fluid change - trans & rear

[chappys4life]

Going through my 87 325e manual next weekend doing some basic maintenance like oil change, air filter, fuel filter the general stuff. I was thinking of doing my trans and rear fluids as I have never done them and who knows the last time they have been done. Any brand preferences? I usually work on old american made so bmw's are still new to me. Also what weights and quantities do I need?

[SteveJ]

I've used Redline products for my diffs and trans over the last 20 plus years with good results. Spend a little extra, as these are usually forgotten fluids. They'll probably go 30, 40, 50k before they get changed again.

For the transmission- Redline MTL
For the diff- Redline 75/90. They have two different types of the diff oil. Get the one for limited slip diffs as it can be used in both open and limited slip diffs, whereas the other type will give you slippage problems if it goes in a LS diff.

Your owners manual and also the Bentley book tell you the quantities needed. As I recall, it's either just at 1 quart each, or a bit over like 1.4. I am pretty sure it is less than two quarts each.

And, always remove the fill plug first, just incase there is an issue with the drain plug. You want to make sure you can refill it before you drain it.

Don't forget to add brake fluid and coolant to that list of items.

[andrewm]

And, always remove the fill plug first, just incase there is an issue with the drain plug. You want to make sure you can refill it before you drain it.

This.

[TurboJake]

Redline MTL and Redline 75/90.

And, always remove the fill plug first, just incase there is an issue with the drain plug. You want to make sure you can refill it before you drain it.

These.

[MR 325]

I am one of those people that doesn't buy in to the hype of gear oil (like Redline) at $14 a quart.

I always run generic gear oil, Castrol or Valvoline brand does the trick at $5 a quart. You should be running either 75w90 or 80w90 in the transmission and differential. Each one takes just under 2 quarts. There IS a chance your transmission takes ATF though so keep an eye out for a green tag.

[SteveJ]

We had a tech session with the reps from Redline at one BMW club meeting years ago. When asked what advantage you would get with synthetics if you changed your oil every 3000 miles, the rep said "none". Their claim was that the synthetics didn't break down as quickly as regular oils and were better suited for less frequent changes.

I use regular oil (non-synthetic Castrol or Valvoline) in my motors as I am pretty good at doing regular changes every 3 to 5k. The diff and trans don't see regular changes and are sometimes forgotten, so I go for the higher dollar stuff in there.

Regardless of what you choose to run, don't go for the cheapest stuff out there. At least go with a known brand name. I am fortunate that Redline is local and Monument Car Parts passes on the savings to the customers.

[u3b3rg33k]

We had a tech session with the reps from Redline at one BMW club meeting years ago. When asked what advantage you would get with synthetics if you changed your oil every 3000 miles, the rep said "none". Their claim was that the synthetics didn't break down as quickly as regular oils and were better suited for less frequent changes.

Insofar as engine oil is concerned, I disagree. I get UOAs on my M20, and at 5000 miles, M1 15W50 still has plenty of life left (good TBN), but it's full of other crap that signals it's time for an oil change. That might be different if I didn't track it (I usually change it right before an event so I'm not running it on old oil).

IMO, the biggest benefits of "synthetics" (or perhaps "partially reformulated dino blood" would be a better term), is that it adheres to the valvetrain for longer than pure dino blood, and has wider safe ranges (15W50 vs 20W50) without falling apart.

I do run redline in my trans and diff though. Trans seems to like shockproof a little more than whatever it had before, and I run 75W140 NS GL-5 in the diff.

[bastianshaw]

We had a tech session with the reps from Redline at one BMW club meeting years ago. When asked what advantage you would get with synthetics if you changed your oil every 3000 miles, the rep said "none". Their claim was that the synthetics didn't break down as quickly as regular oils and were better suited for less frequent changes.

I use regular oil (non-synthetic Castrol or Valvoline) in my motors as I am pretty good at doing regular changes every 3 to 5k. The diff and trans don't see regular changes and are sometimes forgotten, so I go for the higher dollar stuff in there.

Regardless of what you choose to run, don't go for the cheapest stuff out there. At least go with a known brand name. I am fortunate that Redline is local and Monument Car Parts passes on the savings to the customers.

monument car part>everyone else

[ZM Blue Devil]

here is what we use.

Brad Penn Green semi for engine
Brad Penn ATF for trans - where applicable
FUCHS SINTOPOID LS 75W-140 for Diff

[chappys4life]

There IS a chance your transmission takes ATF though so keep an eye out for a green tag.

What do you mean by green tag? Should I just use atf even if no green tag?

I think I am going to use Mobile1 over redline I can get locally synthetic and not have to order it.

[MR 325]

What do you mean by green tag? Should I just use atf even if no green tag?

I think I am going to use Mobile1 over redline I can get locally synthetic and not have to order it.

It's a green sticker on the transmission that says it takes ATF.

You should absolutely NOT use ATF if there is no tag telling you to. Use gear oil in the transmission.

[chappys4life]

Okay good to know I will get under there and check.

[Wanganstyle]

Mobile 1 15-50 or Castrol BMW TWS 10-60 for track/WBS engine cars. Valvoline 20-50 for M20.

Trans: 75-90 for G260, valvoline non-synthetic ATF: Change often with diff fluid
Lubi-Moly 75-90 in organic stock bmw or stock modified diffs


**LSD additive makes the LSD lock up LESS not more. its great for parking lots, not for track use.

LSD additive makes KAAZ LSD's = OPEN diff. KAAZ has no clutch discs -uses oil expansion to lock up. Requires pure oil only. (ideally KAAZ wide range temp)