Guys -

Can someone hook me up with some scans (or evan a fax) from the service manual about the process of changing the rear differential oil.

I'm sure it's straight forward, but I like to do things, "by the book." I want the torque spec's on the bolts and the oil that the factory recommends. However, I'll probably go back with a synthetic (which opens up another can of worms ... I'll do a search about that, advice welcomed).

I'm mainly doing this to check the tone ring to see if its damaged due to an ABS problem I'm having. And to check this tone ring forces a lube change. No biggie, it needs it anyway.

Anyway, if someone can scan me those pages, including info on the tone ring, I would greatly appreciate it. Thanks.

dodgetech77 said:

Quote:

Id pull the diff cover and check to see of the tone ring is damaged. I had one a couple months ago at the shop that the trac lock retainer came apart and smashed a tooth on the tone ring and caused the same condition.

- JyRO

 

Guys - I have learned a ton about this tone ring. Basically I fully understand it. So here's my plan:

Plan A - I'm going to replace the rear differential fluid. While I'm in there I'm going to check the tone ring. I suspect the tone ring is OK. If there is a problem with the tone ring, then I'll go to Plan B.

Plan B - Buy a new tone ring and replace the sucker myself. I've found all kinds of drawings and info (service manual), and I don't think I'll have too much of a problem doing this.


I have a couple questions for anyone who would be nice enough to advise me:

Question - Does anyone have advice on if I should use a flushing oil or lint free cloth to clean the housing cavity? Where would I find either of these?

Question - I'm going to do a search for synthetic rear end lube, but I'm wondering if anyone might make a suggestion on a brand / type. The question is: If I use synthetic, will I still need the friction modifier (I assume yes) and would I use the same amount of friction modifier (10 oz.)?

Thanks for any help.

- JyRO

 

Question - Does anyone have advice on if I should use a flushing oil or lint free cloth to clean the housing cavity? Where would I find either of these?


I just wipe down with a old cloth that does not look like it will produce lint. An old t-shirt will work well, avoid terry towels. I don't feel a rear diff calls for a special lint-free rag, now if you are working on the insides of a VP44 then a lint-free rag is essential.


Question - I'm going to do a search for synthetic rear end lube, but I'm wondering if anyone might make a suggestion on a brand / type. The question is: If I use synthetic, will I still need the friction modifier (I assume yes) and would I use the same amount of friction modifier (10 oz.)?




I use synthetic Mobil SHC 75w90, in Alambama you might want a 80w140. Friction Modifiers are only needed if you have a limited-slip.

 

I use plain old kerosene to flush my differential when changing fluid.
And also, I'm not too worried about a lint free cloth in this application.

I have tried several different full synthetic gear lube viscosities, and have found 75W-90 to yield the best MPG. I have the Dana 80 limited slip and have never had to add any additional friction modifier. If you have limited slip, remember to drive several figure of 8 patterns in a parking lot to get the new fluid worked in the clutch packs. If you have chatter, buy the friction modifier, but only add small amounts at a time until the chatter stops. Too much additive will render the limited slip useless, and will act like an open differential.

I have also found the orange high temp RTV silicone to be the best sealant gasket. No leaks using this stuff. Just let it set for at least an hour before driving the vehicle.

Just my experience. Sorry, no help on bolt torque specs.

Regards

 

Good advice above. I usually just hose out the differential with brakeclean, the same stuff I use to do the final clean on the sealing surfaces before I add the sealant. My favorite sealant is Permatex Ultra Grey.

 

Have you tried 75w110 yet?

Jim

 

If I recall, I think it is 35-40 ft-lb. I may be wrong though.
Is 75-110 ok for towing?
I have seen guys use a can of brake cleaner to spray the ring and inside of the diff out. The liquid runs out, and the film evaporates.

 

You dont need the service manual...

Pull the cover off, clean the inside of the diff real good with brake cleaner (preferrably the low odor stuff) I usually use a can or so, wipe out diff with a rag (dont forget the magnet), take a quick look at the ring gear, clean up the cover (I usually paint mine), run a bead of silicone and button it up. Theres no real need to use a torque wrench here.

Dont forget the friction modifier if you have a limited slip.

 

Brake cleaner isn't compatible w/ diff oil....synth or dino. Make sure you let the film dry and mop out the bottom of the carrier housing as I noticed a lot of brake cleaner pooled in it when I did mine. Its a pretty thick cover, I just snugged the bolts and re-checked 'em after a week of driving and looking for leaks. Permatex ultra grey was suggested and is leak free after 5K miles.

 

Just a question .... Why bother with the brake clean I am not sure if it is a good idea to "Completely clean" the gears etc... most if not all gear oils are compatible and that way there is no metal to metal contact without a thin layer of lubricant. just wipe out the bottom of the diffy and cover plate with a clean cloth and reinstall the bolts "Snug" and fill up with good 75W90 gear oil as it states in the owners maual(06). BTW I used Lucas brand 75W90 and it seems to work well. Also in my owners manual with my limited slip it said not to use any friction modifiers what so ever apparantley they are needed (06) diffys.

 

We are talking second gens here with Dana differentials - they are different the the AAM diffs you have. In most cases, the Danas require friction modifier.

Dont have to use brake cleaner....personal preference I guess. I will more than likely continue to use it in mine though.

 

A few things I do, change after a long trip in truck , no need for break cleaner if oil is hot. I don't like the thoughts of solvents in there around clutches etc.., open cover let that drain for a min then jack up each side for about 10 min a side to drain tubes , let sit over night draining come back in morn. scoop out puddle of oil in bottom with finger then use a rag to wipe dry.Now the foolish part , after cleaning cover and gasket surface with razor blade , break out the break cleaner , spray the cover off then go to the lower bolt holes and spray it in them till no more oil in them and then take a rag and a screw driver and stuff the rag in the bolt holes to dry them up. This is the most important step because when you put bolts back in with oil in there or break cleaner it comes back out on your new silicone and may cause leaks. I'm pretty **** you'd think the truck was in surgery if you were watching me do this. lol. The main thing is keep everything clean because ya don't want to do all this and then see a drip, and have to go through that again.

 

Wow, When I do my next change I will do it exactly as you have, I think you have it nailed!
BTW I agree with the solvent comment.

 

I just blow the holes out with an air nozzle after cleaning them. I also let the sealant cure for some time before filling oil.
It's important to get the speed sensor clean, I use an old clothes hanger with a rag and some brake cleaner on the rag to get the gunk off.

 

A few comments. I spent a lot of time reading the service manual, and searching forums, etc. etc. to learn about the tone ring and in turn, the differential.

george7941 - Why do you suggest that because I'm in AL that I use 80W - 140? The service manual suggests: thermally stable SAE 90W. Geno's website info says basically the same thing: thermally stable SAE 80W - 90.

ruralmedic - The service manual specifically says: "Do not use water, steam, kerosene, or gasoline for cleaning." So I would be hesitant to use kerosene if I were you. Kerosene is a heck of a good cleaner. Maybe too good in this case, and possibly the worry is drying out the clutch pack in the limited slip. I dunno. Oh yeah, I have the service manual, so I'm good to go with torque spec's.

I'm pretty **** about following torque specs.

caper - I like the idea about jacking one wheel up at a time to get the fluid out. Thanks for the suggestion. I'll be following that. And because my truck is not a daily driver I will let it sit overnight and drain.