Alfa Romeo Forums banner

1 - 10 of 10 Posts

·
Registered
Joined
·
53 Posts
Discussion Starter #1
Have transmission out for rebuild, I was looking for your input as to should I replace this bushing with a needle roller bearing or install the original brass type of bushing? Thanks Arthur
 

·
Premium Member
Joined
·
21,672 Posts
I am told to keep the original bushing. To use a roller/pin bearing, you need a hardened input shaft, which the Alfa shaft is not. Not sure there's room, either.
You having some specific problem with the bushing?
Andrew
 

·
Super Moderator
Joined
·
10,584 Posts
I agree with Andrew.

The bronze bushing works fine and lasts a long time. A roller bearing would need lubrication, and there's no way to introduce oil to the back of the crankshaft. Unless you find some sort of a sealed, permanently lubricated needle bearing assembly and harden the bearing surface on the input shaft, I can't see how this would work
 

·
Registered
Joined
·
53 Posts
Discussion Starter #4
Thanks guys...There was a whinning noise coming from tranny or bellhousing area, the noise would increase with the rpm of the motor but would stop when clutch was applied. I was told it could be that bushing causing the noise.... So Iam going to change input and output bearings in tranny...new syncro rings and needle bearing on 4th gear..I had installed new throw out bearing and clutch ,pressure plate last yr to get rid of noise but that didnt help...
 

·
Super Moderator
Joined
·
10,584 Posts
There was a whinning noise coming from tranny or bellhousing area, the noise would increase with the rpm of the motor but would stop when clutch was applied.
If by "applied" you mean that the noise stops when you step on the clutch pedal, then I'd say your evidence proves the innocence of the pilot bushing.

If you get the whining noise with the clutch engaged (e.g., not stepping on the pedal), it isn't the pilot. When the clutch is engaged, the input shaft is not turning relative to the pilot bushing, since the clutch locks the crankshaft and transmission input together.

The pilot only serves as a bearing with the clutch is disengaged; then the crankshaft is turning, while the transmission is stationary (or turning a a lower speed). If the pilot was making the noise, you'd hear it then.
 

·
Registered
Joined
·
53 Posts
Discussion Starter #6
Thanks Jay... It must be the input or output bearing on main shaft...Iam gonna take it apart and check things out I have a new bushing coming from Centerline as I pulled the old one out already.... I wanna get it right this time as its a ***** getting that tranny back into car.
 

·
Premium Member
Joined
·
21,672 Posts
I believe trans bearings are killer expensive. I wouldn't prospectively replace them without being pretty sure they're bad. You know your way through an Alfa trans? Could in theory be cheaper to find a known good one.
Andrew
 

·
Push hard and live
Joined
·
9,591 Posts
The input main-shaft bearing on these transmission takes a fair amount of load, which leads to some motion, which leads to odd wear and noise from the input and secondary gears. The real solution is to put in NEW input bearings. Although apparently pricey, it is still the correct solution at a certain point. The hassle is removing and reinstalling the trans, so once out chasing a noise, I'd consider replacing that bearing as a good idea.
 

·
Registered
Joined
·
5,465 Posts
Having just completed my 5 speed GTV gearbox rebuild, here are some suggestions

1. Don't replace expensive bearings in the trans unless you can prove to yourself they are bad, via metrology, visual or tactile appearance, etc. They are pricey indeed!
2. Change the synchros (obvious)
3. Rebuild first gear synchro to match the others (see sticky)
4. Replace 4th and 5th needle bearings (they are cheap enough)
5. Measure 2 and 3 bushings and don't mess with them unless they are out of tolerance.
6. Check all sliders, crown gears, etc for wear ; replace what is worn
7. Mark the tripods as to where they go and in what direction, 5th is slightly different but its not apparent
8. Don't get scared by this. Its not that difficult, just a bit fiddly. A shop press comes in very handy
 

·
Registered
Joined
·
53 Posts
Discussion Starter #10
Thanks Goat... I will take note, my buddy is a machinist so he will be a big help..My tranny shifts great right now but i will change synchro rings. I will also change input bearing and rear bearing in hope of getting rid of that irritating whining noise, once and for all... Thanks to all that replied to my thread I greatly appreciate all your advice. Wish you all a Happy New Yr.......Arthur
 
1 - 10 of 10 Posts
Top