Towing with T56

[CDeeZ]

It's called sarcasm. Maybe you should learn to recognize it. And then maybe not take yourself so seriously?
Let me restate this yet again
"
These are facts:

My fullsize truck, that wasn't supposed to have a T56 from the factory, now has it.

Scored a USED T56 on craiglist and installed it.

FIVE years later, after much daily driving and spirited driving ( I haven't been nice to my T56), and some occasional towing, still going strong with no sign of failure. That's not good enough of course. Not space age technology......

You're the one with the labratory obviously, why don't we use that for your uber scientific analysis?"
I think you grossly misinterpreted my post. Some of that might not be your fault beacuse this deal is a lot like text messaging. There is no context when you're not talking face to face.
Ang again here we go copying and pasting: that is not the only time I have towed with the T56 since swapping it. It was the MOST RECENT instance. So get off the 100 odd miles of towing like it's the only towing this trans has done.
The reccommended service interval for the T56 staight from GM is to only ever top off the trans if needed, not to ever change the fluid. Myself? I change it every 5,000 - 10,000 miles. Does it need it? Probably not. But I have the peace of mind of knowing that for a few bucks in fluid the trans should live that much longer.
At the end of the day people like you will always nitpick some little trivial detail and try to blow the whole thing wide open, because you have nothing better to do.
I have said multiple multiple times: unfortunately the only data I have on this one is real world experience. By itself it's not the be all end all but it does give an indication of what you can realistically do in the real world. It is, one piece of the puzzle figuratively speaking.
Mr Plow speaks of a pump and cooler. AFAIK, he never used one, just commented to the effect like "hey if you're going to run a T56 in a 6,000 LB bus like my suburban, and you want to do towing regularly of things in the neighborhood of 13,000 LBS; a cooler and a pump would be a good idea". Not sure what gear he towed in, I'm assuming he made use of either of the double ODs.
Torque multiplication is key
. If you gear your axle properly to match the deep ratios of the T56 and the tall tires typical of trucks, you can tow anythign WITHIN REASON. Before I had the 4.88s I run now, I had 3.08s from when the truck was an auto, and with the T56 and 3.08s: you had to slip the clutch alot in 1st to get going, and 6th was all but useless, and forget about towing with those 3.08s cuz it's not happening.
The T56 is not a towrig transmission. Noone has tried to say it should be used in semis and 1 tons and combines. But it is a beefy trans that can hadle alot of what is thrown at it, if you're smart about it.
I drive at least 200 miles every week for my job, if not even more than that. It was a little over a month ago that I drug this truck back. So IF, something was hurt from towing, I think it would have already reared it's ugly head.

[S10LS]

So whats the point of the thread? Are you recomending that people will have no issues towing heavy loads with the t-56? Or is it a thread saying I towed with my T-56? The 4.88 gear might help save the t56. But who wants to tow with 4.88 gears? I could tow 6 times the rated capacity with my old nv1500 as well. At least it has a towing rating. No data to back up any claim you are trying to make, without at least LONG term towing is not really that helpfull. If you are doing it to just mess around an see what it can take then thats cool. But to get your feelings hurt when someone is challenging your finding especially when their statement is that no full size truck came with one for towing is a bit rediculous. All kinds of data would be helpfull from exact combo you are running to the fuel mileage your getting, to a serious longevity test.

[S10LS]

"Torque multiplication is key". Probably the key to keeping it together. Keep the thread updated so we can see how it does.

[CDeeZ]

The point of the thread was just to show what I did. I'm not reccommending anyone do anything other than use common sense.

The 4.88s are perfect for a vehicle with a deep gearspread in the trans (T56) and tall tires 29" or above.

"But who wants to tow with 4.88 gears" Elaboration????

The fact that the T56 was not given a towing rating is kinda irrelevant I think, a simple quick search on google will turn up plenty of people who have towed with a T56, including Mrplow in his 6,000 lb tank.

There is data in the form of real world experience. I have towed a pile of axles, motorcycles, engines, etc. This was the most recent and probably the heaviest tow so I chose to report it. When did real world experience become "not-data"?


Like I said I've been beating on this craigslist T56 for 5 years and have done some occasional towing during that period so I think if towing was going to break this T56 it would have done that in the course of 5 years.


And as far as the oil analysis data and everything else you guys are talking about. Great idea. Do either of you work at Conoco or something because I don't have access to anything like that.


Fullsize trucks did come with the T56 , the SRT10. GM toyed with a concept truck that also used the T56 in a stripped down, vinyl floormat fullsize truck. (Never made full production unfortunately).


