ATF in manual tranny - Fuelly Forums

Click here to see important news regarding the aCar App

Reply
 
Thread Tools Display Modes
 
Old 04-21-2008, 11:46 AM   #1
Registered Member
 
bzipitidoo's Avatar
 
Join Date: Jan 2007
Posts: 112
Country: United States
ATF in manual tranny

I've been using automatic transmission fluid in an old car (a '67) with a standard transmission. The manual says it should have far heavier 80W or even 90W oil. After many miles and years (approximately 20000 miles and 8 years), seems like ATF (Dexron III Mercon) works just fine. I was worried ATF could somehow cause extra wear or other problems.

As to the benefits, I unfortunately don't have hard data to tell how much it affected FE. I can say that it made the gears much easier to shift. 2nd gear especially was getting very hard to shift into, taking a lot of force on the gearshift to do it. Started by being hard to shift into 2nd while cold, and had gotten to the point of being hard to shift when warm and nearly impossible when cold. ATF solved that problem.

Since I had the transmission out last weekend, thought I'd take a pic of the gears so you can see for yourself. Didn't see any metal particles in the fluid.

__________________

bzipitidoo is offline   Reply With Quote
Old 04-21-2008, 01:20 PM   #2
Registered Member
 
Join Date: Apr 2008
Posts: 1,264
Country: United States
Location: up nawth
Chrysler recommended ATF in their manuals in the 60's.
I learned about the BMW requirements the hard way, mineral oil or you get to replace the synchros.

regards
gary
__________________

__________________
R.I.D.E. is offline   Reply With Quote
Old 04-21-2008, 01:44 PM   #3
Senior Member
 
Join Date: Aug 2012
Posts: 261
Country: United States
Location: The slums of Beverly Hills
How about ATF in the differential? Pretty much all FWD automatic and manual transmissions use the same oil to lubricate the gears and the diff. I was thinking about using atf in my RWD bmw differential.
dieselbenz is offline   Reply With Quote
Old 04-21-2008, 02:41 PM   #4
Registered Member
 
GasSavers_Erik's Avatar
 
Join Date: Nov 2006
Posts: 1,027
Country: United States
Personally I'd hesitate to put ATF in a rear differential on my vehicles because of the risk of extra wear. Since the power is being rerouted at a 90 degree angle, the ring and pinion gears have a whole different set of sliding stresses on them (the gears slide across each other rather than just meshing).

It probably would increase mpg though.
GasSavers_Erik is offline   Reply With Quote
Old 04-21-2008, 03:03 PM   #5
Registered Member
 
Join Date: Nov 2007
Posts: 1,111
Country: United States
Send a message via AIM to dkjones96
Quote:
Originally Posted by tjts1 View Post
How about ATF in the differential? Pretty much all FWD automatic and manual transmissions use the same oil to lubricate the gears and the diff. I was thinking about using atf in my RWD bmw differential.
Careful, if it's an open diff you'll probably be okay but a limited slip rear end would probably die with ATF back there. IMHO if you want a thinner oil back there go with a light synthetic motor oil back there. ATF is more of a friction modifier than a lube.
__________________
- Kyle
dkjones96 is offline   Reply With Quote
Old 04-21-2008, 03:21 PM   #6
Senior Member
 
Join Date: Aug 2012
Posts: 261
Country: United States
Location: The slums of Beverly Hills
Yeah theres a lot of issues with the ideas. I have a spare diff in the garage so I might sacrifice this one in the name of science. Its an open diff by the way.
dieselbenz is offline   Reply With Quote
Old 04-21-2008, 03:34 PM   #7
Registered Member
 
GasSavers_RoadWarrior's Avatar
 
Join Date: Feb 2008
Posts: 1,652
The fact that ATF has friction modifiers is what saves synchros from burning up... a fact a lot of people miss when putting synthetic motor oil in the tranny.. it's lubricant properties are pretty high usually too, due to being made from Group III high VI oils, the ones that are practically synthetic... limited slip diffs with clutches probably suffer from not enough friction modifiers, there are special diff additives that are meant for that.

BTW, my trannies are getting TDH UTF at the moment, TDH universal tractor fluid. Generally, it has higher heat tolerance, better lubricity, better quality base oils and damn good detergent and friction modifier packages (it's designed for wet brakes and clutches) .. and the best bit is, it's half the price of generic ATF. Don't use it in anything that NEEDS ATF+4, Mercon V or Type F, but anything that uses regular ATF will probably like it a lot.
__________________
I remember The RoadWarrior..To understand who he was, you have to go back to another time..the world was powered by the black fuel & the desert sprouted great cities..Gone now, swept away..two mighty warrior tribes went to war & touched off a blaze which engulfed them all. Without fuel, they were nothing..thundering machines sputtered & stopped..Only those mobile enough to scavenge, brutal enough to pillage would survive. The gangs took over the highways, ready to wage war for a tank of juice
GasSavers_RoadWarrior is offline   Reply With Quote
Old 04-22-2008, 08:35 PM   #8
Registered Member
 
VetteOwner's Avatar
 
Join Date: Mar 2007
Posts: 1,546
Country: United States
also remember that any oils fluids nowadays are far better than what they had back then...
VetteOwner is offline   Reply With Quote
Old 04-23-2008, 08:24 AM   #9
Registered Member
 
Danronian's Avatar
 
Join Date: Aug 2007
Posts: 652
Country: United States
A popular "band-aid" to worn sycros in a Honda standard trans is to use GM syncromesh ATF fluid.

I've done it already and it did help the syncros work smoother.
__________________


On the never-ending quest for better gas mileage...
Danronian is offline   Reply With Quote
Old 04-23-2008, 04:39 PM   #10
Registered Member
 
Join Date: Dec 2007
Posts: 170
Country: United States
I used GM Dexron in a Borg Warner T5 manual for more than 350 000 miles with no problems at all.
I changed it every 60 000 miles along with the diff oil as a matter of routine.

Pete,
__________________

GasSavers_Pete is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Can we disable hashtags? Helltime Fuelly Web Support and Community News 3 06-23-2013 05:48 AM
Basic Stats darkangel7 Fuelly Web Support and Community News 2 11-21-2010 04:29 PM
How Much Do You Think This Vx Is Worth! panamacolin General Fuel Topics 20 09-10-2007 05:09 PM
Thank Uncle Sam for high gas prices bear15 Automotive News, Articles and Products 9 08-15-2007 07:43 AM
Poll: Should Stability Control be Standard rh77 General Fuel Topics 14 09-30-2006 09:44 PM

» Fuelly iOS Apps
Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 09:20 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.