This is a condensed version of my build thread off the old offroad express forum:
July 3 2013:
...I was wondering how much lift to engineer in to clear 35's. I think I'm going to set it up to have axle centres 50mm lower than std, with all radius arm mounts placed to keep geometry as similar as possible to the std suspension on the diff donors. Any suggestions on this welcome. I might trim the guards up to get the last inch or so of clearance.
No pics of any progress, all the action recently has been rolling around on the floor with the tape measure going 'Hmmm...' I had a crawl around under the neighbour's 80 series the other night & got a few measurements off that, the diffs on the bench & under mine. It looks like fitting the rear 80 4-link should be fairly easy, plenty of room for the top arms in the Prado & a couple of well placed x-members to attach a bracket too. Biggest issue will be moving spring & upper arm mounts inboard.
In the front the pumpkin will be close to the RH chassis rail on full squish but it doesn't look like I'll lose any travel. Panhard might be close too.
Measured up the rear track on the Prado too, 1415mm. So the new setup is 185mm wider. However if I go from the -25mm backspacing on my current rims to zero that is 135mm overall, or ~70mm wider each side than currently, which seems sensible when I hold the ruler up to the wheel & go 'Hmmm...' Bigger flares will be required of course
July 12 2013:
Just sent off a few notes & pics to the certifier to make sure I'm not going to snooker meself with anything & to check if my welding looks ok. Got the go ahead there so time to start hacking stuff up
Saturday was a great day to be in the shed with a warm welder so made a little progress on the back diff, set up a jig to keep the upper arms aligned while being moved in 40mm each side:
The axle spring mounts will be reattached about 50mm inboard each side & 50mm further forward to match the LJ71 upper spring mounts
July 22
Some more minor progress, front calipers all rebuilt & fitted. Front arms threaded for rod ends.
I've been keeping an eye out for some 16x8" rims on trademe & found some for sale close by last week. Good quality ROH jobbies in the desired black colour with -12 backspace which should be ok. They came with some tyres too.
August 20 2013
Fitted up the new rubber before the axle-ectomy to check clearance:
The Cruiser guards are actually quite roomy. Some trimming will be needed though.
With entropy & a 3/4" rattlegun on the job the old axle came out pretty quick.
The old axle & tyres were last seen heading for Huntly on the tray of a hilux so there's no going back now
Currently sorting out bits & pieces for fitting the GQ axle, machined up an adapter washer for the driveshaft last night & redrilled the flange:
Had a look at the tyre vs front radius arm clearance on full lock:
With the steering stops unmoved from what was probably the factory position on the GQ the 36's just kiss the arm, so the -12 backspace rims are perfect
Sept 24 2013
Time to get back into it after the last few weekends have all been spent helping mates with Taupo 1000 prep.
The GQ axle got rolled under, clamped into place & jacked up & down to check clearances. The panhard mount on the chassis was in the way so that got hacked off. Looks good otherwise. It would have been nice to have the axle a bit further forward but as I could only shift the steering box about an inch without major re-engineering of the front end I decided to leave it in place & the axle will be in about the same spot as the original. Next the old radius arm mouts got chopped off the chassis & fabrication of the new mounts, lower & further back, started. Getting these located properly in all directions took a bit of time.
Pedal to the metal on the 200A TIG sticking these together:
Oct 7 2013
Slow but steady progress over the last week. Panhard mount:
This had to be relocated further forward to clear the diff & a bit lower to get the angle right. I've seen these broken off with the combo of big tyres & too much loud pedal so I stuck to the workshop motto of 'nothing exceeds like excess' & made it a bit stronger than std
With that done it was on to the axle spring/shock mounts. Further back to match the top spring mount & packed up to clear the rear radius arm mount. More metal still to be added to these when I pull the axle back out to fully weld them.
...& then she was able to sit on her own 4 wheels again. Shock mounts next, then bumpstops, make up a proper steering arm, put in all new bushes, plumb the brakes, trim the guards... & I'll be 1/2 way there.
Oct 21 2013
Front end mostly done now. Just need to trim the guards, get some longer shocks & a couple of other minor bits & pieces.
Looks a bit goofy but I drove it across the paddock & down the street & back without any issues. Then back in the shed to start on the rear end.
Tore out the old axle & scraped & brushed about a 1/2 ton of dried mud out from underneath, now ready for the next round of fabrication
At 1st look it doesn't seem like grafting in the 80 axle & suspension will present any major puzzles.
May 30 2014
Too much other fun stuff to do over summer has meant fairly slow progress, but I am gradually getting there. All the rear suspension mounts are now done & dusted & the axle is in for hopefully the last time.
