Hey guys,

rebuilding an s5 transmission and I had a question. I am replacing all bearings and synchros. Synchros are all mazda direct parts. Bearings and seals are from a bearing and seal kit off ebay. The bearing I got for the pilot shaft, NSK 6307, was open on both faces. Both of the old pilot shaft bearings I have from scrapped gear boxes were rubber sealed on both sides. Do you think it would make a difference to run with the open face? I would think the bearing seals would reduce the amount of oil flow that the front transmission seal would have to handle.

Let me know what you think

 

Factory bearing open both sides. A seal is then installed after bearing(1881-11-404A).

 

Pilot shaft bearing? The pilot shaft bearing is a needle bearing that is pressed into the tail end of the e-shaft. Did you mean "input shaft" bearing? The NSK Deep Groove Ball Bearing 6307 is 35mm I.D, 80mm O.D. This sounds similar to the input shaft bearing. I once rebuilt an S5 NA transmission. I bought my bearings/synchros from Mazda. The input shaft bearing was sealed. If I recall, there were about 9 bearings in total for the NA transmission. Most of the bearings were sealed ball bearings but there were also a couple non-sealed ball bearings.

 

Geez, if I would have looked up the number would have seen that it certainly wasn't the pilot brg, but the brg in trans, as rebuilding trans.

 

Thats what I meant, input shaft bearing. You don't get much sleep when you have small children