Mobil 1 has (mostly) improved the HTFS viscosity and VII content with API SP

[Deleted member 89374]

2nd doesn't grab it just really does not want to let you in unless you pause.

Sounds like a synchronizer issue. I bet if you rev-matched that gear, it would go in easier. But, I mean, who would want to rev-match 2nd?

Manual transmissions are way more flexible on the fluid you use. If you want to try an ATF, I would go with Castrol TranSynd TES-668. I run it in three transfer cases that are all different: in a BW44-44 (clutch coupling for front axle) in a RAM 1500, a MP2010 (no clutch, just gears and a planetary differential), and a MP3010 (clutch coupling on demand and low range gears) in the Jeep. They all run perfectly fine with it, and I noticed a reduction in noise when switching modes in the RAM 1500 and the Jeep. It's more "stout", so to speak, than any other ATF out there. And if you don't like how it shifts, drain it out. It's cheap enough that it won't burn a hole in your pocket, yet this stuff is unkillable. There is also Delvac 1 ATF TES-295, but the friction modification is based on a spec that's like 18 years old by now. I'd go with TES-668. Oh, by the way, either of the two TES fluids can be used as a replacement for ATF+ 4, but TES-668 will provide smoother shifts.

I don't put much stock in ZF's recommendations. I mean, I run Mobil 1 LV ATF HP Dexron HP in a 8HP70, so, there is that. I also run Delvac 1 75W-90 in all the diffs, very good gear oil. There is also a Limited Slip version of it, but it's nearly impossible to find. So is Delvac 1 ATF TES-668, but it exists, and it uses GTL as the base oil, as does Dexron HP.

 

[chris719]

Sounds like a synchronizer issue. I bet if you rev-matched that gear, it would go in easier. But, I mean, who would want to rev-match 2nd?

What I forgot to mention is that it’s pretty much only an issue on upshifts. Especially if you rev match the downshift it goes in easily. Maybe if you double clutched an upshift it would be perfect, but that would be pretty slow. Would be the first person to take Dominic Toretto’s advice.

I’m not that adventurous so I’ll probably stick to a DCTF while under warranty still . Good to know the Delvac works in the ZF8. The diff uses Castrol SAF-XJ 75W-140 which seems pretty decent.

 

[wemay]

My inference from what @chris719 posted is not that there isn't a difference between specs such as VW504 vs API SP, but moreover a difference between two brands meeting the same spec, with one being an inexpensive house brand and the other a much more expensive major. In that scenario, why pay more? Paraphrasing of course.

In relation to this, in my case at least, brand "trust" and marketing clearly do play a part. I'm comfortable with that even if house brands are used at times.

 

[kschachn]

My inference from what @chris719 posted is not that there isn't a difference between specs such as VW504 vs API SP, but moreover a difference between two brands meeting the same spec, with one being an inexpensive house brand and the other a much more expensive major. In that scenario, why pay more? Paraphrasing of course.

In relation to this, in my case at least, brand "trust" and marketing clearly do play a part. I'm comfortable with that even if house brands are used at times.

I guess I'm avoiding that by using brands with more demanding approval requirements than an API SP license.

But on the other hand if API SP was what I really wanted, I'd pick something like Mobil 1 ESP 5W-30 which in addition to VW 504 00 approval it also is API SP licensed.