Is there a slipper clutch causing my problems?

[Will]

Morning all,

I built up my Punisher last night and took it out for a spin.

It started off fine, driving around pretty happily but as the minutes past, when I rev'd the engine to get more speed it didn't drive any harder, the engine just rev'd up. It's as though the slipper clutch has come undone. Eventually I had to rev the engine pretty high just to get it moving.

So, my question is, is there a slipper clutch which would probably explain all this or have I done something wrong when building up the diffs? Not sure what I could of done exactly.

Cheers

Will

[mradlin]

Maybe check your wheel squres and gears for the set screws? I had mine come loose before and it caused this.

[mooman007uk]

that sounds like the problem...something is loose...happened to me also...wheel square came loose. If one wheel loses drive the truck pretty much stands still due to the centre diff diverting all the power to the spinning wheel. the nutech grub screws are stainless and flatten off at the end easily and then don't bite into the shaft...no amount of loctite will keep them tight, also check to see if a dogbone pin has snapped. if everything is tight check the rear diff

there is no slipper clutch like the nitro slippers on gassers..

[mynameismud76]

Ya dude, the grub (set) screws on the rear diff cup that receives the dog bone from the centre diff, that one..comes loose quite easily.

Check it..loctite it..and then check it regularly.. =)

When you joining us for a bash buddy?

PM sent =)

[Will]

Turns out my rear diff was to blame... I didn't bother wasting too much time investigating why, but the mesh of the inner gears was out. Alsmost as though the springs that sit inside the outdrive cups were too weak. Luckily I had a spare diff to hand!

Runs sweet now. Engine may need a slight tune but I'll leave that for now.

[mradlin]

Turns out my rear diff was to blame... I didn't bother wasting too much time investigating why, but the mesh of the inner gears was out. Alsmost as though the springs that sit inside the outdrive cups were too weak. Luckily I had a spare diff to hand!

Runs sweet now. Engine may need a slight tune but I'll leave that for now.

That's odd. Let us know if yoyu figure out how/why.

[mooman007uk]

bet you had one of the first batch punishers that had the old style inner diff cases that were all plastic and weren't shimmed correctly. does the spare one have large metal insert where the bearing rides? I'd split the diff and see how many shims you have so it doesn't happen again. all my diffs have had 2 big shims between the case and outdrive gears and one small washer behind the spiders

[Will]

Ah, that could explain it.

I built both diffs that are in there now and they seem to be holding up pretty well. Built them as follows:

Black o-ring
Black plastic shim
2 larger metal shims
Gear

Exactly the same for the other side.

I just had a look at the online manual on CML and it's the same as they are showing apart from I'm using 2 metal shims instead on 1.

Link to manual (page 10) - http://www.cmldistribution.co.uk/product/FTX7490/files/Punisher%20Manual.pdf