So I've got this 3.46 open diff ready to go into the eta. It's been sitting outside for a while, but that's really not a big deal since a diff hits rain and all kinds of road grime while it's on the car anyway, right?
It's got a little layer of rust on the outside, which I'm not too extremely worried about.
The main thing I'm worried about is how hard it was to turn the input shaft. It had to be "broken free" because of something gumming it up, probably rust. Now, it's a little bit more difficult to turn than the other diffs I've played with before.
What's the best way to get this thing all un-gummed-up and functioning like a top? I was planning on replacing the diff cover gasket anyway, so if I need to do something to the inside (pour a solvent in there?) that's no problem.
I was going to see about popping off the output shaft flanges just to clean them up, so there's another idea.
TIA,
Best way to remove corrosion from a diff?
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canyoncarver
- Posts: 1123
- Joined: Feb 12, 2006 12:00 PM
I think Jim's recommendation is correct, except that I would use Redline gear lube, yes, exactly what you'll be filling the diff with at some point. I'd then stand the diff on the input flange, prop it up on something, and let the lube soak the seals under the mild pressure of the whole diff being full, not the normal amount of lube, but completely full while standing on the input end, up to the vent which will weep lube if you go past the opening and it's not clogged. Turn the imput flange every few days. In about a week or two, enough fluid will penetrate the "stuck stuff" to loosen it up unless it's really rusted out(unlikely) , if that's the case then nothing will clean it up.
Thanks for the suggestion, Jim.
To Pat: The normal interval for changing the diff fluid is 1 year or every 4 oil changes. I was planning on doing Redline when I put the diff on the car and then changing it out at the next two oil changes just to make sure all of the gunk is out.
Do you think this idea will have the same effect? I may see about going with the carb cleaner and turning the diff every few days and then changing out the Redline after just one oil change.
Thanks for the info, guys!
To Pat: The normal interval for changing the diff fluid is 1 year or every 4 oil changes. I was planning on doing Redline when I put the diff on the car and then changing it out at the next two oil changes just to make sure all of the gunk is out.
Do you think this idea will have the same effect? I may see about going with the carb cleaner and turning the diff every few days and then changing out the Redline after just one oil change.
Thanks for the info, guys!
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Blue Shadow
- Posts: 10281
- Joined: Feb 12, 2006 12:00 PM
- Location: SE PA
[QUOTE="Shifty"]Thanks for the suggestion, Jim.
To Pat: The normal interval for changing the diff fluid is 1 year or every 4 oil changes. I was planning on doing Redline when I put the diff on the car and then changing it out at the next two oil changes just to make sure all of the gunk is out.
Do you think this idea will have the same effect? I may see about going with the carb cleaner and turning the diff every few days and then changing out the Redline after just one oil change.
Thanks for the info, guys![/QUOTE]
The carb cleaner will cut all of the lube off the gears and bearings, while that might be OK for a short period, i.e. a few hours; I wouldn't do it on my own diff.
Diff lube itself is a pretty good solvent, most oils are, so my thinking is that you'd kill to problems with one type of chemical, diff lube. Yes, you'd have to buy extra Redline, but that's really not that expensive in the long run, maybe an extra 10-15 bucks.
Another question I should ask. Is there any evidence of rust on the input shaft or near it? Evidence would be fine rust colored powder around the input shaft and working its way back on the diff. Without any evidence of rusting, is the stiffness in turning the shaft the only thing that's an issue for you? If that's the case, it may only be a stiff crush washer interface that will free up with use.
To Pat: The normal interval for changing the diff fluid is 1 year or every 4 oil changes. I was planning on doing Redline when I put the diff on the car and then changing it out at the next two oil changes just to make sure all of the gunk is out.
Do you think this idea will have the same effect? I may see about going with the carb cleaner and turning the diff every few days and then changing out the Redline after just one oil change.
Thanks for the info, guys![/QUOTE]
The carb cleaner will cut all of the lube off the gears and bearings, while that might be OK for a short period, i.e. a few hours; I wouldn't do it on my own diff.
Diff lube itself is a pretty good solvent, most oils are, so my thinking is that you'd kill to problems with one type of chemical, diff lube. Yes, you'd have to buy extra Redline, but that's really not that expensive in the long run, maybe an extra 10-15 bucks.
