The Ford Barn

jukenut 16 · 01-07-2019, 03:16 PM

Hi guys , hears a link to a problem I have with a '39 transmission I fitted to my 1930 Coupe. Any help appreciated...

https://www.jalopyjournal.com/forum/...#post-12900670

Hoop · 01-07-2019, 04:36 PM

Refer to HAMB for more info

Gary Duff · 01-07-2019, 05:08 PM

jukenut 16
Check page 177 & 179 in the 38-40 service bulletin's. You may have wrong
width synchro sleeve. They changed the width of the large gear on the cluster.
As a result the sleeve rubs on that gear when in high gear.
Gary

Hoop · 01-07-2019, 05:48 PM

Refer to HAMB for more info

rotorwrench · 01-07-2019, 07:40 PM

When folks mention "1939" transmission I always wonder if it really is all 1939 or a mishmash of parts from several different boxes. You need to be sure you have the 91A shift fork. If it is some modified earlier one then it won't shift all the way into direct drive. When you are in Hi gear its 1:1 drive straight through so only the synchro is involved with this position and it has to have that 91A fork to work with the 1939 & later type synchro assembly.

Hoop · 01-07-2019, 08:16 PM

Sponsored Links (Register now to hide all advertisements)

You need to read the entire HAMB thread and study the pics. He posted more info.

Clem Clement · 01-07-2019, 11:17 PM

Talk to Mac Van Pelt

Tinker · 01-07-2019, 11:21 PM

Really you should post this on the Model A forum here. Few guys have a lot of experience putting a 39 trans behind a 4 banger (flathead ford 4).

Not sure why you can't wrap this up on the hamb either...

jukenut 16 · 01-08-2019, 01:47 AM

hi guys, had the person I purchased this from turn up with a complete spare top and another fork, hope to try it tomorrow. He has done his own boxes etc. and looked at mine (top off). He's not sure of fault.Mine does have the small fork.

Will report if I find something.

Terry,OH · 01-08-2019, 07:05 AM

I would believe it is the shift top over-driving the syncro. Did the top get rebuilt with new springs and balls? Check out the condition of the shift rails? There is an old trick to add stop bolt to the end of the 2/3 shift rail through the welsh plug holes. Usually done to 2nd only.

rotorwrench · 01-08-2019, 07:46 AM

If it has the small synchro then don't call it a 1939 transmission because it more like something from before 1939 when they had the small synchro. The small one requires the old type shift fork for 1:1 drive. These types of alterations can use a number of parts but the parts are deigned to work with other specific parts. Mac's book lists this stuff. The main drive gear must be aftermarket so I have no idea what it's supposed to fit.

jukenut 16 · 01-10-2019, 10:39 PM

Have tried new top etc. no change, added some photos etc. to my post on The Hamb. This came out of a 1939 Coupe (NZ) - with early small syncro.

Terry,OH · 01-11-2019, 08:00 AM

I added more photos to your HAMB post. Plus Mac has posted there.

jukenut 16 · 01-12-2019, 01:50 AM

Thanks, a lot more info there so please go there to see. Thanks for all inputs...

jukenut 16 · 02-14-2019, 02:05 AM

Hi guys, forgot to post. All is fixed, turned out to be an alingment problem between crankshaft and trans. Corrected -see HAMB post.
Thanks to all who posted.

01-07-2019, 03:16 PM	#1
jukenut 16 Junior Member Join Date: Nov 2016 Location: Wainuiomata New Zealand Posts: 13	1939 transmission fault Hi guys , hears a link to a problem I have with a '39 transmission I fitted to my 1930 Coupe. Any help appreciated... https://www.jalopyjournal.com/forum/...#post-12900670

01-07-2019, 04:36 PM	#2
Hoop Senior Member Join Date: May 2010 Location: Jacksonville FL Posts: 1,137	Re: 1939 transmission fault Refer to HAMB for more info __________________ "Remember that when it comes to intelligence, half of all of us are below average." Last edited by Hoop; 01-07-2019 at 07:25 PM.

