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Old 11-26-2020, 09:25 AM   #1
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Default Something leaking on the transmission

Hello everybody

Recently started having problems when changing gears, sometimes just can't put into 1st or reverse when the car is at a stop. Sometimes it's also just impossible to downshift to 3rd, 2nd and 1st.

Took a look at the transmission realized there's something leaking. Any idea what's the name of that part, what it does, and what it could be leaking?

If i touch that dark cap some kind of greese/oil comes out a bit.

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Old 11-26-2020, 01:14 PM   #2
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Neutral safety switch? A leak from the toploader's seal?

Have you checked the fluid level yet? It may be fine, or low. Do some reading about the proper, old-school fluid that is required.
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Old 11-26-2020, 02:56 PM   #3
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Like I said in your other thread. Check the fluid level of your transmission before you do anything else. There's a plug opposite side of that switch in this picture. That may solve your shifting problem.
At least it doesn't look like it's leaking down from the shifter boot.
If it solves your shifting problem, great. Then you can do things like fixing that leak.


and it sounded like you should check and flush the clutch cylinder system too with brake fluid.
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Old 11-26-2020, 08:31 PM   #4
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That's your backup light switch. There's a little O-ring in there and that's probably where it's leaking from if you can't trace the leak to anywhere higher up. You don't necessarily need to replace the switch, either. Just find another o-ring in the appropriate size that is rated for oil exposure.
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Old 11-28-2020, 02:36 AM   #5
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I think you would have to leak a ton of fluid out of that tranny to start affecting how it shifts. This sounds more like inadequate 'throw' on the throwout bearing, or the beginnings of a bad clutch. Or your slave cylinder might be leaking, which will cause the arm not to want to move back and forth as it should.

Have someone pump the clutch while you look at that slave cylinder and the arm going to the throwout bearing. The arm should have good back and forth movement. If it barely moves, you have air, or a leak, between the clutch fluid reservoir under the hood, and the slave cylinder. Most of the time it is the slave cylinder leaking.

If you bleed the clutch from the slave cylinder, and then make sure the clutch fluid reservoir is full afterward...and then now you are getting good movement on the throwout bearing arm...but the thing still won't go into gear...

You could be looking at a clutch replacement.

I also see that your leak is 'not much at all'. Looks minimal. And you have no leaking near the slave cylinder. Do the pump test with a friend first, see if the throwout bearing arm is getting good back and forth. If it is, you are probably good up to that spot. Almost sounds like clutch problem.
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Old 11-28-2020, 11:17 AM   #6
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Quote:
Originally Posted by rockcrawls View Post
Like I said in your other thread. Check the fluid level of your transmission before you do anything else. There's a plug opposite side of that switch in this picture. That may solve your shifting problem.
At least it doesn't look like it's leaking down from the shifter boot.
If it solves your shifting problem, great. Then you can do things like fixing that leak.


and it sounded like you should check and flush the clutch cylinder system too with brake fluid.

Thanks for the suggestion!
Replaced the master cylinder fluid with brake fluid Dot3. Also replaced the transmission fluid with Nissan 75w85, but the problem is still there...
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Old 11-28-2020, 11:22 AM   #7
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Quote:
Originally Posted by XoXSciFiGuy View Post
I think you would have to leak a ton of fluid out of that tranny to start affecting how it shifts. This sounds more like inadequate 'throw' on the throwout bearing, or the beginnings of a bad clutch. Or your slave cylinder might be leaking, which will cause the arm not to want to move back and forth as it should.

Have someone pump the clutch while you look at that slave cylinder and the arm going to the throwout bearing. The arm should have good back and forth movement. If it barely moves, you have air, or a leak, between the clutch fluid reservoir under the hood, and the slave cylinder. Most of the time it is the slave cylinder leaking.

If you bleed the clutch from the slave cylinder, and then make sure the clutch fluid reservoir is full afterward...and then now you are getting good movement on the throwout bearing arm...but the thing still won't go into gear...

You could be looking at a clutch replacement.

I also see that your leak is 'not much at all'. Looks minimal. And you have no leaking near the slave cylinder. Do the pump test with a friend first, see if the throwout bearing arm is getting good back and forth. If it is, you are probably good up to that spot. Almost sounds like clutch problem.
Thank you for all the suggestions!

Replaced the master cylinder with brake fluid Dot3 and as well as the transmission fluid with Nissan 75w85 to give me some peace of mind.

Also tried that pump test with a friend but everything looks good. The slave cylinder boot also looks to be in very good shape, so I suppose it was replaced at some point.

Also realized that thhe black boot from the shifting stick is all torn up, if you touch it water falls down. Could this have any relation with the shifting problem?

2 angles of the boot. I think it's called transfer gear control boot.




Went to 2 mechanics to hear their opinion and they both said that the synchros probably gone bad...Hope they're wrong lol

Last edited by PFDSA; 11-28-2020 at 11:27 AM.
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Old 11-28-2020, 03:22 PM   #8
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I think that boot is for your 4wd shifter, not the main shifter.



After changing out the transmission oil (with GL4) and clutch fluid (with brake dot 3), is there any change at all in shifting?


Shifting on these trucks is so finicky. If things aren't just right they show symptoms like you are experiencing. I had a similar situation and I'm not sure exactly what I did that finally fixed it so I'm curious to know how this turns out.
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