Grinding 3rd gear when cold

[Araesk]

When it was warm our (summer) I never experienced and problems with any gear other than first being a little tough to get in. As winter is coming and things are getting colder, I notice first is getting even a little tougher to get in (have to try to push it in for a couple seconds, even reengage the clutch pedal before it will go into first). Then when I shift into 3rd gear it grinds super ridiculously and I cannot even get it into gear. Only a few times out of a great many I can get it into 3rd, but when I can it is perfectly smooth and 0 grinding or resistance. The tranny was rebuilt prior to my buying the car.
From my reading around people are saying BG syncroshift, but that's when the car gets hot at least and the lube runs thin. It seems to be the opposite for me instead. Any ideas?

 

[MQTalon92]

Look at your clutch slave cyl and check to see if it is leaking. Make sure there is no air in the clutch sys by bleeding out correctly. Check the clutch adjustment and look to see if the clutch rod fully disengages the disc. Try pumping the pedal before putting into gear. That will show if the master cyl is bad. All this is in assuming your trans is in good shape and rebuilt properly.

 

[Araesk]

I'm going to pick up some redline mt 90 and swap the fluid since i should do that. Then I'll look into the pedal. Ive been meaning to check it out sometime but have been fairly busy.

 

[Lazyboy]

Also look under the dash and see if the clutch master cylinder is leaking inside the car.

 

[Araesk]

If the master or slave were leaking, how come it literally only happens in third gear? But I'll check it out tomorrow. It wasn't last I checked

 

[vicore]

worn sncros i would suggest

 

[Lou98GSX]

winter time oil stays thicker longer . don't know what oil you are using but it should be 75 w 90 . if that doesn't help then the synchros could be worn . in my car it will grind once in awhile in 2nd and 3rd and my trans was rebuilt from team rip engineering .

 

[Araesk]

I threw the redline in and am letting the miles get to around 50 just from daily driving. From what I can tell, I'm able to use third a bit more. Hopefully as it gets more worked in I will be able to use it more and more. I'm really hoping its not worn out synchro's. Tranny only has about 149k on it.

 

[nelliott500]

Only 149k? That's quite a few miles. When I bought my car, it had ~153k on it and 2nd/3rd synchros were already worn so I had Jack's Transmissions rebuild it.

 

[Araesk]

Like I said in the original post, the tranny was just rebuilt prior to my buying the car. So hopefully they did a good job on it and I won't have to take it apart. I'm 87 miles onto the new tranny oil, and my use of 3 has greatly increased so that's a good sign. I'm just hoping it'll stay that way.

 

[95gstbeast]

i had the same issue. I used a different additive i got from a buddy that works for valvoline. i'm about 20 miles in and noticing an improvement

 

[Araesk]

Turns out when I drained the oil and put it back in the bottles I received, it didn't even fill up the 2 1Qt. bottles I bought. Meaning the previous owner was very low on oil. Which is pathetic considering they rebuilt the tranny and it makes me curious if they actually did a good job on it. Since I swapped though, its happened considerably less, and today was the first snowfall and was about 17°F out. Only grinded once in the morning. And the rest of the day it was fine. That's the 4th time since I swapped the oil its grinded, when before i was never able to get into third.