Gunna change Transfer case & diff fluid...give some input in here

[astrochimp]

I saw the discussion a little lower on Tranny fluid.

I want to use a synthetic in the transfer case and also in the differentials.
I have 60k miles on a 98 XLT 4wd. The haynes manual says to change transfer, tranny, and diffs fluid.
Ford manual says to do tranny and transfer.
WHich is right?

When I figure out what fluid to use on the transfer and diffs...is there any input you could give on the procedure? Maybe some tips?
I have the haynes manual but that doesn't always give the full story. I haven't had to do this kinda stuff(transfer and diffs) before cuz i haven't owned a 4wd vehicle before.

I'm going to have the local oil shop do the tranny fluid cuz they flush out the whole system.

THANK YOU

 

[astrochimp]

bumpidy bump

 

[aldive]

Originally posted by astrochimp
I'm going to have the local oil shop do the tranny fluid cuz they flush out the whole system.

It would a good idea in addition to the complete tranny fluid change to also have them drop the pan and change the filter too.

Good luck......

 

[Robert]

Your Haynes manual uses a generic schedule. If you can believe Ford, the differentials are filled for life. The only time they recommend replacing the fluid is if you tow or have submerged your axles in water. My rear was done when I had my rear wheel bearings replaced last year. If it weren't for that, I wasn't planning on changing my fluid until I hit 100Kmiles (another 13K from now).

The transfer case fluid is easier to change than changing your oil. Remove the lower drain plug and the upper fill plug on your transmission. It takes the end of your 3/3" ratchet. Catch the fluid in a suitable container. You should get about 1 3/4 quarts out. Put the lower plug back in and fill the transfer case through the upper hole. Fill the fluid until it just starts to run out of the hole. Put the upper plug back in. Get a good pump to pump the fluid into the transfer case since there isn't enough room to lift the bottle up there and poor it in.

 

[BUCHVILLEMAN]

use ATF (your preference) in your tcase (3 pints.) same as your tranny. i would get the tranny flushed and filter changed ($75-90 at a shop) to ge the full benefit. tranny holds 11quarts, if you change it yourself (which there is nothign wrong with - i do mine myself) you are only changing 3-4 quarts or so.

diffy fluid grade should be listed in your owners manual - i cant remember right off hand. i got kendell oil last time and it seems to be of good quality. if you have limited slip get posi/limited slip additive for traction+.

the only tiem you need to change your diffy fluid is when youve submerged the diffys for any extended amount of time and there is the chance of water getting in. i have had this happen.

 

[astrochimp]

"if you have limited slip get posi/limited slip additive for traction+. "

How do I know if I have it? We bought this used and the book says the same thing about adding the additive.

I'm going to check the fluid on the diffs and if it looks good then i'm gunna leave it alone.

I'm gunna buy Mobil 1 synthetic for the Transfer case.

I can't find Synthetic 75w-140 anywhere for the DIFFS.
It's always 85w-140 or 75w-90.

Thanks

 

[addkev]

How do I know if I have it? We bought this used and the book says the same thing about adding the additive.

Look on the inside of the drivers door. There is a sticker with various info on it. Look under Axle. There should be a 2 digit code. Then do a search on here for "Axle Codes". That will tell you your gear ratio and whether or not you have a LS or open diffs.

 

[towdriverb]

i have a 5 spd 4x4
-just had it done atf transmission and transfercase
gear oil in diffs and only recomended if suspected water contamination

 

[astrochimp]

"-just had it done atf transmission and transfercase"

I"m gunna check the diff fluid for contamination.

Is it ok to have the shops use the T-Tech system to flush out the tranny and replace the fluid..WITHOUT replacing the Filter? Cuz I don't think they do.

I wonder if I can get them to put in Synthetic fluid instead of regular too

 

[Mbrooks420]

Actually in the book that came with my truck it says to change the diff. fluid at 100k. And the ATF is supposed to be Mercon

 

[Robert]

The 100K interval is for axles that do not have a 3.73, 4.10 or a V8 engine. They got the conventional gear oil which needs to be changed more often. The change only when submerged interval is for axles filled with synthetic which are 3.73, 4.10 and all V8s.

