Thread: Meet my 90, and share the adventure.

This marks another long overdue update.

A little matter regarding a pandemic and 'essential travel' put an end to the Corner Country trip I had planned over Easter. So I chilled out at home and played in the shed instead, and built a few storage racks for the stuff I've accumulated over the years. This had the pleasant outcome of making it a lot more functional space for making stuff.

The evolving shed space has given me the ability to get more into some of the fabrication projects I've had in mind for the Landy. Which brings us to the most recent project:

ROCK SLIDER BUILD

The (almost) finished product (needs blasting and paint):


To see how I got there... stay tuned below!

Started with a bit of googling of rock slider images. I decided to stick to the 'classic' bar style, which fortunately for me is way easier to fab than some of the crazy tube jobs with wheel hoops, kickers etc...
The next step was to get the mounting points sorted. Most 90's use the front body mount (bulkhead) and ear body mount locations. I didn't buck the trend here, and used what was available.

Rear outrigger is approx 45mm dia.


Front mount was mocked up in cardboard then cut from 5mm plate. This was then bent to allow the contour to match that of the outrigger.


Clamp in place, then a puff of tactical spray-paint to get the hole location:






The rear tube was made from 32NB heavy wall pipe (approx 4mm thick). This is as close as I could get to a slip fit, with approx 2mm diff between OD and ID.
Collars for the tube mounting 'stops' were made with 2 suitably sized hole saws.

Tacked with tig wire spacers:

And fully welded.


The rear mount needed a way to be secured to the car, so some M16 gal bolts were procured, linished, and welded to a holesaw slug which matched the ID of the 32NB pipe.

Then welded up, and later sanded smooth for a slip fit


The slider itself is made from some 3"x1.5" heavy wall (~4mm) RHS. This was cut to length, beveled for aesthetics to match the wheel arch line, and capped.


The slider body was notched with a holesaw to saddle the pipe, and maintain the rear height of the slider relative to the rear quarter panel. A mill or mag-drill with an annular cutter would be awesome for this, but alas, small shed means small tools. Plumb-bob used for alignment of outboard spacing beyond the vertical body line (~30mm).

The front mount was lopped down to length using the same plumb-bob method.


As this was the first set I've made, I needed to make some welds for fit-up while items were attached to the car.
When this happened, all welding on the car needed the car to be electrically 'dead'- ie battery disconnected, and ECU removed entirely from the car. The factory manual recommends this.


This left us looking like this- supported by its own weight, and strong as a brick ****house.


Final weld-out was done on the bench, and a extra gusset put in for the front mount.


Tube work
What's a set of rock sliders without tube work? This was a bit I particularly enjoyed.
The bends were sourced from an industrial supply house, which negated the need for any pipe bending shennanigans. Spacing of the whole ordeal was eyeballed based off what looks good on the car.


Pipe notching was done on the drill press with holesaw bits. If anyone wants to donate a mill to me, I'm listening!
Got it centered

Started the notch

Finished it up on the vice

Then off for a bit of fine-tuning with some die-grinding and sanding to get the proper heights.



The elbows were tacked on after a bit of alignment using some proprietary pipefitter tricks


And mocked up for final position


The tube work was welded out on the bench, then the stand-offs were ground and sanded for a smooth finish. The welds to the slider body were left as-welded.













Mounting to the chassis is achieved through a big M16 nut and bolt (will end up using a Nyloc, or a second lock nut). Washers were made with (you guessed it!) a holesaw.




Front mount piggy-backs off the body mount bolt, and a second bolt to be attached to the outrigger via a 'custom' hole

As they stand, sliders are a bespoke fit for this vehicle, with no movement. They even pass the hi-lift jack test!

Next week I'll send them off to be sand-blasted and powder coated.

About time you did an update!!!!

How have you been T.A

I've been well Mike. The shed is organised, and I've added a few new tools to the arsenal, and hopefully time permitting I'll get around to building more cool stuff for the mule.
I've got some ideas for a stainless sill tank, and some rear cargo area dump bins for all the loose bits that seem to float around when you own a 90.

