Builds PZJ78 truck build??

[crushers]

okay, i jumped the gun here.
in my "tired and ill" mind, i stuck in the springs and then bounced the front end by hand and was shocked to see the ease in which the engine and frame moved full travel. that was yesterday.
this morning i installed the shocks and that made a HUGE difference.

so, for now, the vertict is still out as to whether i will be happy with this kit or not.

i do recommend that if you are considering this swap to go with the HD front springs, just to be safe.

 

[lshobie]

Not sure how much room you have for springs, instead of the 80 series fronts which are wider you could go with a 79 series??

 

[Rusty Phillips]

i would suggest that anyone that wants to do this swap locate at least a half cut or a complete donor rig. 3B, 13BT, HZ, PZ, HDT will fit. there is lots of options out there to replace the 2LTE. i would STRONGLY suggest the donor rig be a 70 series platform for ease of installation.

while im thinking about it - to tag on here

relocating that front crossmember forward is (to me) the single most intimidating thing on this build.....
not for the faint of heart or typical backyard mechainic.

Im wondering if the fan/shroud on a 3B / 13BT will clear the factory LJ crossmember... allowing you to leave it in place / untouched, (and retain the LJ sheetmetal)

I do think that even the PZ would would fit in there if you went with dual electric pusher fans and no shroud behinnd the rad which would eliminate the need for the front end framectomy

I discussed with Wayne before chopping the LJ frame but he is no fan whatsoever of adding electric crap to his trucks and really wanted the long front sheetmetal & 70 series ARB bumper.....

well... and of course he has a well equipped shop....

 

[crushers]

79 series and 80 series fronts are the same part number, i have a brand new set sitting here but they don't come close to fitting.

Rusty, i ain't going there...

 

[Jim_Hbar]

Rusty:

IMO, One of the major attractions of these conversions is to end up with an HD 7* series front end and mechanicals, and the mechanical reliability there of. The result would have much less appeal to me, if Wayne squeezed the PZ into the Prado sheetmetal. Or, heaven forbid, put HD sheetmetal on Prado mechanicals.
But I agree that you have a valid concern concerning the frame.

I realize that some are going to flame me for posting this, but they do not understand my experience and background, and that is fine. What's tends to be important on forums is post count, not real world experience, education, and qualifications.

It would be interesting to compare Wayne's result with the HZJ 79 frame, wrt cross-members on either side of the coil mounts.. Technically, for the "home shop" builder, the way Beislebub did it by adding the sheetmetal mounts to the existing Prado frame, preserves the original frame geometry and the way loads from the spring and shock mounts get distributed, and there are no questionable welds in a highly stressed area.

Wayne is going to do it the way Wayne wants to, regardless of who suggests what, and with his "seat of the pants" design and fabrication skills, will have a result that is better than 80 or 90% of the home builds.. If the frame does have issues, Wayne will man up to it, accept that his approach didn't work, fix it, put it behind him and move on - all in the space of about 5 minutes. Wayne is also going to be under his rig on a regular basis, and will be looking for signs of imminent failure.

The problem comes down the road, if/when the rig ends up in the general population, owned by somebody that doesn't understand, or the modification is copied by some snot-nosed kid that welds up the frame with a coat hanger and a couple of batteries.

Understand that I am not saying that Wayne's approach is dangerous or unsafe, just that a bunch of things have to be done correctly, in a competent fashion for the end result to be potentially successful and safe. If I was Wayne, I'd be talking Louis into coming up to view the progress of the build, and sneaking a few peaks under his rig, checking if Toyota did anything different on the later coil sprung frames vs the leaf sprung frames.

If I had to inspect and offer a professional opinion on the modification, done in a home shop, I would be looking for an approach like the one Beislebub used. That's my personal/professional opinion, and if there other licensed professional engineers, or government inspectors out there that wish to assume liability by offering up a differing opinion, that's fine too.

If anybody wishes to discuss credentials, please PM me.


Jim

 

[crushers]

Jim brought some good points and i figured his suggestion of the 79 series to be a valid one.
<post count should never mean more than actual knowledge and experience>
here goes
pic of the 79 series front cross member
pic of the 79 series small little strengthening bar to panhard support
pic of 79 series tranny crossmember.

from the firewall back the frames are identical (except for the coil suspension of course) and factory.
also the steering box and suspension are still on the original portion of the frame, not attached to the extended front nose and cross member.

