Best way to get lower gearing

JP147 · Post by **JP147** » Wed Mar 18, 2015 1:02 pm

I would like some lower gear ratios for my MY, and an auto conversion seems like too much effort.
It has a 4 speed manual with low range and 3.70 final drive.
I guess 3.90 gears are the way to go, but is it easier to swap the diffs or to swap the rear axle and get a 5 speed manual from an L series?

Pillarless Jim · Post by **Pillarless Jim** » Wed Mar 18, 2015 3:05 pm

Put smaller diameter tyres on the car, JP147. Like it was designed to have.

Silverbullet · Post by **Silverbullet** » Wed Mar 18, 2015 4:45 pm

Pillarless Jim wrote:Put smaller diameter tyres on the car, JP147. Like it was designed to have.

Noo! Dont' listen to him JP!

But yes I think the 3.9 ratio box and diff is the easiest way to go for better gearing with big wheels. A bit trickier to find than the common 3.7 box/diff combo though.

JP147 · Post by **JP147** » Wed Mar 18, 2015 6:42 pm

Pillarless Jim wrote:Put smaller diameter tyres on the car, JP147. Like it was designed to have.

It went alright with small wheels, but there was a lot less traction and a lot of bottoming out.

Was there a 3.9 box in the MY Leone? And what about the 5 speed manual with the 1.59 low range, which cars did they come in?

Silverbullet · Post by **Silverbullet** » Wed Mar 18, 2015 6:53 pm

JP147 wrote:It went alright with small wheels, but there was a lot less traction and a lot of bottoming out.

Was there a 3.9 box in the MY Leone? And what about the 5 speed manual with the 1.59 low range, which cars did they come in?

MY series 5 speed were all 2WD I believe. There are some years of L series touring wagon that had all 3.9 stuff in them, good excuse for an L series conversion

Although may be a bit daunting to try it on a weekend when you need the car back Monday.

JP147 · Post by **JP147** » Wed Mar 18, 2015 10:35 pm

I had a look around, it does look like a lot of work for one weekend. I might wait until I have a garage to use and my Datsun is running again.

I guess a 3.8 diff won't fit into an MY 4 speed box?

YouTube · Post by **El_Freddo** » Wed Mar 18, 2015 11:07 pm

The 3.9 diff ratio'd 5 speeds came in the "series I" L series up to 1987. '87 was the cross over year from the series I to series II. Hard to find these days!

You could fit the 3.9 diff ratio into the 4 speed, but this would require you to press every gear off the pinion shaft and back on with the 4 speed gears - if the pinion shafts are the same.

You'd be better off getting a forester AWD gearbox with 4.111:1s - your EA81 would love you for it. You would have to case this gearbox in an L series dual range casing and mod the synchro hub to use the L series low range with the EJ gear

Totally worth it though if you want to play with gearboxes and "do things properly"!

Cheers

Bennie

taza · Post by **taza** » Thu Mar 19, 2015 11:25 am

I'd personally go 5speed L series box. Easy to fit, the bonus of 5 gears and proper low range gearing.

JP147 · Post by **JP147** » Fri Mar 20, 2015 10:58 am

Alright, I think I will go with a 5 speed from a series 1 L. It looks like a bit more work than I can do in a weekend though, so I will leave it for a bit until I have more time and money, and get the Datsun going so I can get to work.
I have a few questions though.

Is it possible to use the original L series linkages with no mods, and just cut the floor a little?

How do you mount the centre bearing for the tailshaft? Weld some metal to the floor and drill and tap it?

My car has a different clutch (225mm) to most MYs as it was made in December '84. Is this helpful?

taza · Post by **taza** » Fri Mar 20, 2015 1:26 pm

Yes it can. Ive done it in a brumby. Ive left the linkages and cut the floor about 20mm further back. Then just drilled a hole and made a little bracket to hold the whole linkage.

Gannon · Post by **Gannon** » Fri Mar 20, 2015 2:08 pm

While sorta on this topic, can you bolt an EJ gearbox behind an EA motor using an adapter plate?

YouTube · Post by **El_Freddo** » Sat Mar 21, 2015 10:08 pm

I've never tried it, but I think you can do that - as to wether the clutch would work in relation to the flywheel I don't know.

Do you want to be the Guinea Pig on this one Gannon?

Cheers

Bennie

purp · Post by **purp** » Mon Mar 23, 2015 10:07 pm

I'm sure I've read a thread on here from someone who put an ej awd box behind an ea in their road going car... Can't find it though.

YouTube · Post by **El_Freddo** » Sun Mar 29, 2015 10:43 pm

I think it was Jonno that wrote one up here.

I don't know if he's ever got around to building one but I've got plans for one in the future for the Redback Brumby

Only because AWD is the best in wet conditions!

Cheers

Bennie