Thread: What happened to your Discovery 2 today?

woohoo! .... and massive difference to how it drives now:

with the original TCU, I got:

* 1st-2nd change at about 15-20k/h.. way too fussy, but usually not a problem .. not noteworthy anyhow.
* 2nd-3rd at a minimum .. 46k/h that I once saw on the nanocom, usually 47-48k/h. This was the 'problem child' for me. Way too fussy when just pootling in heav-ish traffic. I'm an old granny when I drive around town(99.9% of the time).
I see no reason to go screaming hard to the next set of red lights, just to sit there for a longer period and waste both fuel, and brakes. So I pootle along like an old granny
the TCU in the D2 (no longer now) held onto 2nd for wayyyy too long.
* 3rd-4th again a bit high, but the least offensive change point. usually at about 56-58k/h. This one was never a real issue, just nicer to have it lower for those time when less fussiness from the vehicle would be nicer.

NOW! .. awesome, and how it should have been, and if needed to be harder charging, then this is why LR fitted an S button if people want to drive like that all the time! The S button on this TCU was useless, it was stuck in S mode.. never noted any difference.

So now with older 99 V8 TCU I get:

1st-2nd change pretty much immediately when pootling on light throttle .. I'd guess 10k/h. Still super smooth changes too as before.
2nd-3rd .. this is the big deal for me now. just under 20k/h when needed. a bit more loud pedal and it'll change a bit higher. Too much traffic to test it this afternoon, but not a concern for me how aggressive it can be .. I use manual hold and shift if I ever need that anyhow .. it's the old granny style that was the annoyance. Now sublime!
3rd-4th .. mid to high 30's if wanted. this shift is even less obvious now than with the TCU my D2 came with. because speeds are a tad lower lower engine noise so harder to hear the sound. in terms of feeling slippery smooth(ie. can't feel the shift with a light throttle. Again too much traffic to test at higher speeds-more right foot.

TC lockup now is 58k/h on light throttle. tested 3 x to be sure. used cruise control to increment up 1/1.5 k/h at a time, and sure enough at 58(on the nanocom, and just under 60 on the dial) lockup. A bit of right foot for a sec and it'd unlock easily. pull the lever back to 3 and unlock.. again couldn't test if it'd lock up in 3rd at low speeds too(traffic).
Tomorrows run to work witth no traffic will reveal a bit more, but whatever else it shows up.. I love it as is anyhow(compared to the TCU in it).

I say the TCU that was in it because when I pulled it it had blue marker pen writing on it. JLDDII. Someone has mucked about with the TCU previously.
Typical numbnuts types too .. the gorilla footed types that butcher everything(like the inner dash on this D2). The plastic pinserts that are used to hold the TCU to the metal plate were all busted and butchered .. and they tek screwed it into place. So if you weren't careful under there(say for a clean out) you'd easily rip your skin off .. anyhow rant over .. I'll post the numbers of my TCUs below.

Originally Posted by shack

There are several versions of the TCU that will work, but all have nuances that will either make or break the deal.

....

I can't confirm this '02 TD5's original TCU, but the possible replacement that someone may have put into mine has a part number:

02_TD5_TCU_ID.jpg
If anyone has ever experienced the cryptic scriblings that say JLDII(or 11) D on the TCU. But those are the TCU numbers of my TD5. Gone!

99_V8_TCU_ID.jpg
This came out of my 99 V8 parts wreck. Now in the TD5

Anyone wanting to do a NNN Eu3 TD5 TCU conversion from their std TCU to an earlier TCU it seems that more likely to work.
I did nothing other than connect it up and drive it down the road .. and down the next road and the next .. etc.

I then got home with the huge grin, and bolted the TCU down properly.

Like Myles said, when removing/refitting, there is a hook at the end of the plug. Once levered off via the chrome lever it then flips out and off at the other end. The other end has a hook for the plug to slot into. So on reinstalling it this hook end needs to be hooked up first, then the plug cantilevered into place then the lever used to lock it into it's location properly. Once the 3 bolts are loosened, both the look and and the metal plate that holds the TCU need to be moved together in unison to get it all lined up. Loom is too short to remove/fit the plug on it's own. So it needs a small amount of manipulation with the seat still in place. In my parts bomb the seat is already out, so easy to work it all out and remove/refit.

30 mins work from start to finish. Tools needed were philips driver for the screws on the L shaped plastic finisher on the seat. I used gentle persuasion to get it out from under the higher trim piece.. so only removed the L shaped lower piece.
As Myles said, 10mm socket with short extension. Not more than about 3 inch, at least 1.5" extension needed to make it easy for the lonely single bolt. the two on the door side are easy with any 10mm tool(which you've probably lost! )
Remove the seat .. it's easier and all those 10mm tools are probably under there.
Last tool needed was strong fingernails .. to remove the push in plug cap thingie at the back of the finisher trim .. don't 'nearly break it off like I didn't do.

