Warmed Transfer Case Sounds Just Like P/S When Cold, Why?

[Les Summer]

YES!. Both are Exxon/Mobil (see Toyota bottles). But Mobil 1, is top shelve and a full synthetic. Toyota Dealership use bulk, unless issue like with A/T running hot. Than they use Mobil 1, in A/T's calling for Dex II or III.

I'm always against mix oils, coolant, etc. Just to many different variation and additive package.

after swapping out 3 quarts of my AT fluid and adding in 3 quarts of the synthetic mobil 1, I noticed the whine is nearly gone. all I really hear now is normal vibration from the transfer case. after a little while I'll be refreshing another 3 quarts. it must be good ATF, it was sold out in every store, and I had to order it from Amazon. I got a six pack.

 

[Les Summer]

I took a couple pictures of this fitting that if you reach around is in top of the transmission

there is a hose that runs from that fitting and terminates on the dipstick so I think this is the transmission breather tube. I don’t know what part number that valve is, or anything about it, but my guess is it’s a one-way valve because I did a test and I’m not able to blow air into it, so it must be a one-way valve that only lets air out.

The separate picture is of the hose that runs from that valve. Of course with a 24-year-old truck it’s fragile so I have naturally broke it taking it off and improvised a different hose.

As it relates to this thread, I wonder if that plastic valve could become defective and be the cause of a whine in the transmission? I also got to wonder how in the world you would get the thing out because it’s plastic so it seems like it’d be easy to break, Which could lead to a nightmare due to its’ location. You might never be able to get it out of there if it broke, without removing the transmission.

 

[2001LC]

Humm, I've not looked at one of these. I've just assumed the only one way valve, was the one on dipstick.
Did you try blowing in, with a known clear hose?

Edited 6/20/24: Took a look at one. They're not a check valve. Just a two way pass through hose attachment.

 

[Les Summer]

Humm, I've not looked at one of these. I've just assumed the only one way valve, was the one on dipstick.
Did you try blowing in, with a known clear hose?

View attachment 3618563

yes I did. I attached a separate hose to the little one and blew thru it. The air literally compressed in the hose and came back out. I stuffed that little hose into a bigger hose I had on hand. now that I'm thinking more about it, I wonder if I pinched the smaller hose closed by accident without even thinking of it.

Thanks! and thanks for the picture. I'm afraid to take that thing out it'll probably break. I think im going to buy that little valve just so I can examine it closer.

 

[2001LC]

I may to buy one, just to see if a check valve or pass through hose connection.

Let us know if you try again, once new hose attached.

 

[Les Summer]

I may to buy one, just to see if a check valve or pass through hose connection.

Let us know if you try again, once new hose attached

I may to buy one, just to see if a check valve or pass through hose connection.

Let us know if you try again, once new hose attached.

Will do

 

[Les Summer]

I may to buy one, just to see if a check valve or pass through hose connection.

Let us know if you try again, once new hose attached.

I learned the proper OEM hose I needed for that breather has been discontinued. I am happy with leaving the jerry rigged hose I put on in its place. it's not going anywhere. I also decided even if that breather isn't right, although I think it's fine, I'm not trying to remove it and have it break off on me. it's not worth it. I don't think the breather is clogged, although it appears the opening of the 24 year old OEM breather is a little different from what I can see from analyzing photos. I'm not worrying over it.

I never tried to blow air into it again after the first time, which air could not get in. If it does not allow me to blow air into it, then I'd say it's probably fine. I imagine you'd NOT want air to be able to get sucked into the transmission, but rather you'd want it purged out so not to have air bubbles in the transmission fluid.

I focussed my attention more on the circulation of that new Mobil 1 Full Synthetic transmission fluid into my system, and I can honestly say I notice a difference after swapping in 6 quarts of that. In about 30k more miles I plan on swapping in another 6 quarts. my whine has dialed down enough to notice it since I swapped in the Mobil 1 trans fluid. I'm happy with where the LC100 is for now. It shifts good and smooth, and no issues. I'm just gonna leave it be.

 

[2001LC]

I did look at that plastic hose breather, a new one at Toyota parts dep.. It is not a check valve. Air pass in either direction unrestricted.

I'd do a full 12 qt flush with Mobil 1 MV ATF in 98-02. As it happens, I'm doing a full 12 qt flush today. I do them all time, with only good results.

 

[Les Summer]

@2001LC I'll say it one last time, it was all the difference. The whining is virtually gone, even after 370 mile round trip to PA. The synthetic ATF, I'm convinced, has something to do with it fixing the whine, and I'm always hard to convince. Finicky transmission loves it. It's all I'll ever put in it or any other LC100 I come by. Just bought another 6 pack off Amazon.

 

[2001LC]

@2001LC I'll say it one last time, it was all the difference. The whining is virtually gone, even after 370 mile round trip to PA. The synthetic ATF, I'm convinced, has something to do with it fixing the whine, and I'm always hard to convince. Finicky transmission loves it. It's all I'll ever put in it or any other LC100 I come by. Just bought another 6 pack off Amazon.

I'll say it 100 more times.
"Do full 12 qt flush, in one step."

I do like Mobil 1 MV ATF in 98-02 and Mobil MV full syn in 03-up (rated for Toy II, III, IV & WS). But any good fluid where all 12 qt's are the same brand, works okay.

Drain and fills are a waste IMHO! To often they result in mixing of various fluids. Mixing brands is a bad idea, for a number of reason. One being anti foaming agent variation/needs.

 

[Les Summer]

I'll say it 100 more times.
"Do full 12 qt flush, in one step."

I do like Mobil 1 MV ATF in 98-02 and Mobil MV full syn in 03-up (rated for Toy II, III, IV & WS). But any good fluid where all 12 qt's are the same brand, works okay.

Drain and fills are a waste IMHO! To often they result in mixing of various fluids. Mixing brands is a bad idea, for a number of reason. One being anti foaming agent variation/needs.

How many miles do you trust the Mobil 1 Full Synthetic 5W30 engine oil that promises protection up to 20,000 miles? I know this much, I'm not waiting 20k miles to change oil, or even 10k.

 

[2001LC]

Threads getting away from OP & Heading.

The more often we change (ALL) fluids the better. But some people drive 20K a year. They'd rather not change oil 4 times a year.

The M1 EP (AKA: Annually Protection) I do trust for 20K miles or 1 year (whichever comes first) in the 4.7L. But Mobil synthetic oil filter is needed for that many miles, or at least replace the OEM filter at every 5K or 10K.

 

[Les Summer]

Threads getting away from OP & Heading.

The more often we change (ALL) fluids the better. But some people drive 20K a year. They'd rather not change oil 4 times a year.

The M1 EP (AKA: Annually Protection) I do trust for 20K miles or 1 year (whichever comes first) in the 4.7L. But Mobil synthetic oil filter is needed for that many miles, or at least replace the OEM filter at every 5K or 10K.

If I’m changing my oil filter at 5K miles I’m dumping the oil while I’m down there too, man especially since the difference between this premium stuff and the lower end stuff at my local Walmart is about eight bucks or less (for the 5 qt. Jug). While the difference between the 20,000 mile full synthetic and just regular full synthetic is a matter of only two or three dollars. And a lot of times it just comes down to what is left on the shelf. Thanks, Over.

 

[Les Summer]

It has been learned my whining noise was a bad alternator
After replacing my alternator today I don’t notice the whining noise even in the smallest amount like I did before.