Hi All,
I'm a new member that is neck deep in the restoration of my late father's 1959 TR3A. Currently I'm working on rebuilding the 3-synchro gearbox, and am hoping to get some advice (mostly on acceptable wear) due to the fact that this is my first transmission rebuild. I would like to reuse components that are in good condition, but replace the ones that are out of spec, or that would be at risk of failing soon due to age and/or condition. Here are the details...
Gears: No broken gears, but some chipping on 1st. I think I won't be able to tell the difference if I replace with new, but I'm not entirely sure. Also not sure how 1st gear performed when last driven because it was over 30 years ago (I was only around 7 years old). All other main and layshaft gears looks good.
Countershaft: This gearbox has loose needle bearings, and there appears to be little wear on the countershaft. In fact, I really can't measure any dimensional differences across the shaft, but you can obviously see where the bearings rolled. I'm thinking it would be fine to reuse, but it seems that this part is commonly replaced. Not sure if the shaft shown in the picture has enough wear to warrant replacement. Thoughts?
Thrust Washers: I wouldn't have thought twice about replacing these because there appears to be some wear and even a little gouging, but I have seen information that the reproduction washers are inferior because they are not steel backed. Is the wear shown in the picture acceptable? Should I replace even if the new part is of inferior quality?
Bushings: 3rd gear bushing looks good and easily meets float spec. 2nd gear top hat bushing also looks good, but barely meets float spec. Top hat bushing seems to be another part that is commonly replaced due to breakage. Should I assume that it has been weakened and will fail sooner rather than later? I am thinking I should replace, especially since the spec is borderline.
Bearings: I assume replace all 3 bearings regardless, right? Not sure how to check them, but they do turn smoothly.
Countershaft Bearings: Should I also replace the needle bearings? They look good, but I assume go ahead and replace.
Synchros: 2 of the 3 were out of spec, so I will replace. Any advice on the standard synchros versus the premium ones?
Any other parts that you would definitely replace other than gaskets and seals?
Thanks in advance for any advice given. I'm sure there is a lot of experience here, and I am looking forward to contributing to the forum.
I'm a new member that is neck deep in the restoration of my late father's 1959 TR3A. Currently I'm working on rebuilding the 3-synchro gearbox, and am hoping to get some advice (mostly on acceptable wear) due to the fact that this is my first transmission rebuild. I would like to reuse components that are in good condition, but replace the ones that are out of spec, or that would be at risk of failing soon due to age and/or condition. Here are the details...
Gears: No broken gears, but some chipping on 1st. I think I won't be able to tell the difference if I replace with new, but I'm not entirely sure. Also not sure how 1st gear performed when last driven because it was over 30 years ago (I was only around 7 years old). All other main and layshaft gears looks good.
Countershaft: This gearbox has loose needle bearings, and there appears to be little wear on the countershaft. In fact, I really can't measure any dimensional differences across the shaft, but you can obviously see where the bearings rolled. I'm thinking it would be fine to reuse, but it seems that this part is commonly replaced. Not sure if the shaft shown in the picture has enough wear to warrant replacement. Thoughts?
Thrust Washers: I wouldn't have thought twice about replacing these because there appears to be some wear and even a little gouging, but I have seen information that the reproduction washers are inferior because they are not steel backed. Is the wear shown in the picture acceptable? Should I replace even if the new part is of inferior quality?
Bushings: 3rd gear bushing looks good and easily meets float spec. 2nd gear top hat bushing also looks good, but barely meets float spec. Top hat bushing seems to be another part that is commonly replaced due to breakage. Should I assume that it has been weakened and will fail sooner rather than later? I am thinking I should replace, especially since the spec is borderline.
Bearings: I assume replace all 3 bearings regardless, right? Not sure how to check them, but they do turn smoothly.
Countershaft Bearings: Should I also replace the needle bearings? They look good, but I assume go ahead and replace.
Synchros: 2 of the 3 were out of spec, so I will replace. Any advice on the standard synchros versus the premium ones?
Any other parts that you would definitely replace other than gaskets and seals?
Thanks in advance for any advice given. I'm sure there is a lot of experience here, and I am looking forward to contributing to the forum.