A Light Recovery Trailer from Downunder

[Sam Scholz]

Hi all,

With some trepidation, I made a start on disassembling the front end. After hunting around a bit I managed to find a socket that would fit the 2 3/8"AF nut. It was 3/4" drive which I was not confident about. Anyway, after 3 meters of cheater bars and bending my 36" pipe wrench handle, I decided to add some heat.

LRT Remove steering pin heating nut 10 2023.JPG


It is easy to add too much heat such that the material softens so that it can 'pick up' or broach inside. Despite some sniffing around, I have not been able to find the temperature range for mild steel where beyond that is very little to be gained but lots to lose when using heat to expand some material to loosen it. Anyway, that is what happened!

LRT Remove steering pin nut destroyed thread 10 2023.JPG


In the end, I had to cut the nut off. So sometime will be a major bolt re-building job.
Next job was to remove the steering pivot bolt. So I added some pressure, around 20 tons, I estimated. Plus some sledge hammer encouragement all without any action.

LRT Remove steering pin pressing the pin 10 2023.JPG


So time to add more heat, carefully. It didn't help that I did not know the design of the pin which was still out of sight. So, as seen below, I managed to get the whole frame/pin assembly up to about 200deg C. Note that I removed the chains and porta-power as they would not handle the heat real well!

LRT Remove steering pin heating the pin bracket 10 2023.JPG


Then removed the fire, refitted the porta-power and applied a good lot of pressure. The main caution I had was around a chain breaking and bits flying off like shrapnel. I added several wire ties to act as whiplash arrestors. The chain was 5/16" Herc-alloy with a working load of around 1.2 tons. Then six legs gives around 7 tons. Then I wandered into the safety margin, which is around 200%, while standing well back. A pause, then sledge hammer applied. Nothing. Stepped away, added a bit more pressure, waited, hammer again. After a few cycles of this, applying the hammer to the enormous hex head of the pin under the frame, without any warning, the whole pin flew out the bottom the the frame with a great crash!

LRT Remove steering pin sudden release 10 2023.JPG


As it turned out, there is a large diameter 1 1/2" long section under the head of the pin where all the tightness was. Wow! I'm glad that job is done.
One more job done.

Enjoy.
Sam.

[Sam Scholz]

Hi all,

I have compared the CMP wheel cylinders with the remaining LRT ones and they are very similar. The mounting bolts are so close that a very little massaging of the mounting holes and they will bolt up. Yeah! The cylinder is the same diameter and about 1/8" (3mm) longer, which is of no consequence. The pistons are different, engaging the brake shoe in a different manner. However, the manufacture of replacement pistons on the lathe should be a fairly straightforward exercise.

In order to strip out the timber decking, I first unloaded the loading ramps.

LRT Unload ramps 11 2023.JPG


Using my none-too-accurate crane scales, they weighed out at 170kgs, less than I thought, but still a solid 6 man lift!

LRT Weight of ramps 11 2023.JPG


Then stripped out the decking and removed the many cup-head bolts with a cutoff wheel on the angle grinder.

LRT Deck timber stripped out 11 2023.JPG


Earlier this week I was able to collect the special spanner I had made at the laser cutters. The tang on the right side is to use a hammer on, if needed. There is a spanner type specifically to use a big hammer on, called a flogging spanner. The idea came from that.

LRT Rear rockers trunion nut spanner 11 2023.JPG


It fits perfectly, making an otherwise difficult removal into a bearable but slow process. As the keyways (slots) on the nut are at 90° intervals, it worked out that by 'clocking' the handle away from a key by 22.5° (half of 45°) allows 45° bites at the nut instead of 90° increments by flipping the spanner over then back again later. Much easier.

LRT Rear rockers trunion nut spanner in use 11 2023.JPG


So hopefully it won't be too long before I can get the rockers and trunnion disassembled.

Enjoy.
Sam.

[Sam Scholz]

Anyway, back to disassembling the front end.

The towing A frame was a poor fit in its' brackets. This will be fixed when reassembling it. (Don't ask how. I dunno yet!)

LRT A frame misalignment 10 2023.JPG


After the removal of the pivot bolt, the front axle frame could be removed and inspected. Other than the axle bolts (4 on each side) being corroded away to nothing, and so having nothing to grip to extract them with, there are no apparent problems, just very heavy.

LRT Front axle frame b 10 2023.JPG


Next was the front trunnion removal which started with the brass bush caps being removed. They did not want to move, but were gently coerced!

LRT Front axle trunion rear bush removal a 10 2023.JPG


The front cap was easier to move, but even then the trunnion wanted to stay in place. In the end, it was brute force!

LRT Front axle trunion front bush removal 10 2023.JPG


Done! But way too heavy for me to man-handle. I have a pallet jack that does a lot of the heavy handling.

LRT Front axle trunion removed 10 2023.JPG


So far, so good.

Enjoy.
Sam.