Gearbox and Diff oil recomendations

[McMatty]

Hi all, I have a manual BH5B Legacy and im wanting to replace my gearbox and diff oil, any recommendations on the best oil to use?

[Guest]

75w90 or 80w90 gl5 for both. 75w90 works nicer when cold in the box.

[Kiwi_Fozze]

Syntrax

[94 Leone]

how much fluid would the box and diff use in total? planning on doing the same shortly.

3.5 for box

1l for diff google told me,

That accurate?

Edited July 5, 2016 by 94 Leone

[GC8E2DD]

The diff will take a little less than that from memory.

[Rosssub]

3.5L GB

0.8L Diff

[SpeedySub]

 GC8E2DD said:

The diff will take a little less than that from memory.

Thats what Ive been told too. They way I was told was to keep filling till it reached the top bung plug. (with the bottom one in of course!)

[McMatty]

thanks guys, As ive never done the gearbox and diff oil change before is there any special tools or anything i need to get/use before doing it?

[loner]

I usually fill the rear diff with the rear of the car jacked up to get a bit more oil in there... and allow better access of course.

Also a couple of meters of clear hose with an OD to match the filler hole is best.

Gearbox is easy... just go very VERY slow when filling or it will end up all over the floor when air tries to escape back up the dipstick.

[Rosssub]

Diff oil change covered on post #2 in here:

http://clubsub.org.nz/forum/showthread.php?48920-Diff-Removal-CV-Boot-Replacement-Diff-Oil-Change-How-To

Then same deal with the GB oil. Drain through the drain plug in the front/bottom of the GB (19mm spanner/socket IIRC), centre of this pic:

Then fill 3.5L through the GB dipstick hole:

[Andy_Mac]

 loner said:

I usually fill the rear diff with the rear of the car jacked up to get a bit more oil in there... and allow better access of course.

Also a couple of meters of clear hose with an OD to match the filler hole is best.

Gearbox is easy... just go very VERY slow when filling or it will end up all over the floor when air tries to escape back up the dipstick.

Interesting you say that, last time I filled mine I did it that way and had a few months of it slowly seeping out the breather port until it eventually got down low enough to stop, which happened to be almost exactly at the full point when doing it flat.

[loner]

I don't get a lot more in... I only buy a litre bottle and it doesn't all go in.

[McMatty]

Thanks guys, much appreciated

[duncanm]

I just used to use good old Castrol Universal GL-5, but recently changed to Penrite Pro-gear synth 75W90 (be careful, there's a GL-4 pro-gear, too).

It doesn't get too cold where I am (Sydney) - but I've noticed a significant improvement in cold shifts. Box used to baulk quite a bit until warm, now shifts are smooth right off the bat.

No change in synchro crunchieness that I've noticed.

[Kiwi_Fozze]

Refilling rear diff....

Dont drain it until you have the top bung out

[loner]

why?

[Guest]

Because if it doesnt come undone you cant drive the car till you get the f#cker out and new oil in.

[Kiwi_Fozze]

Yep, I scared myself with my v7, dropped all the oil out of the rear diff on my driveway, no worries. Time to refill, uuhh, cant get top bung oit... Ended up sticking the ratchet into the bung and jacking up the back end of the car on the ratchet to get it to crack. Little bit of stress as it was my only means of transport, and it was getting a bit late on a Sunday avo

[loner]

ahh the joys of working on a car that you rely on