Build Another Prado in Montana

[AirheadNut]

Both front wheel bearings have been gradually getting loose, causing wandering and poor handling. I've been putting off doing anything with them since the wheel bearings are going to be replaced when I do a knuckle rebuild later this fall, but it has gotten bad enough that I decided to go ahead and just tighten them up a little. Pulled apart the RH one first, the electric hub came apart easily and looked good inside, but while trying to take off the slip ring that locks the axle nut in place my T20 bit sheared right off in one of the little screws.

I didn't have any way of dealing with it at the time, so that side got buttoned up again. The bit is too hard to drill out, so I'll grind the head of the screw out with a little stone on a Dremel.

Moving on to the LH side things looked a little worse. Water ingress from several deep crossings and puddles this fall made it look like I dredged the parts up off the bottom of the ocean. This was the hub that quit working a few weeks back, I had revived it with a couple spare parts from some used e-hubs from @mudandrock, but apparently that fix hadn't lasted since the hub was still locked when I disassembled it.

I was able to give the axle nut a little turn to tighten up the bearings, but I'm not sure it did much good. After this I am finally looking forward to ditching the electric hubs.

 

[AirheadNut]

@cruiseroutfit here are some photos of the donor axle. I was told it was either a 1984 or 1985 Pickup axle, but don't know enough about those to confirm. For a knuckle rebuild kit would I get this manual hub 70-series kit?

7x Series Knuckle Rebuild Kit - 01/1990 - 07/1999 70 Series Land Cruiser 6-Lug w/Manual Hubs

7x Series Knuckle Rebuild Kit - 01/1990 - 07/1999 70 Series Land Cruiser 6-Lug w/Manual Hubs (FA7X99)

cruiserteq.com

 

[cruiseroutfit]

Nope, you need this kit:

Edit. You're grafting those parts onto your 7x axle not doing a diac brake conversion. You have the right kit, FA7X99

 

[AirheadNut]

Fantastic, thanks! Planning to just swap over the spindles and hubs (and whatever else is essential to swap to manual hubs) onto my existing LJ78 axle.

 

[AirheadNut]

I haven't driven the Prado in the past few weeks because of the wheel bearing issues, a coolant leak and a leaky injection pump causing hard starts. Yesterday I needed to get some lumber that wouldn't fit in the Jetta, so I took the Prado instead. The battery was mostly dead but it just barely started. Drove to town, came back and worked in the shop truck for a few hours. When I went to restart the Prado late in the evening the battery was completely dead again, so I put it on charge.

Three faults could have caused this:
- Bad battery
- Parasitic drain
- Dead alternator

I got the engine started and checked the state of charge at idle: 12.8v. Looks like the alternator is suspect. Not wanting to rule out any of the other possibilities I disconnected the battery, recorded the voltage and left it for about 24 hours. Checking battery voltage this evening revealed that the battery seems to hold a charge on its own, so it is probably still good. Last night's voltage: 12.71v, tonight's voltage: 12.70v. I reconnected the battery again and will check voltage tomorrow evening to see if something is draining the battery down.

A new alternator is on order, yet another thing to put on the list of projects for my wrenching session in a couple of weeks.

 

[AirheadNut]

Tested the battery again after leaving it connected for the past 24 hours, it read 12.70v yesterday and 12.65v this evening. No indication of any significant parasitic drain. Fired up the engine and lo and behold, the alternator put out 13.81v. Not sure why it would be intermittent, but alternator failure is a common side effect of a leaky injection pump head seal: diesel drips off the bottom of the IP onto the alternator and slowly kills it.

I'm relieved that there is only one problem to fix with this and not multiple!

 

[AirheadNut]

Dead battery again this morning, and very nearly dead after work. I dropped by an auto parts store and had them check health on the battery, my supposedly 810CCA battery was down to 495CCA. I've had it 2 years, 8 months; not too happy about it. Supposedly it came with a 36 month prorated warranty, but I'm not sure if I want another of the same.

 

[AirheadNut]

Parts for the upcoming maintenance marathon are starting to arrive. So far I've got:
- Knuckle rebuild kit
- Hub stud kit
- Alternator
- Coolant flange o-ring
- Injection pump head seal kit
- Panhard rod bushings
- Soft brake caliper hoses
- Motor mounts
Going to get the donor axle torn down and the parts cleaned this week in preparation for next week's mad rush. I doubt I'll be able to get everything done, but at a bare minimum the knuckle rebuild/hub swap and injection pump reseal are absolute necessities.

Can't forget the most important thing, either:

I should be set for the knuckle job!

 

[Rigster]

Parts for the upcoming maintenance marathon are starting to arrive. So far I've got:
- Knuckle rebuild kit
- Hub stud kit
- Alternator
- Coolant flange o-ring
- Injection pump head seal kit
- Panhard rod bushings
- Soft brake caliper hoses
- Motor mounts
Going to get the donor axle torn down and the parts cleaned this week in preparation for next week's mad rush. I doubt I'll be able to get everything done, but at a bare minimum the knuckle rebuild/hub swap and injection pump reseal are absolute necessities.

