Clutch shudder Justy

[nipper]

1989 Justy 38,000 miles CVT. At 3500 Rpm while accelerating there is a driveline shudder in the car. Back off the gas somewhat, the shudder goes away then even back at 3500 RPM it is gone. If you cruise at 3500 RPM in D it is not there. When accelerating thorugh 3500 to 3800 RPM it is there. 3500-3800 RPM in Ds and R there is no shudder. Rev the engine in neutral no shudder. NO check lights are on. I may look at the brushes again but when I inspected them a few years ago they had very little wear (34,000 miles). I may change the CVT fluid but i think it is more in the clutch then anything else. Tis car is a blast to drive and I hope this isnt a big problem to worry about.

 

Reading in the FSM (brand new off ebay 15.00!) it mentions low speed range clutch slip as the throttl;e position switch being out of adjustment. The TPS on these things is just a big switch. 3500 RPM is mid range but usually the car is acceleraiting about 20-30 mph so I dont know if that counts as low range on a CVT. 

 

 

Sorry for the odd cut and paste color but I dont know how to fix that.

[ivans imports]

The ecvt is a funny little buggr but first check drive shaft ujionts the powder clutch is off on type so doubt it whould cause shudder the addjustment of throttle kick down is important but would just change shift rpms not cause shudder. Check the ps side axle were the axle gose to the diff on front they get very loose were it gos on trans i glue the stub onto trans when i install them and i put a thick 0ring between axle output shaft and cv to tigthen them up Glue it on with sillacone keeps it from sloping out

[nipper]

OK more info. 

 

Oddly it is exactly 2500 RPM it happens. If I accelerate where the engine RPM holds at 2700 RPM or higher no shudder (3000 RPM is 60 mph). If I hold it at 2000 rpm it will go up to 45 and no shudder. It is very particular and doesn't do it all the time, but I can get the engine to that RPM and that is where it will do it. The car accelerates, passes (as much as a cvt can) decelerates etc just fine.

 

The TPS is just a big ol switch, though the computer does vary the power to the clutch to give it a hil-holder, descent control. Hill holder sort of surprised me when I first got it until I studied the FSM on how it works.