The Greenback Build Thread

[MaestroMan]

So I'm starting a build thread for the P38A I recently purchased, named Greenback for its lovely matching interior/exterior color scheme (and the amount of money I'm sinking into parts for this!). It's a 30th Anniversary Edition in the trim-standard Wimbledon Green, one of only 500 made worldwide and quite a looker, if you ask me. The body paint is reminiscent of the color of a mallard duck's head and it has a very nice matching green/tan/burl interior. More info here.

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(note, these are the original Craigslist photos, haven't taken any of my own glamor shots yet)

Now, with that out of the way, I've already run into issues with putting him up on air springs. The primary of which is that I think I rebuilt the valve block with the diaphragm valve backwards and I didn't think to disable the EAS bypass Arnott's coil spring kit has, which are the main things to address this weekend. As-is I can get it to highway mode height. I also seated one of the air springs wrong or something and it pulled the bladder from the lower retaining ring while driving back from my friend's backyard workshop, blech!

ALSO: The Thomas 327 (purchased here) modification directions on PaulP38A's website are NO LONGER CORRECT. They have modified the design so that the stock motor bearing end plate is too small for the 327, and it uses a new silicone perimeter gasket recessed into the pump head body, instead of a flat paper one on the end plate. I chose to beat on my wallet for some more cash and picked up an Arnott direct-replacement design rather than finagle with it further. The 327 will become a tire inflation pump for offroading instead.

I discovered that you need an absurdly long 10mm drill bit to mount the Terra Firma rocksliders, so I ordered 2 13/32x12" HSS bits from the Homeless Despot to complete that work. At least I got the old running boards off last weekend! I spent way too much time trying to figure out the air springs to do anything else, but hopefully those come together this weekend. I've got a Hard Range Australia kit from Britcar in my possession, and replacement front air spring should be arriving in time for the work to get done on Sunday.
Stuff you guys can help with:

• The front springs were missing the bottom retaining pins & bolts. I purchased some 1/8" (3mm) cold roll steel rod for the pins, but I don't know the dimensions of the bolt that holds it in place...and it's kinda hard to find what size it is just from the hole, anyone know?
  
• Also, the bends in the pin are a bit of a mystery, I could just shove the rod into the retaining hole and bend it until it meets the retaining bolt but if anyone has one laying around and could take a picture next to a ruler for scale I'd love that!

Parts that have come in for this work:

• RSW Solutions EAS Kicker kit
• TF177 and TF176 +2" adjustable shocks (x2 each) from Island 4x4
• Britpart polyurethane bushing kit DC7107 from Island 4x4
• TF834 steering damper (that was actually already installed on the truck, so I guess I'll see if someone at SCARR wants it) from Lucky8
• Arnott A-2691 front air springs (x3 but one is going back under warranty) from Rockauto
• Arnott A-2692 rear air springs (x2) from Michigan Truck Spring
• Arnott P-2514 P38 EAS pump from Autoplicity (NOTE: these guys got it to me absurdly fast; ordered it Sunday 2/24 and it arrived Tuesday 2/27!)
• Hard Range Australia +2" lift kit from Britcar in Oz
• Tom Woods double cardan front propshaft from Lucky8
• Terra Firma RA2107TF rock sliders from Rimmer Bros

Misc repair/refresh items:

• Front Right LHD door handle because the existing one is starting to stick
• New locking hood strut because the old one is bent
• STC1909 front brake caliper kit from Atlantic British because I bit through a boot with my Vise-grip pliers so I figure the rubber's probably toast
• STC1919 rear caliper kit since if the front is toast so is the rear
• 4, 6, & 8mm EAS air pipe collets because I thought I lost one and that was a really terrible feeling that I never want to get in the ass end of nowhere
• A bucketful of plastic push rivets for remounting the wheel well plastic flares

Parts I'm still waiting on:

• Set of manual inflation valves, purchased on Ebay shipped via UK post to Texas so that's going to be quite a wait

Work to be completed:

• Undo the EAS manual bypass by reconnecting wiring disconnected for Arnott coil kit
• Flip the diaphragm back around so it holds full pressure
• Install Hard Range Australia kit & +2" shocks
• Install new poly bushings
• Finish drilling holes and mounting TF rocksliders
• Refresh rubber parts of brake system
• Install replacement front RH door handle
• Install Tom Woods front double cardan shaft
• Calibrate and set ride height to leverage new lift and provide clearance for 33" Nitto Terra Grappler G2 tires

