The great transfer case mystery...Help!

[sebaz]

Hi guys,

Bit of an explanation required before the question..

Car is a 33 Vspec.

Had a bit fun lately with an issue related to TPS that caused my 4wd to keep dropping out.

Since fixed that problem but spent a lot of time driving the car in 2wd as a result of it including a couple of 11 hour drives too and from Melbourne. Been a little worried about the effect of this time in 2wd ever since..

Today at a track day I was getting about 4 laps max before my 4wd and ABS warning lights came on dropping out the 4wd everytime again.

It would appear this time it was due to fluid temp in the transfer case as it got hot enough to pop the breather and leak a bit a fluid. This was noted as a small reduction in fluid in the rear fluid reservior in the boot.

Being an electronically controlled centre pump on the Vspec, I'm assuming that after the 4wd dropped out (the electronic pump is disabled) the remaining fluid bascially cooked (breather popped) before I could get it back to the pits.. And admittedly I wasn't exactly off it :-)

Jacked the car up wiped the excess fluid away let it cool down went did a few more laps, more carefully this time. Again the 4wd dropped out after about the same amount of time and laps give or take, due to what I suspect is over temp, but this and subsequent times I backed right off and pited to let it cool. No leaks.

Question is... shit fluid or something more sinister with the transfer case given the previous long 2wd stints??

Wouldn't have a clue about this. Any ideas?

Thanks,

Sebaz

[Tommyk]

Weird

My lights came on, and dropped to 2wd mode when i didnt have sufficient fluid in the rear reservoir. (it was below the min mark).

[sebaz]

Hi,

Yeah have been bit by that before too. Definately wasn't that.

Also the fluid it lost when the breather popped was such a little amount it was still between the max and min levels on the rear reservoir.

Sebaz

[Duncan]

Hey Seb, maybe pm Sydneykid on these forums, those guys had trouble with the race car 4wd at Eastern Creek last year, sounds similar. not sure what they did to fix it

[ylwgtr2]

do an on board systems check and post up the code you get and i will tell you what it is....generally you wont get a code/light unless you have an electrical problem.....A common problem beleive it or not is a weak battery....the car will start everytime and run great but will display a 4WD code

[sebaz]

I'll try reach SydneyKid, anyone have anymore ideas?

Keep them coming :-)

thanks all!

[ylwgtr2]

dude....i just told you how to find out what your problem is.....i give up

[DoughBoy]

do an on board  systems check and post up the code you get and i will tell you what it is....generally you wont get a code/light unless you have an electrical problem.....A common problem beleive it or not is a weak battery....the car will start everytime and run great but will display a 4WD code

Hey I had that problem, but I was too lazy to get another battery. Thanks for the tip Troy!

[ylwgtr2]

well i am glad someone is listening

[sebaz]

Its brand new battery. But thanks for your input.

Sebaz

[ylwgtr2]

i would still be doing a decode aand a reset after as that sounds like the problem.....many times i have seen a flat battery cause the problem then the battery replaced but the code not cleared out then the problem continues with the new battery....

[sebaz]

hey guys,

Found the issue.. we think.. Umm probably should have mentioned I'm running an aftermarket ecu as well.. sorry bout that..

Anyways.. its looking like the Air conditioning compressor electrical activation, and the way it was wired up to the ecu, is what caused the problem.

The aftermarket ecu in question had been setup to turn the compressor on at a certain rev range. The subsequant 1v voltage drop when the compressor was enabled was enough to make the 4wd computer crap out.

So put the air-con back to pressure fed activation rather than an ecu activation and presto all working again.

Hopefully fixed for good. thanks for those that provided input.

Sebaz

[ylwgtr2]

hmmm well what do you know....was a voltage problem