Servicing The Rear Diff And Repackin Front Wheel Barrings

[redwolf624]

so i went for inspection today and passed  :thumbsup: but the inspector recommended that i get my rear diff serviced and repack my front wheel barrings, i know how to do the diff service myself (i've done enough at work) but i was wondering what fluid to put in there. also repacking the wheel barrings i think i gotta replace the seals when i do that if i can't get em for a 86 comanche could i use a set off a cherokee and if so what year?

 

Redwolf

[Blue88Comanche]

click on the link in my signature.  there should be a pdf in there somewhere with fluid types and capacities.  I think 75w90 is standard

 

repacking the front bearings on dads 2wd 89 MJ was a simple task.  we also replaced the front brakes while we where there.  I think I had some pictures of the process in the build thread for dads MJ, also in my signature.

[AMCJeepMJ]

Redwolf, use 75w90 for both the rear diff and the manual gearbox. I use full synthetic and it runs about $8 for a quart at OReilly's.

 

Regarding packing your bearings, this is something you can do yourself; you don't need to go to a shop to have it done. I use a bearing grease packer similar to THIS ONE; it works well and is very easy. The manual packing method works too but takes longer. Be sure to clean the old grease out of your bearing before packing in new grease; I cleaned my bearings in gasoline and let dry before packing, but use your own method if you don't like cleaning in gas. Clean out the old grease in the hub while you have the bearing out; use something that isn't going to leave lint. I use THIS GREASE to pack bearings and I am happy with it; a can goes a long way.

 

A youtube video that shows both the packer and manual methods may be found HERE; I suggest taking a moment to watch before attempting if you've never done it before. Caveat: I have not watched the video with sound, so I don't know what the guy's saying, but even watching muted will give you a very very good idea of how to do it.

[redwolf624]

click on the link in my signature.  there should be a pdf in there somewhere with fluid types and capacities.  I think 75w90 is standard

 

repacking the front bearings on dads 2wd 89 MJ was a simple task.  we also replaced the front brakes while we where there.  I think I had some pictures of the process in the build thread for dads MJ, also in my signature.

i can use 75w90, 85w90 or 75w140 all depends on what i'm doin, i do a lot of scrap hauls and towing but don't know which one to use

 

Redwolf, use 75w90 for both the rear diff and the manual gearbox. I use full synthetic and it runs about $8 for a quart at OReilly's.

 

Regarding packing your bearings, this is something you can do yourself; you don't need to go to a shop to have it done. I use a bearing grease packer similar to THIS ONE; it works well and is very easy. The manual packing method works too but takes longer. Be sure to clean the old grease out of your bearing before packing in new grease; I cleaned my bearings in gasoline and let dry before packing, but use your own method if you don't like cleaning in gas. Clean out the old grease in the hub while you have the bearing out; use something that isn't going to leave lint. I use THIS GREASE to pack bearings and I am happy with it; a can goes a long way.

 

A youtube video that shows both the packer and manual methods may be found HERE; I suggest taking a moment to watch before attempting if you've never done it before. Caveat: I have not watched the video with sound, so I don't know what the guy's saying, but even watching muted will give you a very very good idea of how to do it.

trust me i know i don't need to go to the shop, my dad used to pack wheel barrings all the time on his vehicles, untill he got my mom's jeep no vehicle with his name on the title has ever seen a shop except for inspection and tires, i'm just wondering with the front axle (lack of a better word, it's not 4wd it's 2wd) i don't know what seal i need,

 

Redwolf

[nitroxsteve]

Any parts store can look up the seals for you. If they don't show it under the Comanche just use the same year Cherokee.

[Eagle]

i'm just wondering with the front axle (lack of a better word, it's not 4wd it's 2wd) i don't know what seal i need,

You need seals for a 1986 2WD Comanche. Why do you even have to ask?

 

 

http://www.autozone.com/autozone/parts/1986-Jeep-Comanche-2WD/Wheel-Seal-Front/_/N-iixsvZ8oxmo

[Blue88Comanche]

For towing and heavy use one of the manuals say to use full synthetic 75w140 or 90w140

[onlyinajeep726]

Synthetic 75w-140 for towing, 75w-90 for DD'ing.

 

On my XJ, I run 75w-90 in my front diff (open).  However, I'm running 75w-140 in my rear since I have a Spartan and I do as much wheeling as I can in 2WD until I'm forced to use 4WD.  Occasionally I pull a trailer also.

[redwolf624]

 

i'm just wondering with the front axle (lack of a better word, it's not 4wd it's 2wd) i don't know what seal i need,

You need seals for a 1986 2WD Comanche. Why do you even have to ask?

 

 

http://www.autozone.com/autozone/parts/1986-Jeep-Comanche-2WD/Wheel-Seal-Front/_/N-iixsvZ8oxmo

 

now why can't advance be that simple, if i look up wheel seals at advance i get an inner, outter, and center seal and i get a 1st design and a 2nd design, it makes no since to me,

 

Redwolf

[Eagle]

Those are for the 4WD hub/bearing assemblies.

