Dana 30 Pinion - excessive play?

When I grab my front pinion yoke and rotate it left and right, I can go a full 1/4 of a turn or so before it stops. In other words, I have about a quarter turn of play when I rotate the pinion yoke left and right.

I compared it to my rear 8.25" which feels very tight. Very little play at all.

Now, is it normal for a HP30 to feel as if it has more play in the yoke? If not, what could be wrong? I am hoping to pull the cover to check it out this weekend but dont entirely know what to look for. I dont have a dial indicator, but have some crappy prussian blue lying around so I could check the pattern.

Both HP30 and 8.25 have 4.88 gears. Roughly 3000 miles on them since install. I followed proper break in instructions. Few wheeling trips.

Definately something wrong, it should feel tight, like the 8.25... The backlash specs on the 30 is 6-10 thousanths iirc.

Is it making any noise when you drive? with that much play if it were the R&P I'd think it would be making all sorts of noise.

Check the u-joints in the axle shafts.

Thats the odd thing.. I dont (dont think I*) hear any whining, although I have a bunch of other things that could be muffling the sound (tires, no muffler, stereo, etc.). I doubt I would hear it in 2wd anyway.

I took it out wheeling in the snow the other weekend and didn't notice any odd whining.. And nothing blew up. There was play in the yoke before the trip.

Ill check the U-joints tomorrow. Thanks for the tip.

If i'm doing my math right, with 4.88 gears 1/4 turn in the pinion only equates to something like a 1/20 turn in the ring gear. So a little play in something further down the line of the carrier can create a lot of play at the pinion.

Do you have a locker in the D30? It is normal to have that much play in a diff with a lunchbox locker. You need to be certain whether the play is backlash or if it is the carrier rotating until it is putting tension on the axles. It would be almost impossible to have that much backlash without the gears failing badly. My guess is the play you are feeling is the carrier rotating until it takes up the lash in the locker.

jeeperjohn said:

Do you have a locker in the D30? It is normal to have that much play in a diff with a lunchbox locker. You need to be certain whether the play is backlash or if it is the carrier rotating until it is putting tension on the axles. It would be almost impossible to have that much backlash without the gears failing badly. My guess is the play you are feeling is the carrier rotating until it takes up the lash in the locker.

Click to expand...

That makes perfect sense. I have an aussie locker in the 30. Ill still try to pull the cover this weekend just for a maintenance check.

Thanks for your help!

jeeperjohn said:

Do you have a locker in the D30? It is normal to have that much play in a diff with a lunchbox locker. You need to be certain whether the play is backlash or if it is the carrier rotating until it is putting tension on the axles. It would be almost impossible to have that much backlash without the gears failing badly. My guess is the play you are feeling is the carrier rotating until it takes up the lash in the locker.

Click to expand...

I was wondering this my self but I don't have any experience with the lunchbox lockers so I didn't say anything. :eyes:

I have a spartan in my 30 and the pinion has a lot of play like you describe. I've had it in there for over three years and haven't had any problems.

I've got a lockrite and have play like that as well. I do have a little bit of a pulsing noise, especially when coasting at any speed above 30 but it's very minor.