Differential Oil

[jas81172 0]

hi, i'm just a new member here and about a year owner of a 320i e30 1988 BMW. i don't have enough knowledge on BMW so, i would just like to know what would be the oil grade that i should use for the differential oil. i'm planning to drain and refill the diff oil and how much should i put in. tks.

[bekker 7]

90w (or 75w-90, 80w-90). Make sure the car is level and fill until it starts to run out the top hole. About 0.9 to 1 litre probably. If you have an LSD you must used a LSD gear oil. Also make sure you undo the top fill hole first - if you undo the drain hole and then can't get the fill hole undone you are screwed.

[jas81172 0]

90w (or 75w-90, 80w-90). Make sure the car is level and fill until it starts to run out the top hole. About 0.9 to 1 litre probably. If you have an LSD you must used a LSD gear oil. Also make sure you undo the top fill hole first - if you undo the drain hole and then can't get the fill hole undone you are screwed.

how do i know if it needs LSD? do you suggest that i should undo the top fill hole first before i drain it to make sure? if i can't is there any alternative? tks.

[_ethrty-Andy_ 2136]

how do i know if it needs LSD? do you suggest that i should undo the top fill hole first before i drain it to make sure? if i can't is there any alternative? tks.

unless the car has been modified at all then it wont be LSD. you cant confirm this though by jacking up the rear end, let the the hand brake off and put it in neutral, and spin one wheel. look at the wheel on the other side if it spins the same way its an LSD if it spins the opposite way its a standard open diff

[jas81172 0]

unless the car has been modified at all then it wont be LSD. you cant confirm this though by jacking up the rear end, let the the hand brake off and put it in neutral, and spin one wheel. look at the wheel on the other side if it spins the same way its an LSD if it spins the opposite way its a standard open diff

hi drew,

if i remember it correctly when i had it safety checked the rear wheels turned the opposite direction when they checked it. so, it's a standard open diff. so i can use a 75w-90? tks mate.

[*Glenn* 855]

You should use a 75w90 full synthetic oil

[jas81172 0]

You should use a 75w90 full synthetic oil

i was thinking of 80w90 but if 75w90 is best then i'll go for it.thank you very much for the replies.

[_ethrty-Andy_ 2136]

hi drew,

if i remember it correctly when i had it safety checked the rear wheels turned the opposite direction when they checked it. so, it's a standard open diff. so i can use a 75w-90? tks mate.

*Andy. yeah thought as much

i was thinking of 80w90 but if 75w90 is best then i'll go for it.thank you very much for the replies.

probably minimal difference between the two?

[bekker 7]

Unless you have a rotary synthetic is almost always best.

[e30ftw 410]

Redline 75w90. Can get it from BNT.