2nd Gen Non-Engine/Transmission Axle backlash

[DESL PWR]

Is it possible to measure backlash without removing the differential cover? Possibly setting up the dial indicator on the input pinion yoke? I seem to have a lot of play when I rotate my driveshaft back and forth with wheels on the ground and xmsn in neutral. I understand that the spec for the DANA 70 is . 005-. 009''. Any help would be appreciated.

 

[Joseph Donnelly]

You can get a rough idea, but oil on the teeth has an effect, and if you move the pinion much you will begin to use up the backlash on the spider gears too. Just take off the cover and do it right

 

[Jschafer]

Has anyone re shimmed the ring and pinion because of wear, or is this not recomended.

 

[Straight6Jeff]

If you are going to reshim for wear due to backlash, you have to pull the carrier bearings off anyway, so might as well replace. The shims on the carrier are under the bearings. The time and effort to pull them apart is the biggest deal. Also, it it is a D70, be sure the axle tube/carrier spacers are in good shape. These spaces were put there to save the axle housing in case the carrier bearings spun. The spacers will get chewed rather than the housing. A case spreader is needed to make the job go easier, and to get the proper bearing preload on the carrier bearings. You can do it without the spreader, but pounding the carrier in is not a great idea. If it slides in easily without the spreader, there is not enough preload.



Measuring backlash at the yoke does not yeild any results unless you took a measurement when the vehicle was new, especially if it is an open diff. It is tough to tell from teh pinion yoke what is the ring/pinion backlash and what is the spider gear backlash inside the carrier.





Note: These observations are based on many axle/differential rebuilds and teardowns, along with many hours on the phone with Dana

 

[DESL PWR]

Thanks for the inputs. I never thought about the spider gears. Just trying to avoid dumping all that fresh lube I just put in.

 

[Straight6Jeff]

You can clean the out side of the housing really well, dump the fluid, and run it through a filter, so you don't have to loose the fluid. If it is a synthetic, that can save you a decent chunck of change. If it is Dino oil, buying it in 5 gal pails is cheaper.

 

[Tom L]

Ring/Pinion backlash

How many miles on it? Always keep the oil changed regularly? I just rebuilt my 70 and after installing new pinion shaft bearings/cups and carrier bearings/cups using the same shim packs as removed from both, play came back to within specs. 70 with limited slip axle... . Tom L... 02 2500 2wd... .

 

[DESL PWR]

Tom,



The truck has 180k on it and I replaced the oil at 100k and just recently at 178k. Amsoil series 2000 75w 90. I should have checked the backlash when I had it apart but did have a caliper to measure it. I had to replace my hub seal which turned into both hub seals, all four bearings and both brakes. But thats another story.