- Jul 11, 2014
- Paradise of Florida
What fluid are you using?
Yes, it is a problem. Low fluid levels and low quality bearings are the main reasons input shaft bearings fail.The input shaft bearing seems to be a big problem on these cars, but I'm not sure what exactly causes the failure.
I just got the Honda fluid for the swap because I was in a hurry and had to go to the dealer to pick up other stuff anyways. I will probably get Amsoil the next time I change the fluid, which won't be too long. This trans had a little bit of glitter in it presumably from the badly worn input shaft bearing and I did my best to clean it out before I put it back together, but I'm going to change the fluid shortly to help flush out any remaining particles. If the fluid comes out reasonably clean I will probably refill with Amsoil. This trans only takes about 1.5 quarts of fluid, so the difference in cost isn't much and is well worth it IMO.Skip the OEM MTF and try some Redline MTL or Amsoil MTF
MT fluid isn't readily available in parts stores where I live, probably because there are barely any MT vehicles on the road here, so I plan to keep a few extra quarts of fluid on hand so I don't need to go looking for fluid when I need it next time.In a hurry, don't rule out the Valvoline MT fluid either
Thanks, that does seem to be the case. I bet automatic transmissions make some noise too, but we don't notice it as much since there isn't a way to make it stop spinning like there is with a MT.It seems to be normal for manual transmissions to make some noise in neutral with the clutch engaged. At that point, lots of stuff in the gearbox is spinning due to mechanical connections and also oil drag.
Thanks for letting us know, it's quite encouraging that your trans is still healthy after 200K miles. The input shaft seems to just be a matter of luck more than anything else. I have heard of people going 200K+ miles on the factory fill with no problems, but I have also heard of very early failures in well maintained transmissions. I'm sure the brand of fluid used is a factor to some extent, but using good fluid and changing it frequently unfortunately doesn't seem to be any guarantee that the bearing won't fail prematurely.I should have been more careful in my wording above, saying the input shaft makes "no noise". You can hear it spinning at idle if you listen carefully; the slight whirring sound. By noise I mean that it is still sounding as new at 200K miles. No rattle, scrape, or grind noise that would indicate the bearing is failing.
The manual states that the transmission oil should be changed at 120K miles, or every 6 years. We know the oil will not hold up for nearly that long! I'm not sure if the failures are related to defect bearings or poor lubrication, but my sample of one is still working fine at 200K using Red Line MTL changed at 30-45K miles.
Good to know, thank you for sharing! I replaced the input shaft bearing before I installed the trans since that's a very common failure on these cars. I don't know the history or mileage of this trans since I pulled it out of a wrecked car at a junkyard, but it seemed to be in good condition inside with the exception of the trashed input shaft bearing.When my Mazda was still fairly new, I noticed the whirring sound was a little louder than expected. That noise slowly worsened until it was more of a roar by the time the odometer reached 340k miles. Replacing 3 transmission bearings then was the most expensive mechanical repair that car ever had, by far. After that, it stayed quieter than when new. I suspect the bearings were contaminated when new, or maybe excessively pre-loaded.
Thanks for the info. Since my swap was from a junkyard, I don't know how this trans was treated or how many miles are on it but it looked alright inside with the exception of the input shaft bearing. I don't think my issue is that bad since it only happened a few times and it shifts fine otherwise.On my 05 Civic 5spd,(200K miles) I have never encountered the problem you describe shifting into 1st while stopped. There are synchros in all forward gears, but not reverse, so this issue sometimes occurs for reverse only. What it doesn't like is down shifting into 1st when going much over 5mph. I don't downshift to 1st until almost or completely stopped.( 1st is geared so low anyway, hardly ever a reason to use it unless starting from a stop)
Maybe your synchro in 1st is compromised a bit....