Converting from Automatic to Manual gearbox

[Growlerbearnz]

This thread is about installing a Manual gearbox into a van that was originally Automatic. Going the other way is much harder: the fuel tank mounting points are different. An automatic gearbox is longer than a manual, so the fuel tank is smaller to clear the transfer case. Fitting a manual gearbox to an auto bodyshell is no problem- there's lots of room- but going the other way (automatic into a manual bodyshell) the transfer case would hit the fuel tank. Swapping the fuel tanks involves fabricating a new front mount.

You will need:
1 Automatic L300 Delica
1 Manual L300 Delica
---I guess you could do it without having a donor vehicle, but you'll need a lot more parts than just the transmission, flywheel, and a clutch pedal. The automatic is longer than the manual, so everything that hangs off the back of the transfer case is in a different place.

From both vehicles remove:
-Driveshafts
-Gearbox/transmission
-Gearbox/transmission mount crossmember
-Clutch/torque converter
-Flywheel/flexplate
-Front and rear differentials (if the manual has the lower 4.625:1 ratio diffs- not all of them do)
-Clutch slave cylinder and hydraulic line
-Pedal boxes
-Gearlevers and shifter boxes
-Gearshift cables
-Instrument clusters

And that's about as far as I've made it, but I expect installation is the reverse of disassembly? Yeah right.

 

[Growlerbearnz]

Progress continues. The Automatic and Manual bodyshells are identical*, so far there's been no drama in swapping the parts. There's even a hole in the floor for the clutch line bulkhead fitting, and a tag on the frame near the bellhousing for the clutch flex line to attach to. Witness the new bulkhead fitting (and the shameful collection of fluff and junk that lives under the carpet

My new gearbox is in pretty good condition, considering it's done 360,000km. The mainshaft retaining nut that holds 5th gear in place was only slightly loose, the staked section had stopped it coming undone (which would have wrecked the gearbox). I'll be using loctite when reassembling.

All gearbox bearings, seals, and synchros are still available, so I've ordered them all (might as well, since it's pulled apart). Selector forks are NLA which is a bit disappointing, since the forks are a bit worn.

So. What to do while waiting for parts to arrive from Japan? Clean and bead blast the gearbox cases:

Mmm pretty.

Now check out this thread for tips on rebuilding the gearbox.

 

[Growlerbearnz]

Some more notes on converting from one to the other:

Gearbox wiring. I kept my existing automatic wiring. I had to connect the two large black wires together (black/yellow and black/white) to bypass the start inhibitor. I connected the manual gearbox's reverse switch to the blue and red/blue stripe wires. Because the manual gearbox is a bit shorter than the auto, I had to unwrap the wiring loom between the front fuel tank and the transfer case switches and re-wrap it to make it a bit shorter.

Speedometer cable: the auto's speedo cable is longer than a manual's. I thought about swapping to the shorter cable, but it's a nightmare to remove. In the end I re-routed my existing cable around the outside of the front fuel tank (above the side step brackets), which used up the excess cable length and kept any bends in the cable nice and smooth.

Instrument cluster: there are a vast number of different instrument clusters available. My old cluster was for an automatic, diesel, 4wd, with hub lock light. The parts van was a manual, petrol (wrong rev counter), 4wd, without hub lock light.
In the end I bought a 2wd manual diesel cluster from the wreckers which gave me the correct rev counter face. I swapped the gauge face onto my old instrument panel and simply removed all the PRNDL bulbs. The circuit board on the back needs to match your wiring if you want all your existing features to keep working...

First impressions: the automatic's torque converter did a *really* good job of hiding the epic turbo lag. There's *nothing* below 1500rpm. First gear is rather short so if you don't wind it out to 3500rpm before shifting to 2nd the engine just falls flat on its face. With the automatic traffic light drag races were fun (which means I'd surprise people- up to 60kph) but I don't think that's going to happen much any more. I'll try adding more fuel at low revs to get the turbo working sooner, but I'm not optimistic.

The van feels really truck-like with a manual. Vrooooooomm... (pause, shift)... vrooooomm... I'm sure I'll get the hang of it, and not having to worry about breaking the transmission is nice, but right now it feels like a bit of a step backwards. My advice: keep your automatic if you can, just don't tow in overdrive. Especially if you've done silly things to your engine.

One final observation: my van only just clears the door to my workshop. After removing the automatic transmission (and associated fluid-cooling accessories) the van was so high it wouldn't fit out the door again. I had to let the tyres down. Reliability plus less weight plus suspension lift? I guess that's a win.