 

[crushers]

the 79 nose section top
the 78 nose section bottom

Jim, does this meet your satisfaction (said in a manor of respect, not derogatory or insulting)?
<i still have to install the small 1 1/4" brace yet>

 

[crushers]

installation of the lift springs and shocks
might as well change out the fuel filter and fill it with seafoam
the location of the shift to the stock tranny cover.

tomorrow, install rad, hook up the elec, install small support brace, install pyro, oil pressure and boost gauges... maybe

yesterday and today 6 hours.

 

[lshobie]

79 series and 80 series fronts are the same part number, i have a brand new set sitting here but they don't come close to fitting.

Rusty, i ain't going there...

Wayne, check your part numbers - they are definitely different - the 79 series fronts are not as wide. The 79 front springs should fit.

 

[crushers]

i did test fit them, and the 79 are too wide to fit the 78 towers.
it is a "no go".

 

[Rusty Phillips]

Rusty:

IMO, One of the major attractions of these conversions is to end up with an HD 7* series front end and mechanicals, and the mechanical reliability there of. The result would have much less appeal to me, if Wayne squeezed the PZ into the Prado sheetmetal. Or, heaven forbid, put HD sheetmetal on Prado mechanicals.
But I agree that you have a valid concern concerning the frame.

I realize that some are going to flame me for posting this, but they do not understand my experience and background, and that is fine. What's tends to be important on forums is post count, not real world experience, education, and qualifications.

It would be interesting to compare Wayne's result with the HZJ 79 frame, wrt cross-members on either side of the coil mounts.. Technically, for the "home shop" builder, the way Beislebub did it by adding the sheetmetal mounts to the existing Prado frame, preserves the original frame geometry and the way loads from the spring and shock mounts get distributed, and there are no questionable welds in a highly stressed area.

Wayne is going to do it the way Wayne wants to, regardless of who suggests what, and with his "seat of the pants" design and fabrication skills, will have a result that is better than 80 or 90% of the home builds.. If the frame does have issues, Wayne will man up to it, accept that his approach didn't work, fix it, put it behind him and move on - all in the space of about 5 minutes. Wayne is also going to be under his rig on a regular basis, and will be looking for signs of imminent failure.

The problem comes down the road, if/when the rig ends up in the general population, owned by somebody that doesn't understand, or the modification is copied by some snot-nosed kid that welds up the frame with a coat hanger and a couple of batteries.

Understand that I am not saying that Wayne's approach is dangerous or unsafe, just that a bunch of things have to be done correctly, in a competent fashion for the end result to be potentially successful and safe. If I was Wayne, I'd be talking Louis into coming up to view the progress of the build, and sneaking a few peaks under his rig, checking if Toyota did anything different on the later coil sprung frames vs the leaf sprung frames.

If I had to inspect and offer a professional opinion on the modification, done in a home shop, I would be looking for an approach like the one Beislebub used. That's my personal/professional opinion, and if there other licensed professional engineers, or government inspectors out there that wish to assume liability by offering up a differing opinion, that's fine too.

If anybody wishes to discuss credentials, please PM me.


Jim

Thanks for your comments..... let me offer a clarification

Regarding Waynes truck.... my fingerprints are all over it (I'll take credit for grinding the powder coat off of the 3/8" plate that Wayne welded inside the frame rails, and drilling the holes in the frame to weld to the plates)

If possible - Id much prefer to leave the prado crossmember untouched and ADDING the front body mounts for the HD cowl - which I think you can do with electric fans.... (although that lower rad hose on the PZ / HZ I think comes close to the crossmember too)

If this were MY truck - Id likely be doing a 3B and electric fans......

from bieselbub's build thread

Was able to scrape together some time this morn, and dry fit the Hz. I had noticed that the stock front drive shafts of both the lj78 and the hzj79 were the same length, and after taking a few measurments it looked like tranny mounts might not need to be moved . After cutting the motor mounts out of the lj and the 79, the Hz slid right into place. I Used the stock placed tranny mount, and then tacked in place the motor mounts ( I'll be able to use both stock drive shafts ). So far it looks like the fan will need some attention, the 18" hz fan just hits the front crossmember, and the smaller 2LT fan clears by about 3/4". Both leave no room for a shroud, I'll have to see what it looks like when the panels are on, thinking if I bring the fan foward about 3" it should be past the crossmember.

Anyone know what the weight difference between the HZ and the 2LTE is? I cross referenced a Bundera (2LTE) and a hzj70, and came to 140kg, I know the suspension is different etc.

Joel.

