Changing diff fluid
 

Did a search, and couldnt find anything. Was wondering what all a diff fluid change includes. Just called Ford dealership and was quoted for $250 for both diffs. Is that about the going rate? Didnt think diff fluid was soooooo exspensive.

Bout 10-15 bucks a quart x 6 with stock differential covers. Labor includes loosening fill plug, unbolting cover, draining oil, removing seal gasket, cleaning gasket pieces from differential housing, inspecting differential and gears, ensuring that there are no particles or waste anywhere in the housing, reseal with rtv, bolt cover on, fill with new 75-140w gear oil w friction modifier if L/S.


That should be about right. Please add/delete steps if I'm wrong. Its been a long day.

250 is a lot of money. I would maybe pay them to do the front if you are lazy, but you should be able to do the rear yourself no problem.

That doesnt sound to hard. Can I reuse the gasket? Also what do I do with the old fluid when done? Axel code is H9, so Im assuming I have the 3.55 LS so I'll have to get the additive.

i just did my rear not too long ago. my cover was rusted so i bought a new one from ford. really isnt a hard job, just get the torque specs on the bolts for when you put cover back on. and no all i used was rtv, no gasket, and after months no leaks. and yes i put in a little bottle of additive

Howdy,

I did mine last April. Mine's a 2000 also with an H9 axle. It's a pretty easy job. Two quarts of 75w90 gear oil for the front diff cost me $9, and three quarts of Motorcraft 75W140 for the rear cost me $47 :eek: and the friction modifier was another $4 or so.

If I remember correctly, the front diff has drain and fill plugs, and I needed a suction gun to refill it. The rear has a fill plug on the front (driveshaft) side. To drain it you have to pull the cover. The Motorcraft 75W140 bottles have funnel tips on them that you can angle into the fill plug so you don't need the suction gun.

There is no gasket on mine, and I don't think on yours either. I cleaned up the mating surfaces throughly without gouging them, giving them a final wipe with a rag sprayed with brake cleaner. Then I put a bead of black RTV on and let it skin over for the required time. (10 minutes maybe?)

I bolted it back up, tightening in a star pattern to the specified torque and have had no troubles. I read that allowing time for the sealant to skin over is key to getting a good seal. I don't know if that's true or not. I did it and mine has held tight with no drips or seepage.

You can get the factory-recommended sealant from the dealer. This thread shows a pic of the official Motorcraft sealant: https://www.f150online.com/forums/sh...d.php?t=276840

Figure I paid $60 for all the stuff, that'd be a savings of $190 for your time vs. the dealer's quoted price. If you need a suction gun, figure $20 or so more.

You should be able to recycle the old lube at a local gas station. I have two places that take my old motor oil and gear oils: the local gas station where Dave, the owner, says "hi" to you when you pull in for a fill-up, and the Tractor Supply store which will take something like five gallons of waste oil at a time.

A diagram of the cover, sealant bead, and torque specs are here: http://www.supermotors.net/vehicles/...y/media/185332

And there's a writeup on the rear fluid change here http://www.fordf150.net/howto/differentialfluid.php with some pictures.

$250 is a lot of dough. I was charged $40 per diff (labor only) when my diffs were serviced.

Mobil 1 75W-90 ($27 for three bottles)
Mobil 1 75W-140 ($45 for three bottles)

$72+$40+$40 = $152

I have found it is usually cheaper to buy the fluids myself. That way I know I am not getting screwed by the service garage because they only charge me for the labor.

Awesome, thanks for the links. Gonna have to get a suction gun though. What exactly is that though? Im assuming by the name its a suction device that works like a gun, but where do you get them?

Hi,

You should be able to find a suction gun at a nearby auto parts store. Here's a link to one at JC Whitney http://www.jcwhitney.com/OIL-SUCTION...9064_10109.jcw this one costs $12.99. I found one at the local National Auto Parts store for $20.

This is a fairly easy job, just a bit messy. Get a pair of disposable gloves and some newspapers or cardboard to catch the drips-- especially with the suction gun-- and you'll be fine.

:thumbsup:

How many miles do yu have on your truck? If it needs new diff fluid, you may want to look at your seals. Any leaking at the pinion or wheel ends? If so, replce them too. Hate to see ya spend any money on fluid and then have to do it all over when/if seals leak.

Little hint: Use white vinigar and windex to get the axle lub smell off your hands... I hate the smell of that stuff.

Oh by the way, If you do replace the seals. Take it to a qualified shop. One that won't just re-torque the pinion nut down. Found this out the hard way..

Have fun!

Worked at Ford. We charged $17 per quart of the 75W140 syn and $4 for the modifier. No need for a gasket, just get RTV. And if you dont have a torque wrench, than before you break the bolts loose, mark them with a paint marker so when you tighten them you can re-align the paint mark on the bolt with mark on the cover. Pretty accuarate, can always go a little further to make up for bolt thread stretch

90K miles. Don't know if the fluid needs changed, just read in the owners manual to do it at 90k. No leaks that I can see either. But I also dont know what seals you are talking about.



Camaro, thanks for the tip on no torque wrench. I would of never thought of that.

He is talking about your axle seals, at either end of the axle. they are KNOWN to be bad. I didnt know mine was until I pulled the rotor off and seen the backing plate was COVERED in dirt and grime bc the seal was leaking. I would check both sides, many people dont eve know they are leaking and then they burn their axle bearings out. Also the pinion seal

Hmmm... intresting. I am planning on getting the gears changed from 3.55 to 4.10, within 6 months too. Just trying to find a GOOD shop around me. Thought about just waiting, b/c wouldnt they change the fluid anyway. Think they would notice the seals as well?

If you plan on doing that, than just wait. If you took it to a Ford dealer they would definately take a look at the seals as they should already be doing a full inspection anyway.

Should I wait on the diff fluid as well?

Man, I was really looking forward to actually working on my truck. :(