Got the sliders powder coated and installed over the weekend. Turned out nicely. Like every other bloody rock slider out there for a defender, but at least I can say I built them myself.
There are a few errant grinder marks that the powder has magnified 11ty billion times, but will be nothing compared to the hiding I hope to give them on some rocks and trees into the future...

Hi Guys. Remember me? That guy who somehow managed to write 500+ posts on designing and installing a dual battery system, and then wiring that to a winch with the most 'extra' industrial cabling, latching relays, and fuses you can only get at the stores department of a power plant... Well I'm back with a bit more.
Below is another punctuation in the story that is this defender.
I am clearly keeping the trend of infrequent yearly updates, this one being 18months from the last installment. You've earned it, so read on!

Some 4-wheeling action
After the rock sliders were built, there was a few local trips with some 4wd guys, just local stuff, a range of different vehicles, and all the usual rivalry that you get from that kind of crew. One fella was particularly impressed by my hairdresser's car. So much so that he gave his '94 rodeo a full send to the point that it was stuffed with a shatterd drag link. I spared him the distress of being towed out by a 'girls car'. Karma works great some days.
All in all, the Landy held its own, but there is always going to be some shortcomings when you start stacking it up against a 37" lifted and locked patrol or cruiser. I did what I could.
The few trips we did included some dumb stuff like this- lots of traction control noise, lots of wheels in the air, and lots of tipping one way and the other. Rock sliders earned their keep on that track.


On the way home I started hearing an odd noise, which I documented on >>THIS THREAD<<

Despite all efforts, It was not diagnosed, and I continued on - it wasn't getting worse, nor could I isolate the problem. I was jimmying suspension components, checking play in bushes, removing rear prop shaft, messing with the phasing, re-greasing whatever I could find. It was an enigma, and it was something that I never suspected.
I was chasing an idea that the driveshaft was the culprit, and even got technical with the phasing on more than a few occasions to see if I could make that right. This is what I settled on for phasing, which is as per FSM, and approx 45 degrees as recommended.


I was so close, but so far. But more on that later... [cue ominous music to punctuate that last sentence].


Exhaust Rebuild

Around April 2021, I parked the car up and rebuilt the exhaust. This was for no particular reason other than getting some fab time, and replacing the beaten-up but fully functional centre muffler which had copped a few knocks over the years. Including that last trip.

As a bonus, this exhaust mod 'may or may not' have been a change the catalytic converter and centre muffer, resulting in a simpler, more streamlined system. The result is a bit more 'whooshy' exhaust flow kind of noise, no drone, a little louder, but definitely not obnoxious. I've had much worse on other cars (twin 2.5" straight thru system on a DOHC 3.0L V6 on a nissan 300zx for example - 92dB on idle, 105 at full song, crackling, popping, droning, it was a hoot).

When I say I rebuilt the exhaust, I actually built it myself. Bought pipe, mandrel bends, flanges, and stuck it all together with the TIG. Even bent up the hanger rods to suit the mounting points... It was a good fabrication / learning experience. It wasn't the cheapest exercise, given that the materials, bends, and labour sure do add up. But I'd probably still pay more at an exhaust shop, and I've seen some horrendous welding jobs come out of some of those places in the past, so I've got that going for me I guess. It was built to my acceptable level of quality, and if it fails, then that's on me.

Exhaust Removal -
Removing the exhaust is fairly simple. Just a heap of 13mm IIRC nuts and bolts. The cat converted I took off for 'inspection' did actually put up a bit of an irreversable fight:



Sawz-all won the fight.


Sourcing pats was a bit of fun. I went with an aluminised mild steel 2.5" system with mandrel bends throughout.
The first piece of the puzzle was the 'lipped flange' that is fitted to the turbo via a V-band clamp.
Dimensions if anyone is wondering:






The other part was a flex coupling for the interface between the moving engine, and the somewhat static exhaust system.


