Bolt-on frame boxing

[scottladdy]

Back to the frame braces. They were installed because the frames were bending there, while being lifted with a crane at GVWR to be loaded on ship/trains.

Thanks,

Do you know when they began to add these? Did they work?

 

[Recovry4x4]

For what its worth, in 1981 GM started using auro locking hubs on their trucks including one tons. A synchro (or the like) was necessary in initiate drive shaft rotation so that the hubs could engage on the 205 trucks. It's possible that this influenced GM along with any means to improve fuel mileage.

 

[The FLU farm]

Back to the frame braces. They were installed because the frames were bending there, while being lifted with a crane at GVWR to be loaded on ship/trains.

That makes sense, Ken. Thanks for the info.
Lifting it would be borderline for my crane, and I have no plans to do it anyway. But since plans are made to be changed, if it got lifted it would be by wheel nets, not the shackles.

 

[scottladdy]

ATF is suitable for gear based transmissions and transfer cases

Please continue with the lesson master. You have our full attention.

Well, since you asked so nicely.

Non-Newtonian fluids in a nutshell defy the expectations of the observer. How could a seemingly thin substance like ATF Hydraulic Fluid protect against shear loads you ask?

Well, for simplicity sake you can break Non-Newtonian fluids into a couple of categories: Rheopectic and Thixotropic.

Thixotropic fluids lose viscosity when a stress is applied over time. Ketchup is a great example of this. This is why you can get ketchup out of a bottle when you smack it. Since it is thixotropic it loses viscosity when placed under stress and comes out of the bottle. Another example is honey which will become liquid when stirred enough.

Rheopectic fluids gain viscosity under stress applied over time.

So, ATF is designed to be Rheopectic. It flows very nicely until placed under extreme stress where the actual viscosity under load can exceed that of gear oil.

A classic experiment used to demonstrate Rheopectic behavior is cornstarch suspended in water. (Rick, can't let you have all the fun with videos now can I? )

https://youtu.be/Vid-Qlr2K-Y

https://youtu.be/RkLn2gR7SyE


https://youtu.be/vsyO8qdqLm0

So, hope that provides everyone with a better understanding of why ATF is a suitable lubricant for a gear based NP205, but why gear oil is not suitable for use in an automatic transmission. While at first observation it may appear that you are changing the laws of physics, as Scotty said so well:

https://youtu.be/nfZ12UGiisM?t=23s

 

[Skinny]

Would an automatic run on gear lube? Apparently you have never taken one apart then. An auto trans is not just gears and bearings. It has friction discs which are engineered to work with a specified fluid that has a specified friction which guess what...works specifically with the friction discs. Not to mention a complex valvebody along with clutches/brakes that require fluid to move very quickly in order to engage/disengage. Not exactly an apples to apples comparison. All of what just went down over what to run in a 205 tcase makes SS look pretty lame. It's a **** gear drive tcase, it would probably be happy with olive oil. This stuff needs to be locked and the thread pushed way back to the end of the pile so that new users don't go through it and assume that everyone here is a chump.

 

[cucvrus]

https://youtu.be/iG9sVvmyqVU?list=RDI5X2BZQNVk8

 

[scottladdy]

Apparently you have never taken one apart then.

Rebuilt my first at 15. Was a TH350. Lost count after 20 ...

All the best!

 

[Skinny]

So then why are stating an idea like putting gear lube in an auto trans which is complete rubbish? This only creates confusion and clutter. NP205 runs on ATF or 75-90, end of story. Only the short bus usual suspects on here have to create a freakin science project out of something so ridiculously simple. Between this and the torque rod, all time SS low...

 

[Rustyshackelford]

I think the whole science thing is a disguise. It's more like bored guys creating drama to give themselves something to be excited about.

 

[rustystud]

For what its worth, in 1981 GM started using auro locking hubs on their trucks including one tons. A synchro (or the like) was necessary in initiate drive shaft rotation so that the hubs could engage on the 205 trucks. It's possible that this influenced GM along with any means to improve fuel mileage.

GM was the only one to have "shift on the fly" NP205 transfer-cases. It was a total flop. They broke so fast and so often they forced to go back to the original NP205 design. They used ATF to help with the shifting.

