From digest.v6.n110 Thu Jan 23 22:59:44 1997
From: kenyons_at_earthlink.net (Kenyons)
Date: Thu, 23 Jan 1997 15:51:18 -0800 (PST)
Subject: <E36> changing diff. fluid
>Now...the rear diff. on an E36 M3 is $ 3,800 to replace, so I'm going to
go beg/barter the local BMW service dept. for 1.8 pints of the magic
goo-juice and stick the factory stuff back in>
Based on the latest service bulletin which someone posted, BMW's "magic
goo-juice" is a castrol-made synthetic diff oil. It is probably identical
to Castrol Syntec 75W-90 synthetic gear oil, which I bought for $7.49 a
quart at the local Western Auto. Castrol says this lube (printed on
container) is recommended for limited slip use. I bought some to replace
the Valvoline synthetic I just put in 2 weeks ago, because I found out that
it is not recommended for use in limited slips (thanks to Curt Kiser). I
didn't notice any obvious chattering with the Valvoline, but probably
hadn't driven it enough.
Someone also wanted instructions so here's how I did it in my 95 318ti:
- Plug tool - You need a 14mm hex key socket - try Snap on, Harbor
Freight, or make one like I did from a sawed-off piece of a 14mm Allen key
inserted in a 14mm socket.
- Get a new set (2) of drain plug crush washers from a dealer.
- Get fluid (see above) and a simple fluid pump at any auto parts store -
I got a valvoline pump (you can also use a sta-lube pump) for about $3.00
that screws right on to the diff. fluid container.
- Bring the car up to operating temperature, and park on a level surface.
- There is no need to jack up the car, even on my lowered 318ti. Plugs are
easily accessible from the back of the vehicle. They are very tight though,
and you don't have much clearance for a big wrench. I "broke" mine by using
only a 8" handle inserted in the plug tool, hanging handle down. I stuck my
leg under from the side of the vehicle and pushed the wrench with my foot.
Make sure you break the fill (upper) plug first. Break the drain plug and
put an oil pan beneath the diff. The plugs are easily unscrewed by hand
- Allow fluid to drain. Some people raise the front of the car to get
every last drop out.
- Insert drain plug with new crush washer, and snug it up.
- Insert the tube from the fluid pump in the fill hole and pump in the new
diff. fluid. My car with LSD took a bit more than a quart. The manual calls
for 1.2 quarts. It will start to overflow from the fill hole when full.
- Insert the fill plug with new crush washer and snug it up.
- Put your plug tool on a big torque wrench (I used one with about a 2
foot handle), and set the wrench to 36 ft-lbs. You only have a small range
of movement, so tighten first with a short handle wrench.
- Tighten both plugs to correct torque.
- Wipe up and dispose of oil properly - takes less than 30 min, no sweat.
Todd N. Kenyon - 95 318tics - BMWCCA# 132004
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