Another question I should ask. Is there any evidence of rust on the input shaft or near it? Evidence would be fine rust colored powder around the input shaft and working its way back on the diff. Without any evidence of rusting, is the stiffness in turning the shaft the only thing that's an issue for you? If that's the case, it may only be a stiff crush washer interface that will free up with use.
[QUOTE="Blue Shadow"]Diff and gearbox service is Inspection II or every 30,000 miles. So every 4 oil changes on synthetic or every two years.[/QUOTE]
Right. Every Inspection II, which is every other Inspection I, which is every other oil change.
Oil changes are 3,000 miles, Inspections are every 6,000 miles. Therefore, Inspection II should be every 12,000 miles or annually.
Is my math fuzzy some how?
Either way, I'm due, because I've had the car for a year & a half and have never done the diff fluid.
Right. Every Inspection II, which is every other Inspection I, which is every other oil change.
Oil changes are 3,000 miles, Inspections are every 6,000 miles. Therefore, Inspection II should be every 12,000 miles or annually.
Is my math fuzzy some how?
Either way, I'm due, because I've had the car for a year & a half and have never done the diff fluid.
[QUOTE="fastpat"]The carb cleaner will cut all of the lube off the gears and bearings, while that might be OK for a short period, i.e. a few hours; I wouldn't do it on my own diff.
Diff lube itself is a pretty good solvent, most oils are, so my thinking is that you'd kill to problems with one type of chemical, diff lube. Yes, you'd have to buy extra Redline, but that's really not that expensive in the long run, maybe an extra 10-15 bucks.
Another question I should ask. Is there any evidence of rust on the input shaft or near it? Evidence would be fine rust colored powder around the input shaft and working its way back on the diff. Without any evidence of rusting, is the stiffness in turning the shaft the only thing that's an issue for you? If that's the case, it may only be a stiff crush washer interface that will free up with use.[/QUOTE]
Pat,
Yes the main issue I'm having is the gunked up input shaft. It would probably free up just fine after a few miles of driving and the Redline sloshing around in there, but I just thought I'd take a few extra measures to make sure all is good and running well. You know, while I'm in there.
I'll look into locating some more Redline. I guess I'll be calling Steve Haygood again!
Oh, about the powdery deposits, I'll have to get back to you on that. The diff is at my friend's house across base. I'll be there on Saturday, so I can go visit the diff in his garage at that time. I'll post a new thread if I find anything worth posting.
Thanks again for the help, Pat.
Diff lube itself is a pretty good solvent, most oils are, so my thinking is that you'd kill to problems with one type of chemical, diff lube. Yes, you'd have to buy extra Redline, but that's really not that expensive in the long run, maybe an extra 10-15 bucks.
Another question I should ask. Is there any evidence of rust on the input shaft or near it? Evidence would be fine rust colored powder around the input shaft and working its way back on the diff. Without any evidence of rusting, is the stiffness in turning the shaft the only thing that's an issue for you? If that's the case, it may only be a stiff crush washer interface that will free up with use.[/QUOTE]
Pat,
Yes the main issue I'm having is the gunked up input shaft. It would probably free up just fine after a few miles of driving and the Redline sloshing around in there, but I just thought I'd take a few extra measures to make sure all is good and running well. You know, while I'm in there.
I'll look into locating some more Redline. I guess I'll be calling Steve Haygood again!
Oh, about the powdery deposits, I'll have to get back to you on that. The diff is at my friend's house across base. I'll be there on Saturday, so I can go visit the diff in his garage at that time. I'll post a new thread if I find anything worth posting.
Thanks again for the help, Pat.
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Blue Shadow
- Posts: 10281
- Joined: Feb 12, 2006 12:00 PM
- Location: SE PA
Shifty,
Your math is fine for a high maintenance car. We all change oil at 3000 if we do not extend due to synthetic, but the BMW recommendation is for an oil change at twice that, but based on the lights it can be considerably longer. So the overall intervals are twice what you posted, unless we are changing the diff fluid every year and adjusting valves twice a year, which I am not. So for those of you that might buy my car if it ever comes up for sale, I do not change my diff fluid every year.
Your math is fine for a high maintenance car. We all change oil at 3000 if we do not extend due to synthetic, but the BMW recommendation is for an oil change at twice that, but based on the lights it can be considerably longer. So the overall intervals are twice what you posted, unless we are changing the diff fluid every year and adjusting valves twice a year, which I am not. So for those of you that might buy my car if it ever comes up for sale, I do not change my diff fluid every year.
