Limping home - disconnecting front or rear prop shafts

[djhampson]

I was out camping with GCLRO this weekend when a D1 developed a clicking noise from the front axle. A damaged CV was suspected at first so the left CV was removed but the clicking continued and the diff became the prime suspect.

It was decided to remove the right CV and the front prop shaft and drive home with the CDL locked creating a 2WD Disco that could still get home without making an existing problem worse but avoiding a tow truck.

It got my Dad and I wondering what would happen if you had a D3\4\RRS that developed a drive line problem and you where in the middle of nowhere... could you remove the prop-shaft and CVs and drive home in 2WD?

I can see the computer having a major fit because it would need to lock the Centre Diff to stop all the drive escaping out the of the TC but it wouldn't detect any wheel spin from the disabled wheel's ABS sensors.

Maybe it would be smart enough to recognise that something was horribly wrong and go into a Limp Home Mode which would by default lock the Centre Diff? Kind of like when it gets a suspension fault it lowers the car and disables the TR system.

Any thoughts?

Do any of the TR modes permanently lock the Centre Diff?

Does the TC have speed sensors on its output shafts? Do they diffs have any sensors that might help the computer work out whats going on?

Its something I'd like to consider now and not when I'm stuck out back of beyond.

[JohnF]

In an older, 1985 RR I got home the same way locking the center diff. I wonder how later ones without dif lock would go. I think maybe one would not get home.

[gghaggis]

I had a CV problem (front passenger - the retaining clip had broken), so no drive via that wheel. Rock-crawl low-range worked best (not so good in high-range), but on sharp corners the car would lose drive. Managed 15km or so before we got a tow-truck out (that was the distance to the nearest pub!).

Hi-range mud/ruts would probably have worked too.

Cheers,

Gordon

[rmp]

I had a similar experience to GGH and also used Rock Crawl as it does the best job of locking the centre coupling which is what needs to be done. I didn't try pulling any fuses as it was just to the edge of the forest.

Not my car I may add ;-)

[gghaggis]

Not my car I may add ;-)


Always good when it's someone else's ;)

Cheers,

Gordon

[Dave128]

Note: If one of the systems fail Terrain Response defaults to General. If it is a gearbox fault, the gearbox drops in to limp mode - third gear, and if an engine fault, it will drop in to the limp home mode. In both of those situations, TR reverts to General.

[stig0000]

we have tryed driving a d3 with the rear prop compleatly off, it didNOT move, it was trying to send power to the front, but was freaking out and wouldent move, if i remember right it broght a systems fualt up on the dash;);)

[rmp]

It's at times like those you wish you could override the electronics and say "just lock the centre diff and forget about traction control etc".

But, you can't.

:no2:

[sniegy]

1800181189:p

[rmp]

1800181189:p

Now THAT'S funny!!!!

Even funnier is out with a group once, one bloke broke a CV. Got the car back to a dirt road, phoned RACV. On speakerphone.

Bloke - "Gidday, membership XXX, need a tow please."

RACV girl - "What's the matter? We need to be sure the vehicle cannot be fixed before we organise a tow."

Bloke - "No, it's definitely a tray job."

RACV girl - "Where are you, and what's wrong with the car?"

Bloke - "On XXX, a 2WD dirt road, and the CV's busted."

RACV girl - "Have you been 4WDing?"

Bloke -- "Err, no. No..."

RACV girl -- "Well you don't do a bloody CV on a dirt road do you! OK I'll get you a towie!"

we all fell about laughing. Literally ROFL time.

Nearly as funny as the time another bloke called his missus, on a carphone, at 6am in the morning after we'd accidentally spent the night int the forest. No, take that back. That was funnier. He was banned from associating with us after that. I still remember that classic line, delivered at sub-zero temperature -- "EXACTLY WHERE IN VICTORIA ARE YOU NOW?" and I nearly called out her name's Helen not Victoria.

Having said that RACV Girl was wrong. Last time we went looking for trouble we expected to lose vehicles to grief, but I didn't expect a 4Runner to retire with a bust CV on the dirt road into the forest. Toyota owners uncharacteristically quiet for a while after that.

[Hoges]

In an older, 1985 RR I got home the same way locking the center diff. I wonder how later ones without dif lock would go. I think maybe one would not get home.

No probs, the viscous coupling in the P38 T/F case automatically swings into action ...can simply drop front or rear tail shaft as required and revert to 2wd. Dropping the front drive shaft is one of the "standard practices" ;) to diagnose driveline vibration issues...

[CaverD3]

Someone from the UK bust a CV in Morroco and drove back to Spain in Rock Crawl mode.