Another problem solved (Formerly "Ultima Woes")

[Jwelch]

[ 07-20-2001: Message edited by: Jwelch ]

[RichieRich]

Check to see if you're missing a drive pin anywhere.

[Jwelch]

Nope, the pins are in order, but for reference, the problem isn't a loose pinion. I've also read too many articles about Loctite to let that happen. :cool:

[ 07-16-2001: Message edited by: Jwelch ]

[DirtRacinFool]

Sounds like the Slipper Pad may be worn out, try replacing that and see if it helps.

[Gutter Ball]

Maybe you have a hung brush on your motor?

[Jwelch]

No hung brush, I've tried 4 motors w/ the same result. DRF, I dont run the truck like mad. I wonder how it could have worn so fast. Its about 8 months old, how long is the life of an average pad??

[Gutter Ball]

Hmmm.. If you hold down the back end of your track and apply some throttle, can you see the spur gear spinning like mad?

[Jwelch]

Yup, the spur spins like mad.

[combones]

Is there a ball diff on that thingy. http://www.plauder-smilies.com/sad/confused5.gif

[DirtRacinFool]

Jwelch, I bought my son a Ultima ST-R Nitro last Christmas, between the 2 of us, we have gone through 2 pads. The first one (because I set the slipper to loose), burned up after 4 weekends of racing. The second one was just replaced 2 weeks ago and it was set up properly. Honestly, I don't have a clue as to how long they should last, but I feel good about getting 6 months of hard running from the second pad I installed.

[outsider]

Just watch out when tightening the spur slipper on the Ultima's. I broke my top end shaft. Good thing tower has em in stock and cheap.

[Jwelch]

I know, I've broken four of them...

[DerekB]

If you have the slipper tighten all the way make sure the diff is not slipping! If you hold the car and watch the clutch nut you can see what is slipping:

With throttle applied and slip induced:

1. If nut is not spinning and spur gear is slipper is slipping. Check to see if it's assembled properly. Even with a worn pad when full tightened it shouldn't slip.

2. If the nut is spinning that mean that the ball differential is slipping, which is bad. Tighten the diff (if not melted) and readjust the slipper.

Figure out which is slipping and let me know. :cool:

[outsider]

I just had a problem. Car is not noticably slower but it makes a rougher noise now. i took it all apart and took the diff apart and regreased it and tightened it. but it still makes that rough noise. Mainly at mid to full throttle. I think my ball bearings in the diff might be flat on a side. Could it be?

[nsane]

If you had the diff too loose and were running it hard, it wouldn't be unusual for it flat spot the diff balls. Probably grooved the diff rings too.

[Jwelch]

Derek, sorry I didnt get back sooner. The problem was a stripped diff screw, so when the diff screw felt tight, it was actually slipping a bit. Thankfully, I fixed it before it hurt the gear. I had a couple flat-spotted balls, so I replaced the whole group. Thanks guys
-John