Go Back   The Ford Barn > General Discussion > Early V8 (1932-53)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 06-23-2016, 04:01 PM   #1
Ford Freak
Senior Member
 
Join Date: Feb 2013
Location: Pittsford NY. USA
Posts: 1,094
Default Tranny experts - ATF in 39 trans ??

I know that some of the todays modern transmissions call for ATF in them .
After telling an "old timer" of my downshifting problems (grinding going from 3rd to 2nd) in my recently rebuilt tranny , he suggested using ATF in it . I had never heard of this before . He says it won't hurt it , just might leak a little .Is this a common practice ? For the record , I have tried 90wt. & 140wt. , and it made no difference . Thoughts ?
Ford Freak is offline   Reply With Quote
Old 06-23-2016, 04:04 PM   #2
Seth Swoboda
Senior Member
 
Seth Swoboda's Avatar
 
Join Date: May 2010
Location: Southern Illinois
Posts: 3,744
Default Re: Tranny experts - ATF in 39 trans ??

I suspect something other than a problem with the transmission gear lube. A properly built and functioning 39 transmission should not have this problem on a down shift, assuming that your are attempting the down shift at an acceptable speed or RPM range. My '39 transmission does not have this problem.

A call to Mac VanPelt may help you further trouble shoot the problem.
Seth Swoboda is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 06-23-2016, 04:04 PM   #3
trainguy
Senior Member
 
trainguy's Avatar
 
Join Date: May 2010
Location: Lehighton Pa
Posts: 1,085
Default Re: Tranny experts - ATF in 39 trans ??

I think it will leak a LOT!!
trainguy is offline   Reply With Quote
Old 06-23-2016, 04:23 PM   #4
cmbrucew
Senior Member
 
cmbrucew's Avatar
 
Join Date: Dec 2010
Location: North of sandy ago, CA.
Posts: 2,063
Default Re: Tranny experts - ATF in 39 trans ??

Quote:
Originally Posted by Ford Freak View Post
I know that some of the todays modern transmissions call for ATF in them .
After telling an "old timer" of my downshifting problems (grinding going from 3rd to 2nd) in my recently rebuilt tranny , he suggested using ATF in it . I had never heard of this before . He says it won't hurt it , just might leak a little .Is this a common practice ? For the record , I have tried 90wt. & 140wt. , and it made no difference . Thoughts ?
Adjust your clutch to 1" to 1 1/4" free play. After you get used to shifting you can do it without using the clutch.
Bruce
__________________
Works good
Lasts long time
cmbrucew is offline   Reply With Quote
Old 06-23-2016, 04:46 PM   #5
Mac VP
Senior Member
 
Mac VP's Avatar
 
Join Date: May 2010
Location: Cincinnati, OH
Posts: 1,356
Default Re: Tranny experts - ATF in 39 trans ??

Some of the new synchros sold are not up to par. Assuming that the clutch is adjusted correctly, I'd guess the synchros were either not replaced, or were the poorly made type.

PS....do not use ATF trans fluid in that transmission. Regular gear oil (GL4 spec in a 140 wt)
__________________
VANPELT SALES LLC
Cincinnati, Ohio
Office: 513-724-9486
www.vanpeltsales.com
www.classictransmission.com
Mac VP is offline   Reply With Quote
Old 06-23-2016, 04:58 PM   #6
Ford Freak
Senior Member
 
Join Date: Feb 2013
Location: Pittsford NY. USA
Posts: 1,094
Default Re: Tranny experts - ATF in 39 trans ??

Sponsored Links (Register now to hide all advertisements)
Quote:
Originally Posted by Seth Swoboda View Post
I suspect something other than a problem with the transmission gear lube. A properly built and functioning 39 transmission should not have this problem on a down shift, assuming that your are attempting the down shift at an acceptable speed or RPM range. My '39 transmission does not have this problem.

A call to Mac VanPelt may help you further trouble shoot the problem.
What is a "reasonable" speed & RPM to be able to downshift this particular trans ?
Thanks for all the reply's so far , guys !
Ford Freak is offline   Reply With Quote
Old 06-23-2016, 05:15 PM   #7
corvette8n
Senior Member
 
corvette8n's Avatar
 
Join Date: Jul 2010
Location: 36 miles north of Albany NY
Posts: 2,931
Default Re: Tranny experts - ATF in 39 trans ??