All these bits were sourced via the exhaust shop. They were happy to sell bits to me with a retail mark-up. I was in and out to them about 4 times getting bits as needed, so not a complete waste of time. You can also find these parts online if so inclined- but need more planning on the bends if that's your plan.

The down-pipe turned out OK. Should allow lateral flex from the engine, with the vertical flex joint.


Next section was a pair of offset 45's to move the pipe towards the LHS of the car. From there it's esssentially a straight shot out the rear, over the diff.





New Dag

Sadly, the little brown dog in some of the last posts got out the front and was hit by a car. It was not nice. But the fortunate outcome was that we were able to give a home to one of our dog's nephews. His mother was out late dog's sister from the same litter. They are special little accidents- part staffy, part jack russel.

This little bugger is Cliff. He has a cleft lip. He also has a micropenis, a single testicle, and a uterus. So yeah, a bit of a loveable little derp of a thing- scraped from the bottom of the genetic barrel to be what he is. He is one of those dogs that would have been put down had we not come along to save him.



Cruise Control and Black Duck seat covers
For kicks, I installed a cruise control module to the mule. The brand was Autostrada, sourced from 4x4 industries (great fellas) and the install was fairly simple. The only downside is the little sticker that goes next to the LED light has failed to stick. If I were super keen, I'd probably disassemble the speedo cluster and mount it all in there. But too late for that as the holes have been drilled. I might get a little engraved plastic tag made up at an engraving shop, if inclined.



After a number of longer trips, especially out here in the North-west of NSW, long uneventful roads make cruise a nice feature. Plus I eagerly await to put more kilometers on the car, as it's still in the 50,000km range on the ODO. A fully maintained company vehicle has that pleasant effect on the other cars in the stable. That, and every time the fuel goes up, it's like getting a pay-rise

I also installed some grey canvas Black duck seat covers around the same time, and gave the interior a full detail while I was at it, to purge some of the persistent outback dust that gets everywhere. The covers fit well, they were fairly straight-forward to isntall, and look good to boot.


Disaster Strikes!

Some buddies and I decided to go camping, sink some cans, and drive some tracks. We met at the camp spot near the state forest one saturday morning in May 2021, and got ready for the first track of the weekend.
I've mentioned before, the devil's staircase on the boundary track on the Nundle state forest. It's a 1.5km long slog up a forest road, 30m sections of rocky shale and mud, with flat drainage contours of about a car length every so often.

I was still chasing that 'suspension noise' I mentioned earlier. It had not got worse, and was a metallic squeaking noise that occurred sometimes at various road and decelleration conditions. This didn't get in my way of a good time, and I tackled this climb with me and a passenger, and a 90's load-space worth of camping gear.

Half way thru the track, on a 30 degree steep section, 2-low, at full engine torque, something made a bang.
Forward movement stopped quite suddenly, so into reverse gear, dump the clutch to engine brake recovery backwards.
Oh****.jpeg Car kept gaining momentum backwards. Grinding noises. Locked LHS rear wheel as car starts to pivot, BACKWARDS, on the locked LHS rear wheel.
By this stage, I'm looking down into the abyss of this colossal hill, via the PASSENGER WINDOW. At this stage, I'm 45 degrees to the slope.
Front RHS gets light, whole car is sliding on the shale, ABS is doing that annoying PUMA thing where it wreaks havoc offroad.
For a brief moment, I feel the front RHS suspension unload, and the wheel lift off the track. We are going over...
.
.
.
Thankfully it settled, and I try to straighten up with a reverse. Still horrendous grinding and locked wheels. Drive is intermittent between the horrible noises. We manage to attach the winch to a car up the hill further, and get me to the next flat section.
Off comes the rear prop shaft trackside. CDL engaged, and FWD mode only, but now the grinding is in the front too.
It's immobile.
We end up winching the car around enough to get it pointing down the hill, and attach a snatch strap to allow gravity and my breaks to get me back down the hill. A 3 hour recovery.
We do the walk of shame - flat tow, back on the tar, to the campsite where we sink beers, cook a giant steak, and celebrate my birthday. 3 cheers for me!

