Offroad gearbox build

Did you do the back lash yourself following the subaru "garage book" ? Its well explained and it worked out very well for me with 0,15 mm of "play" between the pinion and the crown (subaru gives 0,13-0,18 mm) and a nice print on the crowns teeth.

You must be very impatient !
 
Yeah I tried to follow the service manual as best I could and ended up with an good result. Subaru front diffs are the biggest pain in the arse to adjust.

NachaLuva said:
That looks electronic, I thought our speedos were mechanical?
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Not sure about yours but mine is definitely electric. You can see the speed sensor about half way along the gearbox in this pic, about half way up the side.

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It's in!!!!!

It was a very very very long day today but the gearbox and rear diff are in. Changed the clutch and rear crankshaft seal. Initial results look good, all gears select easily, no strange noises and nice and smooth and on the 10min drive I went on this evening it did not explode or fail.
 
Great work mate! It's a good feeling when it all works. Now the test of time.

How's the L low range with the 4.44s and what's the lower 5th like for revs at 100 and 110?

I'd love to do the same with my box, but that's a cut and shut on the pinion shaft for me :(

Cheers

Bennie
 
Well done Dedman, welcome to the 1,59:1 forester club !
 
El_Freddo said:
How's the L low range with the 4.44s and what's the lower 5th like for revs at 100 and 110?
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The low range is very very awesome, equivalent to 72% lower than standard SF 1st gear. The highway revs are almost unchanged from stock, about 40rpm higher for 100 at 3k and around 3.4k for 110

I gave the box a bit of an off road test on the weekend, seemed to perform very well on a greasy hill climb that I would not have been able to get up before. I have a feeling that this was with the centre diff open as well as a found a loose connection in my dccd wiring at the end of the drive which would explain why I was not overly impressed with performance when I have some wheels lifted.

Now for the bad news.... On the way home I though I could hear a slight whine coming from the gearbox that was not there before. When I stopped I had a bit of a look over the box and discovered that idiot me had forgotten to refit my gearbox breather. Unfortunately for me I did go through some pretty deep water and when I checked the oil I found it to be milky as all hell. Lets just say a lot swearing and self abuse followed for the next hour or so.... I could not believe how stupid I had been.....

Anyway I changed the oil for some new oil I a hope that it would fix the whine but no luck. Unfortunately it seems to be getting worse as well. Sound like a bearing noise. Only when moving regardless of gear or load on gearbox and seems to get slightly louder when decelerating and more so when applying the brakes (which I dont understand at all). I have lifted both front wheels of the ground and had them spinning in the air (no load) with back wheels stationary and done the same for the back wheels. Noise is there in all cases which is rather strange. I initially thought it was the front diff or diff bearings but the noise is still there when the front wheels are stationary so it must be somewhere else.

Either way it looks like its time to pull the gearbox and have another look. Bit annoying but on the plus side I am going to get mighty good at gearbox swaps :)
 
What a bugger, DM. Sorry to hear that, mate ... :( :cry:.

And yes, you will get very good at gearbox builds ... :iconwink: :).

But very glad that it does work as designed until you tried running it on water ...
 
Good and bad to hear about your situation mate. Does low ramge whine at all? Does it shift smooth between low amd high while on the move?

I jave machined all my pieces down and will be installing them when I'm back from over seas... getting very excited about it.. what is your top speed in 1st low now?
 
Oh no! Prob a good idea to pull it so you can thoroughly clean out the milky oil.

After that, if you still get a mild whine at certain highway speeds it might just be the machined crown wheel.

You'll find a front LSD will make a massive difference esp on steep rocky slimbs
 
From what you're explaining, I'd say it could be the pinion that has some "play" forward and backward against the crown but if you have that noise even when the front wheels are stationary…BTW, how can you have them stationary while the rear are turning ?

Hope you'll find out quickly…(look at the shaft bearing too)
 
The low range works perfectly so far, no problem shifting. Not sure what max speed would be but fairly low, no really suited for a flying run up for powering up a sand dune in 1st low but great for crawling.

I had the front wheels stationary by jacking up the back wheels and letting the system turn through the open centre diff.
 
I'm sure with the 4.44 final high 1st will be great for hitting climbs where you need a little momentum. I know I use H1 for those situations even with the 4.11. Very inspiring thread and I can see a lot of gearbox builds following suit now that you, phiz, jf1 and venom have pioneered.
 
Have you found where that bad noise comes from ?
 
Yeah you'll have to experiment with gear selection for climbs now. Before it was pretty much always 1st low for any steep climb but now you might need 1st high or 2nd low.

Have you worked out final drives in each configuration? eg, is 2nd low higher or lower than 1st high?
 
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