I have a 1989 f250 with a zf5 speed and a 1345 t-case how much fluid does the zf5 take to fill and what fluid should I run in both of them. I am also rebuilding the motor in what kind of oil should I use to break it in I heard of oil additive but I don't know what to use.

 

Bump bump bump

 

Bump bump bump

 

Break-in oil isn't necessary, really.

Nothing fancy. 20W-50 isn't a bad oil for an older motor, as the oil passages were large enough for it to flow when cold.

Synthetic (or not) ATF in the ZF. Same for the BW1345. Most all chain-drive transfer cases use ATF, not gear oil.

I believe the 1345 uses just over six pints.

The ZF uses almost seven pints.

Thirteen pints is 6-1/2 quarts, combined, so buy seven.

Use these figures for buying purposes, as the units get filled until fluid starts running back out of the fill hole.

Pop

 

Thank you sir

 

I would use a diesel rated 10w30 for break in oil - more zddp.

After break in any 5w30, 10w30 or 15w40 is ok depending on temperature. As said before, atf in the tranny & case - synthetic if in a cold climate or hard use.

 

Thanks a lot guys it'll be awhile till I'm ready but I just wanted to get my ducks in a row

 

if staying Flat Tappet Cam, a Break-in oil is your best bet. something with little/no friction modifiers for quick ring seating. and extremely high in zinc for the cam and anti-wear. no need in running something like a 20w50.. thats just ridiculous. thicker is NOT BETTER. the only time need to run a thicker oil is widening bearing clearances in a performance application.

thicker oil raises oil pressure, which puts more strain on oil pump, slows crank turn, may not get oil into all nooks and crannies due to being thicker and clearances not opened up to take it.

a 10w30 being your in TX will be what I recommend. no need for thicker. if someone up north were to have same question i'd suggest 0w30. same thickness at opperating temp.

after break-in any off the shelf SN rated oil will be perfectly fine. they typically have 800+ppm of zinc which is fine for a broken in hardened flat tappet cam.

and another thing. its perfectly fine to run a synthetic from startup. not what i prefer but perfectly acceptable. MANY manufacturers run em in cars straight from 0 miles

 

Thank you. I was thinking of running rotella t

 

if for breakin, I'd run either Amsoil break in specific oil or Delo 400 diesel.

rotella has just over 1k ppm zinc were demo has 1400+

after 500 miles or so run whatever you want nothing specific needed. the oils aren't as zinc neutered as people think

 

Thanks man i greatly apriecate it