Have a friend replace the oil in his Nisson transfer case...Called for GL4 so He put in AMSOIL the dealer said was GL4...A month later a leak....I was going to use AMSOIL for mine, till I heard this....Comments?
comments on Syn gear oil
- Thread starter ceast
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So because it leaked, it must be because it's synthetic? Or that it's Amsoil?
Nope! That is why I asked...If I knew what caused it to leak, I would not have asked...Wanted more input than what I know and what my friend surmised....Charlie
One theory is that the existing fluid had thickened quite a bit and the new stuff was thinner and seeped through the gaskets (which might be getting really old).
Given that some manufacturers SPECIFICALLY recommend against synthetic gear oils, I have to wonder if there's more to it than just coincidence.
Are gear oil seals more subject to penetration/hardening/whatever by synthetic gear lubes than engine seals and gaskets are? Do synthetic gear lubes have some incidental additive (for example, perhaps an additive used to keep anti-wear additives in suspension better)that damage seals? Some combination of synthetic base oil and the high doses of sulfur-based EP additives? What's going on with gear oils that doesn't apply to engine oils?
I've never been one to believe that there should/could be much difference in synthetic versus conventional engine oils when it comes to leakage, but with all the specific exclusions of synthetic gear lubes, I have to wonder what's different. No manufacture (that I know of) in any way forbids synthetic engine oil, transmission fluid, etc., but at least a few still say don't use synthetic gear oil. I'd really love to know the engineering reason behind that...
Are gear oil seals more subject to penetration/hardening/whatever by synthetic gear lubes than engine seals and gaskets are? Do synthetic gear lubes have some incidental additive (for example, perhaps an additive used to keep anti-wear additives in suspension better)that damage seals? Some combination of synthetic base oil and the high doses of sulfur-based EP additives? What's going on with gear oils that doesn't apply to engine oils?
I've never been one to believe that there should/could be much difference in synthetic versus conventional engine oils when it comes to leakage, but with all the specific exclusions of synthetic gear lubes, I have to wonder what's different. No manufacture (that I know of) in any way forbids synthetic engine oil, transmission fluid, etc., but at least a few still say don't use synthetic gear oil. I'd really love to know the engineering reason behind that...
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Here's a similar story with about as much detail as yours: I installed an Amsoil bypass filter on my car and filled the crankcase (and filters) with Schaeffer oil. Three months later my wife gave birth to a son!
Or in other words, post hoc ergo propter hoc...
Or in other words, post hoc ergo propter hoc...
Originally Posted By: scurvy
Or in other words, post hoc ergo propter hoc...
Well said... or should I say bene dixit.
Usually synthetics just expose leaks that were already there, often via their increased detergency/solvency. Like as not, the transfer case would've leaked soon enough no matter what oil was installed.
The "no syns in oil in diffs" is another topic. Typically it has more to do with traction aids (LSD) than anything else. There are some performance axle builders that spec a mineral gear oil after they work their magic but the arguments the reasons they espouse make little sense to me. I'd love to get a reasoned, informed explanation as to why.
Or in other words, post hoc ergo propter hoc...
Well said... or should I say bene dixit.
Usually synthetics just expose leaks that were already there, often via their increased detergency/solvency. Like as not, the transfer case would've leaked soon enough no matter what oil was installed.
The "no syns in oil in diffs" is another topic. Typically it has more to do with traction aids (LSD) than anything else. There are some performance axle builders that spec a mineral gear oil after they work their magic but the arguments the reasons they espouse make little sense to me. I'd love to get a reasoned, informed explanation as to why.
All seems to be good input...Still hoping for some engineers to chime in with ideas...He said transfer had 30,000 on it 3 years old when he replace the oil with Amsoil and now after gasket replacement, has 70,000 with regular 80/90 with no leaks...He can't remember what brand of oil...just Autozone..He said why go high dollar, just replace the oil every 50K to 75K miles..Please people, don't blow a gasket.. Knowledge is handy though...Charlie
I wasn't aware some manufacturers recommend dino. I know the German cars always require synthetic gear oils.
