BGB Oil Change

[Terry_Hart 0]

How often do you change the gear oil in the BGB. I have a Sovereign with an 18 hp Kohler and changed all the other fluids this weekend and didn't see a drain for the BGB? Also what do you use for gear oil?

[OrangeMetalGuy 20]

On mine, there is a drain plug on the side facing the transaxle. If you don't have one you will have to loosen the cover itself to allow it to drain. Use SAE 90 wt gear oil in the BGB.

[Terry_Hart 0]

If I loosen the plate and let it drain, do I have to replace the gasket?

[PhanDad 3,251]

As stated above, on the newer tractors, you have to loosen the rear cover plate to drain the fluid because there isn't a drain plug for the BGB. It's messy and the cover will weep for awhile, I speak from experience. I didn't replace the gasket. The recommended fluid for the BGB on newer tractors is "multi-purpose powertrain oil" (hydraulic/transmission oil), same as used in the Sundstrand hydros. Older gear boxes used 90w gear oil.

[Terry_Hart 0]

Anyone have experience with synthetics in the gearbox?

[pungo 1]

I have used Dow Corning Gear Oil Additive in a Red Belly 8n Ford gearcase with great results as far as shifting-chatter-noise reduction. Then again,STP oil treatment is also great in worn gearcases like Volkswagon transaxles.

[MikeES 417]

I use Mobil Synethic gear lube in all of my tractors (11) with not problems. They spin easier in the winter also.

[1969nicholas 0]

I run Exxon Moble synthetic 50wt in my newer bevel boxes late 80's and 90's and straight 90wt in the older bevel boxes 1960's abd 70's

[Terry_Hart 0]

Mike what weight Mobile 1 gear oil do you use?

[DanD 9]

I have Mobil 1 75W-90 in the BGB on my 7016. Used it because I run the tractor in the winter for the snowblower. Of course all the BGB does on mine in the winter is run the hydrostat pump as the blower itself runs off the front PTO.

[MPH 12]

I've used Syn gear lube in all ,y BGB and trannys since I got ,my first one, like 8 years ago. I use either Amsoil 75-90 or Valoline since I can buy it here in Tok.

[Terry_Hart 0]

How does it take to fill it after draining it?

[Brettw 1,019]

The question was: How often do you change the gear oil.... My answer would be every other year.

[Terry_Hart 0]

I went out and checked the BGB, no drain plug in the rear plate. I guess I will have to get a gasket and drain it. Then re-fill with synthetic. I still need to figure out how much to add.

[MikeES 417]

The BGB holds 16 oz.

[Terry_Hart 0]

Stoped at the dealer today to get the gasket. They told me to use the same fluid as in the hydro.

[BobT 0]

In a previous discussion of bevel gear lube, some people felt that the bevel gears held up better when lubed with 80-90W rather than multi-purpose fluid. They indicated the change to multi-purpose fluid during production may have been more for convenience than longevity. I use synthetic 80-90W in my bevel gear box (per the manual recommendation).

[jlasater 205]

The manual for my 716H lists Dexron fluid, same as in the hydro.

[HubbardRA 19]

I run 80W-90 in all my tractors including the AC 716H and 713S. I know a guy who rebuilds automobile transmissions. He eliminates the tranny fluid and uses a mix of 80W-90 and motor oil in the newer 5-speed trannys for automobiles. He told me he saw a lot of wear with the automatic tranny fluid, but had gone into several that he had changed over, after a few years of operation, and the wear was essentially non-existent. He said automatic tranny fluid would get you 5-10 years max in a 5-speed, while a mix of true oils will get 20-30 or more years of wear. He said that still didn't fix the loose nuts behind the wheel that usually break the trannys.:D We have put the oil mixture in two different 5-speed trannys, and they work great and appear to shift much easier with the detents feeling more solid. I know this was a little off topic, but I was trying to illustrate the benefits of using the oil, instead of automatic transmission fluid which has friction modifiers to make the clutches in the auto tranny hold better, but can also cause bearing and gear wear in manual gear boxes. Keep in mind that today factory units are only designed to last for five years. Long enough for you to fall in love with the unit, so you will buy another when it breaks. Nowadays most people will replace rather than repair if the unit is five years old or more.