Water level vs differentials
09-22-2013, 11:48 PM
#21
JK Junkie
09-23-2013, 12:42 AM
#22
JK Jedi Master
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Your owners manual will show you the weight. Some stay with dino, some move to synth. I tend to change it yearly so just run the cheap dino.
With a lift, both axles should be tilted and may not hold the amount you may see listed. And some aftermarket covers allow more fluid, so be sure to not overfill with those.
With a lift, both axles should be tilted and may not hold the amount you may see listed. And some aftermarket covers allow more fluid, so be sure to not overfill with those.
Last edited by nthinuf; 09-23-2013 at 01:05 AM.
09-23-2013, 02:13 AM
#25
JK Jedi Master
How to change your diffy fluid (it's really quite easy) ...
wayalife.com/showthread.php?7836-MAINTENANCE-Jeep-JK-Wrangler-Differential-Fluid-Change-Write-Up
For oil weight and stuff, refer to the Owner's Manual, which you can download here ...
Jeep Owners | Download an Owners Manual 2004 - 2011 | Jeep
However, if your Jeep differential has been modified, be sure to consult the literature that came with those mods. For example, my front D30 cannot use synthetic fluid because of the Auburn Ected locker--dino only.
Also, if you use dino and you have an LSD (stock on some JKs in the rear), be sure to use a tube of friction modifier. If you don't that axle will probably chatter while you're driving. There are various brands available--often a parts store will just carry one, so just ask. Here's one on Amazon: amazon.com/Red-Line-80301-Friction-Modifier/dp/B000CPCBGE.
If you are opting for synthetic lube, then it will say on the bottle if it is suitable, WITHOUT modifier, for use with LSD axles. To be honest, I've never seen a synthetic that needed the friction modifier--they all say suitable for LSDs.
If you're not sure if you have a limited slip diff (LSD), here is how to check for that (unless you know a vehicle's history, it's best to do these checks rather than send out for a build sheet--there are lots of mods folks are doing out there to Jeeps and the older it is, the more likely things are different than when it left the factory). Also, do be aware that if the LSD is worn out, it will look like an open diff during this test. In that case, I wouldn't worry about the friction modifier because the LSD clutches are shot and unlikely to chatter.
http://www.youtube.com/watch?v=TI8ewn6HOjg If you have stock diffy covers, just fill it until it runs out the fill port. However, if you have aftermarket covers, these generally have the fill port placed higher. Why? Because when we lift vehicles it rotates the axles, moving the fill ports lower. By moving the fill port higher, aftermarket diffy covers allow you to put oil to the proper level. But, you can have too much of a good thing. Overfill the axle and it will get churned up in the axle and start spitting out of the overflow tube. It makes a big mess, and causes anxiety when you first notice your Jeep spilling its oily guts out on the tarmac. If you have extended your breather lines to the snorkel like I have, then that mess will be pumped into the engine air intake--a bad idea. Here is the correct height to fill an axle (if your diffy cover doesn't have a dipstick, use a ziptie formed into a small loop as one--dip the small loop into the oil to gauge where it's at).
wayalife.com/showthread.php?7836-MAINTENANCE-Jeep-JK-Wrangler-Differential-Fluid-Change-Write-Up
For oil weight and stuff, refer to the Owner's Manual, which you can download here ...
Jeep Owners | Download an Owners Manual 2004 - 2011 | Jeep
However, if your Jeep differential has been modified, be sure to consult the literature that came with those mods. For example, my front D30 cannot use synthetic fluid because of the Auburn Ected locker--dino only.
Also, if you use dino and you have an LSD (stock on some JKs in the rear), be sure to use a tube of friction modifier. If you don't that axle will probably chatter while you're driving. There are various brands available--often a parts store will just carry one, so just ask. Here's one on Amazon: amazon.com/Red-Line-80301-Friction-Modifier/dp/B000CPCBGE.
If you are opting for synthetic lube, then it will say on the bottle if it is suitable, WITHOUT modifier, for use with LSD axles. To be honest, I've never seen a synthetic that needed the friction modifier--they all say suitable for LSDs.
If you're not sure if you have a limited slip diff (LSD), here is how to check for that (unless you know a vehicle's history, it's best to do these checks rather than send out for a build sheet--there are lots of mods folks are doing out there to Jeeps and the older it is, the more likely things are different than when it left the factory). Also, do be aware that if the LSD is worn out, it will look like an open diff during this test. In that case, I wouldn't worry about the friction modifier because the LSD clutches are shot and unlikely to chatter.
http://www.youtube.com/watch?v=TI8ewn6HOjg If you have stock diffy covers, just fill it until it runs out the fill port. However, if you have aftermarket covers, these generally have the fill port placed higher. Why? Because when we lift vehicles it rotates the axles, moving the fill ports lower. By moving the fill port higher, aftermarket diffy covers allow you to put oil to the proper level. But, you can have too much of a good thing. Overfill the axle and it will get churned up in the axle and start spitting out of the overflow tube. It makes a big mess, and causes anxiety when you first notice your Jeep spilling its oily guts out on the tarmac. If you have extended your breather lines to the snorkel like I have, then that mess will be pumped into the engine air intake--a bad idea. Here is the correct height to fill an axle (if your diffy cover doesn't have a dipstick, use a ziptie formed into a small loop as one--dip the small loop into the oil to gauge where it's at).
Last edited by Mark Doiron; 09-23-2013 at 04:14 AM.
09-23-2013, 03:52 AM
#26
JK Jedi Master
To add to this great picture....
An oil quantity number is of little value to anyone wanting to know how much oil to put in the differentials.
The specs don't seem to agree with how much the diffs really take.
The important thing to know is, the oil level must be above the bottom of the axle tube, so it can flow out to the axle bearings in the rear axle, and get into the carrier bearings in the front axle.
An oil quantity number is of little value to anyone wanting to know how much oil to put in the differentials.
The specs don't seem to agree with how much the diffs really take.
The important thing to know is, the oil level must be above the bottom of the axle tube, so it can flow out to the axle bearings in the rear axle, and get into the carrier bearings in the front axle.
Last edited by ronjenx; 09-23-2013 at 04:01 AM.
09-23-2013, 04:18 AM
#27
JK Jedi Master
To add to this great picture....
An oil quantity number is of little value to anyone wanting to know how much oil to put in the differentials.
The specs don't seem to agree with how much the diffs really take.
The important thing to know is, the oil level must be above the bottom of the axle tube, so it can flow out to the axle bearings in the rear axle, and get into the carrier bearings in the front axle.