limited Slip Rear Diff

[verk]

Eaton Truetrac has no lash at all, you are talking about a Detroit Locker which has quite an amount of backlash.

Ah, thanks for clarifying. So then backlash in a Truetrac diff would be purely a product of ring and pinion ? My truck is mostly empty or at least <300lb so I think I could benefit from Truetrac. How much of an improvement in rain, snow and ice over open-diff for lightly/no-load truck ?

 

[Ozymandias]

Ah, thanks for clarifying. So then backlash in a Truetrac diff would be purely a product of ring and pinion ? My truck is mostly empty or at least <300lb so I think I could benefit from Truetrac. How much of an improvement in rain, snow and ice over open-diff for lightly/no-load truck ?

Yes, only backlash from r&p.
Great improvement in every road condition, ask AUDI and several other high end car manufacturer why they use this, and only this, differential technology.

 

[verk]

I've found a somewhat local shop that seems competent with axle work. My thought it to have lash adjusted if possible ( seems so excessive, but perhaps I'll learn it is considered normal ) and a Truetrac installed. If it was your truck with 200k miles would you do pinion seal ? Any other insights ?

 

[Ozymandias]

I've found a somewhat local shop that seems competent with axle work. My thought it to have lash adjusted if possible ( seems so excessive, but perhaps I'll learn it is considered normal ) and a Truetrac installed. If it was your truck with 200k miles would you do pinion seal ? Any other insights ?

Please not, if it isn't totally off then keep it exactly how it was. If you change the contact pattern (backlash) you'll probably end up with a howling axle and accelerated wear on the gear set.
Jfji - the AAM has quite a lot of gear lash specified compared to let's say Dana - but I trust the engineers that they knew what they have done then.

Pinion seal I'd leave alone if it is perfectly dry. If it seeps then have it changed. The price is about the same as it is done from the outside anyway.

 

[verk]

Please not, if it isn't totally off then keep it exactly how it was. If you change the contact pattern (backlash) you'll probably end up with a howling axle and accelerated wear on the gear set.
Jfji - the AAM has quite a lot of gear lash specified compared to let's say Dana - but I trust the engineers that they knew what they have done then.

Pinion seal I'd leave alone if it is perfectly dry. If it seeps then have it changed. The price is about the same as it is done from the outside anyway.

Thanks for insights. Backlash measured today at 0.007". I originally asked about this back in 2015 here so it only took 8 years to finally know what my backlash is . So if installing a Truetrac am I opening myself up to problems because of 200k of gear wear in my diff ? New side bearings would be prudent/necessary if doing job ? but I could leave the pinion gear and therefore not worry about pinon depth adjustment ? If ok to install on diff with 200k is the goal to adjust such that pattern is as close to pattern before install ?

It's an inexpensive job: $1200+ for Truetrac, $265+ for install kit and I'm guessing at least 3 hours probably more so somewhere around $2k.

 

[Ozymandias]

7 is a good measure, right in the middle spec of 0.003–0.010 in.

Side bearings, yeah, new ones are good there as they are difficult pull of the old assembly.

The pinion you leave alone.

My gears looked perfect at 200k, almost like new. Great quality from factory.

Backlash is extremely easy to set at that axle because of the Side adjusters, no need for shims here.

3 hours aren't enough, more like five.