The old what tranny fluid debate....

[DaveWertz]

Looking to change tranny fluid here soon and was wanting to know what is the best to keep in what I believe is the original trans with 68k. I see this debate never gives a straight answer. I was going to add synthetic or syncromesh. But see how so many people have issues when switching. Is it worth it and is switching to syncromesh or syn bad for syncros? Also, what lubes are you guys running in the rear?

 

[TK1299]

I put royal purple in the T5 in my fox and it seemed to really shift much smoother.

 

[shurur]

yup opinions vary...and I do believe that you need to protect the syncros, but it has been years since I looked that stuff up..

I use Valvoline or Caster oil non synthetic for both transmission and steering fluid.
...they are essentially OEM for T45.

That being said, I see LMR sells sycromesh for the T45..

 

[DaveWertz]

yup opinions vary...and I do believe that you need to protect the syncros, but it has been years since I looked that stuff up..

I use Valvoline or Caster oil non synthetic for both transmission and steering fluid.
...they are essentially OEM for T45.

That being said, I see LMR sells sycromesh for the T45..

I see lots use syncromesh and then experience grinding and notchy shifting. Others say the opposite, same with synthetic. I'm not a gear banger so I don't beat my things. Get on it, yes but not destroying the tranny. So much debate on this topic that I want to see real experiance, not he said she said. And typically thats what you hear or read.

 

[9397SVTs]

I've used Red Line Synthetic Oil products for decades. Never had a problem. I ran Red Line in T-5's and TKO's. I have always used Red Line gear oil.

*I am using Mobil 1 ATF in my T-56 Magnum. This is what Tremec recommends and used during the development of the transmission, according to the person I spoke with at Tremec.*

 

[scottydsntknow]

For a T45? Any Mercon V is fine. Don't overthink this. The 96-98 transmissions have paper blocker rings anyway so its only a matter of time before they go. I had one at 112k that shifted like a dump truck so you probably have some time left. 99-01 had much better carbon fiber blocker rings. Synchromesh is what I always run in 3650s and that has always been great but I shift at 7200 routinely in my 2000 T45 and it never misses a beat with regular Castrol black bottle Mercon V.

 

[DaveWertz]

For a T45? Any Mercon V is fine. Don't overthink this. The 96-98 transmissions have paper blocker rings anyway so its only a matter of time before they go. I had one at 112k that shifted like a dump truck so you probably have some time left. 99-01 had much better carbon fiber blocker rings. Synchromesh is what I always run in 3650s and that has always been great but I shift at 7200 routinely in my 2000 T45 and it never misses a beat with regular Castrol black bottle Mercon V.

Did Merc V replace dexIII?

 

[DaveWertz]

I know allot of people use something other than dex III. From 99 the t45s have upgraded sycros so they responded well to synthetics and syncromesh. That's from my research anyhow. I don't believe I have issues I did have clutch adjustment issues but I think I got that squared away. I don't want to ruin this trans, Im not a gear banger and I am cheap so I preserve my parts LOL

 

[SID297]

I have a bunch of extra Royal Purple Synchromesh and Amsoil MTF if anyone needs some.

 

[Revvv]

I have a bunch of extra Royal Purple Synchromesh and Amsoil MTF if anyone needs some.

I may need to make a drive to MB and visit.

Sent from my [mind] using the svtperformance.com mobile app

 

[shurur]

merc v replaced merc III