Engine/Transmission (1994 - 1998) Dana 70 pending problems?

[AWray]

Eariler this summer, I was having some fun smoking the tires. Later that week, I hauled some logs to a mill on gravel roads. Maybe 5-8k on a bumper pull trailer. Since then, the rear end will sound and feel as if something is binding. The chatter/shudder is completely random. It does seem to happen more frequently after interstate trips. I changed the rear end lube to Amsoil 75W-90 4-6 months before the chattering began. I added one 4oz bottle of Mopar limited slip additive at the time of the fluid change and one more 4oz bottle 1-2 weeks later because the LS was chattering.



Any ideas? I pulled the diff cover today and noticed some scuffing on the spider gears. The crosses (or whatever they're called) also have some scuffing. The fluid looked good with very little metal on the magnet. I'll try to get some good pics posted today.



Thanks, Aaron

 

[AWray]

Here are some pics. I couldn't get a better pic of the spider gear. They had scuffing similar to what is on the end of the cross.

 

[BILLVO]

Having marks on the spider gears and side gears is very normal and will not hurt anything. I have tried different types of amsoil in limited slips and have more often than not ended up with clutch chatter. The standard amsoil 80w 90 is about the best for limited slip diffs in my experience. The eaton limited slip unit in my d70 sounds like a locker due to chatter in corners.

 

[carfichris]

AWray, From my own experience this past week, waiting it out could really do some damage. I heard noise, nursed it home and then slowly drove it to the hoist to find many broken pieces. Being all steel parts in our Powr Lok's when they go bad those little broken pieces wedge into any crevice available. Powr Lok rebuild parts are a drop in the bucket compared to the repair I'm facing ... $1000 bucks and it would be more if I didnt have talented friends helping out. Two solid objects cannot occupy the same space at the same time !!!!!! #@$%!

 

[NHays]

I have a good idea... . Pull the diff out, break it down and see if there are any problems. I run GL5 in mine and get a slight bump when I make a turn under light acceleration. my limited slip pads are bad and they grip and release. I get kind of a knock out of it. I am driving it now but plan to put a new carrier and another set of gears in mine. I highly recommend taking a look at bearings. If they are loose then your getting some play, if there is nothing wrong with the limited slip guts. If the bearings are bad, then you will need to replace them before they spin in the housing. If they spin, you will be investing in a new axle and those are around $2500+.

 

[NHays]

Just another word on rear ends. It might not seem like a little bit of slop or free play would be that big of a deal. But think of the amount of torque that they are under. A few thousandths out of whack will spell big trouble. does not take much. :{

 

[AWray]

cafarisch - do you know what caused that carnage?



Who sells a rebuild kit? Approximately what do they cost? Do you need a case spreader to remove the differential?



I raised one tire yesterday and was able to spin that tire by hand. It rotated smoothly. I'm not sure if that is good or bad.

 

[BILLVO]

If you could turn one wheel by hand easily your clutches are toast. pull the carrier out and disassemble it and check out all the bearings. no special tools needed. You can get a clutch kit for under $100 generally if you shop around.complete bearing kit about another 100 bucks.

 

[BILLVO]

If the bearings are bad, then you will need to replace them before they spin in the housing. If they spin, you will be investing in a new axle and those are around $2500+.

You do not need to replace a housing if a bearing spin in it there are housing cutter tools to repair the side of the bores and you can take the bearing carrier caps to a belt sander to take a few thousanths off the caps to tighten them back up again. all can be done for about 2 hours labor at a gear shop. I hate to see people fork out money for no reason other than someone not knowing any better trying to sell you expensive uneeded parts.

 

[carfichris]

I am not 100% on what actually caused the destruction. It looks like one of the clutches broke an "ear" off and from there it was downhill fast. The bearings in mine were in amazing shape for 170,000 miles and some pretty severe abuse during that time. Checking runout on the carrier after the "eruption" still showed less than 0. 003 and actual play in the gear set was minimal. The Powr Lok case, spider gears, cross shafts and ring & pinion would also be used over had some of the wreckage not found its way into them as well. There were no special tools needed to pull the unit apart. The Powr Lok case comes apart easily and the clutch pack was available for under $80 and the bearing/seal kits were another $120 if you need them. Everyone has opinions on replacement parts, after what I saw from 170K factory Dana/Spicer parts, you can sure bet what parts I'm rebuilding with. I am picking up a low mileage 70 tomorrow to rebuild the clutch pack,add new fluid and swap for the wrecked axle while I rebuild it. This sure is one heck of a way to Justify the Mag Hytec upgrade, but I have to buy a cover now that mine has holes in it.

 

[BenMorgan]

My 89 had the same type of chatter you described. I too tried changing fluid and using friction modifier, but let it go on too long before finding the problem.



