Whats the best trans fluid for ZF5?

[boggerted]

Im rebuilding my ZF5 this week with all new syncros, seals, and bearings. Whats the best oil to use in my trans?

 

[Sycostang67]

I used royal purple ATF in my last ZF. I'm not sure whats in my current ZF, but I should probably change it.

 

[BigRigTech]

ATF - be it synthetic or dyno....Anything heavier will shorten the life.

 

[Alex S]

i use this

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[RLDSL]

Zf now says to use synthetic ATF if towing. Regular ATF per spec is 20wt don't use the new 10 wt types. Personally I run a 30 wt synthetic atf and it likes it a lot ( I just did it so I could standardize fluids between my transmissions, but it worked out very nicely )

 

[boggerted]

Is Mercon V any good?

 

[gatorman21218]

Is Mercon V any good?

Dont think so I would stick with the MERC/DEX Universal stuff. Its only 3 qts IIRC so might as well use synthetic.

 

[boggerted]

thanks for the input. Also, should I treat it like braking in a new engine and change it after so many miles so it breaks in?

 

[Silver Burner]

I thought it was 4 qts in these zf's?

 

[Diesile]

ZF-5

thanks for the input. Also, should I treat it like braking in a new engine and change it after so many miles so it breaks in?

Sure couldn't hurt. Cheap insurance.

 

[sle2115]

If I ever get mine in, I'm gonna run Royal Purple Synchromax

 

[RLDSL]

If going to run a quick break in batch, some universal tractor hydraulic transmission fluid from Tractor Supply or similar is a good choice for a quick clean out if you are concerned about getting debris out of the box before putting some high dollar fluid in.

 

[A37782X]

Is Mercon V any good?

Motorcraft Mercon V is synthetic anyway. Going to RedLine MTL from that made no difference on mine, it's is just as hard to shift when cold and sort of notchy on 2-3 when warm. It's ok for the summer now.

 

[RLDSL]

Motorcraft Mercon V is synthetic anyway. Going to RedLine MTL from that made no difference on mine, it's is just as hard to shift when cold and sort of notchy on 2-3 when warm. It's ok for the summer now.

Sounds like you need a different synthetic. I run the Amsoil CTJ 30 wt synthetic ATF in mine , and it made a massive improvement in cold shifting over regular atf. No more grinding the first few miles, even in sub zero temps

 

[A37782X]

Sounds like you need a different synthetic. I run the Amsoil CTJ 30 wt synthetic ATF in mine , and it made a massive improvement in cold shifting over regular atf. No more grinding the first few miles, even in sub zero temps

ok, maybe i'll try that next. Was the regular atf you're referring to synthetic?