Very harsh abrupt initial braking

[2016EnergiGuy]

When applying brakes it's like there is a dead zone for a brief time, but then the brakes hit HARSHLY.

This isn't about skidding, it's a very small but harsh hit. It makes the ride very Jerky.

It is impossible to creep up to anything, forward or backwards. 

It's either rolling or hits just hard enough to stop the car.

This goes away if I set the parking brake on to one click, then it will creep.

If I apply parking brake harder of course, then I can creep using throttle.

It almost feels like there is lash in the drive system???

It still happens at speed and is felt as a blank moment then a harsh initial braking.

It doesn't bark the tires, or even close to it.

I don't think it's broken engine mounts, but it feels a lot like that slop or lag.

There seems to be a surprising amount of lash in the transmission.

When on a lift I can rotate the front wheel, either side or both, a surprisingly large angle in absolutely free rotation. 

This is NOT CV joints. I've painted marks on the shafts as they enter the transaxle case, allowing me to see the CV joints play. There is virtually zero lash in the CV shafts. They each rotate as a properly tight unit.

 

Is there any adjustment in the transaxle and Regenerative Braking system? 

 

Thanks ! 

 

[SnowStorm]

Is regenerative braking functional?  Do you get the spinning circle on the battery gauge when braking and does the HVB charge up when going down a mountain?  On a lift I would expect that you could spin either or both wheels any direction indefinitely.  The ICE, the differential and the two electric motors are always geared together through the planetary gear set and the transfer shaft gears.  There are no clutches and all gears are always meshed (nothing ever "shifts" - even for reverse).  I tore my old one all apart and saw nothing you could adjust.  Maybe there is a sticking brake caliber somewhere.

[fbov]

On 8/28/2021 at 8:09 AM, SnowStorm said:

Maybe there is a sticking brake caliber somewhere.

That's my bet. I had a rear caliper problem that warped the rotor. It made the brakes feel like they failed, a "dead zone" as you suggest. 

[2016EnergiGuy]

Doesn't seem like a caliper issue. I've experienced such things before, but on ICE only. 

It really feels like lash in the transmission. 

Regen works well. Really charges battery up as on long downhill makes it obvious.

Car rolls freely. I'll check if a wheel gets hot  but I doubt it. Will check.

[2016EnergiGuy]

I'll check to see if calipers / pads are too far from rotors.

That would do this. No pulsation in brake pedal. Might be springing open too far though.