Tcase slip yoke leak

[ramv]

This is pretty newby... But it somewhat fits this as it is a common tow rig

I have a light leak on my NV 246 output. It is the std style slip yoke like the 241, 231, 261 all have.

How hard is it to replace the output seal? Just pull the drive like, slip the slip yoke and ?? I have to admit seals, are not my forte. How do you pull it with out damaging the case?

Just replaced the oil cooler line, so fixed the oil leak, but now I need to stop the final drips in the driveway.

Thanks!

[FullsizeYota]

Pull the shaft, catch the spoon full of oil that should come out when you remove the slip yoke. From there it's pretty east, the seal has a lip that seats it on the output housing. Shouldn't take you more than 5 minutes to replace it.

[4x4mike]

I replaced the one in my Chevy a few times and it still leaked. I was told there is a bushing in there as well that might have something to do with the sealing. Replacement of that required removing the tail section. You'll need a seal puller. My first one was a little hard to get out. I was really reefing on it and thought I was going to crack the aluminum around the seal. Let me see if I can dig up some pictures.

[4x4mike]

Here is the replacement Timken seal.







Old leaky one. You can see the underside of the body that's all oily. The fluid would leak over night and them fling off when I started driving.


Here's what it looked like after I got it out.


I used a lisle puller I got from sears and the cheap l shaped puller from Harbor Frieght. To put the seal in I used a chunk of HDPE with a big hole drilled in it. Hole goes over the output shaft and wail away.

[Phill]

buy two seals Aaron, then when you mess the first one up trying to put it in you will have a spare (I always do), and if you dont mess up the first one, when it starts leaking again, and you decide to replace the bushing in the tail section you will have the seal already.

How many miles does the avy have now?

[ramv]

Only 62 000, I guess my fixed yoke in the Dodge leaks, but I don't really care much there...

Ok, so I misread the second post, replacing the bushing requires pulling the tailhousing but the seal is just a matter of pull the d shaft..

HDPE? Cutting board plastic?

[ramv]

Two seals ordered up from Rock Auto...

Still need to get a puller and some more Autotrac II fluid...

[4x4mike]

Originally Posted by ramv

Only 62 000, I guess my fixed yoke in the Dodge leaks, but I don't really care much there...

Ok, so I misread the second post, replacing the bushing requires pulling the tailhousing but the seal is just a matter of pull the d shaft..

HDPE? Cutting board plastic?

Correct on both counts. To replace the seal pull the shaft, I had more than the claimed teaspoon of fluid come out. Put driveshaft aside and yank out the seal being careful not to score the AL tailshaft or break it. It's a press fit so the new one will take some finesse to get in. The HDPE was just thick plastic. With the hole drilled in it, it allowed me to wail on it and get the seal in straight. If you don't get it in straight it'll get stuck and be hard to get out. I couldn't find a whole lot on the bushing replacement, I was looking for a write up or something. Because I was getting ready to sell the truck and didn't really care I didn't do it. I'm not sure if that requires special tools or know how.

[4x4mike]

Now that I'm home I have more pictures from my seal replacement.




Plastic


All the tools used.

[ramv]

Seals showed up from Rock AUto saturday...

Tried to get started but the fill plug was way tight. Case had "No impact" imprinted into it, so I used a cheater bar.... Which promptly rounded the 18 mm hex off.

I screwed around with it yesterday and manage to get my impact lined up with a 3/8" universal and back it out.

No one had GM Autotrac II in stock in town, so I will try today....

Ugh. Projects.

Dodge ran like a top other then the leakign valve stem on Saturday though...

[4x4mike]

Wow, it said no impact? Mine was a 30mm. Before I had a large enough socket I always used an adjustable wrench. Good luck tomorrow.

[ramv]

Yeah, it says NO Impact wrench on drain or fill plugs. I figured it out later. Aluminum plugs!

Anyway put a new seal in last night. Not five minutes, but less then an hour.

Picked up a fluid pump from Checker -- $5.99 (works like a shampoo bottle with a hose, much easier then pouring into a funnel)

Picked up a seal puller and brake cleaner at Autozone -- $17.50

Picked up 3 qts of Autotrac II and a replacement fill plug at the Chevy Dealer -- $33

Two seals at Rock Auto -- $50

So total repairs was about $110, but i have a spare seal, a spare quart of fluid, and the transfer pump and seal puller for next time.

