ZF TRANS LUBE....?

[BigRigTech]

Both of my ZF's didn't have ATF in them when I bought them, I drained the one in my truck today and it smelled like 80-90w with something else in it but it didn't seem to be thick enought to be 80-90w.....Fairly thick and dirty. I filled it with Shell 50w synthetic like we use in big rig trannys....What are you guys running in yours?...... I found it hard to shift when it's -10C and colder outside, now I see why.

 

[lotzagoodstuff]

My ZF had ATF in it when I drained it, and that's what went back in it. I also jacked up the drivers side when filling it to get an extra quart of fluid in it as I read a post that said this helps with extending life.

Doesn't get that cold out here, but I did read every post I could before changing all the fluids.

 

[Cheaper Jeeper]

I put 15W50 Mobil1 synthetic in mine, and I overfilled it - I put 2 gallons in it. Just leave the fill plug in the side and unbolt the shifter assembly, then pour your oil in there in order to be able to overfill it like I did.

I chose the 15W50 because at colder temps it will have about the same viscosity as 15 weight - which is about the same thickness as the ATF that originally comes in the ZF-5. BUT when hot the oil has the viscosity of 50 weight - which is significantly thicker than ATF (or 15 weight) would be when at the same temp (hot). Of course hot 50 weight oil may still be thinner than cold 15 weight - though it won't be nearly as thin as hot 15 weight would. That is the beauty of multi-vis oil. Bottom line, with 15W50 in it mine is not hard to shift when the temp is below freezing OR when it's over 100 outside.

The plate on the side says to use synthetic ATF, so I chose Mobil 1 synthetic because 1) it is synthetic like Ford recommends, 2) it was the only 15W50 I could find at the time, 3) being synthetic it will last a LOT longer than dino juice without breaking down - getting dark, and burned, and loosing its lubricity - even when exposed to heat & pressure.

 

[WildWest]

I have heard alot of people running the mobile synthetic in T5s but chevy and ford

 

[The Warden]

I've been running ATF in my ZF since it was rebuilt. It's been working quite well, although I haven't been in an extreme cold environment. I've got it at the stock fill...I want to switch to synthetic at some point, and might try the overfill when I do...

It had 80W-90 gear oil in it prior to the rebuilt. I was told by the previous owner of the tranny that he knew it was on its way out, and he used the gear oil to try and extend the tranny's life as long as he could. I never drove it like that, though; the tranny was rebuilt before going into my truck

 

[BigRigTech]

It does shift better, I noticed that on the way home from work today.....It can't be any worse than the crap that came out of it.

 

[typ4]

The synchro rings are designed to use atf and 80/90 will burn them up. Too much friction to slow down the gears before engagement

 

[BigRigTech]

My tranny has 275,000km on it so I can't expect it to work like new........Ford recommended a fluid change to the large fleets due to heat that the ATF couldn't dissipate. The 50w should work really well for my purpose. I followed the wife home, found out my speedo is ready 20km/h slow...

 

[geonc]

On 2 different trannies ...1 stock IDI that went 300k +mi and my modded PSD that is at the 300k door, I have had great results using Amsoil Merc V synth atf.

Not pushing a particular brand...I'm sure all the synth ATF fluids give similiar results

BTW....both ZF's were converted to SMFW and rollover noise was minimal....even the IDI ZF that was shifted 90 % of the time without the clutch....


just my couple pennis

 

[f-two-fiddy]

I'm using Amsoil ATF, also. Loving the way it shifts

 

[BigRigTech]

If my tranny wasn't so old or loaded with miles I would put ATF back in it but I think the Syn 50W will help to take some of the slop out of it. They both had the same mileage so I didn't know which one to choose.......I'm going to rebuild the 2nd one with new bearings and synchro's as soon as I get some money ahead.