So he replaced the xfer case gasket and now it doesn't leak?
Huh... who woulda thunk it!
Huh... who woulda thunk it!
Read closely....Transer case 30K mile no leak ....in comes amsoil and leak in one month....Note: the 30 K part...Now comes new gaskets and GL4 from Autozone.... He can't remember what....Not amsoil......Smme else , it was 7 or 8 years ago.... ....Now note No leaks...
Please tell me your experiences...Need input to me ,not output of opinions....
Dear fellows, tell me what happened to you....Good or bad...Thanks Charlie
Please tell me your experiences...Need input to me ,not output of opinions....
Dear fellows, tell me what happened to you....Good or bad...Thanks Charlie
MolaKule
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Originally Posted By: scurvy
So he replaced the xfer case gasket and now it doesn't leak?
Huh... who woulda thunk it!
Ceast, I arrived at the same conclusion from the description you gave.
I think the old gasket was going bad and the synthetic removed a false seal.
I have an '03 PathFinder, 141,000 miles, and have never had a gasket leak from anywhere and it has had synthetics since 500 miles.
So he replaced the xfer case gasket and now it doesn't leak?
Huh... who woulda thunk it!
Ceast, I arrived at the same conclusion from the description you gave.
I think the old gasket was going bad and the synthetic removed a false seal.
I have an '03 PathFinder, 141,000 miles, and have never had a gasket leak from anywhere and it has had synthetics since 500 miles.
Originally Posted By: ceast
Have a friend replace the oil in his Nisson transfer case...Called for GL4 so He put in AMSOIL the dealer said was GL4...A month later a leak....I was going to use AMSOIL for mine, till I heard this....Comments?
I had a similar situation happen on my 2000 Tundra t-case. I had been using whatever the dealer serviced it with until 134K miles. Then I switched to Valvoline Synpower 75W-90 until 150K. I then tried Mobil 1 75W-90. At 157K the input shaft seal started to leak (pooling up on the driveway). The estimate for repair was $1000.
I decided to drain the M1 and filled with Valvoline conventional 75W-90 with 3 ozs of Auto-Rx added. The leak stopped within a couple hundred miles and dried up. After 1K miles I drained the gear oil with ARX and used the Valvoline conventional until I recently sold the truck at 207K miles. Everything fluid related was dry as a bone.
I don't think the "experts" on BITOG would agree with me, But I do think there are seal compatability issues with certain suppliers and lubricants. AN OEM can source many suppliers for just one seal. So don't be afraid to try any lube you want. Just remember that Auto_rx is your friend!
Have a friend replace the oil in his Nisson transfer case...Called for GL4 so He put in AMSOIL the dealer said was GL4...A month later a leak....I was going to use AMSOIL for mine, till I heard this....Comments?
I had a similar situation happen on my 2000 Tundra t-case. I had been using whatever the dealer serviced it with until 134K miles. Then I switched to Valvoline Synpower 75W-90 until 150K. I then tried Mobil 1 75W-90. At 157K the input shaft seal started to leak (pooling up on the driveway). The estimate for repair was $1000.
I decided to drain the M1 and filled with Valvoline conventional 75W-90 with 3 ozs of Auto-Rx added. The leak stopped within a couple hundred miles and dried up. After 1K miles I drained the gear oil with ARX and used the Valvoline conventional until I recently sold the truck at 207K miles. Everything fluid related was dry as a bone.
I don't think the "experts" on BITOG would agree with me, But I do think there are seal compatability issues with certain suppliers and lubricants. AN OEM can source many suppliers for just one seal. So don't be afraid to try any lube you want. Just remember that Auto_rx is your friend!
