TrueTrac shudders on turns from a stop

[rixtrix1]

The TrueTrac diff in my 2002 S10 has developed a shudder on left or right turns from a stop. Feels like driving with a spool on street tires. Not too noticeable above 25 or so, but it does want to slide a lot easier then too. I did remove my summer UHP tires for some all season rollers while the weather is colder. Fluid, Valvoline 75w90 gl5 reg , is full and clean. It's about a year old with 5 autoX events and 4K hard street miles on it. Any idea?

[Whiteghost66]

Are you running the additive?

[RT66ProTouring]

Are you running the additive?

:pat: If you are, you shouldn't be running it. TrueTracs aren't a clutch type posi and don't want the extra friction.

https://www.eaton.com/us/en-us/products/differentials-traction-control/aftermarket-differentials/detroit-truetrac-faqs.html

[Whiteghost66]

I know the Ford 9 trak-lok posi units need friction modifier to eliminate clutch chatter when cornering. Each brand has their own specific guidelines.

[Tim C]

I've currently got a trutrac in the 9" on my Fairlane, and my old tow rig/dd f250 had a trutrac in it's 10.5" rear. Both developed a shudder when turning at an intersection until I added a little friction modifier even though Detroit says not to. Both were running the recommended non synthetic gear oil too.

[chevelletiger]

I know the Ford 9 trak-lok posi units need friction modifier to eliminate clutch chatter when cornering. Each brand has their own specific guidelines.

Read what ryan said NO CLUTCHES
Tru trac has helical gears,no clutches,so you use standard gear oil.

[68Formula]

It looks like what you've been using is synthetic. According to Eaton, you're not supposed to use friction modifiers or synthetic oils in their TrueTrac. I'm running non-synthetic in my truck's 8.6" for about 80k miles with no issues.