Gearbox and diff oil change

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Joolz
Joined: Sat 19 Jul, 2014 20:23
Posts: 6

  Z3 roadster 2.8

Gearbox and diff oil change

Post by Joolz » Fri 15 Aug, 2014 20:10

Hi all,

I am going to change my gearbox oil as the shift is a bit clunky when the car is cold but gets smoother as she warms up. While I am at it, I want to change the diff oil too.

A couple of questions:

1) What gearbox oil do you recommend (2.8 with manual transmission)?
2) Does my 2.8 have an LSD?
3) What diff oil do you recommend (based on answer to question 2)?
4) Are these relatively simple jobs?

Apologies if this has been done to death.

Cheers Zeders,

Joolz

Del
Joined: Sat 19 Nov, 2011 18:35
Posts: 2122

  Z3 roadster 1.9

Re: Gearbox and diff oil change

Post by Del » Fri 15 Aug, 2014 22:34

The Castrol UK site is helpful.
http://oilselector.castrol.com/c/uk/eng/search
The oil for the diff depends on whether or not you have a limited slip diff. The original equipment fitted to your car can be verified by a local BMW dealer. There are also some online sources e.g.:-
http://www.bmwarchiv.de/vin/bmw-vin-decoder.html

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Southernboy
Joined: Thu 07 Oct, 2010 13:39
Posts: 6312

  Z3 roadster 3.0i
Location: Johannesburg

Re: Gearbox and diff oil change

Post by Southernboy » Sat 16 Aug, 2014 07:09

If you raise the car, you should find a sticker on the gearbox which specifies the oil recommended for that type of transmission. Generally it will specify a "lifetime" oil. Since you're changing it, use a similar grade of oil. The diff question is easily reconciled. The stamped number on the diff will signify LSD or not. But another method of checking is to raise both rear wheels and turn one wheel. The opposite wheel will turn in the same direction if you have an LSD fitted. It is a fallacy to use "thicker" oil in the diff with the idea that this will improve smoothness or performance, or even dampen the fairly common "whine" sound. If you really want to eliminate the whine, it is best achieved by using an expanding high density foam and filling in the tubular rear axle carrier (part 1 on the link below). This tubular component resonates sound from the diff and somewhat amplifies it as any hollow pipe will do. Using a high density expanding foam which will harden inside it puts a stop to that amplification. On the BMW M cars, these are filled with millions of small steel balls / grit, to add weight to the rear axle and provide better traction. A side effect of this fill, is to negate the diff sound amplification.

http://www.realoem.com/bmw/thumbs/n/b/18.png
"Normal is overrated"
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Cabrioot
Joined: Wed 23 Oct, 2013 22:31
Posts: 74

  Z1 roadster

Re: Gearbox and diff oil change

Post by Cabrioot » Sun 17 Aug, 2014 18:31

But another method of checking is to raise both rear wheels and turn one wheel. The opposite wheel will turn in the same direction if you have an LSD .

My opposite wheel is thurning into the other direction but the told me that the differendspeed of the wheel block the lsd and i must say it works very well. :D
.

gIzzE
Joined: Mon 06 Aug, 2007 22:32
Posts: 169

  Not specified

Re: Gearbox and diff oil change

Post by gIzzE » Tue 19 Aug, 2014 23:37

I used Redline D4 auto transmission fluid in my manual 2.8, can't recommend it enough, got rid if my sticking gear and no longer tries to pop into 5th instead of 3rd, and now feels so precise.

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