[imghttps://forum.ih8mud.com/attachment.php?attachmentid=]326355[/img]

 

[pradocruzer]

Hey Wayne. Dobinson makes 4 & 6 inch raised coils also for the 78. I have found that here is a fine line to having springs being either too stiff or to soft on the 78 because of the leading/trailing radius arm suspension set up. When the springs are too stiff the flex suffers badly and too soft has no load carrying capacity and relies on the shocks for all of the control. Obviously with the added weight of your new engine and a bumper with a winch, the front springs may need to be stiffer. The first picture below is stock on 32x9x16 the second is four inch Dobinsons and the third is a six inch lift coils I brought back from Rabbit Auto in Japan. I'am running the Rabbit Auto springs up front. These springs are soft and they let the radius arm set up flex. In the back I'am running my four inch Dobinsons (witch was really about 4.5 inches installed of lift) with a front 80 series 1 1/4 " coil spacer. I did this because the dobinson coils are stiffer and since I changed my rear suspension to a three link on hiems it flexed so easy i needed the stiffer springs. From experience only, lock your coils in because when the shock breaks (or in my case forgot to tighten the eye to pin conversion bolt) the spring falls right out.

 

[Jim_Hbar]

Wayne:

Like I said, with your abilities, experience and obvious craftsmanship, I expect the project will approach a factory result. This is only emphasized by the fact you did not patch when you cut the first frame extension a bit short. Most would not have the resources or the experience to 'fess up to that boo-boo, and move on. The pictures show proper prep for the welds with clean metal and good edge prep - all professionally done. Of course, there will always be the "heat affected zone" to be considered, and stress concentrations as a result of the welds and splice plates. The modified frame will not be as strong as a new unmolested HD79 frame, but from what I see in the pictures, it should be pretty close. Of course all the usual caveats apply.

From seeing the pictures of the '79 frame, I would recommend not underestimating the role that the smallish cross tube plays in distributing the loads in the frame. Toyota's use of a "pipe" type cross-sections indicates that they expect the frame to flex fairly extensively. Notice the very robust connection between that pipe and the right hand side of the frame, shown in the pictures in your post #86. That connection has a lot going on, minimizing the stress concentrations, and maximizing it's strength. I would be very surprised if the left side was much different.

Wayne, I believe that you are doing a fine job, and that the result will be worth the effort.. Will you have issues with your frame? I would be surprised if you do, but would still recommend inspecting the welds for cracks the first few trips, and periodically thereafter. A lot will depend on how and where you get that cross tube in there, and the integrity of the welds.

The safest approach is retaining the stock Prado cross member in it's original location, and is the approach I would recommend for the non-professional builder contemplating a similar project.

'Nuff said.

Jim.

 

[crushers]

Jim,
when we had the front clip off, rusty and i had every intention of NOT cutting the frame but running a 2" tube through drilled holes (similar to factory) and welding the support tabs onto that new tube. thus keeping the integraty of the frame complete to the front. i do not like cutting the frame there any more than you like to see it.
then we did the measurments and found the Prado frame to be 1 1/4" short of the HD frame length. we could have proceeded but then any aftermarket bumper WILL NOT fit and more importantly my custom bumper off the donor PZJ70 would not fit.
it was at that point that i decided to go this route.
IF the installation of aftermarket bumper was not a concideration then the original idea wuld have happened.
for the want of an 1 1/4" the frame was chopped.

when i go to extend the frame 28" i will contact you for suggestions on how to do it safely. that won't be till the spring.

once again i appreciate your candor.

<i had every intention of reinstalling the 1 1/4" tube from side to side but i want the engine sitting in the bay first to make sure i clear the oil pan on suspension travel...>

of course periodic inspection just makes common sense, i have no desire to hurt myself, or others, should the frame fail.

this is another reason we cut the original frame where we did, ALL the original steering and engine mounts are still on the unmolested part of the frame. should the added part come loose it will only be sheet metal and rad affected, not the important parts.

i post up my mistakes to warn others to make sure they measure correctly, i am a cabinet maker by trade and when working with wood you get one shot at getting it right and you work with tight tolerences so mistakes like this are a true PITA. i am also human which means mistakes happen and i am comfortable enough with who i am to admit i fxxxed up. Rusty jokenly mentioned "this won't hit mud" but, even though i was upset with myself and embarrased for making such a stupid mistake, i know i needed to let others that might be considering this swap to be careful. most don't / won't have another frame sitting there that they can sacrifice to the Cruiser Gods to get it right a second time around.

s*** happens, deal with it and move on.

heat affected zones, yah, i took this into mild consideration as i pulled out the zip disc to start cutting but the twist of the frame will be much more extensive on the factory original section than the section added. now, i am not trying to make light of the potential, i am just making a statement of what was going through my head at the time. the only real stress that the welds will experience is a tug when i am stuck and the winch pull sideways. i am much more concerned with the winch and the twisting stress it can stick on with the 16,000 lbs of pull than any stress that will happen on the road.
]
i beleive the full weld around the frame and the 3/8" plate inside the frame plug welded to the joint will give the joint "stronger than factory" characteristics. originally i was going to fishplate the joint but i want to test this for the winter, i can always fish plate later if ANY stress cracks appear.

you bring up valid points, keep the advice coming guys.
i might not accept it but i will take it under advisement.

