i asked a question a couple weeks ago about having slack in the drivetrain and i have chased it down to the rearend. now i haven't pulled the cover to see exactly what it is but it's probably either the spider gears or the backlash and i'm leaning towards the backlash cause i just set the rearend up 5000 miles ago and everything is new in the rearend. If it does turn out the to be the backlash how bad would it have to be before i would need to reset it and if so would it be safe to reset it or should i just leave it alone and let it go. I probably set the backlash to wide when i put it together, it was my first time setting up a rearend so i was just going by a book. and i have a friend who is wanting to put a limited slip in his truck with the same rearend do u guys know any good ones for him to check into thank u guys for the info.

 

Any time I thought about doing one, I was talked out of it by a pro because the dana is so tuff to get right the first time. Did you use the old carrier? If so, check the holes fthat the guide pin rides in. They mave gotten egg- shaped. Check the guide pin too, for any advanced ware that'll tell somethings wrong there.

 

i replaced the carrier, everything is new in the rearend

 

I did mine by spec as well and aparently if you set it up with the right amount of shims and you can get the carrier in there without a case spreader then its wrong! I didn't use a case spreader in mine so im gonna guess that its not gonna last me too long so im keeping an eye on it.

You have to be very careful if you take it to a shop to have them do it. You near need to be watching over thier shoulder the whole time. Your regular shop probably won't setup the rear end properly!!!

Its a very timely process as you need to properly shim the pinion shaft as well as the carrier. Its is almost as near as impossible to do it properly without several special tools

 

You can get away without a case spreader, but its a real PITA to get it in without one, just have to wedge the shims in and beat it in with a rubber mallet or dead blow. Backlash shoud be between 8-10 thousanths, a little tight is OK, like6-7 thousanths, anymore than 11 and I would redo it. 12 is gonna kill you in less than 25K miles, same with less than 6. Any other questions let me know.

 

You can rebulid a Dana w/o a spreader. But what you must do is install the carier (without the ring gear) Add shim to the carier bearing until the assembly requires 20-22 lbs of force to rotate.
- Useing a string and fish scale, attach one end of the string to the carier and wrap around several times. Pull on the string ( slow and steady) with the fish scale. Multiply the reading on the scale by the radius of the carrier. it should be 20-22.
Your carrier is now preloaded.
When you want to set your lash ( move the ring gear closer/farther away) what ever shim you remove from one side of the carrier, add to the other (to maintain your preload)

 

what wears out when the preload is not set properly? bearings or gears?

 

Bearings run not under preload will chew up the cone rib and cage.
Gears with excessive lash have too much impact force durring shifts and accel/Decel and improper match ( excessive heel/toe or root/adendum position) applies loads to the weaker areas of the tooth with various issues pertainiing to each possibility.
So to quickly answer your question...Yes

 

My FSM said to look for .003 to .008 backlash???

 

I'd have to say that with 5K miles on an improperly set up rear the R&P are gonna need to be replaced. They have broken in and the bad pattern is there.
I try to shoot for .008" back lash. I only do my non street driven Jeep rears and won't do anyone else's. If i need rear done for street use i take it to my local Dana Spicer shop here in town, pricey but done right.
Preload is critical in order for the bearings to survive.

 

Winr, is this done by forcing the carrier into the housing?

 

Thank you guys for the info I guess i'll pull the cover and check it out and see what i can see and if the backlash is real bad then i'll probably reset it and try to get .008 and maybe add another shim behind the carrier bearings cause i remember that the carrier wasn't too hard to force in the housing i had to use a rubber hamer but i didn't have to hit it too many times again thank you guys

 

"Force" is a strong word... I usaly draw them in with the caps. Evenly distributing the pressure from side to side with an occasional spin of the carrier as I go. I am not a fan of case spreaders.

 

What about the case speaders dont you like?

I was going to make one this weekend and try going that route but if its not the thing to do I wont mess with that.

 

I've done about 6 axles with no case spreader.

Carrier bearing preload I have heard you can never go too high. It's hard to put too much preload on them. Just make it so you have to hammer it in with a dead blow and run it. Backlash on a Dana is easy to set if you have some setup bearings to slip on and off. Once you get it right you take the bearings off, add equal shims to both sides for more preload, then hammer on the new bearings. Easy as pie.