PreRunner 4x4 Conversion Journey Thread

I appreciate these detailed posts, it has helped steer my conversion.

 

Glad it's been helpful! I feel that way about previous conversion threads, so hopefully this one can add to the knowledge base.

 

Day 4: The new trans mount arrived, and it fit perfectly, thankfully. That allowed me to finish getting everything back in transmission related, including the rear driveshaft (which also fit, I was a bit worried about this one). From there I was ready to fill up the transfer case and transmission with oil and take it for a 2WD test drive.

When I drained the pan on the A340F initially, I got about 3 quarts of ATF out, and I know it had been sitting for at least a year in the previous owner's garage. When I filled it back up today, I got about 2 quarts in until I hit the "cold" range on the dipstick. I started the truck up (which went well, no check engine, nothing weird, started right up), and took it for a slow test drive, maybe a half mile total. I noticed that it was hunting a bit when getting into reverse, and into 1st gear. When I got back to the garage and checked the dipstick again, the fluid level was now below the cold level, instead of near the hot level. So, I realized the hunting was likely just not enough oil circulating in the trans yet, and I spent about an hour filling it up, checking the dipstick, taking it for a short ride, re-check. In the end I got between 7-8 quarts of ATF in there. So, just a heads up to expect the filling process to take a little while and to check it several times as you're taking test drives.

It now shifts great, and feels pretty much exactly the same as the A340E did in terms of shift range and such. The extended VSS works perfectly too, speedometer match looked pretty much dead on. Was a huge relief given all the work done. I'm now going to get the front diff and front driveshaft in hopefully tomorrow, and then move onto the spindle overhaul process (which I might take a few days off before doing, been a bit of a grind so far). Oh also, bought a new OEM windshield washer jar and popped that in today, my old one has the classic cracked plastic on the filler neck.

 

If you dont mind me asking. What is the cost of the tank?

 

Of course, I paid $87 after tax for it straight from the online Toyota parts site during a 25% off sale (which actually just started again yesterday and will be 25% off for the next two weeks). I’m lucky enough to live very close to a dealer so I always just ship parts there for free for pickup. Most stuff arrives within 2 days. The part number is

$143 85315-04060 Windshield Washer Reservoir

85315-04060 just fyi, and that’s the one with the low fluid sensor, if your rig doesn’t have that sensor the part number is different.

 

Killer stuff. Nice work.

 

Day 5: finished installing the front diff and front driveshaft, and took off the knuckles to start disassembly/pressing.

I went with the bench press method for the front diff, where I jacked up the front end, laid flat on a creeper, put a mat on my chest, and put the diff on that. It was really heavy and tough to maneuver, but in the end it actually didn’t take much fussing to get it seated, less than 10 minutes. The front driveshaft went in easy and fit perfectly (I was again slightly worried just trusting internet dimensions for my junkyard part). Something I couldn’t find in the FSM was the correction orientation of the front driveshaft, by that I mean if the slip yoke side connects to the front diff or the transfer case. In the end I found enough photo references online to trust that the slip yoke connects to the tcase, but I was surprised there wasn’t more info.

Also got the spindles popped off and my new 12 ton shop press assembled. Hoping to get the majority of the press work done tomorrow. Excited to be nearing the end of the journey!

 

It’s clean work man, clean garage floor too! That diff I’m jelly…what gasket maker are you using for reseal? As well as what rust removal/repaint process?

I’ll have to follow suit for this diff rebuild, it’s seen better days. It’s a 3.90 anyways so will have to open her up for a regear.

 

Haha yes I’m thankful to be able to use this garage for this work. I’m using the Toyota stuff for it, I believe it’s the fipg 1281, for “transaxle”. It’s a bit pricey but figured it be worth it since I didn’t really know what I suitable alternative would be.

I wish there was a good trick for cleaning up the case but tbh it was just a ton of elbow grease. Wire wheels, sandpaper, dremel, etc. I used a rust reformer to paint it first, and then coated with just a flat black rustoleum. It’s possible though, mine honestly looked almost worse than yours to start!

 

Went with a 12 ton instead of the 20 ton? Let me know how that works out when pressing the bearings. I stuck with the 20 ton and am glad I did. I might have lucked out but it did go super smooth.

