View Single Post
Old 10-11-2009, 12:52 PM   #3 (permalink)
darcane
.........................
 
darcane's Avatar
 
Join Date: Aug 2009
Location: Buckley, WA
Posts: 1,597
Thanks: 391
Thanked 488 Times in 316 Posts
Quote:
Originally Posted by abcdpeterson View Post
So my question. Is Synthetic better in a manual transmission? And if so, Do I offer to pay for synthetic transmission fluid?
Definately better, especially in cold weather. When the fluid is fully warmed up, dino and syn should be close. However, before that dino will be significantly thicker.

I remember once starting up my old truck at -40 degree F. It started fine, but I put it neutral to let it warm up and when I let off the clutch it lurched forward and died. The fluid was so thick it acted as if it were in gear. Also, moving the shift lever felt like it was full of molasses I switched to synthetic later and at the same temps it acted normal. Granted, this is a little extreme compared to most, but it illustrates the point.

Quote:
Originally Posted by abcdpeterson View Post
Side note: more info on same issue.
After I felt the transmission go pop into 5th gear it just did not feel right. Sliding it into gear was not as smooth, and when I got up to high speeds it would sometimes grind going into 5th. I found I could produce the grinding issue 100% of the time if I did this:
6mph+, shift to neutral, let the clutch out, push clutch back in, shift to 5th gear.

So now basically what they are telling me:
“You should not double clutch a car with synchro’s, it could cause damage. Double clutching should only be done in large trucks without synchro’s”
That sound like a bunch of bull shift to you also?
I have driven a stick on and off for 30 years, from a VW Bug to large truck. I am shifting as I always have – sometimes leaving the transmission in neutral. This is the 1st transmission I have ever had any problems with. I do NOT see how double clutching can cause any issue. IMO it helps.

If anyone can point me to any verifiable documentation on the issue of double clutching in a car with syncros PLEASE let me know. I would love to hand them verifiable documentation.
There's no harm in double clutching with a synchro. One note though, when double-clutching while upsifting, you should rev match in neutral. Doing it the way you described, there will be a greater difference in speed making the synchros work harder. That's why you heard the sound every time. This still shouldn't have harmed your tranny significantly and certainly isn't the cause of the broken tooth.
__________________
Past Cars:

2001 Civic HX Mods

CTS-V

2003 Silverado Mods
  Reply With Quote