1970 Ford F350 OT

Sammy in Kansas · Apr 12, 2012

I need to change the gear lube in the old 4 sp. and it has had 90 weight in it before and someone suggested to me to use 85-140 along with some lucas additive. Would this work or what would you guys use for replacement fluid.

BCnT · Apr 12, 2012

if its limited slip rear end,i'd be wary of changing lube types...some can cause chattering...its made it this long with 90 wt.

spanky · Apr 12, 2012

If he gets chattering in a 4sp he has some real trouble.

spanky · Apr 12, 2012

If it was mine I'd just put some 80-90 in it and call it a day. 85-140 might get hard to shift when it's cold in the winter

Janicholson · Apr 12, 2012

It will shift much more stiffly in the winter (if you get into the Teens (Fahrenheit) If it were mine I would use 85-90 in it. Jim

ShadetreeRet · Apr 12, 2012

I have always tried to stay as close as possible to original on older vehicles. If it has worked this long, it should be satisfactory for another 40 or so years.

ericlb · Apr 13, 2012

you can use either, a little lucas wont hurt either, especially if the truck has been sitting, the 85-140 wont be your friend in cold weather, but if you let the truck warm up before you drive it and dont use the creeper low, you'll be fine, when you change the fluid, you might pour a little diesel thru the tranny to help clean out the crud in the bottom of the tranny housing too

BCnT · Apr 13, 2012

well sh!t...i musta been asleep when i read that one...coulda swore he was drainin differential.

spanky · Apr 13, 2012

hickbic · Apr 17, 2012

I think I know you are you from allegan michigan if so what is your name?

1970 Ford F350 OT

Sammy in Kansas

Member

BCnT

Well-known Member

spanky

Member

spanky

Member

Janicholson

Well-known Member

ShadetreeRet

Well-known Member

ericlb

Well-known Member

BCnT

Well-known Member

spanky

Member

hickbic

New User

Similar threads