Looking for a company somewhere in Michigan that sells the Sure Grip units, if anybody has a lead for me, that would be appreciated. Thanks

 

Sorry, no leads on the sure grip. I know RockAuto has some trac loc diffs for the 8.25 axle if you're interested in that. Good luck.

 

i have a 01 dak 3.9 V6 auto trans. stock came with a 3.55, open rear, 8 1 / 4. way under powered. so i say to me if i dont have MPG ill just get power. i had a 4.1 Motive Gear C8.25-4.10 gear put in and a DANA / SPICER LOCKER 84852. in 2011. my MPG went from 8-9 to 11-12. cause the O,D. comes in at 30 MPH. the trans thinks its going faster than it really is. and the speedo did NOT need reset. BUT i drive only in town. but my paper factory service manual call it a TRAC-LOK. my 1967 factory coronet manual calls it a 'sure-grip diff'.

 

Thanks guys, and moe, if I may ask, where did you get your hands on the 4.10. I would think the speedo would have to be out a bit going from 3.55 to 4.10, cause a long time ago we changed a Dak from 3.55 to 3.9 and we actually had to change the speedo gear.
That must have made your truck nice and fast!

 

It depends on where the speed sensor reads. If it reads the tone ring on the ring gear, then changing gear ratios won't make it read any differently. If it reads off the transmission or transfer case output, that's a different story.

 

Thanks Tom for that bit of information, didn't know that, usually only work with older vehicles and sometimes when we swap gears it is difficult to get the speedo to read correct.

 

No problem. In this particular instance, I'm not sure exactly which speed sensor drives the speedometer (or if you even have more than one), but I'm guessing it's the one on the tailshaft housing.

 

Tom, if memory serves me right, you are correct on the position of the speed sensor. So if that is the case, do I understand then we would have to change the speedo gear?

 

Yes, but it's super easy. Takes 5 minutes.

 

I think your looking for dr diff. Try f0r a-bodys only fourm or try dr.diff.com good luck