Differential looks little bit oily!

[SaNGRia]

I just got done doing the Oem Muffler mod. Since i was working very close under the car, i noticed that my differential box looks like there was a oil and dried out. I have the car since 2013. I never had any oil leak on the floor what so ever. Is that normal ? Can you guys see the same?

Car has 36k miles on it! I am also planning to replace my differential fluid soon!




I will really appreciate if you guys take yours and share with me!

[atruelunatic]

I'll be getting my diff oil changed this Thursday. I'll ask them to see if I can snag a picture while it's on the lift.

[SaNGRia]

Originally Posted by atruelunatic

I'll be getting my diff oil changed this Thursday. I'll ask them to see if I can snag a picture while it's on the lift.

I really appreciated. I will also do mine next weekend and also will buy the new sealing. I really don't thing nothing wrong since there is no leak on the floor. Either the previous owner replaced the diff fluid and it happened during the replacement, or there is seeping!

Can you also tell me how much they will charge for this process? I am thinking DIY and need to get 3 bottle of fluid which already costs about $155

[atruelunatic]

Originally Posted by SaNGRia

I really appreciated. I will also do mine next weekend and also will buy the new sealing. I really don't thing nothing wrong since there is no leak on the floor. Either the previous owner replaced the diff oil and it happened during the replacement, or there is seeping!

Can you also tell me how much they will charge for this process? I am thinking DIY and need to get 3 bottle of fluid which already costs about $155

They are charging me $105 using Redline Gear Oil. Their labor is $120/hr. I think OEM diff fluid costs a lot more than Redline. I've heard good from both OEM and Redline, but there's lots of debate about what to use. So in the end, it's all up to you.

[SaNGRia]

Originally Posted by atruelunatic

They are charging me $105 using Redline Gear Oil. Their labor is $120/hr. I think OEM diff fluid costs a lot more than Redline. I've heard good from both OEM and Redline, but there's lots of debate about what to use. So in the end, it's all up to you.

Ohh yeah. A lot more! I just had a conversation with ECSTunning representative and he said i used Redline on my m5 and no problem whatsoever. When you use redline you have to use with one other product (i forgot the name of it, he said BMW original one comes with it which protects the gear longer than normal). But Redline cost 50 bucks with this extra stuff, OEM cost 155. Also redline comes with 1 quad bottle, OE Comes 0.5!

So u also have confident with RedLine as well! I might use RedLine as well then! Is there really differences between two of them? I mean if it was my pressure wash motor i would never hesitate to use it Also i just replaced my Jeep engine oil. Just got from Walmart and no hesitation. But somehow this m3 makes me just get the OE products.

[SaNGRia]

from my researching it might be Differential input shaft seal too. Driver side is fine, Passenger side looks oily/dirty!

[dparm]

Originally Posted by SaNGRia

Ohh yeah. A lot more! I just had a conversation with ECSTunning representative and he said i used Redline on my m5 and no problem whatsoever. When you use redline you have to use with one other product (i forgot the name of it, he said BMW original one comes with it which protects the gear longer than normal). But Redline cost 50 bucks with this extra stuff, OEM cost 155. Also redline comes with 1 quad bottle, OE Comes 0.5!

You're thinking of friction modifier (FM). You don't need it in their regular 75w140:

Contains additional friction modifiers for suitablity with clutch-type limited slip differentials - for most LSDs, no additional friction modifiers are required

You can add additional FM if the noise bothers you. This is what BMW used to say until they updated the OEM fluid to include extra FM.

Red Line sells a version of the 75w140 that does NOT contain FM but you don't want that one.

Versus the OEM fluid (Castrol Syntrax Limited Slip, formerly known as SAF-XJ), Red Line's fluid is thicker at all temperatures. Some people might want thicker for extra protection, but bear in mind it will cause extra heat buildup in the differential. It would also sap some power due to the extra parasitic drag. I don't really see a reason to go thicker unless you've proven that the factory 75w140 is insufficient.


If you're looking to go with something other than OEM for some reason, such as cost, different performance requirements, or curiosity, there are three particularly interesting fluids that I've had my eye on. I'll likely try one of these when my fluid gets changed; it will likely be the Renewable Lube stuff -- it's a great value and is from a small Ohio company that is turning out some great products.

Renewable Lube Bio-SynXtra 75w140
KV @ 40C = 153.9 (about 10% thinner than stock)
KV @ 100C = 25.1 (about the same as stock)
VI = 191 (about 10% higher than stock)
$17/L
Contains FM


Gulf Competition LS 75w140
KV @ 40C = 140 (about 20% thinner than stock)
KV @ 100C = 26 (about 5% thicker than stock)
VI = 220 (about 20% higher than stock)
$44/L
Contains FM


Torco SGO
KV @ 40C = 154.5 (about 10% thinner than stock)
KV @ 100C = 25.5 (about the same as stock)
VI = 200 (about 15% higher than stock)
$21/L
No FM, Torco sells one called Type F you add to your taste

[thekurgan]

Originally Posted by SaNGRia

from my researching it might be Differential input shaft seal too. Driver side is fine, Passenger side looks oily/dirty!

You can usually see a spray arc on the heat shield above the seals and if this is the case, it's best to do the output seals at the same time, especially if you're dropping the pumpkin.

[SaNGRia]

Originally Posted by thekurgan

You can usually see a spray arc on the heat shield above the seals and if this is the case, it's best to do the output seals at the same time, especially if you're dropping the pumpkin.

is this a easy process? Can i DIY without a lift?