I'm confused. Are you talking about rear differential or transfer case? I thought transfer cases usually take ATF and the ones I have owned only have a plug for draining and a plug for filling. Maybe I'm wrong but at least that is what it is from my experience. My rear diffs have a drain plug and sometimes fill plug and generally require changing the gasket.
Originally Posted By: 95busa
Some manufacturers require synthetic ....Ford, dodge. Leaky seals don't card what you put in there
Well the seals will get in trouble if that fluid is in there and underage!
Some manufacturers require synthetic ....Ford, dodge. Leaky seals don't card what you put in there
Well the seals will get in trouble if that fluid is in there and underage!
1982 datsun(Nisson)720 D...Transfer case recommended fluid BY MANUAL GL4....First transfer case 100K miles...What ever oil nisson put in there...second was factory new.....At 30K miles...Amsoil.....Leaks . new gaskets....80-90 wt...GL4 No leaks....In 8 years..Read the posts.....Charlie
Originally Posted By: Jim Allen
Originally Posted By: scurvy
Or in other words, post hoc ergo propter hoc...
Well said... or should I say bene dixit.
Usually synthetics just expose leaks that were already there, often via their increased detergency/solvency. Like as not, the transfer case would've leaked soon enough no matter what oil was installed.
The "no syns in oil in diffs" is another topic. Typically it has more to do with traction aids (LSD) than anything else. There are some performance axle builders that spec a mineral gear oil after they work their magic but the arguments the reasons they espouse make little sense to me. I'd love to get a reasoned, informed explanation as to why.
Good info. I too would like to know why some gear manufacturers say syn if fine and others don't.
As far as syn gear oil I put red line shockproof in my hemi this winter,replaced the gaskets and no leaks thus far,perhaps the replacing the gasket part has something to do with it.
I put shockproof in every mustang rear end as soon as they come to me,and I've never had a leak.
When changing my stock 3.27s to 3.90s a couple years ago the fluid that drained out was like mud,and glittery. I put super tech gear oil in for 1000 miles,then put shockproof in,and not a hint of a weep so far.
Originally Posted By: scurvy
Or in other words, post hoc ergo propter hoc...
Well said... or should I say bene dixit.
Usually synthetics just expose leaks that were already there, often via their increased detergency/solvency. Like as not, the transfer case would've leaked soon enough no matter what oil was installed.
The "no syns in oil in diffs" is another topic. Typically it has more to do with traction aids (LSD) than anything else. There are some performance axle builders that spec a mineral gear oil after they work their magic but the arguments the reasons they espouse make little sense to me. I'd love to get a reasoned, informed explanation as to why.
Good info. I too would like to know why some gear manufacturers say syn if fine and others don't.
As far as syn gear oil I put red line shockproof in my hemi this winter,replaced the gaskets and no leaks thus far,perhaps the replacing the gasket part has something to do with it.
I put shockproof in every mustang rear end as soon as they come to me,and I've never had a leak.
When changing my stock 3.27s to 3.90s a couple years ago the fluid that drained out was like mud,and glittery. I put super tech gear oil in for 1000 miles,then put shockproof in,and not a hint of a weep so far.
Originally Posted By: ceast
1982 datsun(Nisson)720 D...Transfer case recommended fluid BY MANUAL GL4....First transfer case 100K miles...What ever oil nisson put in there...second was factory new.....At 30K miles...Amsoil.....Leaks . new gaskets....80-90 wt...GL4 No leaks....In 8 years..Read the posts.....Charlie
I have read them and I still can barely understand what you are trying to say/ask.
So the consensus is to stick with conventional? Sounds good to me.
1982 datsun(Nisson)720 D...Transfer case recommended fluid BY MANUAL GL4....First transfer case 100K miles...What ever oil nisson put in there...second was factory new.....At 30K miles...Amsoil.....Leaks . new gaskets....80-90 wt...GL4 No leaks....In 8 years..Read the posts.....Charlie
I have read them and I still can barely understand what you are trying to say/ask.
So the consensus is to stick with conventional? Sounds good to me.
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