Dodge Challenger Forum banner

1 - 20 of 34 Posts

·
Premium Member
The Pork Wagon (‘14 Cop Charger)
Joined
·
6,493 Posts
Discussion Starter #1 (Edited)
Changing the gear oil in your Challenger’s rear differential may be on your list of preventative maintenances, but is it on the list of maintenances you will be doing yourself instead of taking to the dealership?

If not, maybe this thread will convince you it should be, as it is within reach of any decent shade-tree mechanic I do believe. Read on and judge for yourself though…

Here’s what I used to do this on mine:
- Floor jack and 4 jack stands
- Ratchet, wobbly extension, and 14mm hex driver (all ½” drive)
- 2 x 1qt. bottles of 75W-140 GL-5 synthetic gear oil
- 7 qt. drain pan & some clear plastic tubing (1/4” inner diameter)
- 13mm Ratcheting wrench
- teflon tape for plug threads

NOTE1: those last two are optional; I needed them, but you may not.

NOTE2: For anyone with a limited slip differential (LSD), your diff's internals require extra ingredients in the gear oil, BUT most modern day synthetic gear oils meeting the GL-5/MT-1 spec should already have them mixed in. Check the back of the bottle to verify though.

If you see something like "...recommended for limited slip axles...", then you are good to go with the gear oil by itself; no extra additives necessary!


First thing to do is jack your car’s back end up off the ground enough to allow you to get underneath it and do stuff. For me, that involved putting a jack stand under all 4 jack points, lifted up to the first notch on the stands. If you only want to do the rear two jack points, that’s probably fine, just be mindful of that when checking and refilling the fluid.

Next, you need to locate and identify the 2 plugs in the differential housing you’ll be dealing with: the drain plug and the fill plug (also used to check fluid level).

NOTE3: yellow arrows in pics below indicate Front-to-Back orientation of rear-end housing

The fill plug/fluid level check plug should be on the upper left side of the rear-end housing, toward the front:

fluid level plug 01.jpg


fluid level plug 02.jpg

The drain plug should be on the lower right side, toward the rear of the housing:

drain plug.jpg

Once you have them located and ID’ed, make sure you can get to the fill/level-check plug at the very least. Ideally, you would like to be able to get to both it and the drain plug, but if the drain plug is behind an exhaust pipe or something, you can still do this maintenance with access to the fill plug only.

HOWEVER, the reverse is NOT true.

If you can only access the drain plug for whatever reason, you need to punt and let the pros handle this maintenance for you!

Now, position the drain pan underneath your diff housing and remove the fill plug. If anything comes out, it should only be a few drops of gear oil. If more than a few drops come out, you either don’t have the car level on your jack stands or the rear-end was overfilled previously.

<continued in next thread post>
 

·
Premium Member
The Pork Wagon (‘14 Cop Charger)
Joined
·
6,493 Posts
Discussion Starter #2 (Edited)
<con't>

Next thing to do is remove the drain plug and let all the gear oil drain out, assuming you can access the drain plug that is.

When I did mine, I could not get to the drain plug because of the exhaust running right in front of it, so I attempted to drain the differential by siphoning the gear oil out of the fill hole with some clear plastic tubing:

siphoning fluid.jpg

drained fluid.jpg

That turned out to be a poor approach though, because the tubing I used was too small to allow for easy siphoning of the thick gear oil, and so it drained too slowly.

And to make matters worse, any time it sucked air and I had to move the tube inside the housing, I had to restart the siphon by sucking on the tube again, and let me tell you, gear oil tastes about like it smells – TERRIBLE!!

So after fiddle-farting around with that for a while, I finally deicided to unbolt the exhaust pipes (w/ a 13mm wrench) and manually move them out of the way so I could access the drain plug and finish the job right.

That did the trick thankfully:

plug.jpg

14mm hex.jpg

Once that drain plug is removed, the gear oil will drain out pretty quickly.

(You should end up with between 1.5 and 1.7 quarts of fluid in your pan BTW.)

While it’s draining, you can wrap the plugs in teflon tape in preparation for reinstallation. I don’t know that this is a requirement, but it certainly can’t hurt, right?

Now just replace the drain plug. Service manual says torque to 44 ft/lbs, but I just tightened it down to my best estimation, which I have every confidence will be fine, especially considering the same number of threads (3) are left showing as there were before it was removed.

Refilling the differential with gear oil is next, and that is pretty straightforward. I used 1.5 qts of 75W-140 GL-5 synthetic gear oil, but you should check what your rear-end requires specifically, as it very well could be different from mine.