One of the cross pins between the spider gears had broken. By letting it go on so long (over a year), it finally ate one of the side gears. I replaced the pin, all 4 spiders, both side gears, the ring and pinion (knocked a tooth off), and rebuilt the clutch pack.

 

[AWray]

Should I replace the pinion bearings? Do they "wear out" like the carrier bearings? If I replace some or all of the bearings, does the pre-load, backlash, etc have to be reestablished? The truck has ~126k on it so if it will likely need replaced/repaired soon, I would rather do it now.



I apologize for all the questions. I consider myself a competent DIY mechanic but differentials and automatic transmissions are two things I have no experience with beyond a fluid change.

 

[AWray]

Quad 4x4 carries just about everything to rebuild any Dana rear end and they appear to cater to the Dodge crowd. Lots of info on the website.

 

[Woodenhead]

Dan at Quad 4x4 is a stand up guy and very helpful. He's a wealth of knowlege and I'm sure could answer any questions anyone would have on any of our transmission or diffs. Call him with your questions and as mentioned above he's sure to have whatever parts you'll need. I'm not affiliated with Quad, just a very satisfied customer.



Mike

 

[NHays]

Ok... not to rock the boat here. I was speaking from my experience. I spun a set of bearings in a DANA 80 dually rear end. I was pulling a 30ft loaded goose neck. I stopped at a truck stop and noticed that the rear end of the truck was smoking a little. The paint around where the axle tubes are pressed into the carrier casting was burnt off. I had to trailer the truck home with my 97. The carnage was bad axle shafts, bad ring and pinion, the bearings on the carrier fused together and ate diagonally into the housing along with the ring gear. Yes... . I know this is an extreme case, but this was only about 25 minutes of driving. But most times spun bearings are not this severe and can be taken car if with some machine work and a few bushings.

 

[BILLVO]

Should I replace the pinion bearings? Do they "wear out" like the carrier bearings? If I replace some or all of the bearings, does the pre-load, backlash, etc have to be reestablished? The truck has ~126k on it so if it will likely need replaced/repaired soon, I would rather do it now.



I apologize for all the questions. I consider myself a competent DIY mechanic but differentials and automatic transmissions are two things I have no experience with beyond a fluid change.

You should pull the carrier and see what the side carrier bearings look like before going to deep. If they are in good shape just check the pinion by turning it,it should be smooth and not rough feeling. If the carrier bearings are good chances are the pinion bearings are good also. The pinion bearings tend to catch the debris first because the ring gear splashes the oil into the pinion lube journal carrying all the metal debris if there is a failure occuring. Try pulling the pinion shaft in and out it should be tight.

 

[coyote75]

I am in no way a mechanic enough to tackle a problem as such, so when my truck started making a nasty growling-grinding noise upon acceleration I took it straight to my buddy who works on my truck. He started on the rear end and after replacing pinion, housing, and spider gears, etc. , about $800-$1000. deep problem solved Right. No, put it all back together still making same noise :{ . So now he is in the transfer case and thinks he might have found the noise culprit. It looked like it was a good thing we found the problems in the Rear end when we did though because it was about to get worse and more exspensive. Hope better luck to you !

 

[AWray]

I hope I don't have a massive failure pending. There was the normal collection of metal fuzz on the magnet. I did not see any larger pieces of metal. There was some non-metallic stuff that accumulated on the diff cover. It was extraordinarily fine. I think my clutches are toast.



I'll call Quad 4x4 and get their opinion as well. I'm hoping they have rebuild more differentials than everyone that has read this thread.

 

[JohnnieWinona]

i'm dealing with some of the same symptoms.

The rig has a grinding feeling when i turn sharp. The strange thing is-- i can't quite locate where it is coming from. It sort of feels like you are in 4WD on dry pave -turning. It is bad enough that it vibrates the mirrors.

A friend said it probably is the front end, (ball joints etc... ), but???

My Mag dip stick is furry w/metal, nothing larger then very fine black iron.

Another odd thing is it doesn't happen all the time.

 

[AWray]

i'm dealing with some of the same symptoms.

The rig has a grinding feeling when i turn sharp. The strange thing is-- i can't quite locate where it is coming from. It sort of feels like you are in 4WD on dry pave -turning. It is bad enough that it vibrates the mirrors.

A friend said it probably is the front end, (ball joints etc... ), but???

My Mag dip stick is furry w/metal, nothing larger then very fine black iron.

Another odd thing is it doesn't happen all the time.

That is a very accurate description of my truck. If the front end was the source, wouldn't the symptoms be repeatable? Bad front axle u-joints will make noise when you turn but it doesn't cause a vibration.



Since I popped the cover, the truck seems to be operating as it should. No more popping, grinding or chattering.