 

[crushers]

Prado,
the 4" looks nice, the 6" gives the truck an american look which i will pass on. when i had the old LJ78 test rig with these springs i could get air and not bottom out with 34" tires. the 6" looks like you could jump ot out of a plane and never bottom out.
ihave never agreed with the idea the shock should double as a travel limiter. i was considering a retainer strap from the spring mount top to bottom just short of the shock travel limit. although most of the strain is at compression, full extension puts too much stress on a small pin and nut.
i was surprised that Toyota designed the system with no retainer at all.
thanks for reminding me to do this.
cheers

Hey Wayne. Dobinson makes 4 & 6 inch raised coils also for the 78. I have found that here is a fine line to having springs being either too stiff or to soft on the 78 because of the leading/trailing radius arm suspension set up. When the springs are too stiff the flex suffers badly and too soft has no load carrying capacity and relies on the shocks for all of the control. Obviously with the added weight of your new engine and a bumper with a winch, the front springs may need to be stiffer. The first picture below is stock on 32x9x16 the second is four inch Dobinsons and the third is a six inch lift coils I brought back from Rabbit Auto in Japan. I'am running the Rabbit Auto springs up front. These springs are soft and they let the radius arm set up flex. In the back I'am running my four inch Dobinsons (witch was really about 4.5 inches installed of lift) with a front 80 series 1 1/4 " coil spacer. I did this because the dobinson coils are stiffer and since I changed my rear suspension to a three link on hiems it flexed so easy i needed the stiffer springs. From experience only, lock your coils in because when the shock breaks (or in my case forgot to tighten the eye to pin conversion bolt) the spring falls right out.

 

[beislebub]

Wayne - I have the 40 mm (somewhere around 40) OME heavys up front, and 40mm med in the back. I was a little unsure at first, but the heavys seem fine. Though I still don't have a bumper, winch etc.

Joel.

 

[crushers]

Rusty,
okay, lets discuss this.
elec fans are cool for some and a PITA at the wrong time for others. i will not install them on my rigs.
the main issue here is the hood clearence, we will have to measure the hood clearence for the Playdo and the hood clearence for the HD sheet metal. i suspect you will have an issue shutting the hood over a 3B or any of the HD engines.
i know we discussed a hood scoop, even though i have one for the top mount intercooler i am not a big fan of scoops. most look like crap.
now you could take the Playdo hood and massage it to clear with some good body work. instead of a hood scoop do a hood bump similar to how some hoods have a bump to clear a turbo or supercharger.
finally, the clearence from the rad to the grill on a Playdo front clip is minimal at best and the room to fit a couple electric fans just is not there, even if you eliminate the AC rad. it is TIGHT in there.

but i have a simple solution for you, go buy a Playdo and a 3B and we can work TOGETHER to see if we can get it to fit inside the smaller front clip and LOOK acceptable. after all almost anything can be done with time and money but that doesn't mean it will look good.

Thanks for your comments..... let me offer a clarification

Regarding Waynes truck.... my fingerprints are all over it (I'll take credit for grinding the powder coat off of the 3/8" plate that Wayne welded inside the frame rails, and drilling the holes in the frame to weld to the plates)

If possible - Id much prefer to leave the prado crossmember untouched and ADDING the front body mounts for the HD cowl - which I think you can do with electric fans.... (although that lower rad hose on the PZ / HZ I think comes close to the crossmember too)

If this were MY truck - Id likely be doing a 3B and electric fans......

from bieselbub's build thread

 

[crushers]

Joel,
your truck rode beautiful. firm yet giving.
i will see how i like the setup i have, problem is once in a while i love speed runs in the bush over rough ground so i need to make sure i don't bottom out. i am considering dropping the bump stops to just before the oil pan connects with the steering linkage...just to be on the safe side.
cheers

 

[pradocruzer]

An American look??? Nah!!
It will be a good idea to be all locked up for the lack of flex
and constant wheel in the air syndrome these 78 have.

 

[lulo]

Awesome JOB!

Congrats WAYNE