Rear Diff Leaking

[The Sequel]

This is my first post. I've ben reading the TDR since getting my truck in July 2000, but just got around to joining. My rear diff is leaking, more like seeping I guess. It is not leaving any spots on the driveway but has ran down all over diff. I'm at 32,000 miles (8,000 towing about 7,000#s) so it's still under warranty and I'm tempted to take it to them hoping to get a free fluid change. What do you think, is a small amount of seepage normal? I know I should change the rear fluid anyway but have never done it before, so I'm not sure what is involved. What do you think?

 

[JCockrell]

diff leak

If the leakage is coming from the yoke area, it is probably your pinion seal. Stealer will fix you right up. I had the same problem and they fixed. Whats cool about it is you get a fluid change on their nickel. Good luck.



Jeff

 

[JR2]

My front and rear diff covers both have a small seep. Not enough to leave even a drip on the drive way. I have a buddy that had the same problems and he took it to the dealer and made them fix it. I figure I will wait till I have enough miles on them to need a fluid change and then take it in and get them to fix it.

 

[LSMITH]

LONG post, wow.

Welcome aboard. I would take it in and make them fix the leak, you will get a fluid change out of it. I would also do it soon as you will be out of warranty at 36K without an extended plan. That will give you time to see if it leaks again. To answer your question, any seepage at all is not normal. It should be bone dry.



Changing it on your own is as simple as taking the cover off, the fluid will drain out then. Jack up one wheel for a minute or two and then the other for a minute as well to get the old oil out of the axle tubes. Clean all of the oil you can reach out with a lint free rag or towel, the bottom of the case will be filthy inside and that is normal. Clean all of the silicone off of the cover, clean the magnet, and put about a 1/8"bead of silicone on a dry clean cover. I prefer to use the grey RTV, I have had less leaks with it. Put the cover on and snug the bolts down, do not tighten them as tight as you can get them, you will force all of the silicone out. The bolts on the bottom of the diff case (maybe 6-8 of them) will also need some silicone on the threads as the hloes they thread into go all the way through into the oil inside the diff case. You will see the through holes when you get the cover off and everything cleaned. Tighten them so you get an even amount squished out all around the cover. Let the silicone dry for an hour, and snug the bolts again, then refill with oil. When you fill it fill to the bottom of the fill hole, then put the plug in loosely and jack one wheel up as far as you can. Let it down and fill it up to the bottom of the hole for the plug. Then jack up the other side and let it down, refill again. You should be full now. Jacking it up on both sides and then refilling is important, if there is not enough oil in there the axle seals and wheel bearings will not have enough lube on them and you will develop a leak in the axle seal or have a wheel bearing go out. Tighten the fill plug and go. Find a parking lot or wide spot and drive in a figure eight as tight as possible, do 4 or 5 to mix the oil and modifier and to get the new oil into the clutch packs.

Depending on what type of oil you use you may need to add some friction modifier. The amount will vary depending on what oil you use, the synthetic lubes will typically need less or even none as some of them are pre-mixed with modifier for use in a LSD. If you do not have a LSD then you don't need to worry about it at all, just fill it up and drive. If you need the modifier add the quantity needed during the initial fill. If you get chatter from the LSD after the figure 8's then add a small quantity of modifier and do some more figure 8's, if it still chatters repeat untill it doesn''t chatter.

This sounds a heap harder than it really is, it will take you about an hour the first time being very careful to get it all right. Don't be surprised to find that the cover is stuck to the diff pretty well. Be careful to not damage the sealing surface prying it off, if you do scratch or bend it a little just flatten it out and clean up the scratch, no big deal.

Hope this helps.



EDIT: I had no idea I was that long winded, maybe my wife is right If you let the dealer change the oil fixing the leak I would be sure to fill the diff as I described as soon as I got it home to be absolutely sure it is full. Don't be surprised if it is nearly a quart low, it usually is after they get done.

 

[Pit Bull]

Mine is bone dry after 36K miles. The truck as not and will not see much towing and hauling. I have a 100K wrap warranty and the owners manual does not call for the diff. fluid change unless you it is used for severe service, mine fits the never change recommendation in the owners manual. I like to maintain my vehicles (don't like to abuse the equipment) Here is my question. Should I have the dealer service the diff's (I'm not going to do it myself). Should I just run it and have it serviced at 80K miles which would Identify any problems and if serviced wrong would give it time for the problem to showup before my warranty ran out? Should I have them service it now and tell them to jack it up on both sides and watch and make sure they do it right?

