Gear Oil:

[Rob]

I'm wanting to change the oils in my transmissions, and axles. Is there one type that will work for all so I can buy a single barrel? I've got tri-plexs, quadruplexes, and a TRDXL-1071. Also have a Brown-Lipe auxillary. All the rears are Mack.

Thanks,

Rob

[Freightrain]

I run Coastal gear lube in my box. Can't recall if I used the 75-90 or 85-140?, plus I put it in the rear axle. It definitely quieted up the box after tightening the rear bearing and putting in new oil. Don't rattle as much as in years past.

I think most concensus on Brownies is straight weight motor oil? The stories I hear regular lube is too thick.

[Packer]

From what I remember, 85w GEAR lube is the same viscosity as 50w MOTOR oil.

This is from a long way back - - - late 70's to early 80's.

I.ve been wrong before - - - maybe some one can add to this.

The only issue I ever saw that was VERY BAD was mixing mineral oil and gear lube.

A very nasty goo and a bunch of shiny gear and bearing parts in the bottom.

Seems the two oils do not mix!

They turn to a tar-like substance and won't lube bearings or gears.

Even draining the gear boxes then adding the other oil will leave the inside all black and sticky.

Packer

[theakerstwo]

You are ok to use muligear like 85/90 and were you are i dont think you would need 65/140 but at one tine all mack gears run in that before the snythegitic but the aux should not get any thing better than 50w because it has needle brgs. I have used 50w aershell white can for many years and now i just use a staight 50w engine oil . about 30.00 for 5 gals.

Eaton or roadranger trans need a 50 w oil also.

[Charlie Hatfield]

I work in a truck repair shop that rebuilds transmissions and diffs. We have used Chevron 80w90 Delo in both for many years. Recently we started using Chevron Trans 50 ESI synthetic in the transmissions, but some customers still use 80w90

Charlie

[theakerstwo]

I work in a truck repair shop that rebuilds transmissions and diffs. We have used Chevron 80w90 Delo in both for many years. Recently we started using Chevron Trans 50 ESI synthetic in the transmissions, but some customers still use 80w90

Charlie

And that is even in the mack service manual. There is no snychroizer like eaton uses to get eat up by the mutigear grease but a clutchpac in the later mack trans and mutigear will not hurt the clutch pac and i am saying clutch pac as it is used like a snyronizer . I know some guys use mutigear oil in eaton with out bany problems but why do eaton teach not to.

[Rob]

And that is even in the mack service manual. There is no snychroizer like eaton uses to get eat up by the mutigear grease but a clutchpac in the later mack trans and mutigear will not hurt the clutch pac and i am saying clutch pac as it is used like a snyronizer . I know some guys use mutigear oil in eaton with out bany problems but why do eaton teach not to.

[/quote

Thanks guys for the advice and clarification.

Glenn; Are you saying that an Eaton/Fuller should not use 80W-90? I have an RTO-12513 that I plan to use in a truck someday behind my Detroit, or my Cat powered Mack. It is fresh with 0 miles since rebuild.

Thanks,

Rob

[b61mack]

You are ok to use muligear like 85/90 and were you are i dont think you would need 65/140 but at one tine all mack gears run in that before the snythegitic but the aux should not get any thing better than 50w because it has needle brgs. I have used 50w aershell white can for many years and now i just use a staight 50w engine oil . about 30.00 for 5 gals.

Eaton or roadranger trans need a 50 w oil also.

I have a RTO14613 and have been running 85-140 is that gear lube too heavy, should i use 80-90 just wandering if i should change it. Thanks Ron

[mackmixer]

I do remember from somewhere, some old Ford or Studebaker literature, that you should not use 80/90 wt gear lub in transmissions with synchronizers but I don't think the Mack transmissions have any synchronizers in them do they?

[theakerstwo]

The eaton trans should not ude multigear 85/90 or multigear 85/140 but a 50 w motor oil or aershell in the white can which is airplane engine oil that is mineral oil 50w. a eaton trans has in the past had a materal on the syncronizer that is beleived to be damaged but the multigear oil. The mack trans has a disc plate clutchpac for a snycronizer and untill the snythectic oils came out you could use quote bu mack multigear grease and unless i was in hot country i would use 85/90 and not the 140. the 85/90 is too heavy in a eaton trans also if you are in trhe hot coutry and pulling hard. The oil temp will be higher on that oil than if you had a 50w engine oil in it. I know alot of guys run 85/90 multigear oil in their eaton or roadranger but liston to eaton or go to their website they will ask for snythetic but when it is not under waranty i say and have and will use a 50w motor oil and you will see a cooler oil temp. If i had a 85/90 AMI GL5 gear oil or 85/90 in it now i would not change, if you are not working it in the hot country and pulling at long hours at a time it will be maybe ok but if it was enpty i would use the 50 w in the eaton. If you do a google search you can find some good sounging oils that is supposed to go any where but the reason i think that most gear makes or trans makers ask for a snythetic by a certain part # to get the waranty is they know that there is a magic oil out there that sounds good and supposed to be able to be used every where but they want to know what is being put in there and you have to have prove in order to get waranty.

