FostersPerformance

1) The thin inner washer that goes on the yoke for the half shafts in the rear - they are lipped - which way do they go in?

2) Im getting the new diff in a few weeks. Is it popular/common to drill and tap the diff (or carrier) for a drain plug?

Any thoughts? I tore this car down 4 years ago. Anything i can get done before i finish this up then great.....

Thanks again

WVZR-1

I'm guessing you mean the "rear spindle washer" and the larger diameter toward the flange end of the splined shaft, smaller diameter towards the hub/bearing.

I'd say that's a very good idea. If you don't you'll wish you had when you go to service it the first time.

FostersPerformance

Seems it would be easy and simple to drill and tap out the very bottom of the diff as there isnt anything even NEAR the bottom of it.

Anyone have pics?

toptechx6

All you need is a 5/16” drill bit, a 1/8 X 27 pipe tap and a plug the same size.
Center punch a spot 1/2 inch left of the lowest bolt centerline and 1/2 inch forward of the batwing cover. Use care when drilling to avoid nicking the ring gear, a depth "stop" on your drill bit at about 1 inch will work. (Slide a length of rubber tubing on the drill bit cut to the correct length.)
If you are installing the drain plug with the differential in the car it helps to have a long 5/16” drill bit, use a ¼ drive 12 point socket with extension to turn the tap. The draining lubricant will remove any chips.

Pictures below show the drain plug from inside and outside.





I found a plug with an allen head but other types will work fine, the 1/8" plug seems small but it drains quickly if the lube is warm.

FostersPerformance

Any specific reason you installed it on the drivers side?

toptechx6

Seem to recall the plug is more centered between the exhaust pipes by drilling there, they are directly underneath when installed.

FostersPerformance

Thats what i was wondering.....Thanks for the info!

WVZR-1

Pictured I believe is a D36!

On the D44 the "drivers side" is substantially lower than the balance of the internal "bottom". The drain should likely be 35mm (1.375") on center from the center lower cover bolt. The housing is substantially thicker the rear most 35 -40mm. The 1/8 pipe does very well but the last couple done were metric 12mm either 1.5 or 1.25 pitch. 1.5 BMW/Mercedes, 1.25 Toyota/Nissan. Then you can file a "flat" and use a gasket. It just seems easier to grab the metric tools any more.

If your rear is on the floor with the cover removed you'll see the "lower bottom" driver side if your using the D44.

I borrowed an image of a D44 A "fancy" one at that but you can see the lower "bottom" driver side. On a stock housing it might be "lower"!

FostersPerformance

Yeah its a 36 i have..

I agree on the metric tools! lol....More than half that car is metric anyways. Damn cross-breed...

Im a boat mechanic and on the new engines, they come with what the factory installed as a drain plug for the oil pan. When they are maranized, that plug gets removed and a fitting and hose gets attached (cant drain the engine oil on a boat when its in the boat-oil would go into bilge). But anyways , these are nice plugs with a nice permanent hard rubber gasket. If i remember its a 12mm 1.25 with a magnet. The threads are about 1/2 to 3/4 inch long. I was figuring this would be the way to go. Tap it out, grind a flat, and use this bolt. I hate pipe threads. Plus i figured the magnet would be a good thing.

Qiken

toptechx6

The internal picture is of course a 36, the external one is actually a 44 but nearly impossible to tell in that view.

FostersPerformance

Awesome, thanks again!

srephwed

when you drill it the oil will wash out debris.when you tap the threads pack the flutes of the tap with heavy grease and the chips will embed in the grease and come out with the tap.if you have it available put a little deisel fuel through the fill hole to flush.any minute amount of debris will lay on the bottom and be flushed with the next change.hope this helps

cousinit99

Great information, thank you.

I'm attaching toptech's photos, in case they should ever stop being hosted for whatever unforeseeable reason(s).

Ruby6spd

In other applications I've actually welded on a male -10 an fitting and used an -an cap to seal it as a fill port. Let's you easily fill the diffs by hooking up a line and pumping the amount you need.

Makes it a bit cleaner and can be used as diff cooler line in if you ever go that way.

Supermutt

Ressurecting an oldie and asking clarafication on my first technical question here, time to dime myself out for being a dummy.
post 3 great idea, post 4 great instructions, totally get 1/2 left, 1/2 forward but then it talks about 1.375 on center.

The pics in posts 8 & 14 make sense as to 1/2 left, 1/2 forward for either the dana 36 or 44. Which dif and which pic does the 1.375 come into play

i just don't want to screw up and have to remove the rearend 1990 zf 6speed.
thanks a bunch

Already had the tap and plug, just picked up a 21/64 th drill bit today

FostersPerformance

Wow, forgot about this... here is my car now...tapped to a 3/8 16 threads. You can easy attach a lube pump to the bottom to fill it. Its a d36 at the moment

FostersPerformance

Pics suck...anyways the plug is close to exhaust. But its not an issue. The next time i change fluid im replacing it with a Mercury gearcase drain screw, which is very low profile....this plug has been in since the original post i made, and has never leaked. Used a yellow gearcase drain gasket as well (from a mercury again).

'78CorvetteS.A.

I happen to have one of those kits that you can buy to do this, bought it from a forum member (Haven't installed it yet). Anyway if you'd like, I can make a photo copy of the paper template (exactly where you drill) on some cardstock and mail it to you, if it would make you more comfortable on where to drill....could also photo copy the instructions! If you want me to, just PM your mailing info, it'll only cost me a few minutes and a stamp....no cost to you👍

Supermutt

Thanks guys for the fast response , great info and pics. I have mercury magnetic drain plugs and gaskets.
think i'll try the 1/8-27 first, this way if there's an issue or mistake i can go up in size (may have to move exhaust a bit.
the template would be great, thank you i'll send a pm.

So there's no difference in drill location between dana 36 and 44 ?