The war on rust (differential cover)

popsmckracken

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Ok I'm finished with my new Koyo radiator, B&M super cooler (in series) and brand new Denso Starter. NOW.....I'm set to take a cutoff wheel to my shot rear differential cover and weld this new heavy duty capacity increasing cover on from Barnes 4wd. I'm gonna do a few hours of rust work on anything and everything I can reach and see under there with my grinder and dremel while I'm at it. I finally switched from carrier pidgeon to an IPhone so I can post pics now.
 

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I did the same fix last summer. Good luck.

Looks great. Question, how much capacity increase did you see once you modified? Also I'm just a wee bit worried since I think I drove around for a few days before I noticed the smell and the pinholes. The last time I drove her I noticed the rear end was vibrating a bit , kinda rough. I'm hoping once I get this thing on and fill it up with new good quality fluid that she'll be fine. Wishful thinking? I mean she was dead empty. I suppose when I get inside and clean it up I'll be able to see any damage that may have been done.
 
Mine did not lose a huge amount of oil and I kept a close eye on it. The smell was getting pretty bad too ! However, I did have a rear whine start up a few weeks after the new cover was welded on. It has now been "whining" for over 20,000 miles no better and no worse. I am just living with it as it's only apparent between 30-40 mph. I changed the diff oil twice which did nothing to quieten it down. I had a shop put a stethoscope on it to pinpoint the whine, but they could not be 100% certain of the source. I think I put in the recommended amount of oil, didn't notice an increased capacity.

Each time I drained the oil I did notice a disturbing number of metal shards and filings on the drain plug magnet !!
 
Mine did not lose a huge amount of oil and I kept a close eye on it. The smell was getting pretty bad too ! However, I did have a rear whine start up a few weeks after the new cover was welded on. It has now been "whining" for over 20,000 miles no better and no worse. I am just living with it as it's only apparent between 30-40 mph. I changed the diff oil twice which did nothing to quieten it down. I had a shop put a stethoscope on it to pinpoint the whine, but they could not be 100% certain of the source. I think I put in the recommended amount of oil, didn't notice an increased capacity.

Each time I drained the oil I did notice a disturbing number of metal shards and filings on the drain plug magnet !!

Maybe some material made its way behind the gears during the cutoff stage. I made sure to blast everything clean once I had the old cover off. Everything looks surprisingly good, no obvious wear at all. I put almost three quarts of fluid in with no problem. The vibration I was feeling on empty are gone. At least now I know it's pretty much bulletproof from here on out.
 

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My next step will be some red farm tractor enamel and then it's on to the old rusty stinger bumper my son and I pulled off to get the new radiators in. It's big and heavy and will handle pretty much all the grinding I can dish out. It's funny but I hadn't driven the truck in years without it on. We had about 4 inches of snow on the ground and I must say it drives half as good in the snow without that extra weight in front! What a difference.
 

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Yes. I had a brief misfire on start up last week and then saw that milky oily residue under the oil filler cap when oil mixes with water, however no over heating and no oil in the coolant. Checking today it looks like it was just moisture under the oil cap creating the residue and the temps have warmed up considerably also I dumped in two bottles of injector cleaner, all seems much better now !
It was -25c for a few days then suddenly up to +8c the following days, I think this fluctuation in temps caused the panic.
 
Yes. I had a brief misfire on start up last week and then saw that milky oily residue under the oil filler cap when oil mixes with water, however no over heating and no oil in the coolant. Checking today it looks like it was just moisture under the oil cap creating the residue and the temps have warmed up considerably also I dumped in two bottles of injector cleaner, all seems much better now !
It was -25c for a few days then suddenly up to +8c the following days, I think this fluctuation in temps caused the panic.

Isn't it good to be wrong sometimes? lol after 6 months of being stuck in 4WD-HI I was looking at what would have been my second transfer case replacement and the third on the vehicle. Since this had already happened once and it WAS a bad TC I was resigned but a simple inspection of the vacuum system and there it was...just hanging there next to the valve unplugged...plugged that b1tch in and it was all systems go once more! How often does that happen?
 
