What gear oil to use in 5-speed transmission?

To say that all non world-class T-5's use gear oil just isn't right boys. I have a T-5 out of an '89 S-10. It is non world class. I went to a library several years ago and found an owners manual for an '89 S-10 and it said to use Dexron ONLY.

My suggestion to anyone with a T-5 is to do the same thing - check the owners manual for the donor vehicle.

 

That may be true for all Ford T-5s but I know some Ford pickups had NV4500s and they take a very specific oil.

If a T-5 is rebuilt can it go from non World Class to WC with different parts?

 

ATF here--and don't run it low--ask me how I know. there's a whole thread about it from last year. the short story is it cost me a tranny--not as forgiving as the old toploaders.

 

ATF seems way too thin for a manual trans,would 30# oil be any better.

 

The key word here is "Seems"

I thought the same when I poured this "Runny Shit" [ Mobil 1 ] into a $50K Race Engine.

Even though it is not specified, you can use Dexron in a NWC T5 ,but not the other way round.

Neither oil will cause excessive wear, it is to help the Syncros to work correctly.
I used Dexron in my M22 Road Race Gearbox with no issues

 

Yup, I checked with Napa for my NWC S-10 T5 and they specified Dexron.

 

Good to know.... I use Royal Purple in every stick I change. But I knew there was a variable between NWC and WC, and even sub variables in NWC itself

 

Here's an odd one: Talked to a friend of mine last night, he has an '86 Mustang 5.0 he bought new. At 110K the the T5 started shifting "notchy" so he drained the ATF and put 90w in it! It now has 250K on it, still has the 90w and he swears it fixed the notchy shifting and has had no ill effects. He's just a shade tree mechanic but he did know the trans has some kind of "plastic rings" in it.

BTW the 302 has never been apart, still runs strong and doesn't burn a drop of oil.

 

just do the sniff test, 90w stinks... Sorry to re-energize this old thread but it seems simple, unless you've got a brand new fluid empty trans

 

I just went through this with a used t-5 I purchased from an s-10. I called the chevy dealer mentioned the tag on the side of the trans and he told me he couldnt tell me anything without the vin number off the truck, Huh? Didnt have vin number had id tag.... Not good enough. So I pulled drain plug got sample of oil,smelled like thick tranny oil. Gold in color, used like 70- 85 I think it was and it works great. Non world class. So thins is one question that gets asked a lot. I just went with past practice and it worked out ok. YRUHOT

 

I had an '85 S-15 GMC.. It took ATF also. And it was It is a non world class.

 

Since this thread has been brought back to life I used ATF automatic transmission fluid,a couple of guys here recommended it as did my pal at NAPA.

I can report that in the last 3 years it has worked flawlessly with absolutely no problems whatsoever. HRP

 

My Tremec came with instructions to use GM Synchromesh (GM Part # 12345349 at $20-30 per quart). This is perfect, if your made of money.

 

My lubricants application guide says that 83 - 89 T5 uses a Dexron III type ATF.

 

I use GL4 from amsoil in my sm420 and my diff. Safe for yellow metals and probably $12 a quart. Can't buy it in the store as they will sell you GL5.


Synthetic Manual Transmission and Transaxle
Gear Lube 75W-90 API GL-4 (MTG)

 

I've stepped up to GM Synchromesh fluid. It's clear color and works very well but is very expensive.
My gearbox now is much quieter and shifts much easier with no clunking or odd bearing noises. Well worth the added expense.
Also use it in my Gear Vendors overdrive in my El Camino. It really made a world of difference.

 

ATF

 

I had to research this aswell the trans fluid to use really depends on what style of t-5 you have

I ran into all kind of mis- information and in all honesty the asshole who tells you to put gear oil in it or all t-5s take ATF , isn't going to be with you on the side of the road when it breaks or paying for the rebuild

Synchromesh oil
ATF oil
Motor oil
Gear oil

Were all used in different designs of t-5

Would you put 20-50 in your automatic trans? Would you put ATF in your m22 Muncie ?

To say that one fluid works for all t-5s is incorrect ...do the research and Use what fluid was designed for your model of trans