113

    RG113 Member

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    I plan to use the 1 ton real dually axle i bought as the stock one on the RV are called "foolie" duallys as they a true dually and are only half ton capable with extra wheels bolted to the 5 lug wheel. Honestly not the smartest design because they came at capacity from the factory and thats before you even load up the camper. Idk what im going to do with my foolie afterwards, they arent very liked.

    Im probably going to stick with the 14s because i just bought the brand new tires for it before trying to drive it the 3k miles back from new mexico.

    Also in the US, we never technically got the hilux, is was just called the "Toyota Pickup" in the US before the Tacoma came along in 1995. Ill probably test how it drives with the 4.10s and then see what diff i need to get from there. I feel like if i ever upgrade the rear diff, it may just make sense to go 4wd but thats a ways away so guess i'll keep you guys updated on what happens.

    Appreciate all the information links though, keep em coming!
     
  17. RG113

    RG113 Member

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    Another update!

    Its been about a week since my last update. We are still progressing but at a slow pace. I've welded back on (again, im not a welder so its not pretty but it is functional) the e-brake pivot point on my transmission cross member. I did have to tap the adjustment rod all the way down to the end to compensate for the 1.5in that the pivot point moved back but the e-brake now works again, all i need to finish that off is a cotter pin and washer to lock it in place. See the unpainted but completed mount below:

    IMG_3706.jpg

    IMG_3707.jpg


    Next on the list is to finish up the wiring. The adapter harness from ORS is making this fantastically easy and their responsiveness to their tech support is beyond comparison. I get a response back almost immediately even later at night (im east coast in the US, they are mountain time i believe, -2hrs). And when they don’t get back right away, they get back as soon as they see it. Can not say enough good things about their support and ability to answer even more complicated questions i have. With that praise said, the harness is very easy to wire in thanks to the instructions that come with it, and the individually labeled wires for ones that need to be spliced into the existing harness. I did have to do a little wire tracing as my 1977 (manufactured year, '78 titled year) has been brutally messed with over the years with wires everywhere. This led me to fix the ignition system as the original key slot on the column had been removed and an aftermarket ignition switch installed in the dash. Once removed, it had been shorting and burning, im surprised the thing even started let alone made it 1200 miles. Ive since purchased an original key cylinder ($20...i cant believe i got it in a day off amazon) and ignition switch, two separate pieces shown below:

    IMG_3722.jpg

    IMG_3723.jpg

    IMG_3724.jpg

    IMG_3725.jpg

    70673523840__6A7A1965-319D-4489-B54C-22E33B39A56B.jpg

    70673524766__8C071685-F12A-429D-9781-7DCB6CB2A5DC 2.jpg

    Mechanically, i am mostly done as well and ready to fire this thing up for the first time. Electric fan radiator adapter kit which uses the factory radiator is supposed to arrive today. Here is the link for that:https://www.lceperformance.com/Electric-Fan-Kit-20R-22R-RE-Pickup-1975-1983-Cel-p/1093003.htm

    My buddy helped me run a new hardline from the original slave cylinder to the new slave location on the drivers side (original L43 slave location is on the passenger side). We initially used new fittings but ended up removing the old fittings from the old hard line and adding them onto our new hardline. I also took the old soft/hard line combo that was at the original slave and installed it to the new slave, looks almost factory which is awesome and the fittings worked way better than the new ones we tried. Once i finally connect and bleed the new slave, the starter can be dropped in. Im going to have to extend/modify the starter harness to as the battery for the tacoma is on the driver side, the hilux battery is on the passenger side so it likely wont reach. The exhaust cross over pipe is being welded up this weekend along with the center link adaptation we talked about above. I think it should be fine be it that a professional welder is going to do that for me, but time will tell if i lose all steering control because it breaks.

    Almost there. I feel like i could get it to at the very least turn over by Monday, that is my hope. Will keep everything updated on here.
     

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  18. RG113

    RG113 Member

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    Been over a week since my last update so figured id let everyone know what is going on.

    As of right now, we have a few bugs. Like i said last time, its mostly just debugging and wiring that needs storing out right now. The motor started using starter fluid last night but wouldn't stay running. The issue lies in the fuel injectors. I have fuel at the injector, the injector has power, and i am getting spark but the injectors arent pulsing so its not getting fuel. I'm thinking i have a few things wrong here that ill list below:

    Grounds: There are a bunch of grounds that connect to the fuel injectors, from my research, 4 to be exact. Obviously there are more engine grounds but i need to start wide and hone in. I have the rear passenger side main engine ground to the body connected. i have the front fuel injector grounded to the intake manifold. I haven't checked the others but will tomorrow.

    Something i read about the 3rz is that the ecu hates not knowing what the coolant temp is even if you don’t have coolant in the motor. Im not talking about the front temp sensor that goes to the guage and sits in the passenger coolant hose connection, im talking about the one in the back of the head. Apparently it is very common for those to break when pulling the motor and dropping it back in so I need to check that next time i go back to work on the truck. Then, go from there.

    Other things to touch on:

    The electric fan replacement kit is installed with the original fan shroud on the original 1978 radiator. The tacoma radiator hoses worked perfectly to connect the 3rz to the old radiator and modify it to be electronically triggered using a probe sensor. I still need to wire the fan up but i will be using the optional switch to be able to manually turn on the fan for whatever reason.

    IMG_3770.jpg

    I do not know what the issue is with my primary in-tank fuel pump. Even when the original motor was still installed, the fuel pump needed a bump from a installed auxiliary fuel pump to get the lines pressured and the engine started. I rewired that up to an identical switch to be reinstalled in the dash next to the cooling fan switch. No more of those janky metal flip switches that the previous owner had installed.

    Questions i currently have:

    I have an email out to ORS about why the injectors may not be pulsating, they said they would get back to me with a list of things to check, will post that here once i have it. Any one have guesses as to why they wouldn't be pulsating? Like i said above, they have power at the fuel injector, it ran on starter fluid before dying, and the fuel lines are pressurized thanks to the auxiliary pump.

    Does anyone have a wiring diagram for a 1977 toyota pickup? I did find one that i will link below but not all of my wires match up to it (even the original wires). The file is attached below:
     

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  19. 83pickup

    83pickup Enthusiast

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    79-83 pickups are 4th gens, and prior to that the <75-78s (might be some discrepancies for the older ones there) are the 3rd gens. Camper, so there's all that, Not a diesel so thats some less wiring shebang to deal with, maybe try eBay/online for a diagram. Wish i still had access to ProDemand or AllData, *might* have it but no promises, it's pretty dainty past vehicles made before 1985~ if it was common of course, unlike my '89 Van...
     
  20. Liquidhandwash

    Liquidhandwash Enthusiast

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    Hard to diagnose from my armchair in Oz but I have seen injected jam from sitting around, not likely but it does happen. I removed them and cleaned them in carb cleaner compressed air and run 12 volts to the terminals to get them clicking. Just check the impedance of the injector before putting power to it, you don't want to burn out the coils, some low-impedance injectors may require a lower voltage or a resistor, I'm not sure. It worked for me but it was an old engine and it had High impedance injectors.
    Also, does the ECU have an immobilizer?
    It's also worth checking the fuel pressure at the injectors with a gauge. Just because the pump runs does not mean it is producing any useful pressure. it should be around 50 psi, less than 20 psi the engine is likely not going to run.
     

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