 

[jwgary]

I seem to remember someone saying that there was a problem with the stampings on the cover that caused a small leak. The bottom left corner of mine is covered in lube, but it doesn't leak enough to drip. Now that I am getting some of my school debts paid off, I will probably spring for a Mag-Hytec cover and all those worries will go away.

 

[sdalton]

I had the same problem, and took it in for repair at around 30,000 miles. Three dealers told me they wouldnt fix it unless it was leaking enough to see it drip. They were all real jerks about it and one had the nerve to say that it wasnt covered because it should have been changed at 12,000 miles. he said houston is considered heavy or abusive use on the charts. He was the service manager at the 5 screw dealership in conroe. I had had enough and took it in to a local shop. the changed the fluid and resealed the rear for about $40. they put in fluid with a limited slip additive already mixed in. If you find a place to do it free, stick with them. Most dealerships around here suck.

 

[The Sequel]

Thanks for all the good info. I'll give it a try at the dealer and hope for the free fluid change. BTW, if they won't do it, where exactly is the rear pinion seal and how hard is it to replace?

 

[duaneparks]

Originally posted by sdalton

They were all real jerks about it and one had the nerve to say that it wasnt covered because it should have been changed at 12,000 miles. he said houston is considered heavy or abusive use on the charts. He was the service manager at the 5 screw dealership in conroe. I had had enough and took it in to a local shop.

I've had the opposite experience with Archer Dodge in Stafford, TX. They fixed this problem on my first Ram (a 1500) with no questions asked. They told me the seal was bad to begin with and that they'd take care of it. I never had a problem with it after that.



HTH.

 

[OILBRNR]

Sequel, I'd bet it is your pinon seal. This is up front around the yoke where the U-joing is that attaches to the driveshaft.



It is easy to figure out if this is the source, as there will be oil splater all under your bed in a direct perpendicular line to the seal. You also may have spots of oil on your tailgate that is carried back and up as you cruise at high speed.



Mine was leaking just a bit before I change to synthetic, then it really started leaking. Came back from a trip up to Flag, and wondered what was all over my tailgate, then looked underneath, and it was actually dripping on my driveway!



I have not yet addressed the problem...

 

[Fred Swanson]

Sequel and OILBRNR,

If you need any assistance, I'm here to help if you need it.



OILBRNR, how's the new baby doing?



You still planning on the changes sometime down the road?



Just curious.



I'll be in Vegas later this month for a week at DD. Something about Fords. And I have an install before then.



I'll be working on mine this weekend, and hopefully getting to another customer's VB to modify it, too.

 

[The Sequel]

Fred, I was looking for your shop this weekend. I PM'd you.

 

[Sled Puller]

Sequel,

You are not going to believe this, but some on this site would want you to believe the OIL is causing the leak. (makes sense, no oil, no leak, right?)



Could you tell the Dealer to go after the oil company for money to pay for the seal?

And let us know what they say???





I would appreciate it, it would help me make a point on another thread!!!



duaneparks,



They said the seal was bad to begin with? Thank you for that info, it will help some people out here learn a little, if the dog is not too old.



Hope you get this fixed,

Gene

 

[Ramboy]

Sequel,

If you do a search on pinion seal, you will find this is a fairly common problem on these trucks. Finally had to change the yoke to fix my leak.

Phil

 

[lschultz]

LSMITH well said. When we changed my sons we used the black gasket in a tube and he has not had any leaks. When I switched mine over to Amsoil I used the black on it and after about 20000 miles it was weeping too- not dripping. I pulled it off again and used the grey color this time and 45000 later no leaks. I'm sticking with the grey from now.

 

[mstephenson]

My 2500 leaked also. I took it to the dealer and they said the definition of 'leak' was dripping/spots on the ground. So they wouldn't fix it under warranty. I didn't have them fix it either.



I have had a bigger problem where the drive shaft goes into the transfer case.



mstephenson

 

[The Sequel]

Got it fixed

Great news! Took it in to Lou Grubb Dodge last night and they changed out the fluid. Said it was not the pinion seal (I agree based upon all of your descriptions). No questions, just changed it out for free. They also replaced my track bar assembly. Truck was pulling hard to the right and now it runs straight down the road. I had been holding the steering wheel about 3 inches off center to make it go straight down the road. They are also going to replace the interior carpet due to a hole wearing in it.

 

[Fred Swanson]

Sequel, great to hear. I've done business with Lou Grubb before, and they seemed easy to work with.