Hey guys,

Im having a few probs.
Basically im getting a lot of rev's but im not moving. Looks like the clutch is not engaing. I have the CB off and all looks normal, springs are still strong and shoes look fine. Could it be the centre diff has gone? If so how do i tell? Its Spider diff on my Hyper 8. If i hold it i can still move the car back and forth, should i be able to?

Any one with any ideas?

I'll go out on a limb here and say it's not the center diff. I have never heard of a spider giving up the ghost. It's more than likely that either you haven't tuned the buggy up yet or that fuel has got into the clutch and it's slipping. OR you haven't set the brakes up correctly and they are stuck on past idle.

It was running fine (well needed tuning a little more) but was running around a car park, then bought it in to adjust the HN and went to drive off and it wouldn't move, just revved up high.

Check the grub screw in the drive cups on the diffs. Sounds like one might have come loose.

With the body off, when you rev the car up, does the spur gear move?

Rotor

Well if i hold the the centre diff i can still push teh buggy back and forth, also if all 4 wheels are on teh floor, i can slowly spin the centre diff, it has to be the diff right?

ok, have had it apart and all seems fine inside, but new fluid in it and back together, now i notive that wen i turn it by hand the front drive shaft spins but the rear does not. So the wat hold the cup in on a spider dif? never had em b4. Also how come i can turn the spur gear by hand and not have the buggy move??
Any one help pls? i got a big day on sat and looking like im screwed!!

No, as rotor suggests it's possible that both grub screws have come out of the input cups to the front and rear gearbox or you've lost dogbones, I have never heard of a spider failing in the 4 years they've been on the market. If it is the spider though you could remove it and holding both cups try and roll along the table whilst holding the slots in the cups parallel to the table, if it goes then yes it's diff, if not and it forces one or both cups to spin then no, it's not diff.

There is another option though, your engine has moved outwards and so you've lost the gear mesh.

Ok holdng the spur and rolling forward... front drive shaft spins to the right and the rear spins to the left.
If i spin the spur on my own, only the front drive shaft moves, the rear stays still, how ever ther front drive shaft does not try to move the front wheels?

OK good, we have the problem area. The FRONT. Now look at the diff cup on the back of the front gearbox. You'll need to remove the top plate to do this bit easier. try and roll the car on the front wheels whilst holding the brakes on, if it rolls easily then look at the cup and see if the grub screw is still there or if it's loose, if that's it then find the flat on the pinion and secure the screw again with loctite.

If not then your into the front diff for the fault, probably chewed up the internals as they dont get lubed well from the factory.

mcflyss if you hold an open differential of any kind by the spur and turn either outdrive the other outdrive will spin the opposite direction. thats normal[8D] hope that helps

So even though when im spining the spur with all four wheels on teh floor and teh rear drive shaft does NOT move but teh front drive shafy DOES move, you think it is teh front that has the problem. Ok, will have a look and see if the grub screw is loose.
Cheers agai, you been real helpful

Ok so here is the run down.
Both front and rear diff's out drives are fine, the grub screw is tight so no problems there.

Hoilding the spur andmoving the buggy forward, the front drive shaft turns right and the rear turns left.

If i spin the spur and hold all four wheelson the floor, only the front drive shaft turns but it does not seems to try and move the buggy.

I have had the spider diff apart and it looks fine, not rounded at all. All pins are there so none of them are spinning free.

So what else should i check? i have run out of ideas.

Please some one help im in desperate need of getting fixed by tomorrow.

This now sounds even more like I thought in the last reply, your front diff internals have either let go or the diff is too far off the pinion gear, pull the diff and open it up to examine it, if not the diff then you need to shim it onto the pinion gear a little more.

Or you've lost one of the front driveshafts.


NOTE: When you pull the diff out, before opening it, hold the body and one of the cups still and try to spin the other, it shouldn't move, then try it with the other cup. If either of them spin then it's definately the diff. Either a sun pin has sheared or the teeth have gone south on the suns or planets.

Did you check if the flywheel is loose?

What flywheel?

How's it going there?

He sorry, not been on line for a while. Im unsure what was going on, i think the Centre diff had come loose a little as i took it apart again and re luibed it and now it is wrking fine. Now i have gone and screwed teh front diff! DOH!!!
Thank you for all your help.