My mechanic told me that the only reason ATF is used in a modern tranny is to help with gas mileage, not your issue.
corvette8n is offline   Reply With Quote
Old 06-23-2016, 05:34 PM   #8
rotorwrench
Senior Member
 
rotorwrench's Avatar
 
Join Date: Jun 2010
Location: San Antonio, Texas
Posts: 16,371
Default Re: Tranny experts - ATF in 39 trans ??

If you ever open up a trany that uses ATF you may figure out why they use it. Modern gearboxes are an art form in their complexity. They have a way lot more parts in them than the old buggers have. Some of the newer materials that are used require a whole different kind of lubricant to keep things working correctly. The oil being thinner doesn't always help all that much for windage when they are shifted to direct drive or overdrive.

Mac knows where he speaks on blockers. His early Ford transmission rebuild book illustrates how to check the new ones during reassembly. The external conical shape of the gear has to mate well with the conical shape of the blocker ring to be effective at equalizing rpms.

I learned to drive in an old 1952 F3 with the non synchro 4-speed. Besides double clutching, a person gets good at knowing just how much to increase the engine RPM to match the oncoming downshift dogs. In a partially synchronized 3-speed, there should be no trouble selecting the lower intermediate gear from the high one. The blocker is not working as it should if it does have a grind. Low gear isn't synchronized so a little grind going in is not unusual there.
rotorwrench is offline   Reply With Quote
Old 06-23-2016, 05:51 PM   #9
Mart
Senior Member
 
Mart's Avatar
 
Join Date: May 2010
Location: Solihull, England.
Posts: 8,732
Default Re: Tranny experts - ATF in 39 trans ??

Off the top of my head I'd say it would leak like a sieve. The modern transmissions that do use that type of fluid (oil) have much better advances in sealing than our old transmissions.

Mart.
Mart is offline   Reply With Quote
Old 06-23-2016, 06:04 PM   #10
Kurt in NJ
Senior Member
 
Kurt in NJ's Avatar
 
Join Date: May 2010
Location: on the Littlefield
Posts: 6,140
Default Re: Tranny experts - ATF in 39 trans ??

Quote:
Originally Posted by Ford Freak View Post
What is a "reasonable" speed & RPM to be able to downshift this particular trans ?
Thanks for all the reply's so far , guys !

the 39 sedan i drove I would downshift at 40-45 in hills, it was the 60 with the early type syncros,but couldn't just force it ----the 46 with the later syncro I would downshift at any speed even at 50---just jam it in gear and slide my foot off the clutch as I floored it---that trans was made of all used parts, still worked fine when i sold the car
Kurt in NJ is offline   Reply With Quote
Old 06-23-2016, 07:22 PM   #11
Ford Freak
Senior Member
 
Join Date: Feb 2013
Location: Pittsford NY. USA
Posts: 1,094
Default Re: Tranny experts - ATF in 39 trans ??

Quote:
Originally Posted by Kurt in NJ View Post
the 39 sedan i drove I would downshift at 40-45 in hills, it was the 60 with the early type syncros,but couldn't just force it ----the 46 with the later syncro I would downshift at any speed even at 50---just jam it in gear and slide my foot off the clutch as I floored it---that trans was made of all used parts, still worked fine when i sold the car
I have to slow down to about 15 to get it into second from third .
I believe it is time to take it to" Charlie NY ". He is less than 2 hr. away .
Ford Freak is offline   Reply With Quote
Old 06-23-2016, 07:38 PM   #12
Lawrie
Senior Member
 
Lawrie's Avatar
 
Join Date: May 2010
Location: Qld, Australia
Posts: 4,196
Default Re: Tranny experts - ATF in 39 trans ??

we raced an HQ holden in the series here for a few years,using atf in the gearbox was worth some small bits of HP,and you needed all the HP you could get,,I looked inside the box after three years and it was like new.
Lawrie
Attached Images
File Type: jpg IMG_1043.jpg (67.7 KB, 14 views)

Last edited by Lawrie; 06-23-2016 at 07:44 PM.
Lawrie is offline   Reply With Quote
Old 06-24-2016, 10:54 AM   #13
Seth Swoboda
Senior Member
 
Seth Swoboda's Avatar
 
Join Date: May 2010
Location: Southern Illinois
Posts: 3,744
Default Re: Tranny experts - ATF in 39 trans ??

