Is it possible to use the gearset from a sierra 4x4 box to make a close ratio "normal" sierra box?? Just a thought as I have a spare sierra
T9, and the 4x4 boxes seem to be fairly cheap. Certainly compared to a capri 2.8 box anyway. And I have a handy chappie who loves building gearboxes
and diffs.....
Any thoughts, or is it not a clever idea?
Cheers all!
[Edited on 5/8/10 by cliftyhanger]
quote:
And I have a handy chappie who loves building gearboxes and diffs
the close ratio bit is the first gear which is a bit taller. This is in the T9's which were fitted to the V6 engines.
I'm not certain that the 4x4's have the same ratios so it pay to check this first. also the input shaft is longer on the close ratio first
gear so if you can do as you suggest then you will also need to fit a spacer between the bell housing and the gearbox to take this into account.
Cheers
Mark
probably more money than you want to spend but you could just get a BGH gearset
they do the mix and match / machining to make it work: http://bghgeartech.co.uk/html/gear_kits.html
You can take the rear 4x4 section off and replace it with the tail from a normal type 9. You won't have a speedo drive though and you need to
drill the selector rod to take a pin for the spring mechanism.
Add a spacer plate between gearbox and bellhousing and your off....
Having fitted the V6 type 9 it's a simple job with the spacer between the box and the bellhousing.
It's not just 1st that's longer so is 2nd & 3rd, second being the gear that let the V6 Sierra hit 60 in.
If I were fitting one (again) I would seriously consider a 2.8 first
ratios for a 2.8 4x4 are either: (according to haynes)
3.36
1.81
1.26
1.0
0.83
or:
3.65
1.97
1.37
1.0
0.82
(second set are the same as the 2.0 ratios)
My spare box was built this way using the front from a 4x4 and the tail case from a well used diesel box. A speedo gear was pressed onto the mainshaft
whilst it was in bits thus still have a speedo. Had to change the selector rod as well since the later rod in the diesel box was a different
design.
All the 2.8 V6 (2wd and 4x4) boxes used the first set of ratios listed BUT 2.3 V6's used the second set listed.
Did one a few weeks ago, the 2wd drive doner was an early one and the selector rod did not need changing.
Its a good way to get a box with slightly better ratios since the 4x4 boxes are generally a lot cheaper that the 2wd boxes and if you have a worn out
box to use for the tailcase you are onto a winner.
You will need a space plate between the box and bellhosing since the input shaft is longer, they are available on the internet.
Paul
looking good....My "man" will have no problems mixing and matching components, and I may get him to shorten the first motion shaft while he is at it, something he has done a few times before (he is really old-skool, used to drag race vans with silly engines down Brighton seafront back in the early 70's)