The next morning, we arrange a tilt-tray. After some bush-mechanicing, we pull driveshafts, and prop shafts, and things are not pretty.
It's not the axles, and it's not the CV's. The T-case is doing it's thing.

After I get home the autopsy begins...

The AUTOPSY
Once the car arrived home, I snatched it into the backyard using the work car, and got it up on stands. The task of disassembling the rear differential commences.

The noise I was chasing was a sheared or failing cross-pin.



If I were to guess the filure mode, it would have been a failure of the roll pin. This would have led to the pin walking back and forward in the carrier, and wear to the hole in which it sits. This was probably my mystery noise I was chasing.

When things went bad on that hill, the pin likely failed completely.
The gears bound. The shaft sheared in 2 different locations, and the whole thing fgell apart, SPECTACULARLY.



One of the gears even made it's impression on the carrier:



So that's the rear diff.
The FRONT DIFF suffered a similar fate, at the same time.
What I think happened here was a result of the rear failing, and the TC being locked (F&R prop shafts spinning in sync).
When the front let go, all engine torque went thru the TC to the front diff.
This led to the pinion gear walking UP the ring teeth, shearing about a dozen teeth off.





So... Go me! Killed 2 diffs at the same time offroad. Surely there's an award or medal I can send away for?!

This triggered a road trip to dubbo in June 2021 to get a set of diff centre housings to get the car mobile again.
The mule is now part '98 disco 1.

I made up a special tool (which has since been given away to another forum person) to remove the stupid disco 3 hole diff flange arrangement. Pic for reference- in case anyone wants some advice on how to skin that cat in the future...


Out of this whole ordeal, Both pinion gears are rooted. both ring gears are stuffed. The rear centre carrier is well and truly rooted. The front centre shows some minor pitting that I may be able to either build up with some weld, and finish with a die grinder, or just buff the dings out to prevent stress risers forming if they end up back in service.



In actual fact though, these parts will probably just be scrapped to make way for some built diffs.

I'm not sure what this will entail. I'd love to build some diffs from another non-rover vehicle (cruiser, patrol?), but realistically, I'll probably put some lockers, HD axles, a pegging kit, and a ring and pinion ratio change in the existing diff housings and that will be more than ample for tyres up to 37" (if ever that day becomes a reality).

That is where it currently stands on that front as a 'work in progress'.

You made a real good job of those diffs!!
Glad you managed to find some disco diffs as a temp fix.

Sorry to hear about your dag.
But Cliff looks very cute!

it's amazing how all the parts are just within their limit. one lets go and you get a cascading series of breakages.

hope you hugged your Mum after the experience.

You're not wrong. Mates in the rock crawling buggy scene scoff at the rover diffs, how weak they are I disregarded it as patrol/cruiser fanboy talk, but to some extent, I now agree - a failure in one took out the other. 2 poor design features taken out across two centres- the cross pin half failed, then catastrophically failed, exploiting the long pinion and ring gear flex. If the front was saved, I'd have driven out under my own steam. If I were really remote, or solo, I'd be cactus. My lack of a proper diagnosis didn't help the situation though, admittedly.



I think it would be a great fabrication project to build up some other vehicle diffs to suit the 90. I'm just not sure where I'd even start - what has been trail tested, what works within wheel track / centre location envelope, prop shaft location, pinion angles... might be beyond my little shed and lack of a flat concrete surface to work on. And that's before any engineering legal side of things is covered!

Interested to know from people that have tried and tested diff builds on these cars. I'm not afraid of a bit of cutting and shutting. Can weld. And dumb enough to give it a go.
The easy way would be to just throw wads of cash at the Ashcroft catalogue. I'm still unsure.