Hey guys, got a question for you. This weekend, I crawled under my 90 F150 SC and pulled the differential plug to check the lube level. None ran out, but I can put my pinky straight in there and it comes back out lubed. On my '68 F100, I'd insert the finger, bend it down and if I could feel lube/oil I knew it was okay. Can't do that on the '90 F150 though, no room. My Haynes manual says its low if it don't run out when the plug comes out. I'm tempted to flush and refill even though it looks like a hassle...ie. no drain plug. What's the easiest way to drain and refill a diff with no drain plug? Pull the back cover? What's the best hypoid oil to use? Do I really need the parts store fluid pump to refill it?

 

[font size="1" color="#FF0000"]LAST EDITED ON 15-May-00 AT 09:05 AM (EST)[/font][p]I own a '91 F-150, with which I occasionally pull a 6,000-lb.(loaded) Avion travel trailer, usually in combination with an with an overload in the bed. This kind of abusive treatment has to exceed any kind of load limitations Ford ever designed for.
The original 3.55 R&P was pulled at 150,000 miles and replaced with an OEM 4.10. The 3.55 set showed extremely minimal wear, and sits gathering dust in my garage.
I change lube every 50,000 miles using Red Line brand 75W-140 synthetic lube with Ford brand friction modifier. Use a gasket off an '89 model F-150 or Mustang (Ford converted to a bead of silicone RTV w/o a gasket somewhere around there). Hit a junkyard or a commercial ring and pinion shop and pick up an aluminum cover plate off a Crown Vic which will radiate heat better than the stock steel piece.
I also use Red Line synthetic lube in the Mazda 5-spd. tranny, and it works just fine, thank you, even after 178,000 miles. I change fluid in it, too, every 50,000 miles.
A cheapo pump makes both of these jobs easy and fast.
And yes, you have to pull the cover plate.
Eddie

 

Eddie.

What year(s) Crown Vic (or Grand Marquis?) would I be looking for to get the aluminum cover plate off of for a 1992 F150 Ford 8.8 3.55 rear end?
Thanks in advance.

1992 F150 Supercab SB 4x4 302 AOD 3.55

 

I noticed them throughout the '90's underneath cop cars as they sped past me on their way to the 7-11. I think you can find the aluminum cover plates on all '91-up Crown Vics.

I never looked into sourcing them all that much. When I took my F-150 into Houston Ring & Pinion for a 4.10 swap, I mentioned that I would be junkyard-crawling looking for aluminum 8.8 diff covers; the owner asked me "...How many do you want? I have a pile of them..." I paid $10.00 for two, so I assume they're a pretty common item.

Eddie

 

Thanks Eddie.

1992 F150 Supercab SB 4x4 302 AOD 3.55