dab4133

Hello all- new guy here. I have an 84 AT and I am going to change the oil in the differential. First question is- where do I find GL5 90 weight? Second question is-what size is the hex head for the fill/drain plugs?They seem pretty big. Thanks for any info- Dave

inactiveuser1228

The hex head is 10mm. I found the specified gear oil a at Napa store.

inactiveuser1228

Sorry about the lisdexia, I mean dislexia.

Mark

BEFORE STARTING>>>Remove the top (FILL) plug FIRST!

Many stories of folks that drain the diff, and then find that the fill plug is siezed. Makes it very tuff to refill!.

You may need a pretty sizable breaker bar with the appropriate hex socket.

PorKen

My '81 had 17mm plugs. I used a (cut down allen bar and a hammer).

Motorsports sells a (1/2" drive socket) for it.

ew928

Think it's the same mongo 17mm as VW uses.
http://www.jcwhitney.com/webapp/wcs/...atalogId=10101
for example.

Got one 17mm hex key for my Audi.
Looks like a scaled up normal hex key.

Ernest (NYC) Hope the fill plug comes out nice and easy

dab4133

Thanks for the info- I thought it was quite a bit bigger than anything I had (17mm) I hope it comes out nice and easy, but honestly, in my world that rarely happens. HA - we'll see -thanks-Dave

Steve J.

The plugs are shallow and often already wallowed out. Many hex sockets are rounded like the one on the right and will make it worse. Grind the end flat like the one on the left to get a good bite.

dab4133

Thanks for the advice Steve - sounds like it will help -

pgs928

I know this thread may already have died but I decided to change the diff oil on my 88S4 Auto. The owners manual says the filling capacity is 0.9 Litres. I have already poured 1.5 litres into the thing and its still not full. Just bought another 1.5 litres to fill this evening.

Does anyone know what the real filling capacity for the diff is?

Regards

Peter
88S4 Auto, 97 Boxster

jon928se

Peter

From the technical reference book for the 85-88 models - Should be approx 3.0 Litres of SAE 90 Hypoid gear oil - GL5 75W90 is probably what you will find on the shelf and is the modern alternative for the '88 Auto differential. Not sure where where you found the 0.9 Litre reference - the only things that take that sort of quantity are the brake system (of DoT 4 or DoT5.1 Brake fluid) or maybe the Power steering system (of Dextron 2d but today you probably should buy Dextron 3 - you may not be able to find Dextron 2d

Cheers

SteveG

You must be referring to some other plug. It is 17. Captncarl (sp) sells it. Expensive unless you can't find one at parts store. Then it is cheap.

SharkSkin

Rhut-Rho...

AO

FYI, in my 91 S4/GT owner's manual it says 0.9 gallons.