Wishlist work items:

• Find a way to fool ABS into reading the correct spin rate with 33" tires, hopefully an electronics-savvy friend of mine can help out
• Purchase and install Rock Rover front & rear bumpers ($$$)
• Safari rack
• Maybe shell out for locking diffs & reinforced shafts/CVs, but this is at least 3000USD and I'm not sure I'll need them

PS - I'll attach more photos of the work later, I took a few of the running board removal process but nothing else has been worth photographing so far.

[Keithy P38]

Double post.

[Keithy P38]

A good read, will be watching with interest!

Of note, on 285/75/16 tyres and with a GPS on the dash, I’m doing just over 94kmh by the speedo to achieve 100kmh actual. The speedo in these things must operate on a non-linear curve. Below are my speeds from 60kmh and above (indicated/actual).

58/60
65/70
75/80
84/90
94.5/100
102/110

Don’t quote me on this, but I’m led to believe that the speedo/odometer still reads off a conventional transmission output speed. The wheel speed sensors are only used for ABS/Traction Control (can someone else confirm this?).

Cheers
Keithy

[MaestroMan]

Unfortunately it is not, Keithy. If it were I could get a Yellr and call it a day, but the P38 RAVE says this:

The signal to activate the gauge is originated at the ABS wheel sensors, transmitted to the ABS ECU (Z108) which then puts out a usable signal to the Instrument Cluster (Z142) of 8000 pulses per mile or 4972 pulses per kilometer. The signal is also transmitted to other ECU’s, such as the Engine Control Module (ECM) (Z132) and the Cruise Control ECU (Z121).

In other words you have to either fully spoof or significantly distort (-12%) all 4 inductive coil sensors, and I have a friend who has an idea on a fully analogue circuit that could distort the sensors but that's going to take a lot more thinking to decide on. In the meantime, once I've got the 33s on I'll just drive a little below the speed limits. American cops truly do not care until you're driving at least 10% over the speed limit, for the most part.

Actually, rereading it for the fifth time, it's 8000 pulses/mile to the instrument cluster, not from the ABS sensors! I bet I could just wire a signal interrupter to the signal wire from the ABS unit!

Looking at it even further, the wiring diagrams show no clear wire connection from the ABS ECM to the instrument cluster. I think that it's actually routed via the BECM to the instrument cluster, and their technical writer just didn't know what he was talking about. Or, perhaps, it's just a straight pass-through on the connector, but I doubt it since they specifically mention it's also passed to the Body and CC ECUs. Perhaps they're all passively reading the output wire? Any which way I'm going to have to put an oscilloscope to the wires attached to either C242 or C256, which does not sound like fun given that there are twenty of them.

Maybe I can spoof the YG wire between C116R/C1584 and C114/C1289 connector, from the ABS ECU to the BECM. The Electrical Manual says that's where the road speed signal is. Seems like every single speed-dependent item in the vehicle mentions that wire and those connectors. That would be 10x easier than figuring out how to make a pinout for a 20-pin watertight connector and running an oscilloscope on every wire.

[prelude]

Mate, nice colour!

I have only ever seen one in person at RPI in the UK. They had bought it for a customer in oz and it was about to be shipped out (with rebuild engine it seemed) I wonder if that thing ended up with a member over here? Anyway, it looks so good it would almost be a shame to take it wheeling

Regarding the TF rocksliders: I had to buy an insanely long drill as well and I ran into two problems that have prevented me from mounting them thus far: The steel is really hard and I have had to sharpen the drill every other hole first of all and second, even when trying my very best to keep the holes through the chassis rail as level as I possibly can, I still can't fit the bolts through since only a fraction of means the hole will be a few mil out and the bracket holes no longer allign. I am considering trying to find (rent, borrow or source out) one of those magnetic drills that sit level on the steel you clamp them on. Also, adding them to my setup will probably bring my car close to GVM so -eh- not sure what to do with all those bloody things that weigh so much.

