Underfloor / centre mounted PTO winch on LJ78 - Landcruiser II (1 Viewer)

[rioalemao]

Primed and with seam seller all around. The same sealer started cracking when drying so I had to make multiple passes and letting it dry in-between for a couple of days. Photos show interim pass. I primed first and then seam sealed and the seam sealer actually started dissolving the dried primer. Not happy about this and will try the other way around for next seals. Am also welcoming any tips on this.

 

[rioalemao]

MAKING PTO DRIVE SHAFT
So the distance between PTO box and winch is longer than the original than the drive shaft so I need to fab my own. Unfortunately, the local metal store did not have the right tube (OD 25mm, ID 20m) so I ended up building it from two of the original drive shafts; I don't usually like destroying hard to find original parts but the slip yoke on one of them was seized solid anyway and not usable. Required total length was about 75 cm.

From two make one...

Chopping the seed slip yoke. I chopped it too close to the yoke and you can see that a solid piece of the yoke is still inside the tube.

On the other Shaft, I decided to try bringing out the factory weld. This was more work but I merged to get the sliced slip yoke/shaft end out clean and can reuse it in case I need it for another build.

Weird Toyota design: The shaft ID is 20mm, but the end yokes have a slightly larger OD so the end of the tubes are reamed down from factory to allow the fitment. Not relevant for my purposes since I will be joining the two shafts in the middle.

 

[rioalemao]

CENTRALISING / TACKING JIG

Built a jig from angle iron to keep the two shaft halves centred and allow tacking in three positions, 120 degrees apart.

Welded up and ready to go.

 

[rioalemao]

WELDING PTO SHAFT
Not shown on the photo...: To help centralising the two parts, I slid a 30mm long piece of repurposed scrap tube with 20mm OD into the inside of one half of the shaft and let it stick before pushing the other half on. The shaft was then clamped onto the jig for tacking. After tacking, I checked run-out between the two halves with a dial gauge, before fully welding through (i left a seal gap in between the two halfes so that the root pass would also weld the centraliser tube in place. Had to undo the tacks on the first attempt because of too much run out but the second attempt was within tolerance. Since this is a load bearing weld, I made sure to properly bevel and clean the two ends.

1st photo shows how it was clamped to jig. 2nd shot shows tack on the underside (reason for the square cut-out). The other two tacks are easily made from top

Fully welded through. One good root pass and an additional two (mediocre) top fill passes. I afterwards ground some of the excess material down. Photo is before cleaning/grinding.

Final shaft after painting and 2nd picture of set-up for run-out measurement with dial gauge. Factory service manual allows 0.7mm (28thou) so the bench set-up can be fairly crude . I ended up with a final run-out of about 25 thou which is not great but acceptable in view of low revs that the PTO shaft spins with. I'll see how this welded shaft holds up in the field and replace with a non-welded shaft if I can get my hands on the right tubing dimensions (bear in mind that the end fittings will always be welded but at least then there would only be two instead of three welds). So far no issues after having done some heavy pulls.

 

[rioalemao]

MOCK-UP INSTALL
Winch installed and rope spooled on. Checking rope routing for a good place to place the direction change. Am using an M16 lifting eye for direction change and an aluminum hawse in the front. I will need to shorten the hawse as at full angle on the outside, the rope rubs against the sway bar end.

View towards back and towards front. Found the factory cross bar to be a good position. It's a little bit on the short side for length to drum but the rope still spools on without binding/birdnesting (rope was spooled on under load).

view form font of car

 

[rioalemao]

BUILDING DIRECTION CHANGE BRACKET
Did not want to weld onto the frame anymore so decided to build this from 2 1/2" HD brackets, some 6mm flat bar and an M16 lifting eye. Due to the relatively small deflection angle of ~5-10 degrees, the load acting on this bracket will not exceed 450kg-850kg at a theoretical max load of 5tonnes.

From left to right, (1) source materials (did not use rope guide), (2) lifting eye after vinegar treatment to remove zink (stronger weld), (3) tacking 6mm plate in position

Final bracket welded up, prior to paint job. Will replace this bracket once I can get my hands on stainless lifting eyes as the coating and galvenizing will rub off over time

 

[rioalemao]

FRONT FAIRLEAD

Bracket built from 6mm flat bar. Fairlead is a standard one with 10 inch bolt pattern with about 2 inches cut out in the middle. This trimming was needed for the winch rope not to come in contact with the sway bar ends.

