Transmission Main Shaft issue
 

Need your help again guys! overhauling the roadster transmission and order all new bearings for it. Notice the main drive gear had some pitting and wear on the nose. So I went ahead and ordered a new one and pressed the bearing on it. Now here is the issue. When I install the Main drive gear into the front of the tranny and bolt the housing that hold the throw out bearing I cannot rotate the shaft to move the gears. If I loosen the bolts it moves freely. I have check to make sure the washer is on the main shaft and the bearing that goes in the main drive gear is there. When I replace it with the old drive gear and bearing and tighten it down it will move freely. I post a picture of both shafts.

Does anyone have any recommendations to solve this? Is the bearings a bit bigger than before? All parts were ordered from Synders. Bolts/snap rings/ gaskets are all the prefect size.

Re: Transmission Main Shaft issue
 

My friend had the same issue with his new mainshaft. Look at the radius in the corner where the nose of the shaft transisitions to the larger diameter and compare that radius to the old mainshaft. If the radius is too big the roller bearing will bind on the too big radius.

Re: Transmission Main Shaft issue
 

Are you talking about the inside of the shafts???

Re: Transmission Main Shaft issue
 

I suspect that the main shaft (the one the two slider gears ride on) is binding inside of the input shaft (the one you bought new). There must be some end clearance between the end of the main shaft and where a relief is drilled into the inside of the input shaft. This problem can occur with originals as different suppliers probably made them and there may not have been enough consideration given to the difference between the two parts.

Put some bluing or chalk on the end of the main shaft and insert it into the input shaft with the bearing and see if there is contact. If there is you can grind some material of the end of the front of the main shaft.

Tom Endy

Re: Transmission Main Shaft issue
 

Thanks Tom, I checked that option. I removed the 2 gears and main shaft all together and just left the main drive gear and cluster gear in the transmission it turns fine with finger tight bolts together but as soon as I snug them up I can't rotate the shaft. With leads me to think it's either the bearing or shaft.

Re: Transmission Main Shaft issue
 

Sorry. Corrected the terminology

Re: Transmission Main Shaft issue
 

Just put one together no problem . Did you put the right short bearing in the front shaft ?????? or did you put the long one hence main shaft wont go in home or binding on the gear mesh . just an idea, I found my low gear very tight on new main shaft but 2nd gear a nice no play fit ,

Re: Transmission Main Shaft issue
 

Try sliding each shaft into the front bearing retainer and measure how far the bearing is above the retainer mounting surface. It sounds like the problem is between these two parts.