I have a 2001 F350 crew cab 7.3 DRW truck that I pull a 3 car trailer with! I am trying to find out the rear axle ring gear. I was crawling around under my truck doing maintenance and seen that the rear seal was leaking going into the differential and thought this may be the reason why when I stop and then take off again the rear end slips a lot befor e it grabs! I pulled out the filler plug and stuck my pinky finger in there and had no fluid as far down as my finger would go, I ended up putting in 2 quarts od fluid and it still wasnt completely full. Well after calling my local Ford Mercury dealership all they could tell me was bring it in and let us look at it! I know that it is a 4.10 as that is what is stamped on the tag, however the casing is stamped for a date in 1999 ??? I have no Idea what the ring gear is but have been told by a salvage yard that it is a 11.25 I am going to replace the rear axle but need to know the exact ring gear as it is a 4x4 so it matches the front as far as using the 4 wheel drive and the computer. I pulled off the tag and cleaned it off. Can anybody help and does anybody have a 4.10 rear with the 11.25 ring gear for sale? I was thinking about rebuilding the rear end but there was a lot of metal shavings on the magnetic plug when I pulled it out! I need to get this fixed and back on the road hauling cars, Randy

 

I don't have one for sale but all you have to tell them is that it's a Dana 80. Also be sure to put 75W-185 synthetic gear grease in it.

Denny

 

I topped it off with 75-140 synthetic I thought it was a Dana 60 Shows how really stupid I am huh!! OOOOPS!

 

hey McCune, hows your truck do pulling a 3-car trailer? What's your gross weight?

 

It does good, however I do not take it into the bigger hills and I only haul small cars! This truck has the 3rd tranny in it! My last truck was a 2000 and had 294,000 miles on it and still on its 1st tranny! I thought I needed a 4x4 so I traded it for a 4x4 and this truck has been a money pit! Its pretty much been rebuilt now except for the rear end and the engine! 7.3 was one of Fords (International) best engines! to bad they got rid of it! 6.0 were junk from what I heard 9 out of 10 people I talked with had problems withit. The 6.4 sounds ok so far I guess. Hoping Ford gets a cummins in their smaller trucks, otherwise I am either going F650 or F750 and no more crappy automatics by Ford! However the last tranny I put in 132,000 miles ago by Ford said that this should be the last tranny I need as he explained that Ford did reverse engineering on it! They bought a Allison, tore it down seen how it was built and built one just like it...So they said! I flush and fill every 20,000 miles and so far so good! I know anothe r guy who had 498,000 miles on his truck pulling 5th wheels and his tranny went out at 490,000 and he flushed and filled every 40,000 miles. His 1st 7.3 engine went bad due to electrolysis as Ford didnt put the additive in when they flushed his radiator and refilled it! Another guy know has over 600,000 on his 7.3 and has'nt had a problem with it at all, except for new batteries... Engine and tranny are original and have never been broke open for repairs!

 

The autos Ford uses now behind the diesel aren't crappy, 6.0 has three deficiencies from factory, egr cooler/valve, vgt turbo and weak headbolts, fix those three things and usually you will end up with a motor just as reliable as the 7.3 with a better auto trans and more power.

 

Why dont Ford fix them? Anyway, My next truck will not have a automatic tranny! I miss shifting anyway from when I was driving a 18! Clutches are a lot less expensive then a whole transmission and I will never get a 4x4 again If I need to use 4wd then obviously I dont need to be on the roads driving! I use to be a chevy man, until I couldnt find one to meet my needs,so I bought a Ford and I like Ford trucks! next time I will buy a truck with a manual shift and only 2wd. Replacing the 4x4 front wheel bearings about every 70,000 miles is to expensive at $550.00 a side. $459.00 of that is the assembly itself! Ford decided to speed up production of their trucks by making the wheel bearing and hub all 1 piece, in saving thereselves money they screwed the consumer.

I have been thinking about the new Dodge 4500 and 5500 trucks with the allison tranny and the cummins engine, originally built by sterling, called the Bullet, but now Chrysler! When they come out with a long bed crewcab I am leaving Ford for the Ultimate drivetrain in these trucks! When Ford comes out with a drivetrain like that...I will come back!

 

torqushift is better already. Ford didn't fix them because international made the engines

 

McCune it sounds like your pinion seal is bad. Not to worry real easy and cheap fix! ITs just a matter of unbolting your driveshaft. Lossen and pull the yoke off the pinion shaft then remove (dig) out the old seal. For the new seal try to find something rugged and about the same diameter as the seal. Use this to beat on with a good size tap hammer!! Oh and put a lil lithium grease around the seating surface of the seal to help it slide into home.

I cant see how this would cause "slippage", theres realy nothing in there to slip. I could see if you had one set of wheels in the ditch and the other on black top. But even then, dualls with wieght on them, hardly ever slip.

Ive got a 4.10 rear end Dana 80, but im kinda using it at the moment, if I wasnt Id gladdly let you borrow it!!

Good luck

 

What could it be then! the tranny is fine and shifts normally! Could there be broken teeth in there on the gears! and it slips til it catches onto the other teeth??? I have no idea! Randy

 

Randy- did you think to drop the rear diff cover and take a look at it, if you feel that's the issue? All you gotta do is either save the old gear oil in a CLEAN container, or put in another 4 or 5 qts when you put the cover back on.

 

Gonna do that today, My mechanic is really busy and I am going to take this cover off today and look for myself! I cant afford to sit around waiting! Will let you know!

 

If you've got a limited slip rear diff (very likely) you'll want to put in a fluid with a "friction modifier". I changed the fluid in my rear diff @ 110,000 miles and put in Royal Purple 75w140 synthetic. Pricey? yep. But cheaper than a whole new diff. And it had the necessary "modifier" in it already, so nothing extra to add, just fill & go.

Also, come check out the 7.3 PSD forum - this one is great for general Super Duty stuff, but the 7.3 PSD forum is much more specific to your truck.

Also, HERE is a website from on of our members with a 7.3 that has tons of great info on maintenance & repairs. He also sells many of the o-rings needed for the repairs he discusses at his website, Diesel O Rings

As for transmissions.... lets hope you have no grief again, but if you do, there are 2 options that really will take care of you: Brian's Truck Shop (Arkansas) or John Woods (California).

 

If you need to get back on the road fast and the rear end is trashed call a salvage yard and see if they can find you a different one. Just make sure they know its for a DRW SD.

Denny

 

I just had a thought with the way it's acting I sounds like you broke a axle and the slip you are getting is the lag before the limited slip grabs. It's easy to check just unbolt the axles from the end of the hub and slide them out, If the hole axle comes out with the spline on the end it's good and if there is no spline then you have to figure out how to get the end of the axle out of the carrier. They are full floating so you don't even have to jack it up. Unlike the other rear ends Ford uses the limited slip Danna 80 in the DRW really works. Also make sure the splines are in good shape. If that's the problem make sure you flush the rear completely before you put it back together.

Denny