Quote:
Originally Posted by Ford Freak View Post
I have to slow down to about 15 to get it into second from third .
I believe it is time to take it to" Charlie NY ". He is less than 2 hr. away .
Charlie will treat you right. First class service.
Seth Swoboda is offline   Reply With Quote
Old 06-24-2016, 12:31 PM   #14
Mike51Merc
Senior Member
 
Mike51Merc's Avatar
 
Join Date: May 2010
Location: Northeast Pennsylvania
Posts: 1,582
Default Re: Tranny experts - ATF in 39 trans ??

Modern transmissions use carbon-fiber laminate synchros that must have ATF instead of gear oil.

As for the OP, sounds like you may need some new synchros in that trans.
Mike51Merc is offline   Reply With Quote
Old 06-24-2016, 12:59 PM   #15
JSeery
Member Emeritus
 
JSeery's Avatar
 
Join Date: Nov 2012
Location: Wichita KS
Posts: 16,132
Default Re: Tranny experts - ATF in 39 trans ??

Yep, they changed the lubrication requirements when they went to the carbon-fiber synchros.
JSeery is offline   Reply With Quote
Old 06-24-2016, 01:43 PM   #16
rockfla
Senior Member
 
rockfla's Avatar
 
Join Date: Mar 2014
Location: Jacksonville FL
Posts: 3,927
Default Re: Tranny experts - ATF in 39 trans ??

Use a can of STP in it, it will be the smoothest shifting transmission you;ll own.
rockfla is offline   Reply With Quote
Old 06-24-2016, 02:05 PM   #17
Joe Immler
Senior Member
 
Join Date: Dec 2012
Location: Massillon, Ohio
Posts: 783
Default Re: Tranny experts - ATF in 39 trans ??

I think there is/was something called "Double Clutching"?
Seriously, have Charlie look at it .
Joe Immler is offline   Reply With Quote
Old 06-24-2016, 02:33 PM   #18
V8COOPMAN
Senior Member
 
V8COOPMAN's Avatar
 
Join Date: May 2010
Location: East Shore of LAKE HOUSTON
Posts: 11,106
Default Re: Tranny experts - ATF in 39 trans ??

Quote:
Originally Posted by Joe Immler View Post
I think there is/was something called "Double Clutching"?
Yes, there still is "double clutching". Unfortunately, it does NOT fix worn-out synchronizers.........it only allows you to shift in spite of worn-out synchros. DD
__________________
Click Links Below __


'35-'36 W/8BA & MECHANICAL FAN


T5 W/TORQUE TUBE
V8COOPMAN is offline   Reply With Quote
Old 06-25-2016, 09:13 AM   #19
TStiles
Senior Member
 
Join Date: Sep 2012
Location: Kitsap Peninsula, Western WA
Posts: 276
Default Re: Tranny experts - ATF in 39 trans ??

You may also want to investigate top-quality synthetic transmission oils of the proper viscosity (GL4 spec in a 140 wt). This stuff is incredibly slippery, so if any lubricant is going to help resolve your problem, synthetic is your best bet.
TStiles is offline   Reply With Quote
Old 06-25-2016, 10:15 AM   #20
Ford Freak
Senior Member
 
Join Date: Feb 2013
Location: Pittsford NY. USA
Posts: 1,094
Default Re: Tranny experts - ATF in 39 trans ??

I don't believe there is a lubricant that will fix my trans . I do believe there is something wrong mechanically w/ my trans . Probably syncro related .
I was just throwing the ATF thing out there 'cause I never heard of it being used in old trannys . Thanks to all who replied ! - FF
Ford Freak 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

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 08:27 PM.