[thekurgan]

Originally Posted by SaNGRia

is this a easy process? Can i DIY without a lift?

As long as you can support the diff, and there is enough space, I don't see why not.

[SaNGRia]

Originally Posted by thekurgan

As long as you can support the diff, and there is enough space, I don't see why not.

I will check the ISTA, let me see how can i do that! It really doesn't leak at all, i guess the sealing went bad little bit after like 7 years .

[tdott]

I wouldn't worry about it until it gets worse...

[SaNGRia]

Originally Posted by tdott

I wouldn't worry about it until it gets worse...

What i am going to do is i will clean the differential box with paint thinner today and will watch the situation. I am not sure i can use the paint thinner or not but it cleaned my muffler very well (not the tips)

[thekurgan]

Originally Posted by SaNGRia

I will check the ISTA, let me see how can i do that! It really doesn't leak at all, i guess the sealing went bad little bit after like 7 years .

If you don't see any oil spray around the heat shielding, then it might be something else. Perhaps the fill bolt. The input seal leak is unmistakeable.

[tdott]

Originally Posted by SaNGRia

What i am going to do is i will clean the differential box with paint thinner today and will watch the situation. I am not sure i can use the paint thinner or not but it cleaned my muffler very well (not the tips)

Try to use something less harsh, like Simply Green or something like that. Should be fine at getting the oil sweat off.

[dparm]

Originally Posted by SaNGRia

is this a easy process? Can i DIY without a lift?

No different than any other rear diff, from what I've seen. Book time is probably an hour. Probably take you 90 minutes in your garage.

[SaNGRia]

Originally Posted by tdott

Try to use something less harsh, like Simply Green or something like that. Should be fine at getting the oil sweat off.

I am just done simply greening Yeah it was def. the passenger side and this is look like differential input shaft seal leaked all around. I used toothbrush to reach the upper of this input! It really did not look like wet leak. It looked like dried out. So probably my differential box missing some fluid and i am not aware of (just found out). The Classic BMW Texas took care of the vehicle since the first owner leased and kept the car. They maintenance papers shows what they re done till 25k miles. And i know that the head guy who sold this car to me replaced oil, sparks and tired before the shipping as well but i do not think that they replaced the fluid since the car was only 29k.

Here is the Driver side : (it was clean like brand new)


Passenger Side : (it was dirty like 100k)



I cleaned them but you can still notice the passenger side has left over dry fluid between the screws!

I just purchased Engine Oil and Differential Fluid Kit from ECS.

My question is if i replace the seal after the fluid change is there any possibility it will leak while this exchange from the input area?

Or should i replace the seal than replace the fluid?

Also looked that how can i remove this input when i was washing the differential, it will be really hard without a lift. I need to remove the muffler again! And i don't know how hard will be to remove this screws while has a very narrow work space!

[Get lit]

Drain old fluid, replace seal, then fill with your new fluid.

[SaNGRia]

If this is that easy yeah i can do it :

[SaNGRia]

This is a great info. Thank you

Originally Posted by dparm

You're thinking of friction modifier (FM). You don't need it in their regular 75w140:

Contains additional friction modifiers for suitablity with clutch-type limited slip differentials - for most LSDs, no additional friction modifiers are required

You can add additional FM if the noise bothers you. This is what BMW used to say until they updated the OEM fluid to include extra FM.

Red Line sells a version of the 75w140 that does NOT contain FM but you don't want that one.

Versus the OEM fluid (Castrol Syntrax Limited Slip, formerly known as SAF-XJ), Red Line's fluid is thicker at all temperatures. Some people might want thicker for extra protection, but bear in mind it will cause extra heat buildup in the differential. It would also sap some power due to the extra parasitic drag. I don't really see a reason to go thicker unless you've proven that the factory 75w140 is insufficient.


If you're looking to go with something other than OEM for some reason, such as cost, different performance requirements, or curiosity, there are three particularly interesting fluids that I've had my eye on. I'll likely try one of these when my fluid gets changed; it will likely be the Renewable Lube stuff -- it's a great value and is from a small Ohio company that is turning out some great products.

Renewable Lube Bio-SynXtra 75w140
KV @ 40C = 153.9 (about 10% thinner than stock)
KV @ 100C = 25.1 (about the same as stock)
VI = 191 (about 10% higher than stock)
$17/L
Contains FM


Gulf Competition LS 75w140
KV @ 40C = 140 (about 20% thinner than stock)
KV @ 100C = 26 (about 5% thicker than stock)
VI = 220 (about 20% higher than stock)
$44/L
Contains FM


Torco SGO
KV @ 40C = 154.5 (about 10% thinner than stock)
KV @ 100C = 25.5 (about the same as stock)
VI = 200 (about 15% higher than stock)
$21/L
No FM, Torco sells one called Type F you add to your taste

[JFB]

Looks like mine a couple weeks ago. Input shaft differential seal. Extremely slow leak. Some mornings one drop on ground, some mornings nothing. My diff was wet looking just like your pictures...

The thing is, there is barely any liquid in the diff to begin with, so if it's leaking, you want it refilled ASAP. Get someone to look at it soon.

[dparm]

Originally Posted by SaNGRia

This is a great info. Thank you

You're welcome. Let us know what you choose!

Originally Posted by JFB

The thing is, there is barely any liquid in the diff to begin with, so if it's leaking, you want it refilled ASAP. Get someone to look at it soon.

Excellent point. It only holds 1.25 qt.