Hey everyone,
I’ve got a 2003 Xterra, RWD, manual transmission, with around 110k. It’s been giving me a little trouble shifting into gears 1-3 when the weather’s below 30F. It started doing this when I got the transmission fluid changed last, about 2 years ago. I took it back to the mechanic who fixed it immediately, and he changed the fluid a second time for free, but when the problem persisted, he said he had no idea. Needless to say, I haven’t gone back to him. Since then, I’ve tried to ignore it (not too hard in sunny NC), but it’s getting worse and I’m about to move to Chicago, so I think I should fix it before I move to the land of harsh winters. My first guess would be the tranny fluid weight might be a little low and I should try a heavier weight, but I’m worried it might be more serious. Any thoughts on what’s going on besides this? Thanks for all your help!
In addition to the correct type and amount of tranny fluid, check out the hydraulic fluid in your clutch master/slave cylinder. Maybe have it flushed & bled. Perhaps moisture has built up over time and this is freezing in the cold weather.
What kind of trans fluid is specified in the owners manual?
Did the mechanic use the same kind?
A heavier fluid/oil would make the problem worse, I think.
I meant to say that I was considering a lighter fluid… 
Anyways, Nissan recommends a 75W-85 fluid, but I know its more common for mechanics to put in the thicker 80W-90, since it’s more available and cheaper. It’s possible that the mechanic I went to put in the 80W-90 without even thinking about it. I’m not sure what fluid was put in…
It looks like others are having the same or a similar problem. I just found this site: http://www.clubxterra.org/forums/showthread.php?t=8449. Everyone there seemed to think it was the fluid. What do you guys think? I like Goldwing’s clutch cylinder suggestion, but I wonder how likely this is… Is that a common enough problem that I should have it investigated? I imagine even getting that looked at could get quite expensive.
Your master & slave clutch cylinder probably uses an inexpensive brake fluid. Consult your owner’s manual. Check the level. Perhaps you can change out some of it with a turkey baster? Flushing/bleeding it shouldn’t be expensive.
Based on that website, it looks like a lighter weight tranny fluid should help.
THe fluid vicosity is WRONG…sometimes shops assume that the “gear oil” in manual trannies is actually “Gear Oil” THIS IS NOT ALWAYS THE CASE… I have seen many many manual trannies that actually take ATF Fluid as thier lubricant! Surprising if you know what you are talking about in the auto world…I was wowed by this for some time when I first encountered it.
You MUST ask them what fluid PRECISELY they put in. You MUST find out EXACTLY what NIssan put in there. There is only about 3-4 qts in there anyway…so buying it from Nissan shouldnt be too painful…whatever the cost…YOU MUST use what Nissan Used. If a garage doesnt have the right stuff go and get it yourself and pull the drain plug and fill…its EZ to do…IT MUST be the right stuff or equivalent. If you go aftermarket then there is no guarantee you will hve the same result as what came out of there from Nissan. This def the issue.
The solution is to buy it from NISSAN…their gear oil may behave much differently than others…I have seen equivalent viscosity labeled oils look and feel MUCH different from each other. I dont know why but its true… Nissans 75W-whatever may be way different than another makers identical weight oil… WHY? I have NO idea…and no i dont like it…it is just a fact…
I think a problem with the clutch cylinders would affect the shifting even when the trans is warm.
Still, I like to change brake and clutch fluid every 3 years.
So it’s time for you to get that done anyway, IMHO.
Back in my rookie days I got a clutch replaced at an AAMCO
and they put gear oil in my 1975 Civic, which called for 10W-40.
I knew something was very wrong before I got to the end of the block.
If there is no symptom at all at 34 degrees and a noticeable problem at below 30 degrees, I don’t think you can rule out freezing moisture.
Yeah, I’m going to go ahead and change the transmission fluid as well as the clutch cylinder fluid just to be on the safe side. It’s way less than $50 to do the clutch fluid, and seeing as how I haven’t changed it since I bought the car 110k ago, it’s probably time. I’ll probably have time to do it Tuesday or Wednesday, so I’ll post the results shortly thereafter. Thanks for all the help everyone. I’m glad to see that no one thought my transmission was shot… That would have made me sad. 
So, I changed out the transmission fluid, clutch hydraulic fluid, and adjusted the tension on the clutch. Sadly, things have gotten even worse. It’s now like pulling teeth to get the car into 1st and 2nd, and it hurts my soul to force it in. I had trouble finding the 75w85 oil locally for the transmission, so I ended up putting in 75w90. Is this potentially an issue, or should it be “close enough”? Should I go back in put in Nissan Branded transmission fluid for $17/qt? Could my clutch be bad and need replacing?
$17/qt isn’t so bad compared to opening up the tranny to see what’s what.
I had to break down and pay $9/qt to get my '88 Accord to shift properly.
It called for 10W-40, but motor oils had changed the friction modifiers over the years.
For What It’s Worth, Nissan Recommends Nissan MTF HQ Multi 75W-85 Oil. They Require This Fluid For Any Warranty Repairs And Will Not Reimburse Dealers For Consequences Of Using Alternatives.
I think Honda Blackbird is onto something.
CSA
It would appear your ideas have been substantiated to some extent. I just went out and bought the Nissan oil, put it in, and I can really tell a difference. The car is now shifting much smoother than before. It’s still not perfect, but then again, the clutch is pretty old and I’ve essentially been grinding gears for a while now by using the wrong oil in the first place. The car’s pretty warm right now, so I’ll drive it in the morning for a real test, but this is certainly a step in the right direction. Thanks for the advice everyone! I’ll let you know how the test goes tomorrow.