View Full Version : A Grinding Differential - normal ?

2013.01.12, 11:10 AM
I've got a project car that i'm enjoying repairing - an iwaver IW01. After rewiring it's electronics the car is running and steering well . I noticed while driving it that after accelerating and letting off of the throttle the car will come to a stop (normal ) but the differential will"grind" a but before doing so.
In addition it may "grind " a bit when accelerating. I'm not positive that it is the differential (it may be the motor causing this but it seems to run fine) but assuming that it is ...is this normal?

The rear wheel gears are clean as is the rear axle/shaft.

Even if this is normal i'm still interested in potentially upgrading the differential so that it rolls smoother. What is suggested for this type of upgrade?

2013.01.12, 11:25 AM
I take it the chassis still has a gear diff?

If its still a gear diff you could likely take an opportunity to open it and clean the spider gears.

As for upgrades I expect you'd look for a ball diff that has the same axle length as the original.

2013.01.12, 01:27 PM
Check to see if you have the proper motor spacer for the pinion you are using. If the motor is upgraded (stronger magnets), the car will have some rolling resistance and with the wrong gear mesh, it can cause the pinion to skip teeth from the spur.

2013.01.12, 09:15 PM
Thank you for the replies. Unfortunately I do not have a wheel nut removal tool (this was used when acquired with nothing but the car itself). I've looked through my tool box and I have a socket that fits but it's too large in diameter to fit inside the wheel cavity to grip the nut and twist. With that said I read a post where a member disassembled his used MR01 gear diff and placed it in cleaner. It didn't look difficult but he didn't specify what type of cleaner he used. What did you folks use when you had gear differentials?

I've cleaned the external surface of the gears and they really are clean so I'm wondering if it is simply a spacer and old motor issue. In fact I don't think this motor has a spacer....