[Val Walkinshaw]

Been down the many hours/days long rabbit hole on this forum about what trans fluid is best.....

3rd gear synchro is shitting the bed at 41k on my 2018 Tremec 6060. Weekend car. Garaged all winter. Never seen snow/salt. 6 track days. Spirited drives in the mountains. Otherwise care is driven normally. I don't use NLS and can count on one hand years ago how many shifts I've accidentally missed. 1-2 shift is fine. 2-3 started grinding occasionally above 4k (4 times) All other gears are fine. In the 300 mile drive home from TN to OH I heard it a total of 3 more times.

Got home and swapped out the OEM fluid (it looked really normal/good). No particulate matter or glitter. Put in Redline D4. Took it for a 5 mile drive and the shifting is 100% worse-grinding all the time I currently have 4 bottles each of RP Synchromax and Tremec Manual Trans fluid. Plan is to swap today. Going on the the Hot Rod Power Tour in 3 weeks and just need to do what's best to nurse this through until I get back and can get her into the shop.

I'm inclined to skip the RP and use the Tremec fluid.


Thoughts?




For Reference
Viscosity Index
RPurple 162
Tremec 167

RPurple @ 40 °C = 39 / @ 100 °C =7.5
Tremec @ 40 °C = 71.6 / @ 100 °C = 12.1

[cadyshac]

I put RP in mine and can't say it's any better or worse than the factory fill. My problem is getting it to go from 1st into 2nd under normal driving. I feel like a previous owner tried to force the issue when the 1st to 4th was engaged at low speed. I am thinking they've bent something? I've installed skip shift to defeat the 1st to 4th but still my problem lingers. I am very cautious letting the clutch out when going into 2nd, I have to make sure it is fully in gear.

[Val Walkinshaw]

Thanks for responding.

Update

2nd gear synchro was failing.
3rd gear synchro looked like burnt toast
All were replaced with the carbon hybrid synchros.

I think Redline highlighted my issue just due to the chemical makeup being different than the OEM fluid. Once the break in period post rebuild has passed I will put Tremecs fluid back in. I'm a fan.

The advice from the Tremec certified facility was to replace the fluid every 20k with my style of spirited driving and activites 30k max. I plan to follow that schedule.

[GreyGhost702]

I switched to RP during my build at 17k/mi. Haven’t noticed a better or worse shifting experience, but never had trouble on the OE fluid. All tranny and differentials should get regular fluid changes, 20-30k/mi. Fill for life is a lie. Nothing wrong with sticking to OE fluids. I may switch to Amsoil at my next service since I’ll be running their engine oil due to lack of magic oil viscosity’s in my area.

Did you do the rebuild yourself or dealer or tranny shop?