[redwolf624]

Those are for the 4WD hub/bearing assemblies.

what are, the link or the 3 different seals and the 2 different designs?

 

Redwolf

[yxmj]

.......Walk into the parts store......tell them you want front seals........answer 2wd when he asks you 2wd or 4wd......pay for your purchase and walk out......... . :MJ 1: .

[Eagle]

 

Those are for the 4WD hub/bearing assemblies.

what are, the link or the 3 different seals and the 2 different designs?

 

Redwolf

 

The three different seals and two designs.

 

The original AMC hub/bearing units could be serviced -- you could purchase new bearings and seals, and rebuild a hub. The cost of all the parts was about the same as the cost of a complete new hub, so very few people ever did it -- and it required a 12-ton shop press to do the work. Chrysler changed the design, and the later ones are not considered to be user serviceable.

 

Parts to service ONE 4WD front hub (1984 - 1989):

 

 

And here's an exploded view of the front axle, with the front hub itself opened up to the individual parts:

 

[HOrnbrod]

86 MJ, all RWD (2WD) models, front inner seal. There is no outer seal on 2WD. National Seal p/n 6815.

Advance. O'reillys, everywhere...............

 

 

[redwolf624]

 

 

Those are for the 4WD hub/bearing assemblies.

what are, the link or the 3 different seals and the 2 different designs?

 

Redwolf

 

The three different seals and two designs.

 

The original AMC hub/bearing units could be serviced -- you could purchase new bearings and seals, and rebuild a hub. The cost of all the parts was about the same as the cost of a complete new hub, so very few people ever did it -- and it required a 12-ton shop press to do the work. Chrysler changed the design, and the later ones are not considered to be user serviceable.

 

Parts to service ONE 4WD front hub (1984 - 1989):

 

 

And here's an exploded view of the front axle, with the front hub itself opened up to the individual parts:

 

 

86 MJ, all RWD (2WD) models, front inner seal. There is no outer seal on 2WD. National Seal p/n 6815.

Advance. O'reillys, everywhere...............

 

 

ok so let me see if i got this right, for my 86 MJ RWD (2WD) all i need is the front inner seal, no outter, no center right? just really confused with this all and the fact that there is 2 diferent "designs". another thing, lookin at the exploded picture it looks like 2 seals and 2 bearing for one side of the axle, is that my lack of knowledge or me lookin at it wrong?

 

Redwolf

[HOrnbrod]

ok so let me see if i got this right, for my 86 MJ RWD (2WD) all i need is the front inner seal, no outter, no center right? just really confused with this all and the fact that there is 2 diferent "designs". another thing, lookin at the exploded picture it looks like 2 seals and 2 bearing for one side of the axle, is that my lack of knowledge or me lookin at it wrong?

 

IF your MJ is 2WD (RWD, same thing) forget the exploded view, all that is for a 4WD hub/bearing unit - you don't have these. You have a beam axle with a spindle on each side. That spindle has an inner and outer wheel bearing, bearing races, and an inner seal, nothing else. If you jack it up and pull the wheel, it will become immediately apparent. The bearings, races, and inner seal are all contained in the front wheel one-piece rotor/hub. The outer "seal" is the dust cap on the one-piece rotor/hub. Forget all the 4WD stuff that has been posted, it does not pertain to your rig. The only "seal" you need for your 2WD is the one I posted.

[Eagle]

Hornbrod is correct. I posted the exploded view of the 4WD hub/bearing unit to explain to you what the parts listing was you originally got from Advance (your post #9).

 

Here's a view of a setup similar to what you have (minus the rotor):

 

 

I'll have a better view tomorrow, but for some reason Photobucket is off-line at the moment.

[Eagle]

Here's a view that includes the brakes. This is not for a Cherokee or Comanche, but it's close enough to show you how things go together. The seal is the unnumbered part just outboard of the dust shield, behind the inner bearing.

 

[redwolf624]

ok i got it now, but one more question, bein that i'm just repacking my wheel barrings, do i just need to get the National Seal p/n 6815 posted above and do i just need 2, one for each side or do i need 2 for each side?

 

Redwolf

[nitroxsteve]

1 for each side.

[ajohnson928]

If it were me, I'd replace the bearings instead of replacing them.  They're cheap and the same amount of labor.  Unless, of course, you have already done that recently.  

 

To me it's just like replacing the clutch anytime you have the tranny out.

[HOrnbrod]

^^ This. 

[Eagle]

If it were me, I'd replace the bearings instead of replacing them.  They're cheap and the same amount of labor.  Unless, of course, you have already done that recently.  

 

To me it's just like replacing the clutch anytime you have the tranny out.

On a two-wheel drive? Why buy new ones, you have to pack grease into them before installing anyway, so why not just repack the old ones, like they're intended to be serviced?

[nitroxsteve]

if they are still good I would not replace them. I would clean innspect and repack. I would prefer a good set of OEM bearings in good condition than a cheap set of new bearings from an unknown maker.

[redwolf624]

i agree with yall, when i do the repackin i am gonna inspect the barrings, if they look 28 years old they're gettin replaced, if they still look good and strong i'm just repackin em,

 

Redwolf