G56 durability question

[Motorhead]

I have the G56, AE ratio transmission in my truck. Are there any durability issues with this trans? The AE trans is rated for the 6. 7L engine. I realize that an aluminum case isn't as good as cast iron. I will run max a Smarty jr on high setting (100hp) once in a while but mostly on setting 2 (70hp). I was told by that I shouldn't excessively downshift due to lack of good thrust in the trans. Hey, I bought it specifically for the ability to moderately be able to have engine braking with the Pacbrake while towing. I drove stick in UPS trucks for 30 years and only blew one trans in an old Ford Econoline because I was speed shifting it. (I didn't do that anymore!!)

Has anyone put a heavier synthetic lubricant in their G56 than ATF+4?

I realize that this is a broad question on life of the transmission but I would like to see who has how many miles on their G56 and their problems if any.

 

[WOT]

Well if you want to trade it for the other ratio G56 let me know

Seriously, I haven't heard of many failures so I'd say they are pretty stout. I'm now sure if there is any durability difference between the early and late model G56 but I wouldn't think so.

 

[Motorhead]

Well if you want to trade it for the other ratio G56 let me know

Seriously, I haven't heard of many failures so I'd say they are pretty stout. I'm now sure if there is any durability difference between the early and late model G56 but I wouldn't think so.

Well... No, I wouldn't want to trade. I learned on TDR what to look for and what months of production had the AE ratio.
My question is about the overall durability of ALL of the G56's. How many miles on yours?? All of them with Mods??

 

[ENafziger]

The G56 seems to be pretty tough and reliable to about 600 hp. It will hold up to mid 800's using a little caution. I know of some that have been destroyed at 900 hp on the dyno.

Someone else has had repeated problems at around 600 hp I think, but runs 40" tires as well.

If you're only adding 100 hp with the Jr, and don't sled pull, you should be fine for many, many miles.

If you're concerned, there are several things you could do:

1. Synthetic fluid (Amsoil, Schaeffer's, Royal purple, Redline, etc)
2. Increased capacity PTO covers (from Geno's, etc) with extruded finned aluminum for cooling.
3. Someone makes a filter kit that bolts on the PTO cover, but I can't remember who right off.
4. Mike at Lazarsmith makes a heavy steel girdle to add rigidity to the aluminum case.

--Eric

 

[ENafziger]

I've got 57k on mine... about 30k of that at 550 hp.

--Eric

 

[Regcabguy]

transmission filter.

I've got the "manual transmission filter kit" part# K1444-0600-fltr kit: from Genos. I doubt if I'll ever get around to installing it. I did open the box to confirm parts content(for once:-laf). $40 shipped to lower 48. It adds eight ounces to your capacity. PM me if your interested. No paypal sorry.

 

[Okie-Go]

I have 76k on my g-56. Several trips pulling the 5er, delivering gooseneck trailers and in the hay-field. No problems! I keep an eye on the fluid as Changed at 25k and 50k. The fluid looked fine after 25k. Put in amsoil and now will prolly stretch it a bit longer.

 

[WOT]

I have about 42K on it now, about 15K of "bombed" miles. No sled pulls but I do tow a 10K camper (not much these days, maybe 2. 5-4K miles a year - darn fuel prices).

 

[SierraRam]

45K on mine with the SBDD 3850# clutch and no issues so far.

 

[Vaughn MacKenzie]

The G56 seems to be pretty tough and reliable to about 600 hp. It will hold up to mid 800's using a little caution. I know of some that have been destroyed at 900 hp on the dyno.



Someone else has had repeated problems at around 600 hp I think, but runs 40" tires as well.



--Eric

I would be curious to know what gear they were dynoing in. Since 5th is direct it should be able to handle a bunch. Using 6th is asking for trouble at those power levels, OD multiplies stress on the trans.

 

[SShafranko]

116,000 on my G56 and clutch with Edge juice most of the time on level 4 since 50,000. Pull two to three times a month a five ton excavator, cars, and utility trailer. Haven't had one problem knock on wood.

 

[Motorhead]

116,000 on my G56 and clutch with Edge juice most of the time on level 4 since 50,000. Pull two to three times a month a five ton excavator, cars, and utility trailer. Haven't had one problem knock on wood.

That's what I wanted to hear.

 

[Regcabguy]

That's what I wanted to hear.

Yeah!!!!

 

[RVTRKN]

That's what I wanted to hear.

I have both G56(AE) and NV5600 and my opinion both are good trany,s but the Engines are stock. As far as durability goes, it will depend on the user and application you use them in. I do drive in a normal manor and little 4X4ing but I use them for towing and as a service vehicle, so I would have to say I work them hard.