Trans and diff lubes...

I'm pretty close to actually driving the ol' girl and I need to check the trans and diff fluids...

Not exactly sure what diff I have other than it's a 3:55 and the trans is a 3 speed manual. What fluids should I top off with? Some diffs (posi) require a special fluid don't they?

Anyone have a link to an online manual?

edit...after some research I've found that I have a 741 -8 3/4 but I'm not sure if it's a sure grip or standard

Fendder tag says RA 36

The sure grip should have a metal tag on the diff between quarter and half dollar size. One way to cheat is to jack up the rear end and spin the tire by hand to see if you have a posi or not. Ra36 means is "should" have a 5200 gvw with a 3600 lb capaciity rear end, hold 4 pints of 90w gear oil. The book says your manual uses ATF just like an automatic, but I am still looking for a capacity. All it says is to fill it to the bottom of the filler hole.

The manual I have lists both for the manual trans . Auto fluid or MP gear lube. There is probably a year or serial # change it's not mentioning.

67a 100 pickup wrote: One way to cheat is to jack up the rear end and spin the tire by hand to see if you have a posi or not. .

Ya know, I tried that and it started off like a posi and the switched after a couple of rotations. Wasn't sure if it had just been sitting so long that things were dry and not doing what they should

On a side note, I did check the fluid and it seems up to be up to level

here is a link to what the tag looks like. Sounds like you have a limited slip rear.

http://cgi.ebay.com/ebaymotors/MOPAR-Rear-End-Axle-Sure-Grip-Tag-Rounded-Aluminum-67_W0QQcmdZViewItemQQhashZitem35a08d4faeQQitemZ230326882222QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

Hrmmm...didn't see one of those, bummer. I had hopes since the truck was manufactured in the HD plant

The funny thing is.... my three axles with 3.55's are all limited slip, and the one 3.91 is the posi. I haven't checked the tags from the three vans, but the pickup (3.55) was assembled in warren mi.

if i was putting anything in a 3 speed manual trans it would be 90w gear lube and NOT atf. stiffer to shift but more reliable.........

dont use atf in the 3 speed someone put atf in mine and it burnt up the bearing in the rear of the transmission and had a horrible gear wine in first/ reverse i use a heavy gear oil in the 3 speeds and the same heavy gear oil in the rear end unless you have a posi then i use the mopar gear oil so the clutchs in the rear end dont chatter