75w90 in D30A? What difference will it make?

RED_KJ_666 · **Posted:** Tue Mar 24, 2009 11:29 am

I know alot of ppl say they use 75w140 but can I use the 75W90 without it hurting it? I'm not doing much Off-Roading right now and am just driving to and from work.I bought another Truck for Off-Roading 1994 Dodge Ram 1500 Short Box Regular Cab. The Libby just can't do what I want it to on my budget Off-Road.

ZERO6 · **Posted:** Sun Mar 29, 2009 2:40 pm

Use the 75/140 if it calls for it. Don't start skimpping
out. It is designed by the viscosity required for the
gearing and bearings used, it needs this to stay
properly lubed and cool. Don't forget that the diff's
are moving parts and are in motion when ever your
KJ is moving.
This also requires the required maintance, if not and
your KJ is out of warranty look at spending $3000.00 CND.
Thats to rebuild if it's rebuildable [ REAR Diff.]. I've bin there :cry:

tommudd · **Posted:** Sun Mar 29, 2009 3:08 pm

75/90 if daily driving, 75/140 if off roading / pulling a trailer a lot etc

RED_KJ_666 · **Posted:** Sun Mar 29, 2009 8:55 pm

I 75/140'd both ends the day I added this question so all is good.

Guest · **Posted:** Sun Mar 29, 2009 11:09 pm

ThunderbirdJunkie runs 75w90 in his front diff.

The helicopter mod will also prefer the lighter viscosity oil when it's finished.

JJsTJ · **Posted:** Mon Mar 30, 2009 8:23 am

split the diff (pun) and run 75w110 Severe Gear.

oddball · **Posted:** Mon Mar 30, 2009 10:02 am

JJsKJ wrote:

split the diff (pun) and run 75w110 Severe Gear.

That's what I was told is my both my diffs, and what I plan to do next time around.

sleeve84028 · **Posted:** Mon Mar 30, 2009 11:09 am

Most of the time it's recommended to run the higher oil weight because the front differental case is small and does not get very much cooling so the oil in it is subject to abuse.

DryBones · **Posted:** Wed Apr 15, 2009 1:22 pm

JJsKJ wrote:

split the diff (pun) and run 75w110 Severe Gear.

Front and rear? How many quarts to do both? and what about the transfer case? what weight and how much is needed? (can you tell I am planning my next self taught maintenance operation, right after I do my lift?) :lol:

tommudd · **Posted:** Wed Apr 15, 2009 2:49 pm

DryBones wrote:

JJsKJ wrote:

split the diff (pun) and run 75w110 Severe Gear.

Front and rear? How many quarts to do both? and what about the transfer case? what weight and how much is needed? (can you tell I am planning my next self taught maintenance operation, right after I do my lift?) :lol:

should be I think ( don't have my cheat sheet right here) :roll:

front diff 2 quarts
rear diff 3 quarts
Transfer case ATF-4
3 pints command trac
2 quarts 242 select trac

but then I am old and my memory..... is somewhere
but to old and wise you must first be young and stupid :wink:

oddball · **Posted:** Wed Apr 15, 2009 8:29 pm

Amsoil Severe Gear synthetic 75w110 is in both my diffs.
Synthetic fluid is a MUST in the front diff, and optional in the rear diff.
Note: If you have open diff's, no friction modifier needed.

Diff Capacity;
Front = 1.31 QTS or 2.60 Pints.
Rear = 2.19 QTS or 4.40 Pints.

Trans fluid = ATF +4 (I use synthetic in a 45RFE).
45RFE Trans Filter Kit = ATP # B-196 (includes pan filter & gskt).
ATP # B-200 (spin-on Filter).
Both are required for the 45RFE.

DryBones · **Posted:** Thu Apr 16, 2009 12:16 am

thanks Tom and Oddball. If I can go 75w-110 Severe Gear in both that is probably what I will do so I can buy it by the case. I do have 3 Libby's in the family!
Front is a drain and fill. What do I use to seal the rear after tearing it apart and cleaning it?

tjkj2002 · **Posted:** Thu Apr 16, 2009 1:27 am

DryBones wrote:

thanks Tom and Oddball. If I can go 75w-110 Severe Gear in both that is probably what I will do so I can buy it by the case. I do have 3 Libby's in the family!
Front is a drain and fill. What do I use to seal the rear after tearing it apart and cleaning it?

RTV,Ultra Grey is my choice.

JeepinJarhead03 · **Posted:** Thu Apr 16, 2009 1:45 am

lubelocker gasket was my choice

hehe

JJsTJ · **Posted:** Thu Apr 16, 2009 8:48 am

I have had perfect luck w/ Ultra Copper on everything I have used it on. Ultra grey would be my 2nd choice on RTV. Lube locker on rear diff now since it was cheap and available at the time and so far so good. Real touchy install and torque on that sucker though and never went through that process using any rtv.

JJsTJ · **Posted:** Thu Apr 16, 2009 8:55 am

DryBones wrote:

JJsKJ wrote:

split the diff (pun) and run 75w110 Severe Gear.

Front and rear? Yes.
How many quarts to do both? See oddballs post, I always sell 4 qts for the job and it seems to be enough on all KJ's
and what about the transfer case? what weight and how much is needed? I use the Amsoil ATF, it is an overengineered Full syn that meets or beats all suggested ratings. (darn good stuff)

(can you tell I am planning my next self taught maintenance operation, right after I do my lift?) Sounds that way, good time too, you will have more clearance to roll around under there! :lol:

fwiw, case prices on ATF (or other Amsoil lubes for that matter) are cheaper than single quarts.

DryBones · **Posted:** Thu Apr 16, 2009 11:39 am

JJsKJ wrote:

fwiw, case prices on ATF (or other Amsoil lubes for that matter) are cheaper than single quarts.

exactly why I wanted to get everything in one if I can. Just had my dealer do my tranny service so I just want to do the diffs and transfer case.

75w90 in D30A? What difference will it make?

Who is online