Dana 35 fever dream

[Maddenicks]

Recently my brothers tj had a knocking sound coming from the rear end.
Cracking the case revealed the pinion gear missing 2 teeth, spider gears extremely pitted. All bearings looked acceptable. Full rebuild kit bought, new bearings, gears installed. Backlash was verified at 8 thousand of an inch, pinion torqued until no play, preload was brought to 23 inch pounds (new bearings). Paint pattern looked acceptable. Test drive was ok until coasting with clutch in, knocking in rear again, more of a slapping noise. Back on stands, drive shaft off and yoke has a very generous amount of in out play. Anyone have ideas as to what loosened up? Bearings not fully seated? Will be cracking case again very soon. Any imput is greatly appreciated. Thanks, note: pinion nut was not initially torqued to spec, just tightened until no play then continuous testing of preload. I have a fear this may be apart of the problem.

 

[Maddenicks]

@hosejockey61 ?

 

[xXDavidCXx]

Recently my brothers tj had a knocking sound coming from the rear end.
Cracking the case revealed the pinion gear missing 2 teeth, spider gears extremely pitted. All bearings looked acceptable. Full rebuild kit bought, new bearings, gears installed. Backlash was verified at 8 thousand of an inch, pinion torqued until no play, preload was brought to 23 inch pounds (new bearings). Paint pattern looked acceptable. Test drive was ok until coasting with clutch in, knocking in rear again, more of a slapping noise. Back on stands, drive shaft off and yoke has a very generous amount of in out play. Anyone have ideas as to what loosened up? Bearings not fully seated? Will be cracking case again very soon. Any imput is greatly appreciated. Thanks, note: pinion nut was not initially torqued to spec, just tightened until no play then continuous testing of preload. I have a fear this may be apart of the problem.

Pinon pre-load is set by torquing the pinion nut until you get the specified radial pre-load. There is no way to get the correct pinion preload by just tightening the pinion nut until it has no play.

 

[Maddenicks]

Pinon pre-load is set by torquing the pinion nut until you get the specified radial pre-load. There is no way to get the correct pinion preload by just tightening the pinion nut until it has no play.

To specify further, the nut was torqued until no in out play was felt, then continued tightening and measuring on the nut until the preload was measured at 23 inch pounds, maybe I’m misunderstanding you if you could expand a little more. Thanks

 

[Maddenicks]

The most concerning part of this is when torquing the nut with constant checking of preload, the preload would start out way to tight, ( say 40 in/lb) and the more you would turn the yoke, the preload would loosen to (say 10-15 in/lb) this was continued until preload was consistent at 23 in/lb. I know I’m missing something and that is in no way normal, leaning more toward rear pinion bearing not fully seated? Thanks

 

[xXDavidCXx]

Probably the bearing seat not seated fully.

 

[Rickyd]

Open the cover and find out whats wrong. You did use a new crush sleeve right?

 

[Maddenicks]

Pinion gear had ALOT of play, enough to do the damage you see in the picture, Gears still look acceptable, taking carrier out and pinion will be re torqued to make sure bearing is seated, preload will be re tested. I believe since the bearing was presumably not seated, the crush sleeve may have not even made contact. Will check back with new results.

 

[Maddenicks]

If anyone has an answer for how to know when bearing is seated fully while torquing, (counting threads, space between pinion gear and housing etc…) really don’t wanna double f this. Taking excess play out now, hope to hear a response soon, thanks

 

[KennethS]

You likely can’t seat the race by torquing the pinion nut. You need to seat it by tapping it into place. I used a brass rod and a hammer when I did my Oldsmobile O-Type 12 bolt, and I could visually see that the race was seated fully. I don’t know if you can see it on the Dana rear.

 

[Maddenicks]

Update: play in pinion has been reduced to zero once again (don’t ask me how) **cough cough ugga dooga cough cough.
After play has been brought to zero, was torqued in micro increments while checking preload: 0-5-10-12-20-25 and finally a consistent 29 in/lb as final preload. Carrier installed, backlash .008” paint pattern acceptable. Any concerns are encouraged, will take on test drive and give update once gasket sealer dries.

 

[xXDavidCXx]

Glad you figured it out.

My only concern is for any shavings left over in the case/gears/bearings.

 

[Maddenicks]

Took on a small test drive, rear ended silent while in gear and coasting neutral. Will add small update during/after break in period. Note: if anyone is using this thread and in the same boat, (suspecting rear pinion bearing not seated and cannot remove pinion shaft without replacing crush sleeve) you can re torque until no play, THAN, take a block of wood and hammer (or similar) to the pinion GEAR side and give it a good smack or 2, if play re appears, keep torquing and repeating until play is no more, THEN start checking pre load. if you DO have spare crush sleeve, (unlike me) it is likely safer to remove the seal/pinion again and listen to Kenneth^^ although more time consuming

 

[xXDavidCXx]

Took on a small test drive, rear ended silent while in gear and coasting neutral. Will add small update during/after break in period. Note: if anyone is using this thread and in the same boat, (suspecting rear pinion bearing not seated and cannot remove pinion shaft without replacing crush sleeve) you can re torque until no play, THAN, take a block of wood and hammer (or similar) to the pinion GEAR side and give it a good smack or 2, if play re appears, keep torquing and repeating until play is no more, THEN start checking pre load. if you DO have spare crush sleeve, (unlike me) it is likely safer to remove the seal/pinion again and listen to Kenneth^^ although more time consuming

Actually, this method of smacking the pinion while the bearing is in the race has the possibility of damaging the race surface.

The correct way is to remove the differential and bang in the race with a race driver.

 

[Maddenicks]

Actually, this method of smacking the pinion while the bearing is in the race has the possibility of damaging the race surface.

The correct way is to remove the differential and bang in the race with a race driver.

bearing was presumed to be fully seated, just a smack to verify her, I understand the concern. We like to kick puppies and live on the edge.

 

[hosejockey61]

Just saw your tag. It sounds like you didn't set up your gears properly. Not a jab, but you need to seat the race with a driver. You will hear a different "ping" when it's home.

When you set up your gears, did you use the crush sleeve every time or only for final setup?

So many questions...