UPDATE.....I performed the repair and it went pretty smooth. When I removed the actuator and twisted it to completely remove it from the t case, the reported "crackling sound" appeared to be the cap housing, which covers the oils seal, raking the housing of the t case. Once removed I notices the lip edge of the cap had a small piece broken off. Nothing major.

The shaft remained in the t case. I then switched out the oil seal and o-ring and reinstalled. It went back on without much effort.

I then sprayed off the area with brake cleaner and drove it around for a short time, shifting in all ranges. Came back home and let it set for a few minutes. Afterwards, I noticed a small amount of dripping. I couldn't tell if it was still leaking or maybe some left over residue I didn't get sprayed off. I talked to the mechanic about this and he advised that I should have seated the oil seal when I replaced it. He thought that might have been the reason for my continued leak. I didn't read anywhere where someone stated these seals had to be seated.

After i wiped it off again and let it set it appears to be leak-free. Last two days appears to be dry. I guess time will tell.

 

Did you twist counterclockwise to remove? Keep us posted on the outcome.

 

Yep....it came out pretty easy. Like I said, the crackle you hear is the cap raking out of the t-case. As of today, still dry as a bone. I hope it lasts.

 

I hope your tcase is still dry!

Two more questions if I may?

The Lexus parts diagram shows 2 shafts going into the actuator.
So, when you pull back on the actuator housing, there is a shorter shaft that disconnects first and this allows the actuator to be rotated counter-clockwise. Then the longer shaft with the teeth unhooks from the actuator housing. Is this correct?

How is the shorter shaft connected to the actuator housing?

Sorry 'bout all the questions, but you are now an 'expert' on this.

 

No expert by any means. When I pulled my actuator out the only shaft I saw was the one that stayed in the t-case. That shaft had teeth on the end. When I pulled the actuator out it was only the black box.

 

Thanks. Maybe I had the wrong diagram.

 

Looks like the GX owners in Russia are discussing this same problem. Wish I could read the posts.

http://club-lexus.ru/forum/viewtopic...sc&per_page=50

Anybody know the significance of this particular actuator bolt? It's circled twice in red in the thread.

http://st.club-lexus.ru/attach/u/c2d2e535.jpg

I have the seals on order for this repair. Will try to make a video. Too darn cold to even think about doing in now. If I wrap a Pampers around the actuator, I should be able to go spot-free for at least a month. (Tcase oil level has not gone down any so far.)

 

I have a 2003 GX470 with 166K miles. I had the same transfer case leak as described in the comment strings. I got a quote from Toyota/Lexus to repair for $1600.00. Toyota confirmed failure with the TSB doc that is listed in this sting. Local Private mechanics were hesitant to take job due to potiential issues with the trany controller and did not want to split the transfer case. I ordered the oring part my local Toyota dealer as listed in the TSB for (3$). The leak has gotten progressively worse over the last year, so I followed the instructions for removal of the "black box actuator." Everything disassembled as described in strings listed. As noted the key to the removal of the black box is the rotation and disengagement of the rack and pinion gearing. I had to rotate (the black box) back and forth clockwise and counter clockwise (with the cracking noise) for the actuator to finally break loose. The actuator finally did free up. Upon inspection you can see the oring failure, (oring is smashed to oval shape). Failure of the elastic property found in o-ring material. I replaced the oring with the new one from Toyota. Reassembly through the same rotation process. Make sure areas are cleaning from debris as rotating the box can pickup unwanted contamination on the seal and seal surface. Couple of procedure notes: 1) I did not disconnect the battery. 2) I disconnected the wire harness and vacuum line and reconnected them in the reassemble process. 3) Est. repair time was 1hr. 4) No codes generated and drive train is working perfect. The leak has been fixed to date. The only concern I have, is the function of the low range gearing system in the 4WD. The Lexus GX470 is full time 4WD in high range, so I never plan on engaging lower range for off roading purposes. With the process of the actuator removal, there might be damage to the actuator that will not allow the low range button to function.

 

jeanecw:
Thank you so much for the post!

I work on electro/mechanical systems daily. I can see how not getting the rack re-engaged with the actuator on exactly the same tooth could cause an out of sync problem. If out of sync, a shift into 4-low will not only screw up 4-low, but the shift back to 4-high will mess up 4-high. SCREWED!!!

I WANT to try this, but logic is telling me the Lexus service manual procedure is the correct way to go. I have the O-ring and internal oil seal...maybe on a warm day...with 4mg of Lorazepam...we'll see.

jeanecw- have you tried the shift into 4-low???

 

More:

This - just posted on ih8mud by Dan Kunz (Dan knows his stuff)
http://forum.ih8mud.com/120-series-t...se-leak-3.html

Was already planning on having rock sliders and a 2" lift kit installed along with the rear coil spring conversion at http://acctoyota.com/so this works out perfectly!

I'm in S.E. Wisconsin, but this is worth the trip. Plus, I can go see those totally crazy relatives living down in 'beautiful' Lake City Florida!

 

Hmmmm Just noticed on my 08 nice, oily, and wet around the front of my T-case, guess I have to do this repair as well--from what learned from this thread is I need that one O-Ring 90301-56009 only to do the job?

 

Anybody needs the full instruction pm me yr email on mann68@gmail.com, and you can have it. I cant post here due to security and patent voilation agreements. Hope you can understand.

 

I decided NOT to do this procedure. I have found that turning the actuator assembly to remove it from the rack, internally cracks (chips) the plastic case. That crack allows the rack to be removed. If the case was intact, the rack could never be removed. When the rack is put back into the actuator, there is the possibility that the 'LOCK" function will not work. The crack may allow the rack to pull away from the drive gear during operation.

I learned this by putting a defective actuator assembly in a vise and twisting the rack out just as described on this and other forums. Before doing this, I disassembled the actuator to see just how it worked. Upon inspection, it was evident that there was no way the actuator rod could be removed without some sort of damage. So, I put everything back together, put the rack in a vise, took a deep breath, and turned the actuator housing to extract the rack. I heard the crunch mentioned in the forums. I then opened the actuator and disassembled. That's when I found the cracked plastic piece directly behind the drive gear.

I have devised two alternate methods to repair the o-ring problem, but neither method has been tested. The weather here is not cooperating.

The individuals that have posted this 'twist&pull' repair method ALL have great reputations on the forums. I checked out two of them: The guy in Texas (KillerPea) that stated he would do the the procedure for forum members - was formerly the lead tech at a large Lexus dealership. The guy in Utah (fj55-100) that stated he was a retired Lexus tech with 20 years experience is exactly who he says he is. No info on mann777, but I have learned much from his posts and I respect his opinions.

Sorry to contradict the existing information, but from what I learned doing this on the bench, I personally will not do this procedure on my truck.

This is my opinion only. I am not a Lexus tech. Nor do I repair cars for a living. But, as far as I know, I am the only one to check internally before and after doing the procedure.

Proceed at your own risk.

It's killing me seeing those spots in the driveway!

fj55-100: http://forum.ih8mud.com/120-series-t...case-leak.html

KillerPea: http://forum.ih8mud.com/120-series-t...se-leak-3.html

 

Can you post up pictures of the internals and what is actually cracking--??

 

Sent you an email!