The drivetrain combo is a 350 TBI that I screwed together maybe 6 or 7 years ago. ~ 300-350 HP and 400-450 LB/FT est. Elgin cam, ported and polished heads, Ultimate TBI mods, AFPR, TBI and pod spacers, .060 over, HVOP, midlength headers with H pipe and full dual 3" pipes, ported and relieved oil return holes in lifter valley, 7427 PCM swap and DIY tuning. T56 trans obviously. 14 bolt semi floating 9.5" ring gear with 4.88s and Detroit TrueTrac. 3/4 ton brakes all around.

[EagleMark]

Watching trans oil temps while towing in 4th, 5th and 6th gear would at least say a lot of what the trans is doing with the load and if oil is being heated past it's tolerance.

Oil analysis can be mailed in by anyone to various companies for engines, not sure who does trans? Diesel shops regularly use analysis at service intervals to see what is wearing in motor.

[RobertISaar]

im'ma just do some math here, because i'm curious about this myself:

T56(no model specified, so i'll assume a 95ish LT1 F-body unit for gearing purposes):


NV4500(i'll assume another 95 unit, MT8 RPO):


it's too bad the graph function isn't working at the moment.... it's nice to visualize it as well.

but those are with the same 4.88 gears(and 28" tire). as far as the highway(55MPH) is concerned, 5th in both is 2350-2400 RPM, but the T56 has the option of 6th gear when possible, RPM would drop to just over 1600.

to match the same RPM as the T56 6th gear, the NV4500 would need to use 3.35 final gears. i don't know if this is realistic/normal or not.


anyways, from a purely mathematical perspective..... the T56 gear spacing is VERY nice, has fairly consistent ratio changes, which would certainly help keep the engine in its powerband at any time. the NV4500: not so much. shifting at 3000 will land you anywhere from under 1500 to 2200 in the next gear. some gears, you would need to wind it out a lot further than others to keep the engine from dropping to too low of a speed in the next gear.



as far as the hardware holding up, i won't speak of it, neither the T56 or the NV4500 is anything i have experience with nor knowledge of. i'm much more interested in seeing how to stuff a T56 into a 4WD S10 chassis with a heavily boosted V6 in front of it for my personal use.

[CDeeZ]

I would think that any place that analyzes oil should be able to do trans fluid as well, it's still oil after all, just with some hydraulic fluid mixed in as well.
My T56 is the 95+ model with the 2.66 1st. I believe that is the most common gear spread for T56s, not sure on that one though.
As that shows, the NV4500 has that short 1st gear which would be very helpful in getting a very heavy load moving, and as you pointed out, 5th is nearly identical.
"
anyways, from a purely mathematical perspective..... the T56 gear spacing is VERY nice, has fairly consistent ratio changes, which would certainly help keep the engine in its powerband at any time. the NV4500: not so much. shifting at 3000 will land you anywhere from under 1500 to 2200 in the next gear. some gears, you would need to wind it out a lot further than others to keep the engine from dropping to too low of a speed in the next gear."
The same closely spaced gears that are enjoyable to just drive/hot rod around in are also helpful when towing because as you stated, it will help keep the engine in the fat spot of the powerband each and every time you shift.
The NV and T56 are both great gearboxes. Just depends on what you want to do the most. Do you want mainly fun cruising from a brick-shithouse-tough trans that shifts like a sports car and can still do some occasional towing. OR, do you want a true truck trans with that granny 1st gear to really get the load moving. The NV is a wonderful box and certainly has it's place, but it will never have the shift feel and shift throws of a T56 (obviously). Don't anyone misunderstand me, the NV is a great box.
　
There are/have been/will be some companies offering 4wd T56, not sure if it's available yet? Anyways I have thought much about a 4wd T56 myself, and I know there are people out there who have done it; I believe it usually involves running a divorced T case but check this out
http://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja &docid=9Wt6w2tujfFoNM&tbnid=Lrp-I4q_SnSRUM:&ved=0CAUQjRw&url=http%3A%2F%2Fgrassroo tsmotorsports.com%2Fforum%2Fgrm%2Fcyclonetyphoon-clone-on-a-budget%2F22144%2Fpage1%2F&ei=LWWvUpqZGfTTsAStp4CgD A&bvm=bv.57967247,d.eW0&psig=AFQjCNHrmxo31kDBz7PBX 5FU3MmghzvSBQ&ust=1387311334351554

[steveo]

i can stab my tire with a knife several times without it failing, does that mean

- it definitely wouldn't fail in short order if i keep doing it?
- someone else with a different knife might puncture it on the first try?
- you were perhaps, even subconsiously, stabbing it like a wuss trying to prove your point?

using the thought process "i've done it a few times and it hasn't broken yet" as a metric for component strength and longevity...... is that good?

just sayin'