The Ford Barn

rhphotord · 04-23-2020, 12:53 PM

Forgive a rookie question as its my first go round with a flathead and period correct trans.
Not a major problem on a lttle driven car but it seems the trans on my AV8 build wants to exit third gear at times. Normally I double shift through each gear change and it feels as though it doesn't go all the way into gear. Find myself exerting extra pressure to ensure 3rd gear engagement. Engine and clutch are new, trans is a 1939, rebuilt per the previous owner. Synchros look good with crisp new like pitch. Could my problem be in the shifting mechanism?
Really not wanting to pull the trans and certainly dont want to go to a late model trans. Maybe I have to live with it?

Mart · 04-23-2020, 02:43 PM

Is the UJ pulled up tight, of the right type, and using the correct thick washer? Has the rear UJ got the correct (thick) circlip? Does the trans have the correct synchro sets, shift tower, lever and forks?

Is the front bearing retained properly?

I'm thinking forward and aft movement of the input and output shafts could cause a problem, as could mismatched parts. You say yourself it doesn't seem to go into gear cleanly. How about with the top off the box, does the synchro sleeve engage fully on the input shaft? Does it have the correct fork? Not the wrong type hogged out to clear a 3" synchro?

Just bouncing ideas here.

Hope you can hit on what the source of the problem is.

Mart.

cas3 · 04-23-2020, 03:05 PM

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you should not have to double clutch a v8 trans. years ago they sold some bad syncro rings that did not have the notch cut deep enough. i built a trans with them, new bearings and all, and i had to double clutch it like a model A.

04-23-2020, 12:53 PM	#1
rhphotord Senior Member Join Date: May 2010 Location: West Salem, Wi. Posts: 281	Transmission jumps out of third gear. Forgive a rookie question as its my first go round with a flathead and period correct trans. Not a major problem on a lttle driven car but it seems the trans on my AV8 build wants to exit third gear at times. Normally I double shift through each gear change and it feels as though it doesn't go all the way into gear. Find myself exerting extra pressure to ensure 3rd gear engagement. Engine and clutch are new, trans is a 1939, rebuilt per the previous owner. Synchros look good with crisp new like pitch. Could my problem be in the shifting mechanism? Really not wanting to pull the trans and certainly dont want to go to a late model trans. Maybe I have to live with it?

04-23-2020, 02:43 PM	#2
Mart Senior Member Join Date: May 2010 Location: Solihull, England. Posts: 8,745	Re: Transmission jumps out of third gear. Is the UJ pulled up tight, of the right type, and using the correct thick washer? Has the rear UJ got the correct (thick) circlip? Does the trans have the correct synchro sets, shift tower, lever and forks? Is the front bearing retained properly? I'm thinking forward and aft movement of the input and output shafts could cause a problem, as could mismatched parts. You say yourself it doesn't seem to go into gear cleanly. How about with the top off the box, does the synchro sleeve engage fully on the input shaft? Does it have the correct fork? Not the wrong type hogged out to clear a 3" synchro? Just bouncing ideas here. Hope you can hit on what the source of the problem is. Mart.

04-23-2020, 03:05 PM	#3
cas3 Senior Member Join Date: Jan 2011 Location: sw minnesota Posts: 4,567	Re: Transmission jumps out of third gear. Sponsored Links (Register now to hide all advertisements) you should not have to double clutch a v8 trans. years ago they sold some bad syncro rings that did not have the notch cut deep enough. i built a trans with them, new bearings and all, and i had to double clutch it like a model A.