Rust and other “happy” stuff

[Stuntmonkee]

Hey guys and gals!

So as I mentioned in my rebuild thread, me and a mechanic tore into the drive train today. What we found was a bit discouraging, but maybe you fine people can give me some thoughts.

Inside the Diffs and along the axels we had a good amount of rust. In the diffs is was mostly on the outside of the carrier and gears, but it did sneak into the gear faces a bit here and there.

Along the axels, the shaft itself was pretty rough looking.

His suggestion was a complete replacement of everything except the housing and changing the gearing at the same time. Even the diff covers needed to be replaced in his opinion.

Now I’m not against doing things proper, but my gut is telling me that maybe it’s not as dire as he’s making it sound. Now. . . .theres a chance that my gut just doesnt like the idea of adding in thousands to an already slim budget. . . .that is totally possible. But he wasn’t super confident on how a full floating system worked and almost told me that I needed to replace the housing too.

So I’m just not feeling confident in the opinion of a full replacement.

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Next on the list was the transfer case and the transmission.

We put the transfer case into neutral and gave it a spin and it kinda growled back at us a bit. . . . .that def sounded like it needed a new set of input and output bearings at the very least.

The part that stuck me as strange was that he was dead set on talking me out of a c6 transmission.

Everything seemed to stem from the 35” BFGs that I have on the truck. Apparently those were going to cause everything to wear bad and the only solution is a completely replaced drivetrain from the housings in.

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Anyway, for you mechanics out there. . . . . I’m not trying to be a forum warrior and be the “Yeah but I read somewhere” guy. . . . . But after doing a bit of reading and lurking here in this forum, you all seem pretty awesome and trustworthy.

Anyone who wants to toss 2 cents into the bucket would be very much appreciated.

[Manny]

First off my 1994' dually 10.25 sterling..... this is after 180 grit paper and a maroon scotchbright pad to clean the gear.



That was 2009 its now 2017 that was 35k miles ago. Towed 14,000lbs with it and all... So that's a little fuel for thought. Second i get the dive outta everything and replace it all as he is trying to cover himself. I do that to customers as well trying to make certain i don't get bit. There may be a fair amount of this going on. For myself rust on bearings is a bad no go. Get them out bearings will fly apart if the chrome hard facing is gone. They will also be noisy. Gearing and ring a pinion you just saw what i say. Mild rusting not deep deep gouges covering the whole tooth you may roll the dice. For instance two pits on one tooth when there is tons of surface area left you know just choose. Now if your wanting highway cruising gears we are talking a mute point cause then you just regear for what you want. Axle shafts as long as they are no rusted on the seal surface and there is not a lot of material removed like 1/8th an inch i have no idea why you would replace it..... Again these are my takes on these things i've run a lot of junk and never had a issue. Had plenty of times as well as a field tech you ain't go the part you are but the customer is screaming so you tac it together and let it rip. more times than not it rolls on. You open stuff up and you start snowballing. My 74' bronco 55psi cold 0 psi hot out of a 302. Pulled the pan and checked high volumn pump all the rods wiggled and the crank flopped around. Someone had put .010 under bearings in it the crank was .020 under. Thats .010 of clearance everywhere it ran fine drove fine just had no oil pressure and some thudding idling hot. It now has .020 under bearings a standard volumn pump and has 65psi all the time. That was 5,000 miles ago. Is it perfect no but its no racecar and i saved it for a while longer. Final point you want to convert to a c6 convert to a c6. Your truck your opinion you gotta be the guy happy at the end of the day not any of us. We will be happy for your that you are happy with your truck. You may rebuild the C6 not bad to do but if it drives and shifts out fine then you know its solid. That's my and some been there done that. Lets see some damage pics see how bad this is. One final note i'm not saying aw just run it...... but i am a guy who doesn't have $$$$$ so i pick wisely (loosely used term there ) on what runs and what gets replaced

[Manny]

Second notes transfer case what did the fluid look like murky pond water... does it shift every gear high low it all work smoothly. even in neutral a dana 24 spin some gears and growl as the sliding collars are just not locked on the shafts together. Not saying a bearing kit may not hurt just knock the bottom inspection cover off and look up in there.. that 8 bolt cover on the bottom. Another thing is he says you need new diff covers and they are not rusted thru of smashed to bits......well you know... clean this stuff up and go again.. He's being cautious which i respect but a little to cautious i think.

