40 gearset in a 46 pu case
 

Hi,
I hate to bother MAC till I need to order parts, so I thought I would throw questions out here before I call him. The mainshaft on the 40 has the thrust washer with the little pin to index. The 46 mainshaft does not use that but 2 concerns is one second ger has the oil groove cut in it that goes against the rear splines (1st reverse slider splines) and the 46 2 gear did not. Second question besides the washer inside the 40 syn is there a way to make up about 15-20 thousands to the grove for the snap ring. Thanks

Re: 40 gearset in a 46 pu case
 

Call Mac.

Re: 40 gearset in a 46 pu case
 

I use a steel shim of the correct thickness to take up the additional clearance between the bronze thrust washer and synchro hub. Ford supplied the thrusts in 2 different thicknesses, .065” and .071” nominal thickness.

Re: 40 gearset in a 46 pu case
 

You don't have to bother Mac, most of the info is in his web site. It shows two mainshafts for the closed driveshaft 3 speeds. The 81A-7061 has a pin hole to capture the thrust washer, and as spline length of 2.913 inches. The 51A-7061 has no pin hole (nor thrust washer) and has spline length of 3.100 inches. Here is a case where you need to be careful of mixing since many parts do not match. It is safe to use the gearset as originally matched by Ford.

Re: 40 gearset in a 46 pu case
 

Hi everyone. Thanks for your responses. I have read all of Macs info. I am keeping all the 40 gears and syro (2.913 spline length with the pin and thrust washer) and only using the 46 pu case tail housing and main shaft which is the 3.100 in spline length, thus I cannot use the thrust washer. As Mac states everything is good if clearances are within specs. My 2 questions are where the back of second gear thrusts against the spiral splines is it ok for the (40) gear to have the grooves in the thrust area for oil. 2nd there is about .020 wear in the spiral splines which I don't know of a way to shim this as it would have to be done at the rear of 2nd gear or it will mess with the sycro clearances. Im doing some more figuring but with probably end up calling or emailing Mac. Mainshaft may be shot but still wonder about the oil groove in second gear thrusting against the rear spiral splines. Thanks everyone

Re: 40 gearset in a 46 pu case
 

Hi,
I know parts gets swapped around in the photo is the 2nd gear out of the 46 pu trans which is smooth on the back where it thrusts against the rear spiral splines (in which has worn it .010) can the 40 2nd gear with the oil groove thrust against those spiral splines? If so can I safely shim this setup to make up for the wear without interfering with the scyronizers?
Thanks

Re: 40 gearset in a 46 pu case
 

https://www.fordbarn.com/forum/attac...5&d=1716311894

https://www.fordbarn.com/forum/attac...6&d=1716311894

Re: 40 gearset in a 46 pu case
 

Yes, you can use that 2nd gear. I wouldn’t use that main shaft.

Re: 40 gearset in a 46 pu case
 

FYI……Will Kimble has been an integral part of our transmission rebuild team here for over ten years, so his advice here is based on mucho experience. That mainshaft, as he states, is badly worn out and should not be used. The 81A-7061 shaft is the one with the little pin, located just ahead of the spiral splines, which locates the 81a-7071 thick washer….try to use this shaft combo if you can. That washer protects the leading edge of the spiral splines from the wear seen in the above picture.

Re: 40 gearset in a 46 pu case
 

If you have a used 81A main shaft and want to use it I suggest pulling out the small locating pin and replacing it with a new pin.

Re: 40 gearset in a 46 pu case
 

Good Morning,
Thanks to all. I appreciate taking the time to write. I am doing this trans for a friend and hope it to be the last one of these I mess with. Yes this is mainshaft without the washer and pin. I will see what my friend wants to do at this point. If he wants I may email and see if you have a mainshaft in stock (Mac).
Thanks again

Re: 40 gearset in a 46 pu case
 

Hi Mac,
Will the 21C-7061 be the main shaft I need to use for open driveshaft that uses the thrust washer and locating pin like my 40 closed drive shaft used, as I am changing to open driveshaft. If so Mac do you have one to sell or should I call? Thanks again.