I have tried to copy the 80 series geometry as much as possible.
Thanks to Dan's sheetmetal skillz the wheel arch edges were cut & shifted up about 50mm, just finished migging all those back in & painting/sealing. Dan also helped set up the back diff, all rebuilt with a terrain tamer bearing kit & the Ironman/Harrop/Eaton electric locker.
That's now in the housing, next up is connecting & bleeding the brakes. I also need to work out a longer handbrake cable - might try a MWB 70 one from the wreckers.
The 80 series springs I got with the axle may be a bit wide/stiff/tall but I think I'll give them a go, will help to work out what I need if nothing else. Need to source some shocks too, ideally something not too big in diameter as space is tight.
Other major items on the list are getting a driveshaft made (need to see if I can get a matching bigger flange for the transfer case) & making up the new exhaust. The top arms in the back are where the muffler used to be so I'll be feeding a pipe down each side of the chassis & out the back with home built mufflers under the doors.
Jun 23 2014
Basic structure of the new exhaust now done, still need to swap the cobys in the front, add some hangers & sort joins/flanges. See also chopped guards.
With the pipes in place I can now finish the mods to the sides of the rear bar & start thinking about side bars.
Another pic of the chopped front guard:
Jul 4 2014
Progress continues...
Rear bar has been modded to clear the tyres & fitted back up. Also made a shield to go at the back of the RH wheel arch & protect the fuel filler hose.
Rancho 5000 rear shocks arrived from Summit & have been fitted. These were one of the few things in the conversion that have actually just bolted on with no mods at either end. I was a bit worried about clearance off the springs & chassis at full squish but with the bump stops packed down to keep the tyres off the sheetmetal she's all good.
I finally got my handbrake cable after it went to the wrong address, looks like it might fit up without mods... maybe. Into that this weekend .
Jul 8 2014
More minor progress, handbrake cable went in sweet with a few small mods to brackets. It did take quite a lot of rolling around under the wagon trying different routing before finding the right arrangement that would take up the extra length, not foul on anything & not have any tight bends .
The cable came an Oz outfit on trademe, 'allfourx4' It was about $70 delivered & seems pretty good value. Only issue was they didn't put the right address on the package so it went to a place down the road & I almost never saw it.
Need to get some more argon before finishing the exhausts, so it was onto the other major item left to do, the rear driveshaft. Turns out the 75 series driveshaft I got has quite a short slip yoke spline compared to my original, too short for the travel I need, so instead of shortening that shaft, plan B will be to fit the bigger UJ's off it onto the existing LJ71 shaft with it's longer spline. So it was into the 'machine shop' to spin off the welds:
Jul 15 2014
Got one end of the driveshaft done, still need to upsize the other end & make it a bit longer but it'll do for preliminary testing. If anyone has a munted Prado driveshaft I'm buying, need the t-case end female spline - then I could make up another whole female end & keep the current one as a spare.
Got the exhaust all finished over the weekend, NO RATTLES! The old setup didn't have much room in a couple of places so a bit of a tweak or a flex would always leave it rattling somewhere.
So last night it was time to visit 'a closed road under controlled conditions' for a little test drive ... and it drove pretty well! No vibes, wobbles, pulls or shakes. I didn't push it too much but I think it handles not too bad for a SWB on big Simexs. A bit over geared of course, but a set of lower ratio t-case gears was always in the plan, & they have the option of an 8% high range underdrive which I think I'll be getting. Just need to double check speeds/revs/ratios before ordering.
Still a big list of stuff to do before some offroad testing next month, & another list to work through before getting a cert, but it's real nice to be rolling.
Jul 18 2014
So I did a few gearing calculations for the 4.11 diffs (vs original 4.88) & the big tyres & worked out that if I can rev out in 5th I should hit 275 km/h... Somehow I don't think I'll be able to fit a blower big enough...
So I have just ordered some new transfer case gears from Marks Adapters in Oz, 55% lower low range which will bring it back very close to stock & 8% lower hi range which should have it doing about 2200rpm in 5th @ 100km/h on the road.
Marks Adapters had an NZ distributor listed but when I enquired with them they wanted over $800 more than the price in Oz Not the best business model for them as my gears are currently on the way to an Oz workmate who is coming over in a few weeks. I could have flown to Oz & collected them myself & still come out better off!
Busy on some painting now, want to get that done ahead of putting flares on etc, so she'll look like quite a different wagon by next week. Am using my mentor Klembo's top secret methods in automotive coatings technology
Cheers
Clint