ericdwong

My cars been up on jackstands for the past few days as I'm redoing my exhaust system. I degreased my engine and I noticed my transmission has a slow leak. I have pinpointed the leak to (I dont know the proper terminology) this black roundish unit that has a cable coming out of it. Anyway, I'm considering what is the best way to take care of this leak. I'm thinking to drain the M/T fluid (it was changed only 5,000 miles ago and is synthetic) into a clean container, and then using RTV or a similar gasket maker. Or, I will see if replacing the gasket on the "black roundish unit" is feasible.

emax02

iTrader: (1)

The black roundish thing is probably your reverse cable thingy. Best way to describe it . I am sure there is a seal or a bolt that can be tightened. I bet D.B.M. knows all about it.

QikEnuf

I had a slow leak from my tranny as well, and it order to fix it, the damn thing needed to be rebuilt, apparently there are seals on the inside of the tranny that you can't replace without cracking the thing open. I couldn't pin point where my leak was coming from so you may have something different wrong. Mine was on a 96

Not sure if this helps you in anyway but just a thought

Daniel B. Martin

That "black roundish unit that has a cable coming out of it" is the Park Neutral Position switch. That's a strange name for a component on a 5-speed transmission, but that's what Nissan calls it. This switch controls the backup lights and also signals the Engine Control Module when the gearshift is in Neutral.

The PNP switch is secured to the transmission case with one bolt. There is an O-ring behind the black plastic part which you can see, and perhaps that O-ring should be replaced.

If you remove the PNP switch all the gear lube will come out, so be ready with a catch pan. Some Maxima 5-speed owners prefer to use the PNP switch as a drain plug because the "official" drain plug is difficult to reach. What's more, the factory makes drain plugs far too tight.

Neptune97

I also recently put synthetic M/T fluid in my car, and while I was reading up on the benefits of it, I noticed that several people developed a very small leak like the one you described (not necessarily at the Park Neutral sensor) once they started using synthetic...it might just be the viscosity of the oil, and maybe its nothing to worry about ???

Daniel B. Martin

Any leak is something to worry about. If you have a leak you should measure it. That's easy with engine oil because the dipstick makes it convenient to see how much has been lost. It is less convenient to measure loss with a 5-speed.

When you know the rate of leakage you can decide what to do about it.

Rapid loss (1 quart per week) ==> fix immediately.
Moderate loss (1 quart per month) ==> fix within 30 days, watch the level until then.
Slow loss (1 quart per year) ==> don't fix; replenish as required.

mitch33x

iTrader: (5)

Do you have a slight leak from your tranny after adding synthetic? What brand did you use, Mobil, Redline? Is the shifting a lot smoother? Thanks...

Neptune97

I put in Redline MT-90 and I don't have any leaks to speak of. I don't really notice much of a difference when shifting, but I've been told I will during the winter (only recently put it in so I haven't had a chance to test that)