Hey guys i'm new. I have a 1999 V10 Superduty. Seems to be a pretty nice truck.

 

Cougar,

Welcome to FTE! You'll find lots of useful information here and a good bit of friendly people. Hope you enjoy your 10 cause I know I absolutely love mine! Once again, welcome!

 

Hi Casey,

Thanks for the warm welcome. I find a lot of good sources here for Ford Trucks. This site is awesome. I never thought the Internet can be so useful. Thanks again.

P.S. Any mods to your truck to get 337 rwHP. I am curious

 

Hey Casey,

I don't know if should post a new topic. My rear differential seems to dripping a little bit of gear oil. I see a little oil stains on the differential cover. Do you know why this happens.

Thanks,

 

Cougar,

To get 337 rwHP I cheated a bit... it's really more of a bragging item than a reality now because I've changed the truck so much. Anyways, basically had a programmer write a custom program for the truck here in Birmingham, he added a couple of bolt on mods to his work, and we used smaller than stock tires. He offered to tell me what he did for a hefty price and I could take home the bolt-on's too, but I opted against it because I don't know the specifics of what he did. All that aside... rear differential leaking? Could be a couple of things... first thing you should do is clean the pumpkin really well so it's easier to tell if those stains are old or new... second thing you should do is check the oil level in there... if you're looking at the pumpkin from the back of the truck, the fill valve is on the middle left back side, almost on the same heighth as the axle shaft. (You may already know this, but just in case...) anyways, a standard ratchet drive will fit the valve screw... take it out, the oil should be up to the actually hole itself. Stick a finger in there (after it's cold!! don't drive it and then try this...) and you can tell where the oil level is... like I said, full is up to where it's almost spilling out. If it's really low, I'd be careful driving it until you filled it back up... anyways, the diff can leak from either the cover gasket or actually the bolt holes. It can also leak up where the flange is at the differential drive seal. You would be able to tell by oil stains running from the bottom of the opening (underneath where the driveshaft attaches to the flange) down toward the bottom of the actual differential. If you can tell where the source of the leak is, both are pretty simple fixes. Anyways, be glad to help anyway I can.

 

hey thanx Casey. You are really intelligent. I see about the 337 rwHP. Well the leak is coming from the bottom of the pumpkin. I will clean it and see if it spills more. I have seen other trucks (non-Fords) that had a problem. My buddy 01 dodge Ram had a little leak. He took it to the shop, they replaced the gasket and refilled the pumpkin. I asked him to ask the mechanics if this is normal and hes said yes. Being skeptical he changed it. Now i'm skeptical I wouldn't want to provoke any problems on this beautiful truck. Thanks for the info, you have been very helpful

 

Cougar,

No problem man! Glad to help... rear diff leaks aren't all that uncommon, you just wanna make sure you got some lubricant in there or else you'll have a BIGGG problem... anyways, you could fix that yourself if you wanted... just wrench the bolts off of the cover and pry it off with a oil pan underneath it and use the grey colored RTV silicone gel to make the new gasket. All you gotta do is trace all around the middle-outer park of the cover where the bolt holes are and then bolt it back up and throw some diff fluid in. Let me know if ya need anything else... lots of friendly people on here to help too!

 

Preach on, Brother Casey, preach on!! You two keep talkin' and ya'll will find out your related! You live here in Alabama, you know it's true!

BTW, I am not from here, but I can get any one of my employees in some one else's company and they eventually are related or are related to someone who is "kin" to a friend who is "kin" to them or some such!

Just jokes, just jokes . . .

 

Seriously, Cougar, if you are not a backyard mechanic, get your ride down to a good service company or a competent Ford dealer and get the chunk serviced. A new gasket and fluid change won't hurt a thing and if that solves you leak (it likely will) you'll be mo' better! Your truck is a hoss and it will take a lot of abuse, but maintenance is the key to longevity. Keep all fluids fresh and don't let any problems exist for long. You'll be gettin' a BSEG and wondering why you didn't do this sooner!

Keep us posted on your experience and, um, well, your, um, rear end . . .

I swear, I slay me!!

 

Welcome Cougar...
Since the topic kind of shifted to the diff - I wanted to ask. I bought my X with 114k on it and it was in mint condition. But I don't know if the diffs have ever been serviced and with the summer camping time arriving soon, I was thinking of changing the diff fluids.
What diff fluid (brand & visc) should I use? I've never had a diff issues with my trucks in the past, but we will be towing a lot this summer and... well, an ounce of prevention....

 

Hey Mark,

Good idea, better safe than sorry... it' always good to keep the blood of your f250 fresh no matter what it may be. For diff fluid, you should use 90w-140 gear oil... royal purple is probably gonna be your best bet. If it's limited slip don't forget to get the LS additive (friction modifier) goop... without that your LS will not work! Hope this helped.

 

When you change the rear don't forget the front if it's a 4X4. Over time they will both get dirty and a change of lube is always a good thing, Any brand of gear lube will work. Tim

 

Thanks Guy, I appreciate the help everybody has provided. Thanks again.

 

Welcome to V10_Cougar!

Since this turned into a change my gear oil thread ...take a look at these WONDERFUL links. They are a step-by-step...with pics.

FRONT Axle:
http://guzzle.rbmicro.com/fdiff.html

REAR Axle:
http://guzzle.rbmicro.com/rdiff.html

Also...just a side note: The REAR 10.50 axle takes [B]75w-140 Synthetic gear oil[/B]. If you go with Royal Purple (GREAT product!)...then you do NOT need the Limited Slip friction modifier.

Hope this helps...

biz

 

Awesome, Thanks.