The pins you were talking about, I'm pretty sure that's a metric bolt M6 (10 mil socket or spanner) but I'll check that for you this afternoon, I still have the clips on my wrecker and I'll take one out for a pic or two

The hard range kit comes with new retaining clips for the rear since you modify the rear axle. I'm not sure but I thought the rear and front clips are the same so you can reuse the rear ones if you still have them for the front.

Can't help much with the speedo thing but on a japanese vehicle it is mostly one common wire that only passes the ECU to be amplified sufficiently to be used by all other units. Knowing the P38 and it's infamous BECM though, it would not surprise me a bit if it is more actively involved... Measuring the outputs at the cc and tcs/abs unit with a scope for differences should be relatively easy since you can get to them fairly easy and place a measuring probe over them. At least this could tell you about the signal to start with. I m guessing however that your original plan of 4 yellr's on each sensor is the best way to go if you really want it to be so accurate. This way the tcs/abs will work exactly as it should and your speedo should not be of anymore, if it is indeed fed by those sensors.

IIRC the reluctor ring for the ABS contains 60 lobes so one revolution of the wheel will make for 60 pulses. the original tyres are 29" which make 432 revolutions per km. That's 25920 pulses per km. That does not divide cleanly on a whole number to get to 4972 so the BECM must bo doing something to that signal. That, or the abs/tcs unit does that for the BECM. I would hope the latter is the case. On another note; the car's odometer is stored in memory of the dash unit and inside the BECM. If you exchange either the BECM or the dash unit, whichever has the highest mileage recorded will be used on overwrite the current setting in memory. This was one of the many things landrover did to discourage stealing or commit fraude with these highly priced vehicles and is the main reason for this overly complex system. So in other words: even if you could find the output of the BECM and modify it such that your dash would display the right speed, if the BECM calculates the odometer I'm not sure what that will do...

Come to think of it; you are trying to correct for registering to few miles so in effect increasing mileage... Well I dunno just thinking out loud!

Cheers!
-P

[MaestroMan]

The mileage count doesn't matter. Anything past 10yrs/100K miles is exempt from odometer measurements in Texas and I can always just edit the odo later if I want to correct it as long as I know what the reading was when I changed to new tires. I just don't want to have to do mental math every time I want to know the speed (or, worse, ask someone else to do the mental math).

As to the pin/bolt, I actually did figure it out. I took a look at it, and it looked mighty similar to some M8 bolts I had laying around. Turns out that's what it was. I did the right side already by shoving a piece of 1/8" (~3mm) mild steel rod in and bending it in-situ until it met the bolt. That actually worked way better than I expected. Honestly, it worked better than it should have. Mechanical engagement is very tight, so I think I'll just do the same process on the other side. I'll be picking up a couple of galvanized M8 fasteners today for permanent use. I may also redo the pin in stainless, but first we'll see if the cold roll rod rusts or not. We don't salt our roads in Texas (it doesn't snow here), so it may not matter that much.

For anyone reading this in the future, taper the tip of your custom pin with a file. It is impossible to get the pin into place if you don't make this one small change, and once you taper the tip it is effortless!

As to the hole drilling, Lucky8's video on the TF rocksliders recommends drilling a pilot hole and then running in the larger bit. My solution to the situation is to use water-based paint to mark the outline of the rock slider's mounting hole, center-punch, pilot drill (~1/4" or 6mm) then finish with the 13/32" (~10mm) bit. I figure the 2 HSS bits I bought ought to do the job (though perhaps I should have sprung for the cobalt steel bits). I can always have my buddy sharpening one will the other bit is drilling. And yeah, it does impinge on the GVWR, but I'm planning to get this machine out on some rocks, and good rocksliders will do a lot to protect the body from damage. Lucky me, there are still plenty of retailers for Wimbledon Green touchup paint!

[MaestroMan]

Well, I'm done trying to make air springs work. After having the front right Arnott Gen 3 unseat for the second time and in a spectacularly loud fashion comparable to a shotgun blast in noise, I am done. I do not know why one of the previous owners dumped the EAS, but I suspect it has something to do with the valve system or some other complication not just getting tired of replacing the crappy Dunlops. I'll be getting OME 2764s for the front and 2781s for the rear, and hoping in the meantime I can liquidate the air springs that didn't get blown to **** at SCARR Texas 2019 along with the Hard Range Australia kit and Arnott P-2514 I bought. Probably going to try selling the valve block to eliminate the temptation to make another attempt later. I am very frustrated by this outcome, but realistically I just do not have any remaining patience for the enormous expense and complication of getting this air system to work again. I think I'll keep the RSW Solutions kit since it has other features than EAS these days that I might find a use for.

