Transmission input shaft pilot bearing question

[jeaster]

I have a ’79 124 spider that had a bad input shaft pilot bearing. I replaced it as well as the input shaft. There were a couple of other parts that were replaced but no bearings. All of the bearings and parts were carefully inspected for wear, galling and defects.

Here is the problem, the transmission now whines when in neutral or any gear other than 4th or when the clutch is engaged. So no whine in 4th or clutch engaged.

I purchased the transmission oil from Vick and I’m sure it has the correct level in it.

I have two conflicting books on how to install this bearing. The first one (Brooklands books 1971-1984 Fiat shop manual) says on page 216 to “coat the input shaft pilot bearing with gear oil”, the second (Fiat five-speed transmission by Fiat motors of North America) on page 35 says “Coat bearing with heavy grease, then insert in input shaft” I didn’t realize that there was a conflict on this and I only used the gear oil.

Did I mess up here?

Anyone have any ideas?

[MNspiderman]

Personally I would have to go with the grease. You need it in there for at least 20 years. Oil, no mater how thick will work its way out eventually. Thats why they don't use gear oil for the front wheel bearings.

[BigShirl]

Unfortunately, it sounds as though you may have somehow damaged the main drive gear bearing between the input and output shafts. This would explain the noise going away in 4th gear as the 2 shafts are locked together and the bearing is not spinning. I am assuming that the bearing you replaced was the input shaft pilot bearing in the crank? Is it possible your transmission is misaligned and causing input deflection and stress on the bearing? Just a note, some of my terminology may differ from the fiat standard. I'm fairly new to the fiat world!

Hope I was helpful!
Rizzi