The Ford Barn

soonersace · 08-15-2024, 05:14 PM

I have a slight leak in my 55 tbird differential.

What fluid should I put in there? Regular transmission fluid?

Sent from my iPhone using Tapatalk

RKS.PA · 08-15-2024, 05:29 PM

I use 80W-90 Valvoline...non synthetic in my '56. It's GL 4&5. Don't use ATF!!

Where's your leak...around the pinion seal??

miker98038 · 08-15-2024, 11:24 PM

Same rear end, a Dana. Same oil should be fine. Unless someone fitted a limited slip, then I’d have to go check if there’s a difference. I can’t remember from when I put the limited slip in mine.

rotorwrench · 08-16-2024, 10:46 AM

Sponsored Links (Register now to hide all advertisements)

Any SAE 85/90 GL5 will work just fine in the old Dana 44s.

08-15-2024, 05:14 PM	#1
soonersace Member Join Date: Feb 2021 Posts: 63	Rear differential fluid 55 Bird I have a slight leak in my 55 tbird differential. What fluid should I put in there? Regular transmission fluid? Sent from my iPhone using Tapatalk

08-15-2024, 05:29 PM	#2
RKS.PA Senior Member Join Date: Jun 2010 Location: Oro Valley, AZ Posts: 1,241	Re: Rear differential fluid 55 Bird I use 80W-90 Valvoline...non synthetic in my '56. It's GL 4&5. Don't use ATF!! Where's your leak...around the pinion seal??

08-15-2024, 11:24 PM	#3
miker98038 Senior Member Join Date: Mar 2013 Location: Kent, WA. Tucson, AZ Posts: 1,625	Re: Rear differential fluid 55 Bird Same rear end, a Dana. Same oil should be fine. Unless someone fitted a limited slip, then I’d have to go check if there’s a difference. I can’t remember from when I put the limited slip in mine.

08-16-2024, 10:46 AM	#4
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 17,410	Re: Rear differential fluid 55 Bird Sponsored Links (Register now to hide all advertisements) Any SAE 85/90 GL5 will work just fine in the old Dana 44s.