I’ve got a 1996 Nissan Skyline R33 GTS-T w/ an RB25DET engine. This is not the GTR; it is a rear wheel drive 5-speed transmission.
I noticed recently that it makes a grinding noise and requires a lot of force when shifting from 1st --> 2nd gear. Here are the facts as I know them:
a) The grinding noise does not happen all the time. I would say it happens about 7 out of 10 shifts.
b) When the grinding noise occurs, it takes a fair amount of force to shift into 2nd gear. Usually, shifting is pretty smooth, but in this case, you sorta have to crank it.
c) The rest of the gear shifts are fine. I.e. 2nd–>3rd, 3rd–>4th, etc. 3rd–>2nd is fine too, as is 2nd–>1st.
d) If the car is stopped, I can shift into 2nd smoothly; never feel any resistance here.
Now, the following is my conjecture and/or subjective observations:
a) It seems that this happens more often when I shift after reaching a higher speed. I’m not sure, but maybe > 15mph in 1st, and then shift into 2nd.
b) The way this feels to me is almost as if I let the clutch out early while shifting. That’s the best way to describe the feeling when this happens.
I haven’t taken the car to a mechanic yet, but I plan to do it soon. I was hoping to get an opinion or two about what this could be, and get an idea of what it’d take to fix. Since Skyline parts aren’t readily available, I’m hoping it’s an easy fix…
At this point, I’ve decided to avoid 2nd gear and just shift from 1st–>3rd. The car has plenty of power to do this, but eventually, I’d like to be able to use it like normal.
Thanks for any help!
Is the clutch fluid reservoir full? How many miles on the vehicle?
Will it grind if you double-clutch between 1st and 2nd?
The engine and tranny have about 25-30k miles. I haven’t tried the double clutch technique, that sounds like a good idea. Basically, just lift up off the pedal in neutral for a moment, then go back in? I’ll try that tomorrow.
Haven’t checked the clutch fluid yet. I’m embarrassed to admit how little I know about cars… Is there also transmission fluid separate from the clutch fluid?
Thanks!
The transmission has lubricant inside it, probably gear oil. The clutch uses hydraulic fluid.
If there is a leak in the clutch hydraulic system, the clutch may not fully disengage, which can make shifting difficult. Since you have difficulty only on the 1-2 shift, however, this may not be the cause.
Check the level of the transmission oil and the clutch fluid before you do anything else.
Do you have a service manual for this car?
It sounds like you have a problem with the clutch release system (master clutch cylinder and slave cylinder), or the clutch itself. Personally, I’m guessing the master and slave cylinders are at fault. This car is 12 years old. Even with the low miles, the rubber still deteriorates. Also, since Nissan never imported this car to the US, You may have to get the parts shipped from overseas.
BTW, the clutch release system uses brake fluid, and it is checked on a small reservoir under the hood near the brake reservoir. The transmission uses gear lube, and is checked by a fill plug on the side of the transmission from underneath.
Cool, thanks for the help! Sounds like checking out the fluids is the first and foremost thing to do. Unfortunately, I only have the engine manual; not a full service manual for the car. I do have the original user’s manual, but it’s in Japanese. Hopefully the pictures will help me find what I need. 
Yeah, getting parts may be a problem. I was hoping to bring it to a Nissan dealership, and hopefully they might be able to cross reference parts to use on it (maybe 300Z?).
If I need to order a clutch cylinder or clutch, I guess it’ll be a couple weeks. Until then, would it be ok to drive 1-3-4-5 or is that not a good idea? Also, I’m curious about that grinding noise… I’m guessing that I’m damaging the transmission, right? At any rate, it couldn’t be a good thing if I’m hearing it…
You can skip second gear with no problems. The grinding noise is definitely bad, and you want to avoid it whenever possible. What you are hearing is gears trying to mesh, but not meshing, and grinding against each other. Each time some metal is worn off. Not good.
What about the double-clutch? Does that help?
How does one go about getting a '96 Skyline in the US, anyway? I wish you luck at the Nissan dealer. They’re probably going to scratch their heads.
Haven’t tried the double clutch yet; will do it this weekend when I take the car out again after checking the fluids.
Yeah, I’m not too hopeful about the Nissan dealer. As long as I don’t need parts, I’m ok. Haha, what’s the possibility it’ll just be fluids? Oh well, it’s worth a shot, but I’m probably better off finding a guy with experience with the RBs.
There are many ways to get a Skyline into the US. Most are ILLEGAL, but there are two ways to do it right and be 100% on the up and up. If you decide to pursue this, it will cost you a fair amount of time & money. Send me your contact info or post it here, and we can talk off-line.
Thanks, but I’m not really interested in owning a Skyline. Just curious, since this is not a US model. I didn’t know there was a legal way to license one for the street. Sounds like a fun car, though. I hope you have good luck with it.
Do whatever works to minimize the grinding until you can figure out what’s causing it.
No worries. I appreciate the help! Grinding can’t be good. I’m confused why it only happens on that one gear shift…
The car is a lot of fun. Especially getting to know the other owners, and learning about their cars. EVERY Skyline in the US has a unique story, and it’s fun to learn about them, legal or not. Skylines show up on CL or eBay every now and then; most of them are illegal, but the ones that are legal will come with full documents (DOT).
just a heads up, what your describing sounds more like second gear synchro inside the transmission…you said it only happens going into 2nd gear? if it was your clutch fluid low you would have no or hardly any pedal and ALL gears would grind or be hard to select…being a specific gear the synchro cannot match the teeth up together in time and giving you gears grinding…have it checked to be sure and good luck