Thanks for sharing the windshield fluid reservoir part number. Everything looks good, keep it up you're almost done!

 

Yeahh I initially asked this question on the harbor freight Reddit lol, and several people said they had no issue at all doing wheel bearings and hub pressing with the 12, some even using a table top 6 ton. So I figured I’d be ok with the 12 and it happened to be on sale for significantly cheaper than the 20, so we will see!

 

man everything is looking nice under there. Good job on this project. A lot of patience you got there. Well worth it at the end

 

This project has been very motivating,
My truck goes up on the jacks today…

 

Welp folks, 42 days after the start of this journey, I now have a 4WD rig. I put in a monster 10-hour push today and finished the job.

All of the press work went surprisingly well, the 12 ton shop press handled it with grace. I will admit I was pretty stressed out during that part, fiddling with the steel plates, press sleeves, and awkwardly shaped knuckle was not fun, but if you have the right tools it's really not hard (I'd recommend a couple sets of 1" steel plates, and 100% a press sleeve kit). One thing that made me twitch was seeing that my knuckles really could've used the same 5-star treatment I gave to every other part on this journey in terms of restoration/rust removal/paint, but I just wasn't about to stop for several days and get into all that. It was actually something I thought of before, and I think one of the benefits of getting donor knuckles vs. using your prerunner ones. You get to fuss with them all you want and have no down time when it comes to swapping them in. But alas, I swallowed my pride on that and just got everything back together. I also ended up ripping off the dust shields pre-pressing out the prerunner hubs because it was just not working out well trying to get the things to balance on the press set up with giant metal saucers on there. I think it's worth it to do that just to save yourself some sanity on the press. New shields are relatively cheap and make it look super nice too.

CV axle installation went smooth, I'm so glad I did a full restore on those, they really look the part. I just tapped them into the diff with a rubber dead blow, and the shafts all lined up great on the hub, etc.

Getting the manual lockouts on was straightforward, as was reassembly of the suspension parts to the knuckle. Something that really helped me as I was about 8 hours into the day, mentally and physically out of it, was I started using a yellow paint pen to just mark stuff that I had torqued. Between suspension parts, hub studs, lockouts, and the other million things you're wrenching and torquing, it's easy to forget what you've already done, and it helped me make sure I was buttoning everything up correctly and made for a quick visual inspection come time. Just a small dot did the trick.

The last thing I had to do was connect the front diff breather tube and fill it with oil (I waited because I wanted to get an accurate fill level with the truck on flat ground and it had been jacked up until this point). For those that have already done this, in particular sans A.D.D. stuff, what was y'alls solution here? I just bought 6 feet of 5/16" fuel line, which fit well on the diff fitting, and routed it up into the engine bay for now. My only concern is it's basically right next to the oil pan, and naturally close to some other components that will get hot during operation. I know on the A.D.D. bracket the breather starts out as a metal tube and snakes up near the flange before connecting back into a rubber hose, but let me know if anyone has come up with a solid solution there. The bracket that came on this one's A.D.D. setup was rusted through pretty badly, so I can't use that.

I was shot by the end of it, but of course I locked the dials and did a quick 1-min test drive. Everything felt smooth! It's kind of funny because I've never driven a 4x4 truck/vehicle, ever, so I wasn't really sure what to feel for. The only real difference I noticed driving in 4H was when you turn you can feel the front wheels giving way more grip.

I still have some steps to complete, namely wiring for the transfer position switches and other minor things, but it was a tremendous feeling of accomplishment for something that was a stretch for my mechanical abilities. I filmed a lot of the install process, so will eventually be putting together a YouTube video too. Thanks again to everyone who has lent a hand in the knowledge sharing process, I hope this thread can be of use too.

 

7 pages of useful information that I’ve saved in my tabs for sure. Here’s an interesting question, if you ever get a chance to measure how far out the hub lock sticks out from the rotor that’d be kinda cool to know.

 

Congrats on the completion. I enjoyed the journey. Looking forward to the video release.

 

Great job man! Glad its all done. Time to enjoy the rig.

