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
 
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.
 
You need to read the entire HAMB thread and study the pics. He posted more info.
 
Last edited:
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:
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.
 
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.
 
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.
 
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.
 
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.
 
You must log in or register to reply here.
Back
Top