lees02ws6

This is the third time I have to take my Dana 44 out. The first time it was whirring on acceleration. It was rebuilt with new gears, but then promptly started clunking on decel. The pinion yoke had come loose.

Now the diff make a little chatter all the time, and makes what sounds like metal on metal sliding together. Is this normal with new gears prior to a break-in? I'm also wondering what a normal amount of play is.

Sorry for the crappy pic, but this is as clear as I could get with my cheap camera. I can rotate the pinion yoke 1 mm with the wheels locked up. Would this be considered an excessive amount of play?




Thanks for your help.

cv67

No, its not normal or acceptable what you your hear.
Scraping metal.
Pinion bearings are shot now at least.
Cant see what style of C4 dana 44 you have.
1985 to 1988. Or 1989 to 1996.
Early C4 dana 44's use a pinion preload washers to set pinion preload drag.Must set up correct or bearings will fail in short order.
torque pinion nut down to 190 to 210 ft/lbs that style.
2nd design uses a standard pinion crush sleeve.
must torque down carefully to obtain proper bearing preload & never back off if you went too far.
Too much preload, discard pinion crush sleeve and start over.
Aftermarket Yukon dana 44 HD gearsets use pinion crush sleeve style.
Meant for late model viper & Jeep 4X4 applications.
Have to drill & ream stock C4 diff posi trac loc carrier for 7/16" ring gear bolts. stock c4 3/8".
Do it wrong and posi carrier is junk.

time for removal of your C4 dana 44.
Last guy not much good at Ring & Pinion setup work.
something went drastic wrong because of poor setup & likely workmanship also.

WVZR-1

The "gear set" dictates the set-up procedure for the pinion, early/late have nothing to do with it. Yes there were later production C4's with a sleeve rather than shims to set pinion pre-load but it has nothing to do with pre '88MY or 89+MY. The actual housing casting was changed in production in 88MY but it's only a physical external appearance. The internals are all interchangeable. The housings are generally considered thru '87MY as early and 88MY+ as late.

Again - the "gear set" dictates the set-up procedure.

For sure though yours need removed and inspected by someone that understands "the build"!

Is your rear out and on the bench or still in the car?

lees02ws6

It was rebuilt by a sponsor on here, a pretty popular one at that. For what it's worth it's a '92 Dana 44 with 3.54 gears in it.

WVZR-1

It's the branding of the 3.54 that makes the difference. If it's a GM 3.54 gear set it would require shims. The 3.54 saw production in 89MY with some over-run installs in '90MY.

There's many things that could be wrong with the rear that give you the "slack/slop" you mention, it's not necessarily the pinion set-up. The pinions(2) in the differential could be worn, the washers(2) for the pinions worn or missing and maybe the pinion shaft is also worn!

I wouldn't think a builder could overlook a correct pinion set-up the second time if it's the same builder as the first!

If it's on the bench post the information on the ring gear. The branding of the gear set might be possible with that information. If it's a GM or DANA by brand it can be for sure!

cv67

Has to be getting expensive for you, 3rd time around with your C4 dana 44.
Hope they are setting the rear diff up for free each time and paying for all parts along with shipping costs both ways.
Would be wrong to keep charging you money when you paid to have it done right the 1st time around.
Supporting vendor or not there is a problem with your dana 44 again now.

Don't overlook the possibility that the aluminum Dana 44 housing is Sprung.
Only the experienced can catch the problem early on before hand.
Happens fairly often on straight axle steel & cast iron housings that are raced on hard or abused hard on the street, sprung housing.
Impossible to set up new correct without further noise whining & other gearset noise issues.
Pinion nut & companion flange came loose for a reason on your c4 dana44.

cv67

GM gearset factory installed or over the GM parts counter for a dana 44 is Dana spicer produced.
Stamped clearly on the ring gear outer edge.
Dana corporation

lees02ws6

I have nothing bad to say about them, it has been free of charge, but I'm wondering what is going on. It is a major pain to take the diff housing out considering the camber rods, half shafts, and toe rod all attach to it.

I've considered the case could be part of the problem. I'm going to talk to them tomorrow.

cv67

Glad they are working with you on the problem.

Looking at drive at coast gear tooth patterns with a light to moderate load & understanding what your looking at helps.

I can feel with my right hand & wrist when all is well and no sprung housing present.
Feedback feel through wrist with my eyes closed.
Listen with my ears also with no background noise.
Hard to teach someone from a computer keyboard all there is to know.

Another method to check for a sprung housing takes a 3d coordinate measuring machine with a ruby tipped stylus end & a 1 foot thick pink or black granite inspection table(Starret).
Map out the housing centerline bores.
Must be within .0002" or 2 ten thousandths parallel of each other.
Pinion bearing race bores & carrier race bores.
Not my machine but I do access through a longtime machinist friend.
Pretty cool stuff.
Do it like NASA would & have myself in tough situations like your having.

engle1147

Not normal!
I'm sorry to tell you that if a gear set is not setup properly the very first time, before initial break-in is done, it will never be correct/right after that. If what you've posted is correct/accurate whom ever set this set of gears up for you owes you a new set of gears. Disassemble the unit and inspect everything. Get new gears find a different shop.

TTOP350

Your pinion moving back and forth is normal, its backlash between the ring and pinion. If there is no play you wont get any lube inbetween them and you will have a huge mess when it gets hot. They can be setup a lil looser or a bit tighter depending on what your doing with the car but never 0 backlash.
The noise you are hearing I'm not sure, I would need a better description.
Does it do it on turns, just normal strait driving? or? Whirring? grinding? what type of diff is in your car?clutches? cones? gov lock? or gear type? Is the diff new? rebuilt? or org never rebuilt? cleaned with solvents and clutches/diff not soaked in lube?
Are the gears GM/spicer orginal now? or a aftermarket type? Aftermarket gears are cut a bit different for strength (so they say) but at the cost of more noise.

lees02ws6

Only when decelerating. I have clip on youtube now with the audio, mic as close to the diff as possible. The diff is rebuilt D44, 3.54 gears. I can only here the clacking, chatter, whatever you'd want to call it in the cabin, no other noises can be heard inside the car.

Index in seconds when the sound occurs (decel only)

0:22 slight chatter
0:34-0:40
0:48-0:50 slight chatter
0:52-0:55 slight chatter
1:08-1:12 slight chatter
1:25-1:37 progressively louder as car slows down
1:45
1:52-1:54
2:03-2:07 progressively louder as car slows down
2:28

http://youtu.be/KfKALdCfwtA

FlyDoc

I have a '90 D44 vet IRS in my 92 Camaro, & I am having the same issue, with my pinon becoming lose/excessive back lash. I feel it before, I hear the clunking. It has not damaged the bearings yet.
Before I replaced the bearings the gears seemed to be setup correctly, the only reason I replaced the bearings was that it needed the seals replaced, and it was new to me with unknown mileage.
could our issue be that the pinon races not seated all the way down in the housing?

WVZR-1

Anything certainly is possible and a '90MY if it were the factory build would have a "shimmed" pinion and NOT a crush sleeve. Do you recall which you removed? You did a full complement of bearings (six)? Did you do a new pinion nut? I'm guessing maybe NOT!