[QUOTE="Blue Shadow"]Shifty,
Your math is fine for a high maintenance car. We all change oil at 3000 if we do not extend due to synthetic, but the BMW recommendation is for an oil change at twice that, but based on the lights it can be considerably longer. So the overall intervals are twice what you posted, unless we are changing the diff fluid every year and adjusting valves twice a year, which I am not. So for those of you that might buy my car if it ever comes up for sale, I do not change my diff fluid every year.[/QUOTE]
I see your point, but I still run dino oil. Well, I say "still" as if I'm going to be running synthetic eventually. I won't be any time soon!
Anyway, I still have to change every 3,000, but I try to cut that down to about 2700 or so, if possible. I'm at 2800 right now, so it's getting close for me right now! D'oh!
I adjust the valves every 12,000 miles, whether Bentley suggests more often or less. Brake fluid, MTL, diff fluid, annually. Coolant flush and new hoses, bi-annually.
Your math is fine for a high maintenance car. We all change oil at 3000 if we do not extend due to synthetic, but the BMW recommendation is for an oil change at twice that, but based on the lights it can be considerably longer. So the overall intervals are twice what you posted, unless we are changing the diff fluid every year and adjusting valves twice a year, which I am not. So for those of you that might buy my car if it ever comes up for sale, I do not change my diff fluid every year.[/QUOTE]
I see your point, but I still run dino oil. Well, I say "still" as if I'm going to be running synthetic eventually. I won't be any time soon!
Anyway, I still have to change every 3,000, but I try to cut that down to about 2700 or so, if possible. I'm at 2800 right now, so it's getting close for me right now! D'oh!
I adjust the valves every 12,000 miles, whether Bentley suggests more often or less. Brake fluid, MTL, diff fluid, annually. Coolant flush and new hoses, bi-annually.
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Tammer in Philly
- Posts: 10719
- Joined: Feb 12, 2006 12:00 PM
- Location: CHI, IL
[QUOTE="Shifty"]I adjust the valves every 12,000 miles, whether Bentley suggests more often or less. Brake fluid, MTL, diff fluid, annually. Coolant flush and new hoses, bi-annually.[/QUOTE]
Unless you're driving more than 15k-20k per year, I'd relax on the trans/diff fluids to bi-annually. Unless your magnet is full of gunk every time you switch, but I doubt it is.
Do you do plugs at every valve adjustment?
-tammer
Unless you're driving more than 15k-20k per year, I'd relax on the trans/diff fluids to bi-annually. Unless your magnet is full of gunk every time you switch, but I doubt it is.
Do you do plugs at every valve adjustment?
-tammer
[QUOTE="Tammer in Philly"]Unless you're driving more than 15k-20k per year, I'd relax on the trans/diff fluids to bi-annually. Unless your magnet is full of gunk every time you switch, but I doubt it is.
Do you do plugs at every valve adjustment?
-tammer[/QUOTE]
I may consider that once I finally get settled down somewhere. I may be leaving Missouri in a little over a year, which means more road-trippin. Right now, my average is less than 1,000 miles per month, which is quite low for me. I'm usually about 1500/mo. If my mileage stays low for the rest of the year, I'll relax on my fluid changes.
I need to check and see if I did the plugs last March. If I didn't, I need to do them soon. If I did, I'll wait. The valves aren't making any noise at all, so I adjusted them correctly last March. I'll wait another year for them unless they start making noise on me in the future.
As far as the diff goes, I need to do that fluid when I put the "new" diff in, though. Even if I wasn't doing the diff swap, I'd be due on diff fluid since I didn't do it last March.
Thanks for the insight, Tammer.
Do you do plugs at every valve adjustment?
-tammer[/QUOTE]
I may consider that once I finally get settled down somewhere. I may be leaving Missouri in a little over a year, which means more road-trippin. Right now, my average is less than 1,000 miles per month, which is quite low for me. I'm usually about 1500/mo. If my mileage stays low for the rest of the year, I'll relax on my fluid changes.
I need to check and see if I did the plugs last March. If I didn't, I need to do them soon. If I did, I'll wait. The valves aren't making any noise at all, so I adjusted them correctly last March. I'll wait another year for them unless they start making noise on me in the future.
