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LMichaels

Bevel Gear Box oil change

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LMichaels

So kind of resurrecting an old subject.

Decided to change out fluid in BGB today, lo and behold no drain plug ugh. I guess only way is to remove the rear plate? Decided also to check fluid in it. Thin and definitely NOT regular old gear lube. Feel and odor similar to ATF. So now wondering,

A. Leave it alone and do nothing?

B. Remove rear plate change and fill with some type of ATF?

C. Remove plate and refill with 75W 90 gear oil?

D. Remove plate and fill with universal trans/hydraulic fluid as I used in the hydorstatic trans?

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PhanDad

From a later model Sovereign Operators Manual:

image.thumb.png.1b443923b8c23a67f5943fae41b8f459.png

Note the second paragraph.

A pain to drain fluid - you'll be lucky to get the gasket to reseal after loosing the bolts and prying the bottom of the cover off so it'll drain.  

If you have a later model Sovereign (all 7100 series and newer, maybe some or all of the 7000 series), the BGB uses "Simplicity Multipurpose Hydraulic Fluid".  

Assuming it's not red (Dexron ATF), I'd do "D".  

You might want to suck the majority of the fluid out rather than cracking the rear BGB cover.  I've used an old turkey baster with a piece of tubing on the end so it'll reach the bottom of the BGB.  

 

Edited by PhanDad
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SmilinSam
4 minutes ago, PhanDad said:

If you have a later model Sovereign (all 7100 series and newer, maybe some or all of the 7000 series), the BGB uses "Simplicity Multipurpose Hydraulic Fluid".  

Assuming it's not red (Dexron ATF), I'd do "D".  

You might want to suck the majority of the fluid out rather than cracking the rear BGB cover.  I've used an old turkey baster with a piece of tubing on the end so it'll reach the bottom of the BGB.  

 

My thoughts and methods as well Bill.

If there is nothing apparently wrong with the gearbox, I might not even bother taking the cover off for what little oil would be left. I would just suck what I could out without distrubing any grime in the bottom, then just refill with new oil.

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LMichaels

So this is what I used in the trans is consensus then that it would be good for the BGB as well? The oil in it now is definitely NOT red, and does not smell like ATF though it's consistency seems about the same as ATF. I also have a qt or 2 of ATF Type F in the garage. Or maybe I should not even have used this last year in the trans?

Thoughts?

IMG_20190527_142348.jpg

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SmilinSam

Should work fine. I have used that before myself, as well as  the Deere brand hydro/hydraulic oil. Never had a problem.

If its brown, use brown. If its red, use red. I wouldnt mix the brown and red together If I could help it.

I know the Simplicity ?Sunstrands used either the red atf F , or the brown hydro/hydraulic oils. The newer Tuff torqs I believe use 10w 30 motor oil. The eatons in the 90's Wheel Horses also used 10w30.

If any of this needs corected, anyone reading this feel free to do so, and/ or add to it.

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SmilinSam
1 hour ago, Brettw said:

I would think with the massive shear on the bevel gears, a 75/90 weight gear oil would be the way to go, no?

Well, that was what I always thought. But the newer owners manuals, including the one with the 1999 Soveriegn I had call for the same oil that the hydro uses.

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TimJr

I think the reason the factory went with the hydro oil in the BGB was simply cost savings - they used one oil in the drivetrain instead of 2.  I would only ever run 80w90 gear oil - I run synthetic in mine since it is used year around.  One of the other reasons I was given for the switch to the thin oil was cold weather starting - it took more power to turn the BGB with gear oil in it.  I suppose technically, but if that little difference was keeping an engine from starting, the tractor probably needed other work anyway.