Can't forget the most important thing, either:
View attachment 3775017

I should be set for the knuckle job!

I recall nearly going through an entire box of Scott wipes when I did my knuckles... that's what made me laugh. Once this is all done you should be set for winter... nothing worse than low amps in the winter season. I hope it all goes smoothly for you!

 

[AirheadNut]

I recall nearly going through an entire box of Scott wipes when I did my knuckles... that's what made me laugh. Once this is all done you should be set for winter... nothing worse than low amps in the winter season. I hope it all goes smoothly for you!

Thanks! Despite having owned 8 solid axle Toyotas this will be my first knuckle rebuild. I’ve heard tales of extreme paper towel use during the process so I figured I’d better stock up.

Got 3” of snow last week, and another couple of inches again this morning. The drive to work was a little sketchy due to my non-functioning hub locks, so I’m really looking forward to getting those swapped out too. Going to see if I can get them locked for the 300 mile drive back to @SnowVersion’s shop this weekend.

 

[AirheadNut]

Hubs are locked! The RH hub still works flawlessly, but the LH one is not actuating so I had to pull the outer cap off and manually rotate the spline to extend it. Jacked up the wheel so I could spin it while reinstalling the hub and it slipped right on. Going to leave them locked until I take the axle apart, it is supposed to be cold and icy for the next few days anyway.

 

[AirheadNut]

Made some progress tearing down the donor axle tonight. Disassembly went remarkably smoothly given how crusty it looked; not a single stuck fastener and all cone washers came out with a couple of taps on the brass drift.

Spindle looks like it is in good shape too, which is a major bonus.

 

[Rigster]

Made some progress tearing down the donor axle tonight. Disassembly went remarkably smoothly given how crusty it looked; not a single stuck fastener and all cone washers came out with a couple of taps on the brass drift.
View attachment 3776974

Spindle looks like it is in good shape too, which is a major bonus.

With how crusty that thing looked I thought for sure you would be in a sweat/swearfest getting it torn down, I am glad for your sake this was not the case. I suppose the saying "don't judge a book by it's cover" is apropos in this case. I went to replace the cv axles and struts in my Jetta (all original) and ended up using a sawsall and replaced EVERYTHING except the sway bar due to everything rusted solid. Glad this was not your experience.

 

[AirheadNut]

Well, my maintenance week did not go entirely as planned. The first few days were spent getting the shop ready to work in; the main task was installing a new (used) 12k 4-post lift. The lift was originally over 13 feet wide, so we narrowed it by 12" so it didn't take up so much space in the shop.

The next step was to meticulously lay out hole locations so we could drill the concrete and install the uprights. Everything had to be square and plumb.

Almost every step of the process required some kind of modification.

 

[AirheadNut]

After a couple of mistakes on assembly we finally figured out how all the parts went together and now have a second fully functional lift.

Once that was done we could shuffle things around in the shop again so the Prado could go on the center post lift and I could tear into the front axle. Disassembly went fairly smoothly except for the cone washers on the LH upper trunnion bearing cap/steering arm. None of them would budge, even with repeated penetrating oil treatments and lots of hammering on a brass drift. Eventually one of the studs bent and the nut got seized on, so that stud had to be removed. Luckily I was able to just get the knuckle housing off with only the lower trunnion bearing removed, and a with a little help from a grinder was able to clearance the housing slightly to allow it to be reinstalled the same way. A bolt from the hardware store took the place of the stud/nut until a new one arrives.

The RH side came apart much better with no unpleasant surprises. Overall the knuckles were in great shape, the grease didn't look too bad and there was no evidence of birf soup, but since I was most of the way there with a manual hub conversion and wheel bearing replacement it only made sense to replace all the 33 year old gaskets, bearings and seals.

The knuckle housings, donor hubs and spindles and hardware went through the parts washer to get all cleaned up prior to reassembly.

Two of my front wheel studs were broken, so I had a complete set of replacements. Upon inspection the inner surface of both brake rotors was pretty pitted, so the decision was made to replace them as well.

 

[AirheadNut]

This is where things started to go awry. I had planned to replace the brake caliper hard line and soft line across the knuckle with a single soft line from the caliper to the axle. The soft line recommended for this application is Raybestos BH38881 (Flexible hose to front calipers? - https://forum.ih8mud.com/threads/flexible-hose-to-front-calipers.1346127/#post-15645965). However, while this seems to work great in leaf spring applications, with the LJ coil springs there is far less clearance between the brake caliper and the spring perch and the soft line hits the spring perch and shock absorber long before the steering stops hit.