Your '96 uses Mercon. The original posters '98 requires Mercon V. They are not interchangeable.

 

[Mbrooks420]

My 1996 has the 3.73 with Traction Lok. Does that mean I can't use the MerconIII? I bought some today that isn't synthetic. If i can't use it in the rear diff, I'll use it for power steering fluid and my t-case.

 

[LukeDog3D]

Astrochimp,

You can find 75W-140 Motorcraft synthetic gear oil at a Ford dealer. Be warned, however, that this is very expensive. I think I bought 3 quarts and 2 bottles of friction modifier for around 65 dollars. This was maybe a year ago.

 

[aldive]

Originally posted by Mbrooks420
My 1996 has the 3.73 with Traction Lok. Does that mean I can't use the MerconIII? I bought some today that isn't synthetic. If i can't use it in the rear diff, I'll use it for power steering fluid and my t-case.

Its not the same as PS fluid.

 

[GJarrett]

astrochimp, (where did you come up with that name, LOL?)

The following comments assume you have a SOHC. If not, I don't know what I am talking about, LOL.

As Dean has discovered, Ford charges an obscene heckuva lot for their diffy fluid, because no one else makes it.

But someone else does. AmSoil. PM or email AgExplorer here and get AmSoil synthetic in that weight for about 1/3 the price.

Regarding the tranny fluid change, if you use one of the JiffyLube place T-Tech machines, you need to schedule an appointment and make sure that when they replace their last customer's tranny fluid, to NOT keep the machine filled. They have a holding tank. It has to be empty, so you can bring your synthetic AmSoil tranny fluid with you right after that last customer and then have them fill their tank with your AmSoil synthetic. Otherwise you'll end up with a mix from the last fluid transfusion.

Get them to charge you their standard fee minus what they charge for the fluid. The machine has a vacuum guage that monitors pressure. If the gauge stays in the green you have free flow without a clogged filter raising the pressure and you do NOT have to replace your filter. This is very important. Look at your SOHC and notice the bottom catalytic convertor directly under your tranny's oilpan. You will have to remove that cat from the header to the tailpipe to remove your tranny pan, and three of those bolts are positively not reachable without lifting the body off of the frame. You do NOT want to have to do that unless you absolutely have to.

I just did this exact thing and put AmSoil synthetic tranny fluid in my '99 SOHC and the gauge was way in the green so I won't have to worry about a clogged filter for a long time. As a bonus, my MPG immediately went up 1 mpg going synthetic, according to my onboard Eddie Bauer trip computer.

 

[Mbrooks420]

In 1996, well at least in my truck, it says right in the book to use ATF Mercon III in my power steering pump. Actually my old car took ATF in the power steering also. Things must have changed since 1996.

 

[aldive]

Originally posted by Mbrooks420
In 1996, well at least in my truck, it says right in the book to use ATF Mercon III in my power steering pump. Actually my old car took ATF in the power steering also. Things must have changed since 1996.

The original comment was about rear end lube not ATF.

 

[Mbrooks420]

rear diff lube

What is supposed to be used in the rear diff. The guy at Powell Auto said the Mercon III I bought for my t-case could be used. I thought rear ends took a thick oil. I have a 3.73 Traction lok so I bought 4oz of the friction modifier. Any brand recomendations for the diff. I bought Pennsoil Mercon III for the T-case. I think I will eventually go full synthetic.

 

[aldive]

Re: rear diff lube

Originally posted by Mbrooks420
I thought rear ends took a thick oil. I have a 3.73 Traction lok so I bought 4oz of the friction modifier. Any brand recomendations for the diff

The rear end lube is thicker.

I use Mobile 1 75w130. I have a LS 3.73. Its been used for 60k miles with NO troubles.

Good luck.....

 

[Mbrooks420]

I think I am going to change mine soon. My truck has almost 90k on it and it's prob. never been changed. How much did it take? I figured 2 quarts should be enough. Any special friction modifier for the LS