I realized while working on it, why mfgs changed to some of the stuff that off roaders hate. It sure was easy to pull the straps and slip yoke style d-shaft. Just a 7/16" 1/4" drive ratchet and about two minutes. I did use a pry bar to pop it out of the yoke, just because its easy that way. The seal puller only took 3 or 4 trys to grab the seal and knock it out, which hit my magnet light and knocked it into my face.....

I then use my Dana 70 wheel bearing socket ( 2 9/16" -- perfect) to drive the seal in. Also went well.

Put in 1.5 quarts of Autotrac II and called it a night. Hopefully I didn't hurt the case running it low on fluid, I think it only holds about 2.5, but it wasn't hot and didn't smell burnt at all... (And it was new fluid from the summer).

[KWTMECH]

There is a chance that changing the seal will not work--again. There is a factory defect on those cases. If you follow the groove up the casting (above the seal) to where there is a rubber plug, you may find a hole in the casting. That hole is from a stainless steel clip/retainer inside of the case that helps hold the pump. That clip works back and forth creating a hole in the case. The only fix/update is to replace the back half of the case available at your local dealer. Chances are they have about 3-4 of those in stock

[ramv]

I thought that was only on the 261s? I have seen people "repair" it with silicone, but I know there is a kit you can put in when you have it apart...

I will keep an eye on it...

The problem is only fluid loss, correct?

[KWTMECH]

I've done 2 autotrac cases with that problem

[ramv]

I had no idea, I thought it was an issue with the magnesium case...

Well I will take a look at it.

What's involved in the replacing of the back half of the case? Obvously pull the entire unit out of the truck, but do bearings have to be pressed on and off?

Hopefully it was just the seal, whats a case half run? $500?

[ramv]

Looks like $70 for the problem solver
http://www.riversidegear.com/categor...oduct-630.html
and
$339 for the rear case
http://www.riversidegear.com/categor...oduct-618.html

A new case appears to be about $1500....

[Mud Slayer 2.0]

Originally Posted by ramv

I had no idea, I thought it was an issue with the magnesium case...

Well I will take a look at it.

What's involved in the replacing of the back half of the case? Obvously pull the entire unit out of the truck, but do bearings have to be pressed on and off?

Hopefully it was just the seal, whats a case half run? $500?

you can actually do the job with the case in the truck but it is soooooo much easier to pull the case and do it on the bench.. basically pull the big rubber plug out and there's a snap ring you have to hold open as you pull the rear case half off..

[guidolyons]

RamV, was there a wear ring on your slip where the seal rides?

I had one that would not stop leaking, after the second seal replacement, I took some super fine scotchbrite and polished the slip up a little. Slap some grease on the lip of the seal. G2G

Edit: Also, if you don't booger up the old seal too much, (i.e it's still kinda round) I flip it around and use the old seal to drive the new seal in.

[ramv]

Ok so the seal isn't leaking any more. (I am sure it was leaking before).

But I did have fresh fluid on the outside of the case! Nice green stuff.

I inspected all over and could not find a hole. Also the interesting thing is it was startign much lower then described in this thread for the hole. about the same level, or a little lower then the fill plug. Its concievable it ran across when I over filled it, but....

The rubber plug area down to the slip yoke is perfectly dry.

It almost seems to be leaking between the case halves? Never seen one do that before.
I will look again for hole, any one with a picture of the likely location (s)?

That snap ring would be the death of me if I tried to pull it apart in the truck I fear....

[mudevil]

246, 261 and 263s are all magnesium cases and the hole the oil pump wears in them starts at the bottom not the top. The 07 up new body style went back to alum. cases.

[ramv]

Huh, I had no idea the 246 was magnesium. I have learned a lot in this thread. Unfortunately, it looks like I also learned I will be spending some time and $$$.

Leaked about 150 ml in 2 days, 140 miles. Don't think that is seepage. I stared at it for twenty minutes last night and couldn't find the hole.

Oh well, guess I will go aftermarket. I would complain about GM, but I have blown my BW 13-54 in my Ranger (High Range Planetaries) at ~ 80 000 miles, and my 231 DHD in my Ram 1500(it stayed together but seized up) at 50 000 miles, so I guess its just par for the course.

[heybob]

This is the pump rub hole location for a 263xhd, not sure if your tcase has the same problems, wouldn't hurt to check.

[ramv]

Yeah, exactly there. I put some silicone on it, and have about 900 trouble free miles so far...

[heybob]

If that fails just jb weld the crap out of it, a lot of people get away with it like that