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 09-09-2021, 09:34 AM   #1
drfromnc
Junior Member
 
Join Date: Oct 2017
Location: Smithfield, NC
Posts: 27
Default remove surface rust on transmission gears

I plan to tear down the 39 transmission in my pickup to inspect and replace what i should but how do I go about removing all the surface rust on the gears? or should I just look for something else? I do have several later model transmissions that are side shift. maybe i can use gears and gearsets from them?
Attached Images
File Type: jpg PXL_20210814_223443810.jpg (91.8 KB, 145 views)
File Type: jpg PXL_20210806_171144641.jpg (79.4 KB, 103 views)
drfromnc is online now   Reply With Quote
Old 09-09-2021, 10:14 AM   #2
Terry,OH
Senior Member
 
Terry,OH's Avatar
 
Join Date: May 2010
Posts: 3,892
Default Re: remove surface rust on transmission gears

Take the gears out and clean in a bath of Kerosene, using wire brushes and scotch bright pads. Dry them off and use a wire wheel to clean off light rust. Sometimes the gears can be lightly bead blasted. Since you have several other transmissions look for what you need in them. I believe your 39 gear set may clean up nicely using wire brushes. The cluster, input, output shaft, 2nd and 1st-Rev are the important gears many of the small parts can be replaced with ease. Don't let the other transmissions get the same way as your 39. Prevention is worth a pound of cure. Looks like you have 3, 1940 transmission cases in spare.
Terry,OH is online now   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 09-09-2021, 10:14 AM   #3
tubman
Senior Member
 
tubman's Avatar
 
Join Date: Dec 2013
Location: Minnesota, Florida Keys
Posts: 8,127
Default Re: remove surface rust on transmission gears

Those look pretty far gone to me, especially if you have the sideshift transmissions. If that truly is a '39 transmission the later gears will go right in. If it were me, I'd still dump them in a bucket of Evaporust (or equivalent) to see what I really had. I think the first thing you should do is get a copy of Mac Van Pelt's (Van Pelt Sales) transmission book (if you don't already have it) and develop a familiarity with these transmissions.

I should clarify that by "later", I mean '40-48' transmissions. I believe that the '49-'50 gears can also be used, but I have never done that particular swap, so take it for what it is.

EDIT : I agree with "Terry, OH" on the clean up if you decide to do it. I think this should be a two step process, first the Evaporust treatment to take the rust off with the least disturbance of the original surface possible, and then the suggested clean-up procedure.

Last edited by tubman; 09-09-2021 at 10:25 AM.
tubman is offline   Reply With Quote
Old 09-09-2021, 10:34 AM   #4
drfromnc
Junior Member
 
Join Date: Oct 2017
Location: Smithfield, NC
Posts: 27
Default Re: remove surface rust on transmission gears

thanks. I am fairly certain the trans in the truck is a 39 because of serial #18-5018526 but has single detent shifter. I will double check the case number once I get it pulled. I bought Vern Tardels book but will buy the Van Pelt one so I can ID all the transmissions that I have.
drfromnc is online now   Reply With Quote
Old 09-09-2021, 11:16 AM   #5
Step-down
Senior Member
 
Step-down's Avatar
 
Join Date: May 2012
Location: Hat City (Danbury CT)
Posts: 618
Default Re: remove surface rust on transmission gears

I believe a 39’ case would be stamped on the bottom back “78” if not maybe “48” would work .
__________________
"I can't cry as long as I know the Lord has risen "
Step-down is offline   Reply With Quote
Old 09-09-2021, 01:05 PM   #6
marko39
Senior Member
 
Join Date: Oct 2016
Location: harpursville ny
Posts: 657
Default Re: remove surface rust on transmission gears

Sponsored Links (Register now to hide all advertisements)
A gallon of muratic acid is cheap, works fast and is smelly. be sure to degrease first and neutralize with baking soda after.
marko39 is offline   Reply With Quote
Old 09-09-2021, 01:14 PM   #7
Darin
Junior Member
 
Join Date: Jul 2019
Location: South Carolina
Posts: 24
Default Re: remove surface rust on transmission gears