[cep62]

clean this stuff up and go again.. He's being cautious which i respect but a little to cautious i think.

[tsherry]

I'd change the bearings, pull the axle shafts and clean them up a bit, change the fluids, and drive it. I'd then change the fluids again as that surface rust wears off. I'd also change the trans to a C6...and maybe find another mechanic.

[Stuntmonkee]

Thanks guys! This all sounds great!

My gut was saying to clean it up and see how it all pans out after it’s running. . . . .but dang! Felt like I got X-rays at the dentist and found out all my organs needed to be replaced before I left.

[Manny]

Thanks guys! This all sounds great!

My gut was saying to clean it up and see how it all pans out after it’s running. . . . .but dang! Felt like I got X-rays at the dentist and found out all my organs needed to be replaced before I left.

Yeah your gonna be fine watch the bearings but rust on axle shafts a such is not rods hanging thru oil pans.... Heck at the rate he would have you run your build by the time you got done it would all be rusted again. Remember anything sits more than 6 months to top of the ring gear gets dry as no fluid moves. Add a winter and a summer change for condensation.....rust.

I'd change the bearings, pull the axle shafts and clean them up a bit, change the fluids, and drive it. I'd then change the fluids again as that surface rust wears off. I'd also change the trans to a C6...and maybe find another mechanic.

He's right on bearings are critical but other than that go. You get to the second fluid change and its still going murky rusty fluid quick then worry. That first 150 miles it will feel tight I promise. Then one day you will be driving and it will just loosen up. Take less throttle to keep speed coast farther and just feel better at the wheel. At that point its run back in broken in again. After that drop all the fluids and freshen it up again and enjoy. Remember it will break in or break you don't know till you drive a little....

[DuckRyder]

A few thoughts...

First off, always look an the bright side, if it needs everything, you’ve got little to lose by trying to save some of it...

Secondly, you didn’t explain the deal with the mechanic but if you are going to pay him, it might be cheaper to replace things than pay him labor to clean them, and it is easier for him to stand behind. Since you didn’t say “my friend the mechanic” or anything like that I’m going off the assumption this is a business relationship.

There is rust and then there is RUST.. are things going to still be pitted when it is cleaned up? Might not be a huge deal even if the shafts are, but pits on the gear faces are going to be noisy at best.

RE the axle assemblies: I agree if the bearings need to be replaced if any rust on them.I’d try to clean everything else up and assess the condition afterwards, particularly with respect to the axle shafts and carrier itself id be pretty surprised if you couldn’t clean them up, the gears depend on where it is and how bad but if it is on the gear teeth (particularly drive side) it is probably a no go...

Transfer case you’ll have to get into but it doesn’t sound promising.

C6 should handle most anything you throw at it, but they are heavy and do consume a lot of power, plus (and I’m not a 4x4 guy) I don’t think they ever put them in 4x4’s - need to determine what his objection is.

As always a picture is worth a thousand words, a good picture maybe even more words...

[Stuntmonkee]

I’m going to get you guys pictures this weekend - sounds like everyone is pretty close to being on the same page.

[Stuntmonkee]

Update on this over on the build thread - http://www.fordification.com/forum/view ... 3&start=45

[markguiver]

With regard to the C6; I have a 75 Highboy that came with a C6 from the factory. It was a full time 4WD (NP 203) until I bought it 23 years ago. First thing I did was pull the 203 and replace it with a 205. I've run 33X12.50X16.5's, 305X85X16 Mudders (36.5"X 11), and for the last 15 years 285X75X16 (33X11.50). Other than changing the filter and tranny fluid on the C6 it 's still going strong. My opinion is your mechanic is mistaken about the C6. Ford used them on the F250 HD's and F350's into the late 80's. I'll admit there are times I think about replacing the C6 with an NP435 for the lower gearing but, it ain't broke so why fix it .
On a side note; If the 305X85 Mudders were still made I'd still be running them.
Mark.