Motul 75w90? (1 Viewer)

[wpwilder]

hello everybody, i search and read the FAQ but haven't found any mention of

Motul Gear 300 75W-90 SynTransmission Fluid Oil​

i have some left over from the last car i owned (subaru wrx) and was wondering if anybody has used this brand in their transfer case? i would rather use it than purchase a different brand to save money if it's ok to use.

 

[jblueridge]

I think it comes down to GL4 vs GL5 ratings.
GL5 could potentially harm copper alloys like brass and bronze as used in old gear boxes.
I think it is the phosphorus added to make the oil handle “extreme pressure” that is the culprit.

 

[wpwilder]

I think it comes down to GL4 vs GL5 ratings.
GL5 could potentially harm copper alloys like brass and bronze as used in old gear boxes.
I think it is the phosphorus added to make the oil handle “extreme pressure” that is the culprit.

thanks for the info. i was a bit confused by all the GL4 GL5 stuff in FAQ. although these bottles state "GL4/GL5" on the back of the bottle. you think that means it's good to go for a 90 HZJ77?

 

[jblueridge]

My understanding is not comprehensive but I believe the ratings do not take into account "safe to use with brass".
GL5 can handle heavier loads.
I would not use it in my t-case due to my lack of specific knowledge: I have always read that GL5 is bad for old gearboxes.

 

[wpwilder]

My understanding is not comprehensive but I believe the ratings do not take into account "safe to use with brass".
GL5 can handle heavier loads.
I would not use it in my t-case due to my lack of specific knowledge: I have always read that GL5 is bad for old gearboxes.

View attachment 3339135

noted. don't want to take any chances. i'll be looking for GL4. thanks

 

[misterclean]

FWIW, a number of members here run 75W90 in the t-case. I recently did a drain and fill with Valvoline 75W-90 pouches which is also rated GL4/GL5. No problems thus far, but I would ask some of the gurus on here what their opinion is, just to make sure.

The manuals call for Toyota LT Gear Oil when changing t-case fluid, but those coffee can containers are about $75 per liter.

If you don't want to run 75W90 in your t-case, Royal Purple offers a low(er) cost option that they claim meets the standards of the Toyota LT gear oil: Royal Purple Synchromax Manual Transmission Fluid - https://royalpurpledirect.com/royal-purple-synchromax-manual-transmission-fluid/

 

[wpwilder]

FWIW, a number of members here run 75W90 in the t-case. I recently did a drain and fill with Valvoline 75W-90 pouches which is also rated GL4/GL5. No problems thus far, but I would ask some of the gurus on here what their opinion is, just to make sure.

The manuals call for Toyota LT Gear Oil when changing t-case fluid, but those coffee can containers are about $75 per liter.

If you don't want to run 75W90 in your t-case, Royal Purple offers a low(er) cost option that they claim meets the standards of the Toyota LT gear oil: Royal Purple Synchromax Manual Transmission Fluid - https://royalpurpledirect.com/royal-purple-synchromax-manual-transmission-fluid/

i just went with redline MT-90 75w90 GL4. it's the "GL4/GL5" on the back of the Motul bottles that steered me away. worried about the whole "yellow metals" thing. thanks for the info. though, i appreciate it.

 

[ATL Cruiser]

Transfer cases have no brass. GL4/GL5 is fine. I run that exact same MOTUL in my diffs and transfer case.

Manual transmissions use brass in their syncros. GL4 is required for those. Supposedly GL5 is harsh on the brass over a long period of time.

 

[wpwilder]

Transfer cases have no brass. GL4/GL5 is fine. I run that exact same MOTUL in my diffs and transfer case.

Manual transmissions use brass in their syncros. GL4 is required for those. Supposedly GL5 is harsh on the brass over a long period of time.

the kind of definitive answer i was looking for. would you suggest i save the redline for the transmission (auto) and use the motul for the tcase?

 

[bj70_guy]

Never had a problem with plain old 80w90 in my T cases for 30 years now. The only place I put GL4 is in the H55f.