 

[rustystud]

Why does Ford and Chrysler only recommend that the NP205 use gear oil ? Why is it that GM is the only one who used ATF ?
I said it before, the military wanted a simple system for their trucks. No problems with gear oil contaminating the transmission. There was a Bulletin on that I read a few years ago. In the end it makes no difference what you do. It's your truck do with it as you please. As for those who say all this is just mole hills and mountains. They are the usual ones who say really stupid things just to stir the pot.

 

[rustystud]

View attachment Scan0210.pdf

Another thing you must consider is the make up of ATF and gear oil. Gear oil has "sulfur" anti-wear compounds which help in shifting. Now Automatic transmissions do not shift gears. They use "planetary gear sets" which are always in mesh. As do the newer transfer-cases. Also the newer transfer-cases have clutches which need the thinner ATF fluid. Because of this difference using ATF in a gear only unit like the NP205 will cause higher gear wear. Remember your shifting gears in the NP205 unit (or sliding clutch gears) . I've seen this in my rebuilding of these units. All gears that use ATF have much more wear then any gear unit using gear oil. I've also seen this in the planetary gear sets in all the automatics I've rebuilt. I didn't know until years later that it was due to the sulfur compounds. So if you want your NP205 to last longer use gear oil. Simple.

 

[cucvrus]

It's more like bored guys creating drama to give themselves something to be excited about.

I think the excitement is all you. I know I learned a lot from the gentlemen that are posting facts. NOT a thing from the guys that go on the defense every time someone has documentation that proves the facts. Rustystud Scottlady recovery4X4. Thank you for the chatter. It is useful information. As far as what others looking at the site. I think they see and know who has the experience and who is just trolling and adding worthless argumentative information. Really you think I need something to do? I am doing it every day and still getting time to chat here. And I am sorry if you can't exchange ideas and information in a social media setting. I have met guys like this. Have a great day. Remember cheap talk is just that nothing else. Some times you just have to go out and do things and get things done. Ambiguous information is still great information no less. Thank you. Have a super progressive day.

 

[wuznme]

FYI....The NP205 will not hold 5qts of anything even with a PTO still attached.

FYI II....I used Gear Oil.

Yes, according to the -12 Lubricating Order Dexron II at 5.0 qt or 4.7 L.

Also, in the 1986 Chevy Pickup Trucks Service Manual, Page 7D1-6 205 Transfer Case - Dexron II

View attachment 687011

 

[scottladdy]

FYI....The NP205 will not hold 5qts of anything even with a PTO still attached.

FYI II....I used Gear Oil.

Not sure if you saw it, but I attached the page from the Chevy Service Manual. That states 5.2 pints or 2.6 qts. There are errors in the TM's.

 

[Eliteweapons]

Well, I'm just going to go out on a really shaky limb here and say, if it was feasible then the answer would be yes. You pretty much answered your own question.

It is commonly misunderstood that the shear strength of a fluid is directly related to that fluids viscosity, commonly misstated as a fluids "thickness". Viscosity is more properly defined as a fluids resistance to flow.

Newtonian fluids do have a general behavior that roughly correlates shear resistance to that fluids viscosity. For all Newtonian fluids in laminar flow the shear stress is proportional to the strain rate in the fluid where the viscosity is the constant of proportionality. However, for non-Newtonian fluids, this is no longer the case as for these fluids the viscosity is not constant. The shear stress is imparted onto the boundary as a result of this loss of velocity.

Gear oil is Newtonian. ATF is non-Newtonian. I will save you from all of the math that goes with this unless you really really want to see the formulas involved. But the short answer is that equating the suitability of either of these fluids as a gear lubricant based on how closely they resemble honey flowing out of a jar is based entirely on ignorance and tribal knowledge. It is not based on science, engineering or empirical testing.

Some additional light reading: Low and High Temperature Non-Newtonian Behavior of Automatic Transmission Fluids

Mountains? Molehills? I never get insulted or upset by someone else's ignorance. I provide science and engineering to back up my statements and where I do provide opinion I try to clearly state that. I just try to help out those who are willing to learn. Those that are not, well it is a free country.

And guys, let's try to be fair to Dante's peak. It scored a whopping 27% rotten tomatoes.
https://www.rottentomatoes.com/m/dantes_peak

Funny, the government puts engine oil in the automatic transmission in the M35A3. I converted it to ATF for better road manners and to keep the trans cooler. I personally prefer gear oil to handle the heavy loads and temperatures in the differentials and the T-case. I run gear oil in the np205 in my pickup.

