Honda VTM-4 UOA

[youdontwannaknow]

Hi,
never really got around posting this uoa and then almost forgot about it. But here it is! A UOA for the Honda VTM-4 Rear Diff fluid. Have never seen a vtm-4 uoa around here or maybe my search isn't working. If you know of please let me know so we can compare.

Anyone care to comment ? Why can't this be just substituted by their fancy ATF (Z1) ? Why a different fluid for this ?

 

[Pablo]

No wear!

Like a light gear oil. Interesting.

 

[VK56VD]

I assume this is the original VTM-4 from the factory that has never been replaced in 58k miles.

 

[youdontwannaknow]

nope. as the uoa says it got 15k miles on it and the car had 83.5k miles.
I think Blackstone's comment is indicating that the universal avgs are from 58k (propably because they dont have any for this diff for more than 58k miles ? )

 

[IntegraVT]

Originally Posted By: youdontwannaknow
Anyone care to comment ? Why can't this be just substituted by their fancy ATF (Z1) ? Why a different fluid for this ?


Thanks for the UOA. Looks like Honda had the same questions since they have transitioned to ATF-Z1 for the SH-AWD system on the 2007+ MDX.

 

[youdontwannaknow]

really ? wow. thats news to me. I didn't know that they use Z1 for the SH-AWD VTM(rear diff)!
Although they still keep supplying the VTM-4 fluid for the pre-shawd models ? I'd imagine they would come out with some sort of an addendum to transition the older models to z1 as well ?

 

[Tempest]

Fe of 4 in 15K miles? That just seems way low to me??

 

[shanneba]

Did you send in a UOA when you changed your fluid at 58K?
That may be the only sample Blackstone has for a comparison.
Do the universal averages match your 58K OUOA?

 

[youdontwannaknow]

ok. Here's the deal. I emailed Blackstone and they said that the univ avgs were for generic differentials for a ~58k change interval. Today they sent me an updated report with the Honda/Acura differential at its normal change interval which is ~12k.
So only the univ avgs changed. I will post the updated one later when I get a chance, but still looks like a great uoa.

 

[cderalow]

Originally Posted By: IntegraVT
Originally Posted By: youdontwannaknow
Anyone care to comment ? Why can't this be just substituted by their fancy ATF (Z1) ? Why a different fluid for this ?


Thanks for the UOA. Looks like Honda had the same questions since they have transitioned to ATF-Z1 for the SH-AWD system on the 2007+ MDX.


Honestly, I'm not sure why they use the ATF Z1 for the SH-AWD systems, but I'd have to assume because they're closer to automatic transmissions than they are the typical differentials from Honda (being the DPF required CRV/Element or the VTM4 required Pilot/Ridgeline).

My only guess (comparing the ATF Z1 to DPFII) is the relative viscosity (DPFII seems slightly more viscous at room temp).

I might spend the $$ and test both in a virgin state at some point so we can compare.