Also, bonus: one of the huge 22mm nuts for my new TF-176 front shocks fell on my phone screen and destroyed it, so no photos of this weekend's results, sorry guys. Also, TF's bottom-end rubber bushing assemblies for the TF-176 and TF-177 shock dampers are ridiculously thick. It is completely impossible to get any thread engagement on the shaft without cutting them down about 25% in thickness with a utility knife. Not sure who designed those, but at a guess they did not actually do any installability testing before shipping the product.

Aside from that, I've successfully put the Arnott (essentially OEM design) coil spring seats back on, so getting the springs in should be a 10-minute job when they arrive later this week at my local 4 Wheel Parts. Once it's up on springs I'll be buying some Nitto Terra Grappler G2s or Falken Wildpeak AT3/Ws (haven't decided) in 265/70R18.

[MaestroMan]

So he's up on the OME springs with the +2" shocks. Got out and wheeled this weekend for a few hours. Weak points right now are the differentials (need covers) and the tires, which are too small, also one of them dry-rotted and completely shredded to ribbons, previous owner had a completely unused Michelin A/T lurking in the spare well to replace it with, though! Strange world, this. Going to buy a set of 5 tires from Discount Tire, Falken AT3/W 265/70R18 (~33").

Some photos of the work completed (before I put the fender flares back on) and glamor shots of mud and overlooks I hit today. Had to get snatched out of the mud pit I am parked next to by a Jeep! Didn't have quite enough speed to wheel him back out at the end of the patch. Took over half an hour to power wash all the mud off the undercarriage and I still have more touch-up work to get him really clean!

See this Imgur album for the photos.

[prelude]

Sorry to read that mate!

A P38 on air is a brilliant ride. With normal springs they are still quite nice and comfortable but... they loose some of their magic. I think there must be something wrong with either the eas, sensors or maybe the valveblock although I would not think that to be the case. Since you already threw the towel in the ring I guess any more pointers on this subject are pointless

in any case, good to see that beauty on the road and tracks. Different tyres will make a difference!

Cheers,
-P

[gavinwibrow]

If as I suspect, the speedo system is the same as a disco 2, then the C6100-4 sold here in AU will provide you with the capacity to reset your speedo for any given set of tyres by amending the ratio within the electronic unit.

If interested I can locate and post more details.

I recently bought a second unit hopefully to fit in my RRC TD5 if it will work (already have had one in the D2a for about 5 plus years).

The price has gone up since and now about AU$200 plus freight.

Unfortunately it is not, Keithy. If it were I could get a Yellr and call it a day, but the P38 RAVE says this:


In other words you have to either fully spoof or significantly distort (-12%) all 4 inductive coil sensors, and I have a friend who has an idea on a fully analogue circuit that could distort the sensors but that's going to take a lot more thinking to decide on. In the meantime, once I've got the 33s on I'll just drive a little below the speed limits. American cops truly do not care until you're driving at least 10% over the speed limit, for the most part.

Actually, rereading it for the fifth time, it's 8000 pulses/mile to the instrument cluster, not from the ABS sensors! I bet I could just wire a signal interrupter to the signal wire from the ABS unit!

Looking at it even further, the wiring diagrams show no clear wire connection from the ABS ECM to the instrument cluster. I think that it's actually routed via the BECM to the instrument cluster, and their technical writer just didn't know what he was talking about. Or, perhaps, it's just a straight pass-through on the connector, but I doubt it since they specifically mention it's also passed to the Body and CC ECUs. Perhaps they're all passively reading the output wire? Any which way I'm going to have to put an oscilloscope to the wires attached to either C242 or C256, which does not sound like fun given that there are twenty of them.

Maybe I can spoof the YG wire between C116R/C1584 and C114/C1289 connector, from the ABS ECU to the BECM. The Electrical Manual says that's where the road speed signal is. Seems like every single speed-dependent item in the vehicle mentions that wire and those connectors. That would be 10x easier than figuring out how to make a pinout for a 20-pin watertight connector and running an oscilloscope on every wire.