Driveshaft to trans seal issue

[MantisX620]

So I recently did my carrier bearing and everything seems fine but now, I have a small leak where the driveshaft meets the transmission.

 

My question is: Is the driveshaft supposed to push all the way into the trans? I ask this because when I tried to push mine all the way in, the bracket for the carrier bearing didn't line up to the carrier bearing, so I had to pull it out a little for everything to line up.

 

If it is supposed to sit flush against the trans, whats wrong? Driveshaft too short?

 

Thanks all

MantisX

[MicroMachinery]

I don't think your driveshaft shrunk while you had it out. If the carrier bearing bracket bolts in and lines up where it was supposed to be, it's probably where it should be. Your rear tranny seal probably just needs to be replaced. I just did mine two days ago. No biggie.

[ggzilla]

Question: Is the driveshaft supposed to push all the way into the trans?

 

Answer: No way, it requires some clearance.

[MantisX620]

I guess ill try another seal. Do you guys know the correct Rock Auto part number for this seal? All the transmission seals look the same.

 

Thanks

MantisX

[ggzilla]

When you get your old seal out, it will have numbers on it identifying it. Or just take it down to Nissan or to the auto parts store and they'll match it to a new one.

[MantisX620]

Well I replaced the seal and its still leaking! The same slow leak pretty much as before. Any ideas?

 

MantisX

[ggzilla]

Is the slip yoke worn? Is the transmission output shaft bushing worn? Is it the correct seal (fits tight on the yoke)?

[datzenmike]

Look for damage on the outside of the spline that goes into the tranny.

 

The old surface where the seal ran could be pitted or worn. New seals are often thinner front to back so that they will ride on a fresh 'un-worn' spot on the spline.

 

Be sure when prying the old seal out that you do not scratch the inside or the seal mating surface on the tranny.

 

Always rub grease on the seal lips before installing the spline to prevent tearing a dry seal.

 

The seals all look the same because most of the Nissan tranny seals ARE the same number. The 510, 520, 521, 620, 720, 280z and zx , 810/Maxima, 610 and 710 all use the same seal.

 

The Nissan # is 32136 E0100 but seals from NAPA, like I said are made to run on a new section of the spline and may seal better.

 

[MantisX620]

Yep, the very seal in your picture is what I installed datzenmike. So the seal is made on the spline only then? I made sure to grease the inside of the seal before installing. I wonder could I just try to find a seal with a tighter inside diameter?

 

Is it possible that the bearing/bushing holding the rod thats behind the rear seal is bad and is moving around allowing oil to seep past the seal?

 

Thanks for all the help everyone

MantisX

[ggzilla]

The seal is against the slip yoke. Nothing to do with the splines.

 

 

wonder could I just try to find a seal with a tighter inside diameter?

Why, is your slip yoke worn, have visible groove worn in it or pitting? That's the only reason you'd want a different type of seal.

 

 

Is it possible that the bearing/bushing holding the rod thats behind the rear seal is bad

Yes, a bushing keeps the output shaft from moving side to side. That could be worn. If you grab the yoke and shake it, can you see it move sideways relative to the seal or the tailshaft housing?

[MantisX620]

Hi all,

 

So I know this is an old thread but im back to trying to get this leak to stop LOL. The last comment by ggzilla got me thinking and im looking to locate the output shaft bushing. Does the transmission need to come out to replace this? I imagine id have to take the rear cover off and change it from there?

 

Thanks

MantisX

[BillM]

I don't know about the latest question but it sounds to me like your vent on the top of the transmission is plugged and when the trans heats up during use the case pressurizes and forces oil thru the seal.

Check that the vent seems clear and you may solve your problem.

BillM

[MantisX620]

Ill check that, but ive found that it leaks slowly even when the truck is sitting in the garage cold.

[Guest kamakazi620]

What Gear oil is in it??? I ran synthetic and mine leaked all the time,i switched back to GL4 and NO leaks.

[MantisX620]

Im running Coastal GL-4. Im about ready to buy another trans. Id like to park her in the driveway someday :)

[banzai510(hainz)]

rear output seal its called from the drive shaft.

 

I pry it out with a screw driver then insert the new one with a 2x4 to keep it flat put some grease. insert driveline

Find the double lip seals. SKF (usa made)sell them but they are only one lip. dont get this one.

 

rockauto.com or the nissan dealer

 

 

to replace this seal you got to drop the drive shaft and get the carrier bearing out of the way to pull the drive line out.(at least my 521) unlsee there is a ezer way for you.

 

driveline going into the yoke can be a little short as this adds for flexing of the frame.

[zed]

I have exactly the same problem with my Hardbody - I replace the gearbox extension housing seal about every 6 months. Nissan seals last the longest. A few years back I had the bushing ggzilla talks about replaced. I suppose it needs to be done again - it is something an amateur can do at home?

[MantisX620]

Ok so I think ive beaten the leak.

 

For those that dont know any better(like me) I found that I didnt drive the seal far enough into the trans. I had it sitting flush in the hole instead of recessed. This appears to have solved my leak! Now the damn things burning tons of oil lol.

 

Thanks

MantisX

[datzenmike]

I noticed the stock seal is wide front to back. The replacements go into the tail further and this may be to place the new seal on a fresher unworn part of the outer spline. Chevy front crank seals are this way also.