Those photos were taken with the wheels pointing close to straight. The hose can clear the bottom of the spring perch but runs into the bottom of the shock absorber at full lock. Unfortunately one of the hard lines was destroyed upon removal (seized fitting) and I made the mistake of cutting the junction blocks off the backing plates before checking to see if the new hoses would actually work. I can't go back to original spec, but I think my only option is to make a close approximation of it.

Here is the original setup (apologies for the poor photo):

There is a hard line that makes a sharp 180º bend right out of the caliper and follows close along the caliper up to a right angle female/female junction block.

A short male/female soft hose goes across the top of the knuckle to the axle housing.

The hard lines are still available, but I cannot find the correct type of female/female junction block to reproduce the original setup. My question is: does Toyota (or anyone else) make a short (8-12") female/female soft hose with the same type of female fitting shown above? My other option would be to use a female inverted flare/-3AN adapter on each side of the knuckle and a premade -3AN brake hose between them, but I would like to keep the number of connections and adapters to a minimum if possible.

 

[AirheadNut]

Results of an image search for "toyota flexible brake hose" came up with this: 90947-02G20. North American applications include the later 4.0 V6 4Runner and FJCruiser. From what I can find online these appear to be 12.7 inches long with 10mm x 1.0 inverted flare fittings, which would be just right. Fabricating the appropriate bracket to hold the backing plate end should be fairly easy.

 

[cruiseroutfit]

Use these:

Backing Plate Eliminator Kit - Fits 1958 - 1997 4x/5x/6x/7x/8x Series & 1979 - 1985 Mini Truck Applications (FAXTBPELIMLR)

Toyota Land Cruiser Backing Plate Eliminator Kit

cruiserteq.com

Brake Replacement Hard Line w/Fittings - Caliper to Backing Plate - Fits 8/1980 - 1/1990 60 Series Land Cruiser - BJ/FJ/HJ60/62/62 Models - Left Hand (BRH60021)

Toyota Land Cruiser Replacement Brake Hose

cruiserteq.com

Brake Replacement Hard Line w/Fittings - Caliper to Backing Plate - Fits 8/1980 - 1/1990 60 Series Land Cruiser - BJ/FJ/HJ60/62/62 Models - Right Hand (BRH60031)

Toyota Land Cruiser Replacement Brake Hose

cruiserteq.com

Brake Replacement Hose - Axle to Backing Plate - Fits 8/1980 - 1/1990 6x/7x Series Land Cruiser - BJ/FJ/HJ60/62/62/70/71/73/74/75 Models (BRH39855)

Toyota Land Cruiser Replacement Brake Hose

cruiserteq.com

 

[AirheadNut]

Use these:

Backing Plate Eliminator Kit - Fits 1958 - 1997 4x/5x/6x/7x/8x Series & 1979 - 1985 Mini Truck Applications (FAXTBPELIMLR)

Toyota Land Cruiser Backing Plate Eliminator Kit

cruiserteq.com

Brake Replacement Hard Line w/Fittings - Caliper to Backing Plate - Fits 8/1980 - 1/1990 60 Series Land Cruiser - BJ/FJ/HJ60/62/62 Models - Left Hand (BRH60021)

Toyota Land Cruiser Replacement Brake Hose

cruiserteq.com

Brake Replacement Hard Line w/Fittings - Caliper to Backing Plate - Fits 8/1980 - 1/1990 60 Series Land Cruiser - BJ/FJ/HJ60/62/62 Models - Right Hand (BRH60031)

Toyota Land Cruiser Replacement Brake Hose

cruiserteq.com

Brake Replacement Hose - Axle to Backing Plate - Fits 8/1980 - 1/1990 6x/7x Series Land Cruiser - BJ/FJ/HJ60/62/62/70/71/73/74/75 Models (BRH39855)

Toyota Land Cruiser Replacement Brake Hose

cruiserteq.com

Unless I’m missing something about how the backing plate delete kits work, I think I’d still be missing something to connect the caliper hard line to the soft line going across the knuckle. Both have a male end; my backing plates originally had a 90° female/female junction block on them to connect the two, but those are no longer there.

Ideally the soft line would have two female ends, then no additional junction would be needed.

 

[AirheadNut]

I was digging through some boxes of parts and came across something I believe was a clutch hose, probably from a T100. Pretty sure it was originally 96816-50290. It has the correct 10mm x 1.0 female inverted flare fittings on each end and is just the right length. That part appears to be discontinued, but after some searching I found a clutch hose from a 1980's 4Runner is pretty close, Dorman H38113. Ordered a pair from Rock Auto, anxious to see how well they actually fit.

Got the hubs finished up and the wheels put back on, stuck the Prado on the flatbed trailer and towed it to my brother's place a couple of miles from the shop due to limited parking. Planning to pick up where I left off next weekend.

An HDJ81 makes a decent tow rig, but we were definitely pushing its limits with this load.