As far as the diff goes, I need to do that fluid when I put the "new" diff in, though. Even if I wasn't doing the diff swap, I'd be due on diff fluid since I didn't do it last March.
Thanks for the insight, Tammer.
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Blue Shadow
- Posts: 10281
- Joined: Feb 12, 2006 12:00 PM
- Location: SE PA
Plugs (the silvers anyway) will last 60K in these cars. Sure there may be a bit of benefit from a change at 15 or the recommended 30K but they show so little wear at those intervals I was always concerned I was throwing away good plugs. The higher power ign systems in these cars compared to the older stuff has made the plugs last longer and the recommendations I have seen is 60K is the life of them.
As Tammer said, the gear adn rear fluids are good for 25-30 K on dino oil and MUCH longer on synthetic. I don't know if these cars will benefit from the over maintenance some of us do to them. I geuss we can hope.
As Tammer said, the gear adn rear fluids are good for 25-30 K on dino oil and MUCH longer on synthetic. I don't know if these cars will benefit from the over maintenance some of us do to them. I geuss we can hope.
The other problem I have to deal with is disposal of used oil. I put it into a 5 gallon Jerry can and take it into Kragen Auto Parts locally and they recycle it, a free service.
Changing oil every 3k miles would effectively double my used oil output, a royal pain in the ass. Since I have five running vehicles, I'd be covered up with oil at such a short change interval.
Thank the Gods synthetic came along when it did.
Changing oil every 3k miles would effectively double my used oil output, a royal pain in the ass. Since I have five running vehicles, I'd be covered up with oil at such a short change interval.
Thank the Gods synthetic came along when it did.
As far as plugs go, replacing them every 30,000 miles means you have plenty of spares in case one goes bad, someone else's goes bad, you buy another E28, etc.
As far as oil changes go, Autozone takes my oil every 2700 - 3000 miles, and I refuse to change to synthetic! At least for now.
So, what do y'all think about me toting my diff to the corrosion center and PMBing it, hmmmmm? I bet it'd be the cleanest, shiniest diff you've ever seen!
As far as oil changes go, Autozone takes my oil every 2700 - 3000 miles, and I refuse to change to synthetic! At least for now.
So, what do y'all think about me toting my diff to the corrosion center and PMBing it, hmmmmm?
I bet it'd be the cleanest, shiniest diff you've ever seen!-
Tammer in Philly
- Posts: 10719
- Joined: Feb 12, 2006 12:00 PM
- Location: CHI, IL
[QUOTE="Shifty"]So, what do y'all think about me toting my diff to the corrosion center and PMBing it, hmmmmm? I bet it'd be the cleanest, shiniest diff you've ever seen![/QUOTE]
Do it! Then hit it with some good chassis black paint. Just make sure you REALLY seal up all points of ingress before you hit it.
<sarcasm>
Ooh! Ooh! Then you can put a lift kit on the back and shove some 13" drag radials underneath, and show off yer shiny black diff just like the 'Stang-banger crowd! Although I don't know if you'd get the same visual effect without the Panhard rod.
</sarcasm>
Actually though, good idea on keeping some used-but-good plugs for spares; I always just chucked 'em. However, at my last change they were really fouled (fuel, I believe), which I hadn't seen before. Consequence of more short trips than normal? No other signes of rich running.
-tammer
I bet it'd be the cleanest, shiniest diff you've ever seen![/QUOTE]Do it! Then hit it with some good chassis black paint. Just make sure you REALLY seal up all points of ingress before you hit it.
<sarcasm>
Ooh! Ooh! Then you can put a lift kit on the back and shove some 13" drag radials underneath, and show off yer shiny black diff just like the 'Stang-banger crowd! Although I don't know if you'd get the same visual effect without the Panhard rod.
</sarcasm>
Actually though, good idea on keeping some used-but-good plugs for spares; I always just chucked 'em. However, at my last change they were really fouled (fuel, I believe), which I hadn't seen before. Consequence of more short trips than normal? No other signes of rich running.
-tammer
[QUOTE="Tammer in Philly"]Do it! Then hit it with some good chassis black paint. Just make sure you REALLY seal up all points of ingress before you hit it.
<sarcasm>
Ooh! Ooh! Then you can put a lift kit on the back and shove some 13" drag radials underneath, and show off yer shiny black diff just like the 'Stang-banger crowd! Although I don't know if you'd get the same visual effect without the Panhard rod.