UPDATE: see post #20 below for more info on newer rear diff's spec'ed gear oil weights

------------------------------------------------------
Again, you folks with an LSD rear-end need an extra additive for your rear-end's clutches, but most any gear oil you buy nowadays will already have those additives in them, as long as it meets all the specs, e.g. synthetic, GL-5/MT-1, and its the proper weight.

You can verify this on the back label of the gear oil bottle, look for something like
"...recommended for limited slip axles..."

Find that, and Bob's your uncle!!
------------------------------------------------------

To refill, I was able to just jam the bottle nipples into the fill hole and squeeze to get my fluid in; yours should be about as simple to do as well. If not, you may have to attach some tubing onto the bottle and run it into the fill hole to get the fluid in that way. Whatever works for you, do that obviously.

Once the fluid level is at the point of dripping out of the fill hole, you are done.

fill level.jpg

Reinsert that plug into that hole, torque or tighten down, and this maintenance is complete! Well, get the car down off the jack stands, and THEN it is complete.

Now make a note of the date and you mileage, and plan on doing this again in <insert your desired intervals here>. The books says to do it every 24 months or 30K miles. That is a wonky schedule for me, given how many miles I put on my car in a month (3500), so I plan on doing this maintenance once every 12 months. You should adjust your schedule according to your car’s needs of course.
 

·
Premium Member
Joined
·
567 Posts
I plan to do the fluid changes and brake pads and rotors myself I have a drive on lift in my garage that makes the under side work a lot easer. I am getting to old to be flat on my back using a floor jack and jack stands is a young mans job.
 

Attachments

·
Premium Member
The Pork Wagon (‘14 Cop Charger)
Joined
·
6,493 Posts
Discussion Starter #4
I plan to do the fluid changes and brake pads and rotors myself I have a drive on lift in my garage that makes the under side work a lot easer. I am getting to old to be flat on my back using a floor jack and jack stands is a young mans job.
Nice, but unfortunately that disqualifies you from attending any parties/get-togethers I might hold in the future...sorry, that's just a rule I have - if I'm insanely jealous of anything you have, I cannot in good conscience invite you to my shin-digs ;)

There is a loop hole to that rule that some have exploited in the past though...if you allow me unfettered access to whatever it is I'm jealous of, your name will somehow show up on the guest lists :icon_razz:
 
  • Like
Reactions: PaVaSteeler

·
Premium Member
Joined
·
567 Posts
You are welcome to use my lift any time but it will be a pretty long drive you better start out 2 days before you want to use it. Ohio and Texas are pretty far apart Here we are using it to reinstall my brothers 57 Olds front bumper because it weighs 80 lbs. the last time we had the bumper off was 1980 and we needed 3 people 2 holding it up and 1 putting the bolts in not much fun. this way it can be done by 1 person but 2 still makes it easer.
 

Attachments

·
Premium Member
The Pork Wagon (‘14 Cop Charger)
Joined
·
6,493 Posts
Discussion Starter #6
You are welcome to use my lift any time but it will be a pretty long drive you better start out 2 days before you want to use it. Ohio and Texas are pretty far apart Here we are using it to reinstall my brothers 57 Olds front bumper because it weighs 80 lbs. the last time we had the bumper off was 1980 and we needed 3 people 2 holding it up and 1 putting the bolts in not much fun. this way it can be done by 1 person but 2 still makes it easer.
An 80 lb. bumper?!?!

:jawdrop:

Holy SMART Car repellent, Bat Man!!

:eek:

Now, THAT's a bumper!! Yeah, definitely a job for a lift...I'd hate to have to try to mount that sucker with just some floor jacks and a couple buddies...can't imagine it ending up too good!

Between my current Challenger and the last one I owned, I have definitely done just about everything a shade-tree can do to one of these cars short of replacing major components like an engine or trans...and while I've managed to make it work with nothing but floor jacks, homemade ramps, and jack stands, there have definitely been times where I would have traded my 401K for a lift to finish up whatever problem job I was doing at the time.

Swapping out the OE springs/struts on my last Challenger for a set of SRT ones is at the top of my "damn, I need a lift to be doing this crap!" list though. Especially doing the rear springs...I was using a short-cut method which skipped dropping the rear cradle like the book specifies, and while it did save the hassle of dropping the cradle, it required becoming very adept (in a short amount of time) at maneuvering two different floor jacks at the same time to get everything lined up to allow for reassembly. I managed to invent some new cuss-words that day that would make a sailor blush when uttered out loud, in rapid succession, over and over. :cursin:

And then of course, there was that near-death experience at disassembly of the same rear springs where I got mad at that one bolt because it was stuck in between the control arm and the exhaust pipe and said, "to hell with it" and cranked down on it with the impact, only to have it suddenly spring free and go flying into the door frame, embedding itself an inch or so...pretty cool to see, but good thing it was moving so quickly as it flew by my face at mach 2, missing me by only an inch or so, because I didn't have time to realize how close death I had just come, and thus I didn't have a chance to soil my underwear right there on the spot. :yikes:

Ironically enough, I've been thinking I want to do the same spring/strut mod to my current Challenger, but now that I think about it a little more, I believe I may have to come up with a better plan before I dive into this one...like taking a trip up your way :D
 

·
Registered
Joined
·
9,456 Posts
I plan to do the fluid changes and brake pads and rotors myself I have a drive on lift in my garage that makes the under side work a lot easer. I am getting to old to be flat on my back using a floor jack and jack stands is a young mans job.

I can't figure out from your pictures how high the car goes up in your garage with the car on the lift. Doesn't look like you have high ceiling. Or I could be wrong.
Love that 57 Olds by the way. Looks amazing.
Nuke, sorry to hijack your thread. Great writeup as usual.


Sent from AutoGuide.com Free App
 

·
Registered
2015 Scat Pack
Joined
·
2,230 Posts
Subscribed...(Nuke, you need your own "ChallengerTalk Channel"....your stuff is too good to miss!)
 
  • Like
Reactions: Nuke

·
Premium Member
The Pork Wagon (‘14 Cop Charger)
Joined
·
6,493 Posts
Discussion Starter #10
I can't figure out from your pictures how high the car goes up in your garage with the car on the lift. Doesn't look like you have high ceiling. Or I could be wrong.
Love that 57 Olds by the way. Looks amazing.
Nuke, sorry to hijack your thread. Great writeup as usual.
Heck, I don't consider a good day unless I can find at least one thread here on CT to hijack myself, so I don't reckon I mind others doing the same to me :grin2:


Subscribed...(Nuke, you need your own "ChallengerTalk Channel"....your stuff is too good to miss!)
Thanks...I'm actually just trying to catch us up over here on ChallengerTalk with where those yahoos* over on ChargerForums already are. They got lots of write-ups over there. Only thing is, theirs are all jumbled and not intuitive to find...not to mention, not especially well written IMHO. So I figure we better set the standard for DIY write-ups over here on CT!

And seeing as I am about to clock 100K miles, it's a perfect time for me to do all these 100K mile maint. services and write em up as I go.

* (yes, I am allowed to call them yahoos over there because I am a CF member as well!)


If you have the "Limited Slip" do you need an additive like on older Sure Grip rear ends?

Does this stuff still have that distinct odor?
You know, that's a good question, and I'm glad you brought it up. I remember reading somewhere while researching the rear diff fluid change for mine that there is an additional additive necessary for the LSDs, but I did not make note of it and so I cannot reference it here. :frown:

But that's a pretty important piece of info if you have one, so I will at least edit my original post above to point out there may be an additional additive necessary for LSDs, and more research is necessary in that instance.

Thanks!
 
  • Like
Reactions: PaVaSteeler

·
Premium Member
The Pork Wagon (‘14 Cop Charger)
Joined
·
6,493 Posts
Discussion Starter #11
...

Does this stuff still have that distinct odor?
Oh yeah, it's definitely got that gear oil smell...something akin to sour milk, stagnant pond water, and toe jam all mixed together into one aromatic scent!!

And as of the other day when I did this maint., I will now be able to recognize its unique taste any time in the future as well...and let me just say that it tastes about as good as it smells, if that gives you any hint... :icon_puke:
 

·
Premium Member
The Pork Wagon (‘14 Cop Charger)
Joined
·
6,493 Posts
Discussion Starter #12
If you have the "Limited Slip" do you need an additive like on older Sure Grip rear ends? ...
I amended the original posts to include a note and a reminder to anyone with LSD rear-ends that they need to make sure to find out if an extra additive is necessary, and if it is, hopefully they will reply back with the info for the rest of us.

thanks again for catching my slip-up here, limited as it might have been...

<groan>

yes, that pun was intended...and yes, it sounded much better in my head than it does now that I read it out loud...oh well, I'm leaving it in!!

Nuke, OUT!!
 
  • Like
Reactions: Frank Julian

·
Registered
Joined
·
5,856 Posts
Oh yeah, it's definitely got that gear oil smell...something akin to sour milk, stagnant pond water, and toe jam all mixed together into one aromatic scent!!

