New World Datsuns...

Changed the seal and went for a spin.

At first I was getting some spraying, then changed to a slow drip. So I might have to live with that. Ill For sure keep an I on it. But I believe I can drive the truck more. As I'm slowing down there's a humming vibration.. not sure if it's bad or not just noticeable. Once I get more moneys I'll have the means to take it in to get looked at and fixed. It just feels odd having someone other then my self work on my truck.

Move back. I'll look at it.

I need to get it way in the air.

I have found turning the radio up real loud fixes a lot of things, well at least temporarily.
I have heard there is more than one seal for these 5 spd. transmissions, but I have never had a bad one that I had to change.

The two I have are different a little. The inner rim is taller on one then the other.

I went for another drive and it leaked again the same way.
Lots at first then it slowed down to a drip. Was able to drive a ways so the air passing by can clean up some of the oil that made a big puddle. Either way I am still losing some oil, more then I'd like.
Should I take the washers out from under the trans? An see what that does for me?

I have never dealt with the 520 one piece driveline, I don't know what to tell you.
Regular height trucks have way more angle coming out of the rear of the transmission, so I don't believe it is angle that is causing your leak, without being their it's hard to diagnose anything.
If the driveline is out of balance or not far enough into the back of the transmission, that could cause an issue, in the same respect if the driveline yoke is jammed into the back of the transmission, that likely could cause an issue also, that would depend on if the yoke shaft where it ends is hitting the face of the seal.

If I didn't leave my stock drive line the tri cites I'd put that shit back in! This is getting pretty irritating..
I'll go get the drive line checked to make sure it's balanced I guess.

The drive line is in pretty far, when I finally get the bitch in the transmission I have to pull it back out just a tad. I feel like the yoke is in there enough but maybe it's not and it really needs to be a far into the transmission as much as it can go. But it then seems like there wouldn't be any play in the drive line yoke for travel.

That sounds about right, almost all the way in without it bottoming out ever.
The photos of the seal make it look screwed up big time, I can't even tell if the seal was in backwards.
Just to clarify, the seal goes in with the flat face out/towards the rear.

uberkevin » Sat Oct 04, 2014 3:57 pm wrote:If I didn't leave my stock drive line the tri cites I'd put that shit back in! This is getting pretty irritating..
I'll go get the drive line checked to make sure it's balanced I guess.

The drive line is in pretty far, when I finally get the bitch in the transmission I have to pull it back out just a tad. I feel like the yoke is in there enough but maybe it's not and it really needs to be a far into the transmission as much as it can go. But it then seems like there wouldn't be any play in the drive line yoke for travel.

Heres the new seal I put in today.
Got it flush with the end of the transmission.

Did you slide the seal on the yoke to see how it fits before you installed it?

Yes sir. It was snug.
Seemed good to go, so I went. Ha.

And this one also leaks?

uberkevin » Sat Oct 04, 2014 4:42 pm wrote:Yes sir. It was snug.
Seemed good to go, so I went. Ha.

Yep. Seems less with this one.

Again I'll check to see that the drive line is balanced. I'm not sure how one can mess that up. I had it balanced..
but again would it leak as much as it is just being unbalanced?
Also i don't have a deadly vibration while I'm driving only on decell.

And I wouldn't say it's that bad of a vibration. But what do I know.

I haven't read your thread entirely , but check your slip yoke surface.
I guess we all know that crankshafts , and slip yokes alike will get a groove cut into them over time (but moving your seal should help that like you did).

If you have a bushing/sleeve in the rear of the transmission that could be worn (not sure which one you have).
Feeling for tolerance or play that can seem a bit much in all directions or it putting to much stress on the seal itself.

Any vibration is bad, but there are different vibrations also, so what your vibration is could have nothing to do with the driveline, or it might have everything to do with it.
Are you the one that cut and made your driveline?

Okay.
Here's what I did.



Got under the bitch and unbolted the DL.
Push it in the transmission as far as it would go.
This leaving a 1 1/2esh gap from the rear diff to the drive line.
However as you can see the yoke is pretty long. That's a 720 yoke being it came with my 720 short transmission.
There's a lot of the yoke in the trans when all is bolted together.
However maybe that's still not enough.

Wayno,
I took the DL to a shop.

Here's what happened.
I didn't type here on NWD 'this thread' that I had the drive line balanced with the 720 yoke on it... I first had it balanced without the 720 yoke on it... I did get it balanced... just with the flange that has the 4 bolts holes that bolt to the slip yoke what has a plug in it..

I feel dumb. I had to look through my thread to see that I didn't remember not getting it balanced again. I guess dealing with moving, packing, not being in the er for stomach pain Annnnd braking in a newly built lz2.3 while keeping the gf from flipping out all got to me and I just couldn't remember.
Fuck I really hope this is it and I didn't get it rebalanced.

But if it's balanced then well..

When you jacked up the truck did the rearend drop some, if it did that would pull it out of the end of the tranny a little or make the gap larger, if you jacked it up, and then put jack stands under the rearend housing and then dropped it onto them and made your measurement, that would be the truest measurement your going to get.
I will admit that it would have been better to balance it with the yoke on it, but if the driveline has been balanced, I don't think the yoke will make that big of a difference.
I actually mis-measured my 47 chevy pickup driveline about an inch short, it did not leak for years and it was a huge/heavy one piece, but eventually it did start to leak, a weenie little 520 driveline that is half the size couldn't be that bad.
Your sure it is the seal, right?