Transmission advice

[erikgiles]

When I push in the clutch on my 70 240 (with a 78 transmission) its impossible to shift into gear (reverse or 1st), unless I let the engine run for a few minutes, in neutral. Then I can shift but its difficult.

After a little driving it shifts well, but whenever I start i go through this process. What's wrong and what should I do?

[hmsports]

When was the last time you checked or changed your transmission fluid? It almost seems like it is old and viscous - once things heat up, it flows easier.

This may be a good first place to start.

Rick

[erikgiles]

Thanks alot! I'm not really much of a mechanic (yet!) but I'm learning all the time -- can you tell me how to check this? I do have 2 Z shop manuals.

[hmsports]

Raise all four corners of your car and support it on jack stands. Try to make sure it is level - and solidly and safely supported.

If I remember correctly, the inspection/fill port is on the passenger side of the transmission. And again, I can't recall if the plug takes a 1/2" ratchet post or an allen wrench to remove. Either way, carefully remove the plug - I'm sure your manuals have details on doing this.

The fluid level should be such that any more in the transmission would cause it to run out of the hole. If you have a suction canister, you can suck some of the old fluid out to check its condition. You might just want to drain it anyway. The drain plug looks like the inspection plug but it is on the bottom of the transmission.

You may want to replace it with a good quality synthetic gear lube. I'm sure there are others on the site that have recommendations for this. If your old fluid is real gummy, you may have to clean the transmission out. I'm not sure of the best way to do this - maybe someone else can assist here.

Good luck.

[erikgiles]

Well, the drain plug is missing on the bottom of the transmission! Any idea where to get one?

I noticed the symptoms right after I took my Z to a repair shop for some welding underneath.

The one on the side is still there.

[carguyinok]

Have you been on the road without the lower plug in???

[carguyinok]

for sale 4 speed with new centerforce clutch. Let me know.

[hmsports]

Sounds like the repair shop may be looking for some extra business on repairing your transmission.

I'm not sure of the size or thread, but I'm sure the plugs are a dime-a-dozen at a junk yard - find an old Z and scab one from it.

May have caused some permanent damage to your bearings if you drove a long time without fluid. Get a plug, fill it up and hope for the best.

[erikgiles]

Yeah, I drove it home (about 12 miles) from the shop after I picked it up. It shifted, but not smoothly.

The bolt I am looking at has a square head about 1/2 inch. This is the correct part, right? I see the side one, but on the bottom all I see are threads.:sick:

One thing got me thinking - on my way out of the shop when I dropped it off, I saw another Z heading in the direction of the shop - probably a coincidence I rarely see those around here - it got me all paranoid after the malfuctions on my Z after the visit to the shop.

[2ManyZs]

If you only drove it 12 miles without transmission fluid, it probably hasn't done any permanent damage yet. Just don't drive it till you have refilled it and then it's time to find out why the repair shop took the plug out in the first place (if they did). The drain plug on the bottom as a 1/2 inch socket head, the one with the square head is used on the fill plug, the drain plug should be one with a socket head so that it can't get ground off in the even of an "off road excursion" or whatever. If it ever did get the square head ground off, it would be nearly impossible to remove it.

I have used Red Line's MTL(Manual transmission lubricant) in all my Z's since I raced years ago, it is a bit lighter viscosity than the mineral based lubes and it is a bit easier to shift with it. It is a bit expensive, but you should only need two quarts to fill the trans.

You can get it from Pegasus Racing supplies(I put their link in the web-links) or any other racing parts supplier.

[erikgiles]

I'm going to top off the tran fluid after I replace the plug. I'd rather get a new one than go to one of these junkyards around here.

Do you think the nissan dealer's have these parts?