H55F tranny - gear or transmission fluid?? (2 Viewers)

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When we use a GL-5 product in a transmission that requires GL-4, we normally find 2 to 4 times as much copper in the used oil as we would with a GL-4 product. Eventually the synchronizers wear to the point that they no longer make contact with the other half of the cone, bottoming out before stopping the opposing gear.


Just remember that GL-4 and GL-5 are gear oil ratings, not transmission oil ratings. Transmissions have gears AND synchronizers. These seemingly conflicting requirements must be met differently.

When someone tells you that their GL-5 covers GL-4, remember they are correct as far as EP protection, but that is only half the answer. When they say their Sulfur/Phosphorous additive will not corrode the yellow metals, they are also correct, but if there are enough to meet GL-5 protection, they will slowly peel away your brass synchronizers.

http://www.widman.biz/uploads/Transaxle_oil.pdf

Not from my inspiration .. was taken from website ..


THIS IS THE MOST CORRECT ANSWER , not from my inspiration too , it's my job.

infact the focus is that transmission (gearbox) it's not only gear

cheers
 
oil geeks!
 
Been happy with Redline MT-90 in both the transmission (improved shifting) and t-case of my BJ74 since 2005/6. I have Marks Gears in the t-case and to my ear it seems a little less whiny with the Redline. Delo synth 75/90 gear oil in the diffs.

EDIT 2024: Still running Redline in a replacement used H55F as I think I lost a bearing on the original H55F (has not been apart to see what failed but lots of silver glitter in the oil and it did not sound good) and switched a while back to running whatever I have in the diff's in the t-case. And a reminder to self to actually change the Redline out once in a while. :doh::hillbilly:

From Toyota Maintenance Procedure Manual Pub. No. MMOO1U for Canadian and USA Model 1986 Land Cruiser

Transmission and transfer oil –

Oil grade: API GL-4 or GL-5

Viscosity : SAE 90

Capacity: (M/T) Transmission 4 .9 liters (5.2 US qts, 4.3 Imp. qts)

Transfer

(M/T) 2.2liters (2.3 US qts, 1.9 Imp. qts)

(A/T )2.1 liters (2.2 US qts, 1.8 Imp. qts)

Differential oil -

Oil grade: API GL-5 hypoid gear oil

Viscosity: Above -18C (0° F) SAE 90

Below -18C (0° F) SAE 80W-90 or 80W

Capacity:

Front 3.0 liters (3.2 US qts, 2.6 Imp. qts)

Rear 2.5liters (2.6 US qts, 2.2 Imp. qts)

gb
 
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I changed the oil in my tranny and tcase h55f and it leaked right away?! Maybe it was pist i hadnt read this thread.
Great little gear oil post.
 
old thread but what are you guys running now in your h55s. everything i find is gl-5. i don’t want to wreck my tranny with the wrong fluid

edit
found this..
2FEC9624-B1CA-4F3E-AED6-0352C1A1127C.jpeg

hope the synthetic doesn’t make my tranny leak too much!
 
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I am leaning towards this with mine. How many quarts does the H55 hold if anyone knows off top of their head.
 
i read somewhere it was around 5 1/2 but don’t quote me on that. fill it till it runs out!

my shop didn’t have that otherwise i’d go that way. i’ll use this stuff for this for now but i’ll search for that and maybe do a tranny oil flush later. i have a top plate leak that’s driving me nuts i want to fix first
 
Still running Redline MT-90 in my H55f. Cheap wal mart 80-90 everywhere else.
 
my input on this H55f will run only on W90 non-synthetic GL-4 is a must.
first 10K milled if transmit new it will be a bit bitty as synchrony will need to get use to.
I tried Redline W90 synthetic and that did not went well at all on the new trany
 
When we use a GL-5 product in a transmission that requires GL-4, we normally find 2 to 4 times as much copper in the used oil as we would with a GL-4 product. Eventually the synchronizers wear to the point that they no longer make contact with the other half of the cone, bottoming out before stopping the opposing gear.


Just remember that GL-4 and GL-5 are gear oil ratings, not transmission oil ratings. Transmissions have gears AND synchronizers. These seemingly conflicting requirements must be met differently.

When someone tells you that their GL-5 covers GL-4, remember they are correct as far as EP protection, but that is only half the answer. When they say their Sulfur/Phosphorous additive will not corrode the yellow metals, they are also correct, but if there are enough to meet GL-5 protection, they will slowly peel away your brass synchronizers.

http://www.widman.biz/uploads/Transaxle_oil.pdf

Not from my inspiration .. was taken from website ..
Does anyone run PennGrade GL4?

 
Been happy with Redline MT-90 in both the transmission (improved shifting) and t-case of my BJ74 since 2005/6. I have Marks Gears in the t-case and to my ear it seems a little less whiny with the Redline. Delo synth 75/90 gear oil in the diffs.

EDIT 2024: Still running Redline in a replacement used H55F as I think I lost a bearing on the original H55F (has not been apart to see what failed but lots of silver glitter in the oil and it did not sound good) and switched a while back to running whatever I have in the diff's in the t-case. And a reminder to self to actually change the Redline out once in a while. :doh::hillbilly:

From Toyota Maintenance Procedure Manual Pub. No. MMOO1U for Canadian and USA Model 1986 Land Cruiser

Transmission and transfer oil –

Oil grade: API GL-4 or GL-5

Viscosity : SAE 90

Capacity: (M/T) Transmission 4 .9 liters (5.2 US qts, 4.3 Imp. qts)

Transfer

(M/T) 2.2liters (2.3 US qts, 1.9 Imp. qts)

(A/T )2.1 liters (2.2 US qts, 1.8 Imp. qts)

Differential oil -

Oil grade: API GL-5 hypoid gear oil

Viscosity: Above -18C (0° F) SAE 90

Below -18C (0° F) SAE 80W-90 or 80W

Capacity:

Front 3.0 liters (3.2 US qts, 2.6 Imp. qts)

Rear 2.5liters (2.6 US qts, 2.2 Imp. qts)

gb
Does this mean run the same oil/fluid in the t-case that you are running in the tranny (in case of migration past the seal)?

I don't know if the transfer case has any yellow metals in it, does it?
 
it *shouldnt* be migrating fluid but ya if it is gl4
 
Does this mean run the same oil/fluid in the t-case that you are running in the tranny (in case of migration past the seal)?

I don't know if the transfer case has any yellow metals in it, does it?

Yes, originally I was running the redline in both just for the reason of migration (usually tcase to trans). As mentioned in the edit I've taken to running whatever is in my diffs in the t-case too.

hth's
gb
 

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