DIY Front Differential Fluid Change Complete

[Lambeau]

Real-world 100,000 miles of proof Trumps opinions every time.

[wsmeyer]

That TTY bolts cannot be reused is not an opinion, it is a fact, and the reasoning is because of physics and what happens when you tighten them to yield.

That TTY bolts need to be used there is an opinion. It's not MY opinion though, it was the opinion of the mechanical engineer that designed the part. His is what's called an EXPERT OPINION as he his highly trained and qualified. He also had access to any and all data needed to form an opinion on the clamping force necessary for that plate to do it's job. He also had very specific, quantitative data on what exactly that plates "job" was.

For the opposing view, we have "Lambeau". A home mechanic with no engineering degree, no access to any data on the forces the plate is subjected to, and no idea what a TTY bolt is as he thinks they are reusable, who is justifying his opinion based on the anecdotal evidence that he reused the bolts and has driven 100,00 miles now with no negative effects that he can see.

[Lambeau]

There are many in this thread to prove you otherwise with not one instance of reusing the bolts causing an issue. There is in fact many more instances that they didn't fail than did. You have zero knowledge of what my degree is and you personally attacked me. Grow up.

[stltri]

Was reading some info on the ISTA+ regarding recommended fluids for the differentials. I know different DIY'ers have used different kinds. But I was curious about any drawbacks to using cheaper alternatives over the more expensive fluids recommended by BMW (for e70 N55 motor, per ISTA+ updated 2016) before I tackle this DIY:

1. Front differential: Hypoid Axle Oil G2 (BMW part no. 83-22-2-413-511)

2. Rear differential: Final-Drive Gear Oil Saf-Xo 832514 (BMW part no. 33-11-7-695-240)

3. Transfer case: Transfer Case Fluid - DTF 1 (SAE 75W GL-4) (BMW part no. 83-22-2-409-710)

[Entropy]

Originally Posted by stltri

Was reading some info on the ISTA+ regarding recommended fluids for the differentials. I know different DIY'ers have used different kinds. But I was curious about any drawbacks to using cheaper alternatives over the more expensive fluids recommended by BMW (for e70 N55 motor, per ISTA+ updated 2016) before I tackle this DIY:

1. Front differential: Hypoid Axle Oil G2 (BMW part no. 83-22-2-413-511)

2. Rear differential: Final-Drive Gear Oil Saf-Xo 832514 (BMW part no. 33-11-7-695-240)

3. Transfer case: Transfer Case Fluid - DTF 1 (SAE 75W GL-4) (BMW part no. 83-22-2-409-710)

The front and rear differentials are nothing fancy (no limited slip)... Same technology that's in just about every car on the road. You can use any quality gear oil in them. I went with Redline 75W-110. The transfer case is where you MUST go with the BMW fluid.

[Kostyan]

Originally Posted by stltri

Was reading some info on the ISTA+ regarding recommended fluids for the differentials. I know different DIY'ers have used different kinds. But I was curious about any drawbacks to using cheaper alternatives over the more expensive fluids recommended by BMW (for e70 N55 motor, per ISTA+ updated 2016) before I tackle this DIY:

1. Front differential: Hypoid Axle Oil G2 (BMW part no. 83-22-2-413-511)

2. Rear differential: Final-Drive Gear Oil Saf-Xo 832514 (BMW part no. 33-11-7-695-240)

3. Transfer case: Transfer Case Fluid - DTF 1 (SAE 75W GL-4) (BMW part no. 83-22-2-409-710)

Called SilverSpring BMW GetBMWparts counter...

You got the transfer case fluid part # right, and that is the only fluid to use. I was told need only 1 500ml container

Front differential - was told to use part 83 22 2413511 , need 1.25l via two $45 containers
Rear differential - was told to use part 83 22 22 95532 , same capacity, about the same 2 x $45




Called Northwest BMW parts counter and they would not confirm/give out part #s over the phone. I am a bit confused as last time these fluids did not cost me $300 and can't recall where/what/how much I bought.....

[SF2000x5]

Looks like 75w-85 is the correct fluid for the front Differential Oil. Not much different.

I've removed the reinforcement plate and zipped them on and off with an impact gun numerous times.

[robnitro]

Color doesn't mean much. Some oils are dark like that from the bottle, depending on what kind of EP additives they use.
I'd still do the rear diff and the tc every 40k, those are the stressed parts, especially the tc since the clutch in there does controlled slip to vary front torque.

[jcattletown]

Originally Posted by robnitro

Color doesn't mean much. Some oils are dark like that from the bottle, depending on what kind of EP additives they use.
I'd still do the rear diff and the tc every 40k, those are the stressed parts, especially the tc since the clutch in there does controlled slip to vary front torque.

Thanks for the suggestion. Will do the rear differential next week. A new TC was installed late last year so no need to change fluid. Have you done trans oil change? I have a GA8HP45Z transmission and it seems the procedure is complicated. Have to use ISTA to adapt and balance the new fluid during and after filling. Any comments?

[Aquamania]

But, but, it is life time fluid!!!!