Took it for a test spin with winch pulls on steep river banks and it came bake severely bent from the bumper digging in and the bracket basically folding back. Reinforced it with some gussets and its been fine since. Also tapped and countersunk some stainless allen screws to prevent the rope catching not he edges and bending the fairlead where it has been cut in the middle. Will tig weld this gap once I have some time (and learned how to actually tig weld aluminium).

Location of front bracket underneath bumper and offset to the left (electrical winch sits central in the bumper).

 

[rioalemao]

REMOTE FREESPOOL
Am using a throttle cable I still had in my parts box. 1st Step building the cabin side mount.

Mount welded from flat bar and angle.

Nuts welded on to fasten it near footwear of driver side.

 

[rioalemao]

2nd step building the winch side brackets. I wanted to do this without chopping the original freespool handle (just in case I want to later move the winch to the front) and found that a 1 inch exhaust clamp fits perfect for and can clamp onto the lever knob.

50lb hammock spring as spring return. First fitment... found that throttle cable has to much flex (see photo) so needed to build a fixing/adjustment mechanism.

 

[rioalemao]

Building cable fixing/adjustment bracket. Hollow bored M10x1.25 built sitting in a welded nut with a flat nut that can be adjusted to set right tension on the cable. the bracket bolts into tan existing bracket for the rear brake lines.

Boring the M10 bolt so that the cable can go through, countersunk another 5 mm or so for the cable housing to sit in.

L Bracket with welded nut. 2nd phot shows it installed: Pull action via cable. Push action via spring, clamped with another 2.5" exhaust clamp to cross member.

 

[rioalemao]

Final touches. The plastic throttle cable knob broke off pretty quickly as it was not designed for the pull force needed so I re-purposed a spark plug socket to a make-shift T-handle. T handle lives in the glove compartment and is only put on when needed.

Cut and drilled, before tapping.

Bracket painted and handle on.

All installed. The is after a couple of months underneath the car. I only spool the winch line on when off-roading. I'll be pulling the winch off soon and giving it a fresh coating; I'll also be using a different underbody paint as some of it has already peeled off from the mounting tubing, with primer showing through.

View through the camera.

 

[clintnz]

Good work! I have thought about building a remote freespool for my PTO winch but have never go around to it. One of the tidiest setups I've seen used a hydraulic clutch master/slave to actuate.

One thing we found on my mate's rig with a similar setup to yours was to frequently lube the PTO freespool with lots of WD-40. Grease would get too sticky then the cable or spring would struggle to move the lever. He went to a much heavier duty cable than the one you have.

Cheers
Clint

 

[rioalemao]

Yep same thinking here. I already have a much bigger mechanical sealed push/pull cable on order. am also thinking about the hydraulic version but have not found a small enough lever yet. I don't want to put a second hand brake lever into the cab.

 

[AirheadNut]

The W460 Mercedes G-Class used a plunger style lever to actuate the hydraulic cylinders for the differential locks, something like that might fit better than a pedal or brake lever type actuation for a hydraulic free spool system.

 

[Ben7007]

Hey mate.
Great write up!
PTO looks to be the same assembly as the 60 landcruisers which is very helpful for me!

Did you have much trouble placing the bearings into the PTO drive housing?

 

[rioalemao]

Hey mate.
Great write up!
PTO looks to be the same assembly as the 60 landcruisers which is very helpful for me!

Did you have much trouble placing the bearings into the PTO drive housing?

No it was fairly easy. They sit with a press fit in the ID on the PTO shaft and I drove them off with a hammer, piece of pipe and some wood as counter. The housing side has a bit of play and the OD of the bearings just slide in, you just need to watch out for it going in square.

 

[Ben7007]

No it was fairly easy. They sit with a press fit in the ID on the PTO shaft and I drove them off with a hammer, piece of pipe and some wood as counter. The housing side has a bit of play and the OD of the bearings just slide in, you just need to watch out for it going in square.

Awesome stuff! Thanks mate!