Transfer Case / Front Diff Knock

[CeJay]

Recently my car has developed a drivetrain knock when 4wd engages. When torque goes to the front wheels I was getting a repetitive regular knock. Goes away when you reduce the throttle. It does not occur when 4wd is disabled. Am running the car in 2WD atm

Anyone had this problem before? Didn't find anything while searching. Had a look underneath the car as I did run over a branch on the road before the car started doing anything. Couldn't find any obvious damage. I have checked the attessa fluid, it is over maximum.

I do have a few error codes, 8, 9, 18, 18 is the ETS pressure switch.

Could something in the front diff or transfer case have let go?

[CeJay]

Had one shop tell me it might be the transfer case driveshaft on the way out. Can't really tell without looking at it, anyone have any other thoughts?

[central coast person]

Not sure but i have a r33 GTS-4 and it will do this aswell. Mine doees it the second i release the acceletrator and ussual only ever in first or second.

Im going too be looking into mounts and bushings before anything like the shafts

These are the 4WD codes you are reciving from the attessa system

8 ABS actuator motor, motor relay or circuit

9 ABS actuator relay or circuit

18 ETS pressure switch or circuit

Edited April 30, 2010 by central coast person

[Duncan]

Hey Chris drop the front driveshaft out and see if that quietens it down. 4 bolts out she comes

[CeJay]

  Duncan said:

Hey Chris drop the front driveshaft out and see if that quietens it down. 4 bolts out she comes

thanks Will see if I can manage that myself when I get back, but I would of thought I'd have to cover up the holes if I was to take it out onto the road without a front driveshaft. (let me know if it's a stupid query as I haven't tried taking one out before)

Not exactly to confident on jacking the car onto 4 jack stands and then running it up to see how it goes. Sound dangerous to me.

[Duncan]

nah its cool - there is a seal at one end and a bolt on flange at the other.

[CeJay]

Do the bolts need to be torqued to a particular setting? And what would be a good spot to put the chassis stands?

[snozzle]

if u take the shaft out wont it leak out of the transfer case on the gbox side? :S

[central coast person]

  snozzle said:

if u take the shaft out wont it leak out of the transfer case on the gbox side? :S

You can buy toos from supercheaps and repco's that are about $10 and are a plug. You could make your own aswell i guess....

I found my problem mate, its my clutch plate hitting the clutch cover on harsh decel ........ Does it only happen to you when you decel in 1st and 2nd gear????

[CeJay]

Well the 32 attessa system is different to the 33, my problem only happens when significant torque goes to the front wheels, ie medium to hard acceleration, and it literally feels like something is going to rip up the gearbox or go at any moment, it's a repetitive sound as well. I think I have the tools for this but would be interested to hear from anyone with a 32 who has done this.

[Swiper the Fox]

  CeJay said:

Well the 32 attessa system is different to the 33, my problem only happens when significant torque goes to the front wheels, ie medium to hard acceleration, and it literally feels like something is going to rip up the gearbox or go at any moment, it's a repetitive sound as well. I think I have the tools for this but would be interested to hear from anyone with a 32 who has done this.

the drivers side axle has popped out of the diff...just pop it back in with a long screwdriver or pry bar.

[CeJay]

  Swiper the Fox said:

the drivers side axle has popped out of the diff...just pop it back in with a long screwdriver or pry bar.

Hmm suppose I can check this as well, and pardon my ignorance, but I thought if something like that would happen the noise would be constant?

[CeJay]

Transfer case had no oil in it, was fuba. My bad.

[Duncan]

damn, bad outcome. At least it is simple though.