[Speed]

The eaton trans should not ude multigear 85/90 or multigear 85/140 but a 50 w motor oil or aershell in the white can which is airplane engine oil that is mineral oil 50w. a eaton trans has in the past had a materal on the syncronizer that is beleived to be damaged but the multigear oil. The mack trans has a disc plate clutchpac for a snycronizer and untill the snythectic oils came out you could use quote bu mack multigear grease and unless i was in hot country i would use 85/90 and not the 140. the 85/90 is too heavy in a eaton trans also if you are in trhe hot coutry and pulling hard. The oil temp will be higher on that oil than if you had a 50w engine oil in it. I know alot of guys run 85/90 multigear oil in their eaton or roadranger but liston to eaton or go to their website they will ask for snythetic but when it is not under waranty i say and have and will use a 50w motor oil and you will see a cooler oil temp. If i had a 85/90 AMI GL5 gear oil or 85/90 in it now i would not change, if you are not working it in the hot country and pulling at long hours at a time it will be maybe ok but if it was enpty i would use the 50 w in the eaton. If you do a google search you can find some good sounging oils that is supposed to go any where but the reason i think that most gear makes or trans makers ask for a snythetic by a certain part # to get the waranty is they know that there is a magic oil out there that sounds good and supposed to be able to be used every where but they want to know what is being put in there and you have to have prove in order to get waranty.

So-all this time I've been pumping 80W90 through my Brown-Lipe I've been wrong ;As bad as the input seal leaks with gear oil,I'm thinking with 50Wt. motor oil I might as well just pour it on the ground. Oh-well.I was planning to replace that seal anyway,just hoped to get some work done with the truck first. SO--What do I have to do to make this right? Is it possible to flush the box out and re-load with that Aero-Shell 50 wt? What should I flush it with? I've run it less than 500 miles on the gear oil-is there a possibility I haven't damaged the innards yet?

Sorry to step on your subject,and thanks for your advice.

Speed

[theakerstwo]

The eaton trans should not ude multigear 85/90 or multigear 85/140 but a 50 w motor oil or aershell in the white can which is airplane engine oil that is mineral oil 50w. a eaton trans has in the past had a materal on the syncronizer that is beleived to be damaged but the multigear oil. The mack trans has a disc plate clutchpac for a snycronizer and untill the snythectic oils came out you could use quote bu mack multigear grease and unless i was in hot country i would use 85/90 and not the 140. the 85/90 is too heavy in a eaton trans also if you are in trhe hot coutry and pulling hard. The oil temp will be higher on that oil than if you had a 50w engine oil in it. I know alot of guys run 85/90 multigear oil in their eaton or roadranger but liston to eaton or go to their website they will ask for snythetic but when it is not under waranty i say and have and will use a 50w motor oil and you will see a cooler oil temp. If i had a 85/90 AMI GL5 gear oil or 85/90 in it now i would not change, if you are not working it in the hot country and pulling at long hours at a time it will be maybe ok but if it was enpty i would use the 50 w in the eaton. If you do a google search you can find some good sounging oils that is supposed to go any where but the reason i think that most gear makes or trans makers ask for a snythetic by a certain part # to get the waranty is they know that there is a magic oil out there that sounds good and supposed to be able to be used every where but they want to know what is being put in there and you have to have prove in order to get waranty.

For a toy truck it may not hurt it but on a hard working truck get some 50w in there but you can drain and then put some diesel in there and run in nutral for a little bit and drain and refill.

[Speed]

For a toy truck it may not hurt it but on a hard working truck get some 50w in there but you can drain and then put some diesel in there and run in nutral for a little bit and drain and refill.

I'll do that after I change the input and output shaft seals.

Thanks!

Speed

[b61fred]

Hi,

I have read that 90weight mineral oil has the same viscosity as 50w engine oil. I went to look for 90w mineral oil and all I could find is 90w EP, the EP is for extreme pressure, The viscosity is much higher than 90w mineral oil. I looked at some old owners manuals for the b-series, It said to use 50w in all spicer auxilery transmissions and 90w mineral or 50w mineral oil in mack transmissions and 90w or 140w in rear axles. This was writen in the fifties and oil specs. have changed quite a bit sence then. I used 50w engine oil in all my transmissions and 90w in the rear axle ( I think Charlie got me a 5 gallon pail for me) so far everything works great, the trans shifts very smooth, not too much noise at all. Thats my two cents,

Fred

[theakerstwo]

I'll do that after I change the input and output shaft seals.

Thanks!

Speed

That is what i remember hearing also and i remember the old r96 and eary rt series roadranger trans using mineral but dont remember what weight but ever one got away from it because mineral oil and a multigrade grease turns to a hard tare looking grease. I remember seeing it mixed and if let go it would set up and was impossable to drai9n with out puting some fuel in it and runni9ng for a while.