Transfer Case and Differential Fluid Help

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Nov 13, 2006 | 04:38 PM

KyEdExpedition

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Transfer Case and Differential Fluid Help

I am about to change the transfer case fluid and differential fluid for the very first time in my 1997 Expedition 4x4 5.4L.

Is their anywhere on this forum that has step by step detailed instructions?

Also what kind of fluid should I use for each?

Thanks!

-Kyle

Nov 13, 2006 | 07:04 PM

vze2sgxa

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From: Where the war is...

This is for the transfer case: Get under the truck with a drain pan. Remove the FILL plug first (just to make sure you can get it off after 8+ years. You use the square end of an extension bar connected to your 3/8" socket wrench. Then, remove the DRAIN plug and drain the fluid. Replace the DRAIN plug and fill with MERCON V fluid or whatever your truck manual says (most likely, it is MERCON V). Replace the FILL plug. You will notice a big difference, your clutch packs will not grab anymore. I've changed the fluid two times in 72k miles.

The procedure is the same for the front differential, but most like you need to use 75W-90 gear oil.

The rear differential is - well "different", pardon the pun. If it is a limited slip differential you need to take the cover off and then drain the fluid, clean the casing and cover out, then replace the cover. Remove the FILL plug and fill it with 80W-140 gear oil and add the Ford friction modifer.

For all of three of these jobs, you need to check your manual for the exact fluid type and amount.

Last edited by vze2sgxa; Nov 13, 2006 at 07:09 PM. Reason: Forgot a couple lines...

Nov 14, 2006 | 02:07 AM

KyEdExpedition

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Thank you very much for the reply. SO I should just stick with the Ford recommended fluid? There is no synthetic blend or anything that is enthusiast recommended?

-Kyle

Nov 14, 2006 | 07:03 AM

Power Strokeme

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From: Southeast Iowa

I just spent over $40.00 on 2 qts of Royal Purple mercon and 2 qts of Royal Purple 75W90 for the X-fer case and front end on my 01. I didn't change the rear end oil because Ford put synthetic gear oil in at the factory and they consider it "lubed for life" I figure it is good for 80 - 100K. I haven't drove it enough to tell much difference but I will say the 75W90 is MUCH easier to pour than conventional 75W90 and I hope that adds to the MPG's. BTW on my 01 I had to pump the oil in, there was no way to get the bottle with the pointy nozzle/cap up to the fill hole. If you don't have a way to pump it in maybe a 3' or 4' piece of 1/4" id hose on the nozzle/cap with the other end snaked down to the fill hole would geterdone you would also have gravity on your side. Once again the synthetic would flow a lot easier but whether it's worth the cost is up to you. You can get an idea of how much better it would pour by picking up a qt of synthetic gear oil in 1 hand and a qt of conventional gear oil in the other and shake them, you will feel the difference.
Good luck

Nov 14, 2006 | 06:28 PM

vze2sgxa

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From: Where the war is...

No way is a rear differential lubed for life, at least not in my experience. If it's a limited slip differential, you should change it based upon the manufacturer recommendations, but more often if you tow, 4x4 alot especially in water, put a lot of load on it. Ford LS diff clutch packs wear faster than you would expect. Just my $.02.