Ok I'm finished with my new Koyo radiator, B&M super cooler (in series) and brand new Denso Starter. NOW.....I'm set to take a cutoff wheel to my shot rear differential cover and weld this new heavy duty capacity increasing cover on from Barnes 4wd. I'm gonna do a few hours of rust work on anything and everything I can reach and see under there with my grinder and dremel while I'm at it. I finally switched from carrier pidgeon to an IPhone so I can post pics now.

Did mine on '02 T4R in December 2016. A little different look for '02 cover from Barnes. Finished with Amsoil Under rust inhibitor undercoat. saved $2000 over new axle. Here's pics. T4R Rusted Diff_Barnes 4WD Replace.
In Southern Maine call Zack @ (207)-615-6934, for welding on Barnes covers.
 

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Did mine on '02 T4R in December 2016. A little different look for '02 cover from Barnes. Finished with Amsoil Under rust inhibitor undercoat. saved $2000 over new axle. Here's pics. T4R Rusted Diff_Barnes 4WD Replace.
In Southern Maine call Zack @ (207)-615-6934, for welding on Barnes covers.

Nice, looks like a huge capacity upgrade. Heavy duty
 
I have the same cover on my crawler.

Just curious how much fluid do you get inside the pumpkin now...I just put 6 quarts of lucas in and it didnt even reach the plug! They weren't kidding when they said "capacity increase". I thought I was good with 3 but after sticking my finger in the hole (practice makes perfect) I noticed I couldnt even touch oil.
 
Just curious how much fluid do you get inside the pumpkin now...I just put 6 quarts of lucas in and it didnt even reach the plug! They weren't kidding when they said "capacity increase". I thought I was good with 3 but after sticking my finger in the hole (practice makes perfect) I noticed I couldnt even touch oil.

no clue really.....i filled it till i could see fluid.
i have to drain it soon, do to blowing up the ring and pinion. if i remember when i drain it i'll let ya know.
 
Yes. I had a brief misfire on start up last week and then saw that milky oily residue under the oil filler cap when oil mixes with water, however no over heating and no oil in the coolant. Checking today it looks like it was just moisture under the oil cap creating the residue and the temps have warmed up considerably also I dumped in two bottles of injector cleaner, all seems much better now !
It was -25c for a few days then suddenly up to +8c the following days, I think this fluctuation in temps caused the panic.
I think its your valve covers. My covers were bad, a seal was letting oil into the spark plug tube in cyl one, causing the misfire. Pull the airbox and inspect your wires for oily residue in the tubes.

It would still run, and once it warmed up a bit it would no longer misfire. It was oil causing intermittent spark.

I too battle the rust. My rig is driven on the atlantic coast, and i travel in the salt belt which is like i park in the ocean. Going to look into that cover. Is everyone taking it all apart and sandblasting off the vehicle?
 
I'll have a check, but my valve cover gasket seals were replaced back in the spring and they don't leak at all now. The PCV is also new, worth checking into the pipes though for residue. I have not had any issues since I posted this over a week ago now. It hasn't been -25c either!
 
I need to find someone in south east MI to do my 99. It needs bearings AND it's got the wet back cover. I don't want to put in a used rear end since they are hard to come by it seems.

Does anyone on here know a shop that will do this kind of work in the Detroit area? None that I have talked to want to do it since it's outside of their normal 'thing' I guess (slap new parts on, run your card).

Thanks!
 
Welding a new cover poses too high a risk of ruining your diff from debris contamination. I do not recommend this unless you remove the third member. Also, these aftermarket covers have a shape which may not allow the oil to spread through the diff as the original design does. That square cover posted may just be downright moronic if those sharp angles do not allow proper oil dispersion at highway speeds. Hello pinion whine.

My advice: you need to get a new differential with a good cover and lube it up with a pornographic amount of oil to prevent rust. If your cover looks like shit but does not leak, DO NOT duck with it (wire brush, dremel, grinder) unless you intend to waste your weekend laying on your back and dicking with JB Weld and gear oil when you poke a pinhole through. You will get what you deserved.

My "bush mechanic" aka "a guy that has spent enough time repairing old FJ40s on the side of a mountain in Asia without an ego and the coolest new Snap-On wrench", said to put roofing tar on a shitty looking diff cover(that isn't currently leaking). It's thick and oily AF, will stop the rust in its tracks, and will be a ***** and a half to remove until the day you cough up for a new rear axle. It's not a guarantee that a leak will not form, but this is the safest bet, and damn does it work well.
 
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