01-07-2019, 05:08 PM	#3
Gary Duff Junior Member Join Date: May 2010 Posts: 23	Re: 1939 transmission fault jukenut 16 Check page 177 & 179 in the 38-40 service bulletin's. You may have wrong width synchro sleeve. They changed the width of the large gear on the cluster. As a result the sleeve rubs on that gear when in high gear. Gary

01-07-2019, 05:48 PM	#4
Hoop Senior Member Join Date: May 2010 Location: Jacksonville FL Posts: 1,137	Re: 1939 transmission fault Refer to HAMB for more info __________________ "Remember that when it comes to intelligence, half of all of us are below average." Last edited by Hoop; 01-07-2019 at 07:27 PM.

01-07-2019, 07:40 PM	#5
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,422	Re: 1939 transmission fault When folks mention "1939" transmission I always wonder if it really is all 1939 or a mishmash of parts from several different boxes. You need to be sure you have the 91A shift fork. If it is some modified earlier one then it won't shift all the way into direct drive. When you are in Hi gear its 1:1 drive straight through so only the synchro is involved with this position and it has to have that 91A fork to work with the 1939 & later type synchro assembly.

01-07-2019, 08:16 PM	#6
Hoop Senior Member Join Date: May 2010 Location: Jacksonville FL Posts: 1,137	Re: 1939 transmission fault Sponsored Links (Register now to hide all advertisements) You need to read the entire HAMB thread and study the pics. He posted more info. __________________ "Remember that when it comes to intelligence, half of all of us are below average." Last edited by Hoop; 01-08-2019 at 12:37 AM.

01-07-2019, 11:17 PM	#7
Clem Clement Senior Member Join Date: May 2010 Location: Fairfax, VA Posts: 3,393	Re: 1939 transmission fault Talk to Mac Van Pelt

01-07-2019, 11:21 PM	#8
Tinker Senior Member Join Date: May 2010 Location: MN Posts: 7,053	Re: 1939 transmission fault Really you should post this on the Model A forum here. Few guys have a lot of experience putting a 39 trans behind a 4 banger (flathead ford 4). Not sure why you can't wrap this up on the hamb either... Last edited by Tinker; 01-07-2019 at 11:31 PM.

01-08-2019, 01:47 AM	#9
jukenut 16 Junior Member Join Date: Nov 2016 Location: Wainuiomata New Zealand Posts: 13	Re: 1939 transmission fault hi guys, had the person I purchased this from turn up with a complete spare top and another fork, hope to try it tomorrow. He has done his own boxes etc. and looked at mine (top off). He's not sure of fault.Mine does have the small fork. Will report if I find something.

01-08-2019, 07:05 AM	#10
Terry,OH Senior Member Join Date: May 2010 Posts: 4,743	Re: 1939 transmission fault I would believe it is the shift top over-driving the syncro. Did the top get rebuilt with new springs and balls? Check out the condition of the shift rails? There is an old trick to add stop bolt to the end of the 2/3 shift rail through the welsh plug holes. Usually done to 2nd only.

01-08-2019, 07:46 AM	#11
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,422	Re: 1939 transmission fault If it has the small synchro then don't call it a 1939 transmission because it more like something from before 1939 when they had the small synchro. The small one requires the old type shift fork for 1:1 drive. These types of alterations can use a number of parts but the parts are deigned to work with other specific parts. Mac's book lists this stuff. The main drive gear must be aftermarket so I have no idea what it's supposed to fit.

01-10-2019, 10:39 PM	#12
jukenut 16 Junior Member Join Date: Nov 2016 Location: Wainuiomata New Zealand Posts: 13	Re: 1939 transmission fault Have tried new top etc. no change, added some photos etc. to my post on The Hamb. This came out of a 1939 Coupe (NZ) - with early small syncro.

01-11-2019, 08:00 AM	#13
Terry,OH Senior Member Join Date: May 2010 Posts: 4,743	Re: 1939 transmission fault I added more photos to your HAMB post. Plus Mac has posted there.

01-12-2019, 01:50 AM	#14
jukenut 16 Junior Member Join Date: Nov 2016 Location: Wainuiomata New Zealand Posts: 13	Re: 1939 transmission fault Thanks, a lot more info there so please go there to see. Thanks for all inputs...

02-14-2019, 02:05 AM	#15
jukenut 16 Junior Member Join Date: Nov 2016 Location: Wainuiomata New Zealand Posts: 13	Re: 1939 transmission fault Hi guys, forgot to post. All is fixed, turned out to be an alingment problem between crankshaft and trans. Corrected -see HAMB post. Thanks to all who posted.