</sarcasm>
Actually though, good idea on keeping some used-but-good plugs for spares; I always just chucked 'em. However, at my last change they were really fouled (fuel, I believe), which I hadn't seen before. Consequence of more short trips than normal? No other signes of rich running.
-tammer[/QUOTE]
HA! It would be pretty cool to see a newly-blasted diff, though. The cover looks to be a different metal than the actual diff. Does anyone know for sure? Diff looks like iron (judging by the amount of corrosion, and the rear cover looks like aluminum or something.
Tammer, on the fouled plugs, you could be spot on. I'm terrified to look at my plugs since my drive to work is about 2 miles every day. The only thing keeping my car from going insane from lack of exercise is when I drive it 10 miles into town on weekends!
<sarcasm>
Ooh! Ooh! Then you can put a lift kit on the back and shove some 13" drag radials underneath, and show off yer shiny black diff just like the 'Stang-banger crowd! Although I don't know if you'd get the same visual effect without the Panhard rod.
</sarcasm>
Actually though, good idea on keeping some used-but-good plugs for spares; I always just chucked 'em. However, at my last change they were really fouled (fuel, I believe), which I hadn't seen before. Consequence of more short trips than normal? No other signes of rich running.
-tammer[/QUOTE]
HA! It would be pretty cool to see a newly-blasted diff, though. The cover looks to be a different metal than the actual diff. Does anyone know for sure? Diff looks like iron (judging by the amount of corrosion, and the rear cover looks like aluminum or something.
Tammer, on the fouled plugs, you could be spot on. I'm terrified to look at my plugs since my drive to work is about 2 miles every day. The only thing keeping my car from going insane from lack of exercise is when I drive it 10 miles into town on weekends!
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Tammer in Philly
- Posts: 10719
- Joined: Feb 12, 2006 12:00 PM
- Location: CHI, IL
You're right. The rear cover (with cooling "mini-fins") is Al, while the forward part is cast Fe.HA! It would be pretty cool to see a newly-blasted diff, though. The cover looks to be a different metal than the actual diff. Does anyone know for sure? Diff looks like iron (judging by the amount of corrosion, and the rear cover looks like aluminum or something.
-tf.
[QUOTE="Shifty"]I adjust the valves every 12,000 miles, whether Bentley suggests more often or less. Brake fluid, MTL, diff fluid, annually. Coolant flush and new hoses, bi-annually.[/QUOTE]
[QUOTE="Tammer in Philly"]Unless you're driving more than 15k-20k per year, I'd relax on the trans/diff fluids to bi-annually. Unless your magnet is full of gunk every time you switch, but I doubt it is.
Do you do plugs at every valve adjustment?
-tammer[/QUOTE] jeez thats still is overkill., On old 'merican cars diff lube is considered to be lifetime.At 260k, I checked the diff level for the 1st time ever. It was right at the top. guilt drove me to R+R with Mobil 1 75-90. It quieted down the LSD clutches and seems to have rejuvenated them somewhat. . The tappets sound fine, I've never lifted the valve cover on the Borman6. I use dino juice at 3k intervals.
[QUOTE="Tammer in Philly"]Unless you're driving more than 15k-20k per year, I'd relax on the trans/diff fluids to bi-annually. Unless your magnet is full of gunk every time you switch, but I doubt it is.
Do you do plugs at every valve adjustment?
-tammer[/QUOTE] jeez thats still is overkill., On old 'merican cars diff lube is considered to be lifetime.At 260k, I checked the diff level for the 1st time ever. It was right at the top. guilt drove me to R+R with Mobil 1 75-90. It quieted down the LSD clutches and seems to have rejuvenated them somewhat. . The tappets sound fine, I've never lifted the valve cover on the Borman6. I use dino juice at 3k intervals.
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Tammer in Philly
- Posts: 10719
- Joined: Feb 12, 2006 12:00 PM
- Location: CHI, IL
How many old Murrican cars go 300k miles?jeez thats still is overkill., On old 'merican cars diff lube is considered to be lifetime.At 260k, I checked the diff level for the 1st time ever. It was right at the top. guilt drove me to R+R with Mobil 1 75-90. It quieted down the LSD clutches and seems to have rejuvenated them somewhat. . The tappets sound fine, I've never lifted the valve cover on the Borman6. I use dino juice at 3k intervals.
An ounce of prevention ....-tammer