EA82 box into EA81 Brumby

Brrrummmbeee · Post by **Brrrummmbeee** » Sat Mar 14, 2009 8:21 pm

I see some brumby's have an EA82 box. Was that standard for the later models? I have an '84 brumby that I would consider fitting the 5 spd box to if diff ratios were compatible. Can someone advise the differences if any between the 2 boxes and their fitment issues (if any) in this application?

Brumble · Post by **Brumble** » Sun Mar 15, 2009 6:32 pm

I am about to put an ea82 five speed box into my brumby. From the research I have done (predominantly on this site) the gearbox should bolt straight in with a few tweaks here and there such as the gearbox crossmember mounts. The biggest issue seems to be the fact that the tail shaft needs to be longer so you either have to lengthen the brumby shaft or use the two piece shaft with a centre bearing from the ea82 donor vehicle. I have also recently learnt that the fifth gear in the ea82 box is a similar ratio to the fourth gear in an ea81 so if you are looking for lower rpm at cruising speeds it may not be worth it. Remember I'm only speaking from what I have read and through talking to people not through actual experience. There is some good stuff on the conversion in this site if you search the forum.

I wasn't aware that the brumby ever came out with a five speed box.

nncoolg · Post by **nncoolg** » Sun Mar 15, 2009 7:42 pm

Yeap, You are correct about the 5th gear, as top gear in the 4 speed is already overdriven.
they are split-up better though, which helps with the limited power of the ea81's.
If your current diffs are 3.9, changing to 3.7's will make the gearing a little taller, but you'll still pull (depending on tyres) 2900 at 100k's
What annoyed me too, is where the stereo is in the MY, with a CD player, you have to change out of 5th to get the disc out.

dfoyl · Post by **dfoyl** » Sun Mar 15, 2009 9:17 pm

>>What annoyed me too, is where the stereo is in the MY, with a CD player, you have to change out of 5th to get the disc out.

Not with a factory slanted console - it's a tight angle but certainly works.

I wouldn't recommend a 3.7:1 diff ratio for an EA81 - you'll only use 5th going down hill. With a 3.9:1 mine just ticks along on a flat surface but I need to drop to 4th on anything other than a very slight incline.

The value I found was I can drive in suburbia in 4th now, while with the stock 4-speed box I was often dropping to third. The gap between 3rd and 4th isn't big on the 5-speed, but it's huge on the 4-speed unit. The other option is to use an early EA81 4-speed box (1982 or earlier), which has a better 3-4 ratio.

Dean.

steptoe · Post by **steptoe** » Mon Mar 16, 2009 8:40 am

I fitted a 3.7:1 L Series 5 speed in my 84 Brumby about 4 years ago now.

No one has mentioned the better gear selection mechanism !!

I am always in 5th in no time at all and it feels it is a fraction lower than the 4 speed top, but thats just my impression

Use the L series two piece tailshaft. Do some research in here , its all in here somewhere

SOMEONE PLEASE PRODUCE A $9.95 CD on this one !!

Brrrummmbeee · Post by **Brrrummmbeee** » Mon Mar 16, 2009 4:58 pm

Thanks for the input! I'll add it to the 'to do' list on the ol' crate - behind brakes, fuel tank, driveshafts - but in front of body work - metal termites seem to like the LHS metal. I have temporarily fumigated them here (passivated with rust converter) but 'grafts' (from a donor guard) are still to be hot-stitched in..