IMG_20210913_190958[1].jpgIMG_20210913_191022[1].jpg

Started on the shuttle valve switch just before 6 pm

3 amigos were painted over when I got disco, were always on with wheel sensor fault

replaced FR sensor few months back b4 it came apart for head work, and still had intermittent 3 amigos so picked a nice cold night coz it's just me

6e858611f222a0eca5a916bfa1daa6e9.0.jpg
Changed the auto gearbox filter + oil and installing a temperature sensor in it. Haven't actually installed the ems3 unit but thought easier to put in while the autobox was empty. Tad annoying the angle spade terminal ended up at but eh

Fitted extended 150mm+ braided brake lines today and then a flush of the system with new brake fluid. Pedal feel now firmer and reassuring. Hard yakka all that pushing the brake pedal to the floor!!!

Had a visit by my three Mexican friends, Nanacom telling me that the right rear (new hub fitted to both rears) had a weak signal with 16 instances of the fault, cleared and fine again for three brake applications and the ABS light lit up, reset again. Heading back home and they all came on to say hello, at the end of the freeway turned the car off and the Mexican friends disappeared and not to come on again???

Once I got above 85kph there was a driveline vibration (not felt through the steering), not ground shaking but present and stayed unchanged up to 105kph. Changed down to 3rd and the noise went up but the vibration was steady. Thinking it must be one of two things that have changed since changing the diffs, driveshafts and new brakes which I discounted as the root cause.

1. Removal of the harmonic lump from the rear diff
Have others found it to be speed specific, that is upon reaching a certain speed and staying or maybe at certain speeds only - upon removal of the lump?

2. Imbalance of the new front drive shaft
Again has this been found to be a specific speed being reached and remaining or at certain driveshaft speeds. Utah reckon they do both a high speed and low speed balancing of the driveshaft. One thing we did was to reuse the bolts as the $60 worth of bolts I got were not suitable, What are the spec of bolt that should be used?

Loving the ride by the way even without the billies yet on the front, need to find some bigger speed bumps to give it a good work out in Dan's lockout state.

A bit of an update on the V89 TCU in the TD5.

Torque converter lockup in 3rd is at about 40-ish .. maybe 43 was the lowest I could achieve. Eager to lockup in 3rd, at 50-ish on a light pedal, and then hold it say up to about 50% throttle .. maybe even a bit more, so it just pulls without the fuss of high revs with less forward progress. The mapped Td5 has more than ample torque to pull in lockup 3rd.

the 0.1% downside now tho is that it's a lot more eager to unlock in 4th. While it locks a lot earlier say in the high 50's(call it 60) and holds ok in a very light pedal as you'd want between about 60 and 80 more than say 25% pedal and it unlocks and you rev down the road .. feels normal.
It's over 80 where it now feels less normal. Still too eager to unlock and the start of the slightest incline .. like a smooth rise over a freeway overpass .. eg. 3m in about 100 or so .. whilst using the cruise control.
The cruise is too aggressive to maintain and overshoot(always has been) set speed.
Even on the pedal tho. With a bit of time(getting used too it) I'll learn how much more pedal to use whilst still maintaining lockup.
The td5 has more than ample torque to get up and over those rises, even the tdi has enough torque to get around the ring road(Melb) without ever unlocking above 80k/h.

it's only a 0.1% negative tho .. the TD5 TCU never had trouble holding 4th lockup once locked .. unless a whole lott'a bootful was asked of it. Because of the speeds and how quickly it settles back to lockup .. it's a downside more than most would happily ignore.

Drove a few backstreets out west this arvo with the technique to just hold it back in 3rd all the way .. maybe 10 mins or so, and up to about 70 for a brief moment. Seems to be the best way now to drive it around town now. With the low 3rd lockup and up to about 70(80- at a pinch) and the revs and locked TC seem just about right.

The unlocking issue over 80kmh is due to the different throttle mapping on V8 Vs td5 tunes.

The td5 requires more throttle % the TCU then uses that info to decide to come out of lockup as the engine isn't making enough power to stay locked up.

Cheers
James

Originally Posted by RRT

Once I got above 85kph there was a driveline vibration (not felt through the steering), not ground shaking but present and stayed unchanged up to 105kph. Changed down to 3rd and the noise went up but the vibration was steady. Thinking it must be one of two things that have changed since changing the diffs, driveshafts and new brakes which I discounted as the root cause.

1. Removal of the harmonic lump from the rear diff
Have others found it to be speed specific, that is upon reaching a certain speed and staying or maybe at certain speeds only - upon removal of the lump?

I doubt that it is the removal of the harmonic balancer, mine was removed ages a go. No vibrations up to 110kph.

Originally Posted by Bohica

I doubt that it is the removal of the harmonic balancer, mine was removed ages a go. No vibrations up to 110kph.

THought came to mind, could it be the rear rubber ring which is one thing we didn't replace on the drivetrain? How does this react in relation to speed?


EDIT

Just did a whole lot of research and am going to replace the rotoflex, seemingly the most probable cause