Technical T-5 disassembly trouble - I need advice

I don’t think Alchemy was arguing, just asking politely for confirmation. If I opened a trans and found ATF, while being told that it should be GL4, I’d want to confirm it too. The follow up info on NWC / no bearings / needs GL4 vs. WC / bearings / needs ATF is great, because it gives a way to distinguish one from the other and conform what fluid should be installed.

 

Yes, I wasn’t arguing, I just wanted confirmation from the expert. Even if the last guy who filled this trans did it wrong, I wanted to be sure I did it correctly.

I want to also point out an error in one of those videos posted above. The tech disassembled a NWC and pointed out the worn snout of the main shaft. He said it was because the trans had gear lube in it but should have used ATF.

 

That happens when you put gear oil in a WC T5.

Gear oil will not flow well into the tiny needle bearings between the main gears and main shaft. The clearances are very tight.

 

That tech in the videos posted above is Paul Cangialosi. He literally wrote the book on building performance T5 transmissions. He has built winning performance race boxes all over the world. He is the one who originally designed the WC t5 billet steel counter plate that everyone has copied since the 90's. I have been building T5's and manual transmissions for over 20 years. Running ATF in NWC t5's has been argued for years. From my experience it is better to run ATF than gear oil. However I recommend Royal Purple Syncromax or something similar. You sound like you are new to the T5 world, My advice if you are going to complete the rebuild yourself is to watch Paul's videos and follow his advice to the letter and you will be just fine. Also if you need any help or advice feel free to message me.

 

Yes it has been argued for years.

A great many people are very fervently wed to never admitting that they are wrong.

ATF, again, was responsible for thousands of NWC T5's being replaced under warranty.

I'm not making this up.

ATF is between 5W-10, and 5W-20.

The required lubricant is 70W.

 

Agh! Now what do I do?!

The guy that wrote the book about rebuilding these transmissions after they were worn out. Vs. the engineers who designed the things in the first place.

 

I run Pennzoil Synchromesh in my None WC T5:

Pennzoil® Synchromesh fluid is a manual transmission fluid designed for certain manual trans axles and manual transmissions used by general motors or Chrysler.

• 
  Excellent yellow metal compatibility
• 
  Meets GM specification 9985648 and Chrysler specification MS-9224
• 
  Excellent synchronizer performance
• 
  Exhibits excellent low-temperature performance

 

Bone fides and facts vs. folklore with no end in sight.

 

When Covid hit, I was teaching a Manual Drivetrain class. We used WCT-5's for manual transmissions lab. That lab was scheduled for after the shut down. Best I could do was find a video and make up a work sheet to make sure they watched it and understood what they were seeing. (Yes, the students got cheated, big time!) I picked the Junkyard Doggs. He seemed more novice oriented, explaining every step and piece and adjustment.
I can't fault Cagialosi's knowledge or expertise. The difference maker, for me, was when he was setting the preload on the bearings on one of the shafts. He rotated the shaft and said, "I think this needs xxx more thousandths of shim." After changing the shim, he rotated the shaft again and declared, "That feels right." No video is going to give you that feel. The novice needs specs and measurements.

 

Gimpy, You are correct about GM using 70W gear oil in NWC units. I personally don't rebuild very many NWC units these days but about 10-12 years ago I still did quite a few. The ones I have done in the last 10 or so years I told my customers to use Redline or syncromesh or Royal purple Syncromax. I let them know up front that if they used gear oil It would Void any kind of warranty I gave them. I have not had any units come back accept for one that was involved in a crash and it was brought back to me so I could swap it into another maincase. When I opened it up everything looked normal. I don't know how many miles he had on it and didn't think to ask him but there was no issues that was concerning to me. From some of your previous post I know you are a Die hard GM guy, And I am not trying to debate GM's recommendations. I am just speaking from my own personal experience. Since I make and sell the closed drive adapters for the Jeep T5's now. I recommend to my customers to stay away from gear oil. A good friend of mine is running a synthetic ATF in his S10 T5 and has had No issues. And he drives his coupe everywhere and has been on many long distance trips in the last 8-10 years.

 

When a vehicle comes into a service bay, it is really easy to check the mileage. If it is fully plausible that it indeed has less than 30,000 miles on the odometer, and the transmission is shot, there has to be a reason.

