Merry Christmas!
What do people know about the Gemini diff? I have one in a gear box I purchased, and its pretty harsh.. Where it grabs at low speeds and is quite a handful... I'm sure the preload can adjusted, but what's involved in doing this? As always all help s appreciated....
I have no idea about it's current settings by the way
I had one (well I still do, it's currently broken). It is a plate diff so yes they are pretty harsh to use, not what I'd want in a car used on the road all the time, definitely not in a daily driver!
They are a bit fragile, to get them to fit in such a small gearbox the casing is very thin in parts. This is what happened to mine some years ago:
(http://derby.polog40.co.uk/photos/index.php?cmd=image&sfpg=KkltYWdlMDE3LmpwZyphNDc4NWUxYTY2NWM4NDgzODZkZWM0NGZmMWRkYTMyNA)
The bearing hub has sheared right off.
I do want to fix it but I've been unable to find a spare casing top half.
I use a Gripper diff now which is every bit just as harsh but only has a single clutch pack inside it (the gemini like most plate diffs has a clutch pack on both sides of it). This means they are get away with much stronger casings and I've had no trouble in that respect, it does lose it's preload and needs resetting with replacement clutch spacers fairly often though (the gemini does too just perhaps not as often).
You can take the diff apart and remove clutch spacers or fit thinner ones to get the preload set how you want. If it's from a Cup Car (which being a gemini it probably is) then it'll have the preload set pretty high. Measuring static preload can be done with a vice, a big torque wrench and some way of attaching the torque wrench. I use a piece of box section with a big but welded to the centre and then two holes for bolts to go through to screw into the driveshaft cup. Then with two more bolts in the other cup gripped in the vice to keep it still. Keep adjusting the torque wrench until you figure out the point at which the diff starts to slip. I tend to set my Gripper to 80-90 lb/ft but that's for track use.
If you're using the car on the road all the time then I'd not waste your time, no matter how you set the preload (unless you set it so the diff never locks at all and acts as an open diff which would be pointless), you'll never get it so it's nice to drive on the road.
That's exactly what I wanted to know cheers... It's in a competition car and works pretty ok when the ground is smooth, however at speed and hitting a pot hole, it grabs and the car gets twitchy as expected.. I figured a bit more slip would help this, as well as making slower speed manoeuvres more achievable!
(http://i281.photobucket.com/albums/kk211/matthew_makes_graves/IMAG0032.jpg) (http://s281.photobucket.com/user/matthew_makes_graves/media/IMAG0032.jpg.html)
(http://i281.photobucket.com/albums/kk211/matthew_makes_graves/IMAG0031.jpg) (http://s281.photobucket.com/user/matthew_makes_graves/media/IMAG0031.jpg.html)
URL=http://s281.photobucket.com/user/matthew_makes_graves/media/IMAG0025.jpg.html](http://i281.photobucket.com/albums/kk211/matthew_makes_graves/IMAG0025.jpg)[/URL]