And as of the other day when I did this maint., I will now be able to recognize its unique taste any time in the future as well...and let me just say that it tastes about as good as it smells, if that gives you any hint... :icon_puke:
You drank skunk juice!!! LOL
 

·
Premium Member
The Pork Wagon (‘14 Cop Charger)
Joined
·
6,493 Posts
Discussion Starter #14
You drank skunk juice!!! LOL
I didn't drink it, but I definitely got a good taste of it when trying to restart my ill-conceived siphon using a too-small tube stuck in the fill hole. After that, I decided I'd had enough and unbolted the exhaust so I could get at the drain plug and do it right. BLECK!!

Although, in the interest of full disclosure, I guess you could say that I did drink some skunk juice, if you count the nasty IPA flavor of Blue Moon I tried for the first (and last) time. I had me a sampler 12 pack, and there were 3 of their IPA flavors in it, and I tried one while doing this maintenance. I did NOT care for that flavor at all, and that's saying something with as big a homer for Blue Moon as I am!

In fact, I poured that one out and the other two as well, as I didn't want to accidentally drink them sometime in the future if they were left in the fridge as frags for someone else to have.

I swear, for the life of me I'll never understand why everyone is so in love with the IPAs nowadays...the next one I try that I can stand more than one swallow of will be my first!!
 

·
Premium Member
The Pork Wagon (‘14 Cop Charger)
Joined
·
6,493 Posts
Discussion Starter #15
I plan to do the fluid changes and brake pads and rotors myself I have a drive on lift in my garage that makes the under side work a lot easer. I am getting to old to be flat on my back using a floor jack and jack stands is a young mans job.
As I was sitting here day-dreaming about the day that I too have a lift in my shop, it suddenly occurred to me that there is one definite drawback to going with the lift over jacks & jack-stands like I have now -- it will kill off my inner redneck's ingenuity at jerry-rigging solutions to problems I might face while working on my car.

For example, if I'd had a lift when I did my trans fluid and filter change recently, I would have never had need to invent The Trans Pan Caddy Man

Getting the job done more quickly and with less hassle is one thing, but depriving myself of my most favorite outlet for creative expression is a big price to pay! :weed:
 

·
Registered
Joined
·
9,456 Posts
Most gear oils now these days come with the friction modifier already mixed. Usually It'll say on the bottle. I changed mine with Mobil 1 75W-90. 1.4 qt is how much it took. That's the 226mm Getrag LSD 3.92 differential.
ImageUploadedByAG Free1491235715.873262.jpg
The 15+ models come with the ZF differentials. It seems like they're noisier than the Getrags. Some extra modifier usually does the trick.



Sent from AutoGuide.com Free App
 

·
Registered
Joined
·
14,388 Posts
This high dollar Mopar 75W-85 GL5 supposedly has the additive, I'd still put some in.

68083381AA

Sent from my SM-G550T using Tapatalk
 

·
Premium Member
The Pork Wagon (‘14 Cop Charger)
Joined
·
6,493 Posts
Discussion Starter #18
Most gear oils now these days come with the friction modifier already mixed. *Usually It'll say on the bottle*. I changed mine with Mobil 1 75W-90. 1.4 qt is how much it took. That's the 226mm Getrag LSD 3.92 differential.
View attachment 789985
The 15+ models come with the ZF differentials. It seems like they're noisier than the Getrags. Some extra modifier usually does the trick.



Sent from AutoGuide.com Free App

Now that you mention it, this is on the back of the bottle I used: "Recommended service fill lubricant for limited slip axles."

So I guess it does have the additive LSDs need already in the mix...good deal, one less thing to buy, spill, recycle, etc.

BTW, I ending up going with Super Tech 75W-140 gear oil...I was hesitant to use a house brand oil at first, but I figured as long as it's a synthetic gear oil and meets the GL-5 & MT-1 specs, it'll work just fine for my Challenger's rear pumpkin.

Thanks for the info!
 

·
Premium Member
The Pork Wagon (‘14 Cop Charger)
Joined
·
6,493 Posts
Discussion Starter #19
This high dollar Mopar 75W-85 GL5 supposedly has the additive, I'd still put some in.

68083381AA

Sent from my SM-G550T using Tapatalk
My 140 weight oil seems like the odd man out here...is 85/90 weight what Dodge specs for all the new(er) rear-ends? (Haynes manual specs 140 for 2005-10 rear diffs)
 

·
Registered
Joined
·
14,388 Posts
My 140 weight oil seems like the odd man out here...is 85/90 weight what Dodge specs for all the new(er) rear-ends? (Haynes manual specs 140 for 2005-10 rear diffs)
Pretty much they spec the 75W-85 or 90 with limited slip and 85W-140 for open axles. With ZF rear, looks like they recommend 75W-85 with all and using the Mopar number above with LSD or the standard 75W-85 without.


Sent from my SM-G550T using Tapatalk
 
1 - 20 of 34 Posts
Top