 

[scottladdy]

Why does Ford and Chrysler only recommend that the NP205 use gear oil ? Why is it that GM is the only one who used ATF ?

I think these are great questions. Unfortunately I know I don't have the specific answers and none of us really can know without some form of communication with the manufacturer/engineers at the time (which would include documentation from them). Clearly GM AND New Process/New Venture certified the use of Dexron IIE in the GM units. That is the only fact I can corroborate.

As I have never owned Ford or Dodge products with NP205 TC's I cannot certify that the manufacturers only specified the use of gear oil for all years and combinations. I would look to official manufacturer service and owners manuals to corroborate this. Are these something you can provide as has been done for the GM products?

I do know that Ford stopped offering the NP205 after 1979 in favor of the NP208 unless it was an expensive special order. This is before the GM cut over to ATF.

I said it before, the military wanted a simple system for their trucks. No problems with gear oil contaminating the transmission. There was a Bulletin on that I read a few years ago.

This may be an accurate statement for the military. However, it does not explain why GM changed the specification for their entire fleet.

Any way you can share that bulletin? I think folks would benefit from it.

All the best!

UPDATE! So I reached out to a MOPAR fanboy buddy of mine and he confirmed that Chrysler made the change to ATF at about the same time as GM.

 

[ken]

Scott,
I read they started adding them In 1984. Not long after they went into service. The story I read said they found the problem while loading trucks to go to Europe/Germany. Not all trucks went on RORO ships. They had to unload each truck, then load it on the ship.

 

[scottladdy]

So then why are stating an idea like putting gear lube in an auto trans which is complete rubbish?

Because I am NOT stating that. My exact quote is:

"So, hope that provides everyone with a better understanding of why ATF is a suitable lubricant for a gear based NP205, but why gear oil is not suitable for use in an automatic transmission."

Suggest we all read these postings a little more carefully before making statements.

(I made it really big so you would not miss it this time )

All the best!

 

[scottladdy]

View attachment 687179

Another thing you must consider is the make up of ATF and gear oil. Gear oil has "sulfur" anti-wear compounds which help in shifting. Now Automatic transmissions do not shift gears. They use "planetary gear sets" which are always in mesh. As do the newer transfer-cases. Also the newer transfer-cases have clutches which need the thinner ATF fluid. Because of this difference using ATF in a gear only unit like the NP205 will cause higher gear wear. Remember your shifting gears in the NP205 unit (or sliding clutch gears) . I've seen this in my rebuilding of these units. All gears that use ATF have much more wear then any gear unit using gear oil. I've also seen this in the planetary gear sets in all the automatics I've rebuilt. I didn't know until years later that it was due to the sulfur compounds. So if you want your NP205 to last longer use gear oil. Simple.

Sorry, I have to disagree with a number of these points.

1. No synchronized transmissions shift gears to my knowledge. Instead they engage a synchronizer (typically a cone type device that couples the gear to the appropriate shaft in the transmission made of a much softer sacrificial material). The majority of modern automotive and light truck transmissions use constantly meshed gears whether automatic or manual.

2. Some automatics don't have a single planetary gear set in them (e.g. Honda).

3. Thin vs thick is not relevant as to whether or not these are suitable for the NP205. Nor is the makeup of the fluid, sulfur or not. It is the very fact that these fluids are "different" which is causing this debate. What is important is whether or not these fluids provide the same level of protection. For example both fluids MUST pass ASTM D4172 testing at minimum which dictates the maximum amount of wear that each fluid can allow under controlled conditions. How each achieves this is irrelevant unless the additives cause some other undue harm, in which case they would NOT be certified for use.

4. If both fluids pass the ASTM D4172 then it cannot be the fluid causing any increased wear you may have observed. Did you take into consideration whether or not the gear boxes were properly maintained in your analysis? Were they ever run dry? (I think this is a highly plausible scenario since the at rest viscosity of ATF is much lower and more likely to leak out much more aggressively when a seal no longer seals). Can you show us any pictures of these failures?

Fun facts:
Did you know that 40/50 weight motor oil is essentially the SAME viscosity as 90 Gear Oil?
Did you know that there are currently 3 gear oil standards established by the API in use? Each one has a specific intent.

All the best!