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MrSteele

I am putting one together for a 1965 and debating the lube. I am leaning hard toward 20W50 engine oil, but will consult a lubricant specialist I know first. In the old days, 90 wt was about all that was available, then came multi weight, now synthetic.I used 80w90 in it last time and never had a problem with lubricant. Bolt backing out, Yep! My Ford truck uses automatic transmission fluid in the transmission and rear end. I would think there is much more shear in a vehicle than in these old mowers. I checked with the bearing folks at Motion. Their recommendation on the bearings, needles and balls is a light weight oil, not anything as heavy as 90 wt

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TimJr

I don't know about a lot of new vehicles, but what truck uses ATF in a differential?  Year and model?

A BGB has an almost hypoid gear set.  The gears run in the same plane, but are not a simple straight cut bevel gear.  There is a slight twist to the teeth - lots of shear - no way on the motor oil.  80w90 gear oil for me.

How does Motion explain an NP205 transfer case.  80w90 gear oil.  Has ball bearings and needle bearings.  Simplicity ran 80w90 in your transmission - it has needle and ball bearings.

Peerless 4 speeds in JD 100/200 series used 80w90 and again used needle and ball bearings.

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MrSteele

I misspoke on the rear end, but it is recommended in the transmission. I use 75W90 in other gearboxes around the house, will likely simply put it back in, but. If there is better in synthetics, will likely go there. As I said, I am going to check with a lube specialist I know, before I do anything

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maxwood

Hello, Instead of a turkey baster to remove the fluid I use a pump from a Dawn dish soap gallon bottle . I put a tube on to extended it . It pumps an ounce at a time , it takes a while but easier than removing  the back plate from the BGB

 

Thanks Ken in Mi

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Bill725

How about removing the BGB rear cover, drilling a hole towards the bottom, welding a nut on the outside and usung a magnetic oil drain plug.

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ShaunE

Older models of the "Big BGB" tractors have a pipe plug threaded into the back plate.  I have one that I use as a template to drill & tap a plug into the newer ones without such provisions.

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LMichaels

Well I have the new bronze bushings for the king pins coming hopefully tomorrow. Once they get here I think I will put the machine in the garage and get after the BGB (still not sure what I will put in it though leaning toward synthetic differential/gear lube) and get the new bushings in

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Bill725

LMichaels,

Consider installing thrust bearings between the bottom of the spindles and the front axle tubes. Order (2) Koyo NTA-1220 thrust bearings, (5) Koyo TRA-1220 0.030" thick thrust washers (2 for top & bottom of each thrust bearing and (1) for the top of the RH spindle) and (2) DCM Classics BR269-CS 1.5" wheel cylinder cup seals. Order the seals on line at dcmclassics.com. I bought thin wall tubing the same OD as the axle tube and put a knife edge on one end and use it as a punch to cut the center out of the seals. You will be happy as to how nice it will steer afterwards.

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rbstuartjr

I did this on on my 910 6 speed which did do a lot of snowblower work with a 42inch blower and it did help. It all does fit in there. Although my new to me Sovereign still turns nicer without this mod than my 910 with the mod. There’s just a lot of wear on my 910. 

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PhanDad
2 hours ago, LMichaels said:

How does this all "fit"? It doesn't look like there is any extra "space" for all this. Would like to see photos

See this post:

https://simpletractors.com/forums/topic/40296-poor-mans-power-steeringeasy-mod/

This post has some other details:

https://simpletractors.com/forums/topic/48138-poor-man-power-steering-issue/

 

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PhanDad
2 hours ago, LMichaels said:

How does this all "fit"? It doesn't look like there is any extra "space" for all this. Would like to see photos

In your last fall post about worn spindles pics of the dust seals are shown:

https://simpletractors.com/forums/topic/62004-worn-spindles/?tab=comments#comment-495081

 

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Tom45

When I did it on my 7117, the left spindle did fine since you can shift the spindle arm for clearance.  There was no extra space on the right spindle without grinding on the axle, so I left the normal washer.  I used a cut off piece of bicycle inner tube for a seal.  

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Bill725

Replace the OEM washer on the top of the RH spindle with a Koyo TRA-1220, 0.030" thick, thrust washer, and no modifications such as "grinding on the axle" are required.

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