G56 fill and drain plugs

[kowaliga]

I've the worst luck in my self-service attempts. I purchased a 1/2" drive socket with a 14mm ( or is it 19mm ? ) hex head to remove the plugs. It is the correct metric, but, not having looked before I leaped. . its too long to use on the fill plug ( unless I remove the exhaust pipe ). What works for an '05 model? Thank goodness I didn't drain it.

 

[ToddK]

I have an '06 with the g56 trans. I bought a set of hex drivers from Harbor Freight. They range from 6mm to 17mm and were 10. 00. the 14mm is a 1/2" drive and I put it onto the socket and insert it into the fill plug at an angle then straighten it up. I have done this twice now. The most recent time I had just had a 5" exhaust installed so it was tighter, however it can be done. you may also try cutting part of the tip off of the socket. The ones I have have about an 1" of drive past the socket casing.

 

[Regcabguy]

Geno's G-56 wrench.

I bought the 14mm hex wrench from Geno's. It fits perfectly with no obstructions. Incidentally,I just completed my first oil change using Geno's oil filter wrench. Combined with a 3/8" ratchet and 18" extension,filter was out in a minute. Ziplock bag contained the oil residue.

 

[kowaliga]

Toddk. . I thought to reduce its length. . but tool steel is too tough for me. I'm appreciative Lowerbob, er... Bajabob. . I'll check Geno's. . as I should have initially. Thank you both for taking time.

 

[kowaliga]

I'd like to re-activate this thread now that I've got the 14mm hex wrench.

To check the fill plug's accessibility and removal, I parked on a 10 degree incline with side-to-side esentially level. . nose up if you will. I loosened the fill plug, adjacent to the exhaust pipe, and ATF-4 began to seep out. . so I stopped and re-tightened it. I re-positioned the truck to a 20 degree incline and also put both driver-side wheels in a depression that produced about 20 degrees of tilt. . a nose-up roll to the left. I loosened the fill plug and ATF began to seep again, so I stopped. How do y'all position the trans to be able to re-fill it to it proper level?

 

[AKaiser]

What exhaust pipe? I don't recall having any exhaust pipe issues. Got my hex key sockets at Autozone. What sucked is the fact that the T-Case uses a smaller hex key than the set had. Luckily, Dad had a smaller set that had one on it that fit the T case.

 

[kowaliga]

The fill plug is 2. 5-3" to the side of the exhaust, on the passenger side of the G56. I initially used a 1/2" drive ratchet and 14mm hex-head socket, together over 3" and un-workable. The Geno's specialty wrench does fine, but I want to know how to position the truck for re-filling the G56. . to its proper level.

 

[steved]

You probably got one of the units that had the TSB performed for the overfill.

IIRC the TSB was to address a potential problem with bearings that were not prelubed during transmission assembly, and the fix was to overfill the trans at the dealership... hopefully before it was purchased and driven very far.

You should fill the trans to level with the filler hole (with ATF+4 or a fully synthetic ATF, IIRC).

If you feel like it is needed, you can also over fill the trans... not sure how easy it is on the G56... if you have a PTO that is higher than the fill plug, you could use that. Or you could fill through a bolt in the top cover. Obviously overfilling doesn't hurt anything.

steved

 

[roperteacher]

All I do is park with my right front and rear tires on a 2x4 board. Allows full 6 quarts of fluid to go in the G-56. Actually mine will take 6. 5 quarts when parked level before running out the fill hole...

 

[JGheen]

Since we're on the subject of G56 fill and drain plugs... ... what is the large Torx plug near the top of the side of the trans above the hex fill plug? Can one use that plug to overfill the trans? Not even sure what size that Torx is, gotta be a 40 or 45.



Thanks, Joe

 

[steved]

Since we're on the subject of G56 fill and drain plugs... ... what is the large Torx plug near the top of the side of the trans above the hex fill plug? Can one use that plug to overfill the trans? Not even sure what size that Torx is, gotta be a 40 or 45.



Thanks, Joe

That might be used to retain something in the trans (a spring or such)... be careful if you do decide to remove it...



steved

 

[AKaiser]

Obviously overfilling doesn't hurt anything.

Except fuel economy as a result of excessive "windage" from too much trans. fluid.

 

[kowaliga]

Mine was born in March,2005, well past the stoppage of underfilled G56's that

were shipped in Jan. But, it did come from Mexico so January or March may be interchangable. Thanks for your re-assurance guys, especially STEVED, who advised me long ago to check the fill plug first! I think I'll try positioning front-to-back level, with a driver's side downward tilt, a la ROPERTEACHER 2x4, to see if I can re-fill the drain amount. What seeped out looked like new, but I got 8 quarts of ATF-4 to do something with.

 

[kowaliga]

Except fuel economy as a result of excessive "windage" from too much trans. fluid.

I get close to 21mpg, but I drive s l o w l y ( but I understand your point). Some have over- filled via the shifter boot, but because I'm high most of the time, my dexterity is compromised, not to mention that I forget what I'm doing. Being straight is too intense. Thanks again.

 

[steved]

Except fuel economy as a result of excessive "windage" from too much trans. fluid.

Do you think that has a real application in this case? I mean the fluid is "pumped" through the gear-train at normal levels... there's inherent windage in every manual transmission, its how most of them lubricate.



Or am I missing something?



steved

 

[AKaiser]

Do you think that has a real application in this case? I mean the fluid is "pumped" through the gear-train at normal levels... there's inherent windage in every manual transmission, its how most of them lubricate.



Or am I missing something?



steved

Right, there is inherent "windage" in every manual transmission. We're talking about wet sump systems, not dry sumps. It's not much different from when you overfill any mechanical unit: engine, transmission, T-case, differential. When there's more lube to move, it takes more energy to move it, period. We live with a certain amount of windage because without the lube, the friction from metal-metal contact causes greater power losses than the windage. Above that, we're inefficient.