Tool sizes for fill/drain plugs - gearbox/differential

dwc · #1 (**permalink**) 07-14-2007, 02:07 PM

Hi Group:

I seem to have misplaced my tools for draining/refilling the gearbox and differential, so I guess I'll hit Sears and get some replacements. If I recall, the filler plugs are a 12mm hex key, but what about the drain plug? is it a 21 or 22mm, I just can't remember. TIA.

**Tifosi** · #2 (**permalink**) 07-14-2007, 04:33 PM

Fills are 12mm, dunno about the other size drain as mine are 12mm also.

**Andrew** · #3 (**permalink**) 07-14-2007, 06:26 PM

Some of the Allen bolts are 14, some are 12. The big hex heads (non-Allen) are usually 22.

Andrew

**Andrew** · #4 (**permalink**) 07-14-2007, 06:28 PM

And some hex heads are 17, if I remember right.
Andrew

dwc · #5 (**permalink**) 07-14-2007, 09:20 PM

Thanks guys. I know the Allen keys on all 3 of my cars are 12mm, and it looks like all the large hex nuts are the same size. I just wasn't sure if they're 21 or 22mm. Anyone know for sure before I run to Sears in the afternoon? I've got the new '92 up in the air and I'd like to get it finished in the evening. The last task is to change all the fluids.

**Tifosi** · #6 (**permalink**) 07-15-2007, 07:25 AM

Well, the nice thing about the 21 or 22 part is that Sears has them in a double box end with 21 at one end and 22 at the other so it's the price of one wrench to cover both sizes. (and if you buy 2, you can do your own trailing arms)

the_sicilian · #7 (**permalink**) 07-15-2007, 11:52 AM

Oil Drain is 27mm.

Tranny is 22mm drain. fill is 12mm hex (Sears is the only place i could find the key in that size)

Differential is the same. a 12mm hex socket (instead of key) can help impact-off the rear fill plug.

REMEMBER - dont remove the drain until youve removed the fill. (just in case. but it also helps the oil flow out)

dwc · #8 (**permalink**) 07-15-2007, 05:18 PM

Thanks, guys. 12 and 22mm did the trick. Of course, now I'll find where I left the original set I've had for ~20 years.

Slo Motorsports · #9 (**permalink**) 11-28-2007, 10:41 AM

I don't have a shop manual and I need to verify the location of the filler plug on an 83 Spider differential. I see the drain plug on the bottom under the section where the oil seal is (that I just replaced). I also see an "allen" style plug on the back of the differential about halfway up. Is this what I am looking for?

PS
I promise to buy a shop manual.

**Andrew** · #10 (**permalink**) 11-28-2007, 10:42 AM

Yes, the one on the back is the filler plug. Fill till oil runs out.
Andrew

Slo Motorsports · #11 (**permalink**) 11-28-2007, 10:48 AM

Thanks, will do. Hey, what is the small rubber cone on the top of the section where the drain plug is? I couldn't quite see it but could feel that it had flat sides so I tried to remove it thinking that this was the filler. Well it snapped off.

**backfeeder** · #12 (**permalink**) 11-28-2007, 01:53 PM

...........omg!

**Andrew** · #13 (**permalink**) 11-28-2007, 01:55 PM

It's a snubber for when the axle moves all the way and hits the underside of the body. You want that to happen only rarely.
Andrew

Slo Motorsports · #14 (**permalink**) 11-28-2007, 03:22 PM

Yeah, I don't plan on that happening any time soon. The car gets driven very infrequently (1983 w/only 24K). I guess that I could try to glue it back on.