1987 LJ70 frame swap + mods build thread (2 Viewers)

[Gubbtratt1]

Temporarily put the front back together to see how everything fits together. Seems pretty perfect to me.

I had planned to cut out the lower spring mounts from 4mm plate today, but the weather was a bit too unreliable so I'll do it tomorrow instead.

The Land Rover air springs have a pretty maintenance friendly mounting system. You put them on the axle, rotate a quarter turn, attach the air hose, extend them to the frame, and fasten with two clips. I'll have to make the top mounts a bit more complicated to fit the LJ frame though.

 

[Gubbtratt1]

I tried to do some oxy acetylene cutting today. It went very well for the first 5 centimeters, after that I noticed a flame where there shouldn't be a flame.

I have no idea what might have caused the damage, but it caused an acetylene leak that was apparently close enough to the nozzle to catch fire. The plan now is to get either a 25mm hole saw or a Parkside plasma cutter.

I finally got a brake drum off. The springs are more than strong enough to keep the brakes from dragging.

Now bleeding is the only concern. If it's impossible with the cylinder standing up I could replace the last bit of line with a hose and unbolt the cylinder when bleeding. A bit extra work to remove the wheel, drum, shoes and two bolts, but it should make up for not having to hammer the lever straight every time I go off road several times over.

 

[Gubbtratt1]

I also put some thoughts to the shocks. The original ones are too short and aftermarket ones are too expensive, so I've decided to go with Mercedes 508 shocks. They have 24.5cm of travel and costs about 60€ each.

The only problem is that they don't have the same bushings. All the front and the rear left top bushing is a completely different design, so for those I'll have to weld on bolts to the shocks, but for the rest I have three options.

From left to right:
1. Cut off the eyes from the original shocks and weld them onto the Merc shocks. Use stock bushings.
2. Cut down the stock bushings to fit the Merc shock eyes.
3. Press out the metal center from the Merc bushings and either slightly bore out the hole or hammer them onto the axle and frame mounts. The mounts on the car are the same diameter as the metal centers.

Opinions?

 

[Gubbtratt1]

Fun fact: Range Rover Classic shock bushings are identical to Toyota LJ70 ones. I'll go the route of welding on new eyes and using stock (although made for a Rover) bushings. I tried welding on a bolt today, and it went very well.

Seems like I accidentally took all pictures in vertical 16:9 instead of horizontal 4:3 as I usually do. A lot of unnecessary scrolling, especially if you're on a PC.

Anyways, I also sketched up the front suspension in FreeCAD as I did with the rear suspension a while ago.

I did it to figure out if I need to add spacers to the springs or to the shocks. Turns out neither, at full articulation the lengths at the compressed side are within 4mm of perfection.

In my quest to get as much suspension travel as possible I've also achieved a lot of theoretical articulation. I put together some numbers in a chart and ran them through a ramp travel index calculator:

I don't know how much sense it makes when you don't know Swedish and isn't the one who made it. Ask if you're curious, I started explaining each one but that would've ended up long enough to qualify as a novel.

 

[AirheadNut]

I would caution against modifying replaceable parts like shocks, and recommend instead modifying the shock mounts if possible. One of the things I have been battling on my swap project as I rack up the miles is needing to work on or replace parts that I had to modify the first time around. Every time one of those items has to be replaced you'll have to modify the new ones too, whereas if your permanent parts (like shock mounts/frame members) are modified instead you can simply swap the parts out like you would on a stock vehicle. More work up front, but much nicer for the future.

 

[Gubbtratt1]

I would caution against modifying replaceable parts like shocks, and recommend instead modifying the shock mounts if possible. One of the things I have been battling on my swap project as I rack up the miles is needing to work on or replace parts that I had to modify the first time around. Every time one of those items has to be replaced you'll have to modify the new ones too, whereas if your permanent parts (like shock mounts/frame members) are modified instead you can simply swap the parts out like you would on a stock vehicle. More work up front, but much nicer for the future.

I've considered the same, but I have no idea if the Merc shocks is the permanent solution. They might be way too soft. If that's the case I wouldn't want to have the frame and axles modified to fit parts that give a terrible ride and won't pass inspection.

 

[Gubbtratt1]

When I disassembled the lever on the handbrake cable I lost the nut and bushings, so I made a new solution from a M16 bolt, M16 washer and an M8 nut and bolt.

We'll see how well it works. Corrosion could be a concern as there's no plastic bushings. If it turns out to not work I believe I have the stock parts on the spare parts body.

I slightly relocated the air compressor to get it further from the shock tower.

It obviously needs at least one more bracket and a bit of modification to this one, but I think this is the final position. If the experts thinks it's too close to the shock tower it should be possible to get it a bit higher and closer to the engine if I modify the wastegate bracket though. There isn't enough wiggle room to tilt the compressor to tension the belt, so I'll also have to make a tensioner of some sort.

 

[AirheadNut]

A thought about your parking brake: rather than rotating the brake mechanism, maybe it would make more sense to use a hydraulic line lock type device to engage the rear service brakes? You’d get far better parking brakes than the stock setup and not have to go to the effort of setting up all the cables and levers.

 

[Gubbtratt1]

A thought about your parking brake: rather than rotating the brake mechanism, maybe it would make more sense to use a hydraulic line lock type device to engage the rear service brakes? You’d get far better parking brakes than the stock setup and not have to go to the effort of setting up all the cables and levers.

For my use that would be perfect. It absolutely won't pass inspection though, so I need a mechanical handbrake anyways.

 

[Gubbtratt1]

I've made a hydraulic press that almost works. The jack tips over backwards when any meaningful amount of force is put through it, so I'll have to reinforce the center bar a lot. I'll probably make a new one out of the same 6mm u-section as the top and bottom ones.

The CST tyres I had planned to get for the cruiser have risen a lot in price recently, so I started looking at alternatives and found Comforser Thruster. 240€ for 33s and 250€ for 35s. The Russians care almost more than me about the actual size, so googling in Russian gave both metric sizes and actual measurements from the first result:

33x10.5-16
265/80-16
814mm tall, 240mm wide
823mm tall, 243mm wide mounted on 5.5" rim

35x10.5-16
265/90-16
875mm tall, 245mm wide

Both have 16mm tread depth in the center, and over 30mm at the edges.

 

[Gubbtratt1]

I haven't made any reinforcements to the press yet, but I have managed to get it stable enough to put quite a lot of force through it. The bearing didn't budge before the brake backing plate started bending, so I'll have to make a jig.

However, I've decided to put the axle back together with the old parts. After a lot of considering I've decided that the best course of action is to put both axles under the new frame with the body, leaving the old frame with the drivetrain on the barn floor. That way I can wheel the cruiser into the tent to fab up winch mounts and air spring plates.

When that is done I can either first rebuild the axles and then send them off for sandblasting and painting, or I can do it the other way around. Most likely the other way around as it'll take 50 days for the chinesium locker to get here, and I haven't ordered it yet.

The frame will be sent off for sandblasting, inspected in case the sandblasting reveals any problems, and sent off for galvanising.

I have also done some actual work during the last few days, although not much. The trailing arms are installed in the new frame. All brackets I'm sure I won't need are cut off from the rear axle. I've discovered that the panhard rod mount is not only filled with rust and mud with no way to get it out, it might also be in the way of the left air spring at full compression. I haven't figured out how to best cut it off yet though. I've gotten started on removing the front axle. The shocks and steering rod are disconnected and the nut on one of the radius arms is loose.

Apparently the last picture made it despite me removing it. It's a 7.00r16 tyre. Doesn't look to bad despite being just 30 inches tall.