Part time / under drive / reduction 3.11 gears Issues (1 Viewer)

[ccslider]

Took the transfer case back apart.
Pressed apart the differential shaft and cleaned the needle bearings, they had alot of grease, Lubed with gear oil and reassembled.
It felt really good with the front housing only and the preload plate on the differential bearing torqued to spec. (Had to manually lock center diff to be able to turn with front shaft)

Put the rear housing on and it all went to s***. So maybe the idler shaft is my hang up. I'll be stripping that down tomorrow, cleaning bearings of grease and checking that preload.

At least I can rule that out. If the preload is good and the grease is gone then it has to be a clearance issue I'm missing when I torque the rear housing on.

 

[shocktower]

If you have a snap ring you cannot put on something is wrong, I know the VC one's are tough, but any others you should be able to that sound like your problem

 

[ccslider]

If you have a snap ring you cannot put on something is wrong, I know the VC one's are tough, but any others you should be able to that sound like your problem

That's what I thought.

What were you saying secondly ?

 

[shocktower]

That's what I thought.

What were you saying secondly ?

The Viscious coupling snap ring can be a PITA, I really believe he has something wrong either one of the bearings is wrong or a race is not installed correctly, or just wrong and don't put grease in a gear box ever . So did you put all new bearings and races what alll did you do on the rebuild, are the bearings OEM or something else

 

[shocktower]

"Tip: We chose to only grease the two forward-facing bearings so we wouldn't get grease all over our hands while inserting the assembly into the case. If you do this, be sure to add grease to the rear tapered bearings before installing the rear case (housing #2). "

I'll go back out there and dab some grease on the case to make sure 200% there it no rubbing.

Grease does not belong in a gear box ........................................

 

[ccslider]

The Viscious coupling snap ring can be a PITA, I really believe he has something wrong either one of the bearings is wrong or a race is not installed correctly, or just wrong and don't put grease in a gear box ever . So did you put all new bearings and races what alll did you do on the rebuild, are the bearings OEM or something else

Same bearings, same races. All oem koyo

Followed instructions about adding grease to bearings. No one else seemed to have issues.

Removed the viscious coupling and snap ring for the part time kit.

 

[shocktower]

Same bearings, same races. All oem koyo

Followed instructions about adding grease to bearings. No one else seemed to have issues.

Removed the viscious coupling and snap ring for the part time kit.

Well it is not normal to put grease in a gear box, but hey you have something improperly spaced, pressed or the bearings might be different, I have seen it before where the bearings had changed and the fitting was not the same

 

[ccslider]

Making progress over here.

First thing I did was press the idler apart and clean the grease, lubed with fancy synthetic gear lube, soaked all bearings in same gear lube. Put together and still stiff in low.

Removed rear extension. Housing and spun until felt good. Noticed it pushed the idler race out some, was at .154 thous or so deep

Reset the case and measured my two shims (.139 and .010 thou) for that idler bearing (.150 measured together not accounting for crush) removed the smaller shim that was .010 thou and reassembled with just the .139 thou shim. Imagine what happened, it actually turns by hand now.
Removed the case and measured where the race was at, .146 thou.

I'm confused about the manual. When it talks about determining the correct shim size. It wants you you to hold the race loose against it and measure from the case to the race, then use a straight edge and feeler gauge to measure that distance. Is this while holding the race lightly against the rollers still?

Measured A (.136) + B (.003) +(.0009-.0019) means my .139 shim is about 1 thou too small but I think that should be fine because you can't hold the race against the bearing. It's tight in the pocket so I used a brass drift to seat it against the bearing, rotated the output shaft and made sure it felt good.

I chalk .001 thou up to matter of feel and opinion.

Still weird that I have to remove .010 thou. I guess I should mic the old gear vs the new.

 

[ccslider]

Pulled the idler gear again.. measured against the stock one.. only .001 difference..

hesistant to pull shims out. Not sure how the preload could change

 

[bigredmachine]

did you happen to measure out clearance "c"?

I agree that these instructions are pretty confusing but I would think that if you didn't replace any bearings you should be good with reusing the shims that originally came out of the case.

 

[ccslider]

did you happen to measure out clearance "c"?

View attachment 1933708

I agree that these instructions are pretty confusing but I would think that if you didn't replace any bearings you should be good with reusing the shims that originally came out of the case.

Yeah I did and it was good. I even tried removing the small shim of those two and confirmed that the tightness stayed. Only way it's not tight is to mess with the idler.

I just shut the garage and called it a night.

 

[bigredmachine]

did your gear kit come with a new idler or did you reuse the original?

 

[bigredmachine]

maybe incorrect clearances in the rear housing after removing the vc? theres another fitted snap ring in the extension housing but that's for the ball bearing in the case and the difference between the two snap rings is .004 in so even if that snap ring was incorrect it shouldn't cause that much of a clearance issue

 

[ccslider]

did your gear kit come with a new idler or did you reuse the original?

Replaced the idler gear. Measured .001 same as old

 

[ccslider]

maybe incorrect clearances in the rear housing after removing the vc? theres another fitted snap ring in the extension housing but that's for the ball bearing in the case and the difference between the two snap rings is .004 in so even if that snap ring was incorrect it shouldn't cause that much of a clearance issue

View attachment 1933716

Yeah I removed the VC and snap ring. The other snap ring is to limit endplay on the rear bearing I believe

 

[Rock40]

I'll chime in and say that the grease isn't your issue and it's perfectly fine to use it in the transfer case during assembly. I just did 10% OD gears in mine and also PT and 3.1 low range gears. I used Lucas #2 to hold the shims in place during assembly of the case half without issues. Everything spun freely and the grease is just going to rapidly dissolve in the gear oil once you start running the truck around and then it'll get flushed out with the next oil change.

 

[ccslider]

I'll chime in and say that the grease isn't your issue and it's perfectly fine to use it in the transfer case during assembly. I just did 10% OD gears in mine and also PT and 3.1 low range gears. I used Lucas #2 to hold the shims in place during assembly of the case half without issues. Everything spun freely and the grease is just going to rapidly dissolve in the gear oil once you start running the truck around and then it'll get flushed out with the next oil change.

Yeah I pressed everything apart and changed to gear lube, it made a very small difference. Not worth doing.

You could turn yours by hand in low ok?

 

[Rock40]

Yes, it turned easily in both high and low. Check that the low range gear (the large one) is not contacting the hardline oiling tube either. Mine was just slightly and I bent the tube a bit to clear it.

 

[bigredmachine]

The other snap ring is to limit endplay on the rear bearing I believe

ya I would agree with that, it looked like it was there to just act as a retainer for the bearing in the case