If you pull the drain plug and find Dexron II or Dexron III, then what?

That is exactly what GM witnessed. This happened with the T4 and the T5, very shortly after the WC versions were first made.

When you put a T5 on the bench, irrespective of the type, you may have recorded the mileage of the vehicle that it came from, but you will have no way of knowing if it is original, a warranty replacement, or on its 14th rebuild.

You, and they simply cannot know.

"Had ATF in it and it was not too bad inside" means nothing if you do not know the exact history of the transmission. The only time that it may have been possible to do that is when a vehicle was new, and still under warranty.

When that was the case, ATF killed a whole ton of NWC T5's, and it is still is.

The problem now is that we are taking anecdote as gospel from those working on ones with no known or knowable history, or who put 1,000 miles on them per year. Neither of those two scenarios, or similar ones actually could produce statistically significant data.

All of the statistically significant data under controlled conditions was already gathered long ago.

A NWC and WC T5 might as well be two totally different transmissions. They are that far apart in design and lubrication requirements.

If you run ATF in a NWC T5 it is a matter of power application, mileage, and driving style.

If you run API GL-5 hypoid gear oil in one, it is only a matter of time.

 

Do your own research and decide what is best for you. One thing to keep in mind is Borgwarner stopped making the NWC T5's in 92 and made all T5 units WC. There is a reason for that! Tremec Bought the T5 line from Borgwarner in 1994 and stopped making any replacement parts for NWC units. I am happy to help you in anyway I can. And would be happy to put you in touch with a buddy of mine who has been running ATF in his coupe for 8-10 years and has logged many miles on it.

 

One thing to keep in mind as trans failure goes is it also depends on what engine you are putting in front of a NWC T5. The Reality is the NWC T5 started getting a bad rap from the camaro with a 305. In 1988 GM replaced the NWC uint in the camaros only with a WC unit. They still left NWC units in the S10's until 92. That is because the S10 didn't have enough power to do any damage to them unless you just did not know how to drive. What I am saying is basicly if you are putting a NWC t5 behind a flathead you will be ok with 70W gear oil. But If it were me I would still use Royal purple as you will also be ok. As said above Paul (who made that video above) is no clown when it comes to T5 transmissions. Look him up and see what he has built and done for guys all over the world and decide for yourself if you should listen to what he says to use.

 

The "no gear oil" recommendations come directly from one thing.

If you go down to your FLAPS (friendly neighborhood auto parts store), and look at the gear oils, you will find just one thing in conventional gear oil.

That one thing is hypoid gear oil. Hypoid gear oil belongs in one place, and one place only, a differential.

There is not one single hypoid differential that I have ever seen that has a brass part in it from the factory. Even the vents are steel.

Why is this the issue?

It is near-impossible, to actually impossible to find a gear oil on the shelf that is not API GL-5, or now even higher.

That which makes hypoid gear oil hypoid gear oil, and the best thing for a differential is that additive package.

The concentrations of additives, commonly known as the EP (Extreme Pressure) package is largely derivatives of dithiocarbamate (an analog of a carbamate in which both oxygen atoms are replaced by sulfur atoms) and actual sulfur.

Those compounds destroy brass. It does not even take operating conditions to see this damage happen, only exposure over time. Heat and pressure accelerates it. Humidity accelerates it.

https://hero.epa.gov/hero/index.cfm/reference/details/reference_id/1712250

If you want API GL-4 (the highest rating for devices with yellow metals like brass present), you have to seek it out, and more than likely order it.

Casual users do not do this. When they make that mistake, they make warranty claims.

Redline MTL, GM Syncromesh or Royal Purple Syncromax all do NOT have the EP package. They are all API GL-4, or equivalent. That is why you are seeing success.

I am not a "die hard" GM guy.

I am an Automotive Engineer, and now former third-generation Engineer at General Motors. I hate that I have to keep reminding people that I am not some shade-tree dude down the old county road.

I don't need someone's "opinion". I worked directly with the Borg-Warner engineers that designed this entire line of transmissions. They are the authority here.

 

Ok, we’ll get one of these in a 70 weight. Thanks