 

Picked up a donor gauge cluster to harvest the temp gauge face for @Area51Runner 's AT/P light mod for when the t-case is in Neutral. Wiring and electrical stuff is by far my weakest mechanical skill as I don't have a great grasp on the principles of electrical circuits and such, but going to do my best to interpret the threads here on the topic for the tcase sensors. At least the cluster face plate seems fairly easy to swap, and I've been looking for a reason to pull my cluster back out as I've had a dead LED bulb behind my speedo for quite some time.

As I'm starting to drive the rig more after finishing the 4WD conversion, I have noticed a slight vibration, mainly when I'm coasting between ~35-65mph. I'm trying to diagnose what could be causing this, here are some of the facts:

• I got new tires only a couple thousand miles ago, I had them balanced and an alignment done, and there was no vibration in this way prior to the conversion.
• On the new driveshafts, I used brand new OEM u-joints and a new OEM carrier bearing for the rear shaft. I'm quite confident in my torque specs all the way around the truck as I was diligent about this during the conversion.
• I didn't replace anything to do with the front suspension during this process, just removed stuff to pull the spindles, but everything was re-torqued to spec.
• When driving, I can feel the vibration with my feet, and a bit in the steering wheel.
• There is no vibration coming from the tcase shifter or trans shifter.
• No jerking/swaying/shaking of the steering wheel.
• Everything is smooth at lower speeds, and when accelerating for the most part.
• Transmission shifting feels good and smooth.
• I had done poly bushing replacements on the steering rack probably 8-9k ago and haven't had any steering issues prior.
• I replaced my rear leafs probably 10kish ago (admittedly I haven't been happy with them since, I went with the standard duty General Spring ones and they squeak like hell and seem to be in a frown at a resting state, but I haven't had driving issues with them).
• I had both the front and rear driveshafts balanced at a professional driveshaft shop immediately before install.

The only thing so far that I've thought of that could be a possible cause is the fact that I just slapped probably 300ish or more pounds of additional parts (between the t-case, front diff, front driveshaft, CVs, fluids, etc) onto the frame, and perhaps that changed the suspension angles in a significant enough way to throw the alignment off a bit?

I just read this in another thread, "axle wrap due to engine braking. My truck does the same. Your pinion gets pulled down due to the engine braking and creates "bad" driveline angles. As soon as you get back on the gas your pinion moves back up and puts the pinion in an angle that doesnt have the harmonic." But not sure if that could cause this for me.

Let me know if anyone has any thoughts! I'm gonna get an alignment next week as I probably should regardless after all this work, so will see what that yields. I know I'm just hyper tuned into the driving feedback of the truck right now and the reality is its a pretty minor vibration, but it is a change from before, so I'm just trying to get to the bottom of it if possible.

P.S. something that I also noticed is the "thud" that I was used to upon coming to a full stop and starting back up again has disappeared. I had originally diagnosed it as axle wrap, but now I'm wondering if it was my old carrier bearing, it definitely had some play to it.

 

The extra weight can possibly change the angles on the drivetrain just how it does when doing a lift. Check angles on the drive shaft. May have also put the alignment off a bit. IMO I would take it to the alignment shop and have them see what the numbers are and go from there. Definitely check the angles on the DS. I dont remember reading about the driveshafts during the process of your conversion. Did you get these drives shafts used or cut to length? If so maybe taking them back to have them checked make sure they were spun/balanced.

I had similar issues when I did my conversion. Mind ended up being the angles on the driveshaft. I had did a lift prior to the conversion and didnt have any issues. Once I got done with the conversion and drove it I noticed these issues. Took me a while to figure this out until I started reading on this. Weird how before the conversion it was fine.

 

Yeah good idea, I'll have to see what the angles look like under there. I'm getting an alignment tomorrow so will also see if there was any significant adjustment needed as I had gotten one very recently so any changes I'd have to correlate with the conversion. But yes so for the rear I sourced a used OEM one from a 1st gen double cab. I replaced the u-joints with OEM and had it balanced at a driveshaft shop. They removed the old factory balancing weights and welded their own on, so I assume it came out balanced, but you never know.

How did you end up fixing the driveshaft angles? I was reading a bit and seems like you can do some pinion adjustment, but curious what your solution was?