I think you might consider what Terry suggested , lightly bead blasting. Seems to me they are a bit more that surface rusted not that they look terribly pitted or anything but you want to not feel much if you were to drag a finger nail over the surface where the gears mesh.
Also if you do bead blast , you might need to tape the tapered area where the synchronizer contacts with rubber tape to keep it silky smooth unless it is really pitted already and in that case you might want to look for a replacement unless you can polish that area without taking any surface off .
I built 3 of these last year and one of them was probably a bit worse than yours , It ended up working pretty well, then I traded for another trans with later synchronizer and the gears were really nice and in the end it was quieter it seems that the other one .
Whatever you do remember they will flash rust real quick just sitting around the work bench if not coated with some preventive solution.
Darin is offline   Reply With Quote
Old 09-09-2021, 02:20 PM   #8
hotrodart
Senior Member
 
hotrodart's Avatar
 
Join Date: May 2010
Location: Shenandoah Valley Virginia
Posts: 186
Default Re: remove surface rust on transmission gears

You probably will want to also check the bearings closely......any rust on them will most likely make them trash......
hotrodart is offline   Reply With Quote
Old 09-09-2021, 02:39 PM   #9
Pete
Senior Member
 
Pete's Avatar
 
Join Date: May 2010
Location: Wa.
Posts: 4,377
Default Re: remove surface rust on transmission gears

That is way beyond surface rust. Look for something better.
Pete is offline   Reply With Quote
Old 09-09-2021, 02:45 PM   #10
Clem Clement
Senior Member
 
Clem Clement's Avatar
 
Join Date: May 2010
Location: Fairfax, VA
Posts: 3,239
Default Re: remove surface rust on transmission gears

Put the whole shebang in a tub with apple vinegar for a week. Rust gone.
Clem Clement is offline   Reply With Quote
Old 09-09-2021, 03:28 PM   #11
tubman
Senior Member
 
tubman's Avatar
 
Join Date: Dec 2013
Location: Minnesota, Florida Keys
Posts: 8,127
Default Re: remove surface rust on transmission gears

Muriatic acid (duh!) and vinegar are both acids and will damage the surface unless your timing is perfect. This is why I recommend Evaporust. It works by a process called chelation, which does not effect the actual metal itself. You want as little change as possible for inspection purposes. I wouldn't bead blast except as a last resort.

In the final analysis, I will have to agree with "Pete".
tubman is offline   Reply With Quote
Old 09-09-2021, 07:35 PM   #12
JM 35 Sedan
Senior Member
 
JM 35 Sedan's Avatar
 
Join Date: May 2010
Location: Near Rising Sun, Maryland
Posts: 10,455
Default Re: remove surface rust on transmission gears

Quote:
Originally Posted by drfromnc View Post
I plan to tear down the 39 transmission in my pickup to inspect and replace what i should but how do I go about removing all the surface rust on the gears? or should I just look for something else? I do have several later model transmissions that are side shift. maybe i can use gears and gearsets from them?
drfromnc, I think Terry, Oh gave you some good advice. Take that 39 transmission completely apart and clean all the parts as he suggested. Pitting of any bearing journals, sliding surfaces, surfaces that rotate against each other, etc, would be parts that are highly questionable for reuse. As already mentioned, if you do any bead blasting, make sure critical areas of those parts are masked from the bead blast. I would suggest getting any bearings, synchronizer rings, spacers, thrust washers, replacement gears, gasket set, and seals that are necessary from Third Gen Automotive, or Mac Van Pelt. They both carry the best of whatever you may need. Also, regarding books available from Vern Tardell and Mac VanPelt, I think both are good, but Mac's is much more comprehensive. Good luck with your rebuild, and if you have any questions on this, post them here on this same thread, and I'm sure you'll get some good answers.
__________________
John

"Never give up on what you really want to do. The person with big dreams is more powerful than one with all the facts". Albert Einstein

Last edited by JM 35 Sedan; 09-09-2021 at 08:12 PM.
JM 35 Sedan is offline   Reply With Quote
Old 09-09-2021, 07:39 PM   #13
tubman
Senior Member
 
tubman's Avatar
 
Join Date: Dec 2013
Location: Minnesota, Florida Keys
Posts: 8,127
Default Re: remove surface rust on transmission gears

What is it the doctors say? "First, do no harm". I think this applies to old cars and parts as well.
tubman is offline   Reply With Quote
Old 09-10-2021, 01:05 AM   #14
cas3
Senior Member
 
Join Date: Jan 2011
Location: sw minnesota
Posts: 2,961
Default Re: remove surface rust on transmission gears

I am no expert, but a friend who is in the trans rebuilding service always poo poo's my thoughts of using rusty trans parts because he say's the hard surface is not very deep, and rust will remove it and leave you with soft metal. Not sure i believe it, but he does this all day long. Now that said, I agree with Terry, clean it up, see what you got, and most of all inspect the inside of the input shaft, and inside of the ends of the cluster gear where the roller bearings there need a good surface
cas3 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 06:48 AM.