Engine/Transmission (1994 - 1998) WARNED: Not to take Dana 80 apart

[Sled Puller]

I have several guys telling me go ahead pop the center section out, unbolt the LS, and replace your destroyed spiders, slap it back together, add oil, no problem, she runs again!





A call to a differental shop, says at the very least doing that, it will howl, and possibly ruin other parts.



Bring them the ENTIRE rear, they will put it in a jig, go all over it, replace only what is messed up,(says almost for sure ruined more than just spiders) fix it up right.





Tough decision, do it fast and cheap, figuring on more breakage in the future, or do it right-- and still have more breakage in the future.

 

[Bhale]

IMHO, there's only one way to do things; The right way. Spend the money and do it the right way



"It's the stingy man who always spends the most money"

 

[zjones]

My uncle has worked on diffs for over 20 years & still is. From what he has told me I would take it to the shop. (despite the knowledge & help I could get for free)

On the other hand you can get install kits from major diff gear manufactures.



You have to smear grease in the gears then install, rotate & pull apart, check your tolerances - over & over till you get it right.

Then you get to take it for a test drive, & listen. (you may get lucky & get it right the first time) do you have a trained ear??



If it where me - off to the shop (would not want to shread a new set of gears, or cause premuture wear, ect. ect. )



Just my $. 02

Zac

 

[gitchesum]

Gene Gene Gene,

Ddin't you learn anything from your good ol buddy Steve and his transmission woes? You don't wanna be stuck riding around in a mini-van do ya??

Sorry Steve, just makin a point.



Let the shop handle it!!!!

I'm sure they know the little things that keep it all together.

 

[Snow man]

Gene,I rebuild rear ends once in a while,if you have a dial indicator,and some patience ,and a freezer. you can do it. If not let the pro's do it. The thing that matters to you,is are you going to replace the ring and pinion or not?If not,then the job is easier,since your not going to disturb the pinion depth,all you'll have to contend with when your done is backlash,and bearing preload. If you replace the the ring and pinion,let a pro do it,the pinion depth needs to be perfect or it will howl,and wear prematurley. Its going to be difficult to get the carrier in without a case spreader,but it can be done,when you do the final install after the backlash,and pattern are right,I slip it in the freezer for an hour,and it slips in snug,and then expands to a perfect fit. PM me if you need anything else. If there is doubt as to your capablitys,just bring it to a pro,the money you save is certainly not going to break you,and its money well spent if you doubt yourself.

 

[jstarnes]

Just my 2 cents

If you ONLY remove the diff from the housing and you dont plan on removing the bearings then youll be ok just make sure that you keep the brg races with there correct bearing you cant change the back lash unless you remove the brgs and change the shims so its just the way you said remove the diff ,prick punch the case halves so that you dont clock them differently (you can buy a spider/clutch kit)replace the inards re torque the case halve bolts and re install the diff into the axel housing re torque the bearing caps and re lube. What can you hurt if you Fup just take the hole lot to the axel shop Its only money!

 

[Sled Puller]

Took it apart, looks like just spiders, I have everything marked.



Soon as I get a spider kit, I'm slappin her back together. Afd wait for the carnage.





I am Not Steve St L... ...

I am Not Steve St L... ...

I am Not Steve St L... ...

I am Not Steve St L... ...

I am Not Steve St L... ...

 

[HerbW]

If it's just spiders, I'd go for it!! They are a dumb set of gears without any adjustment to them other than make sure you have a matched set. My factory service manual says: "If replacement gears and thrust washers were installed, it is not necessary to measure gear backlash. Correct fit is due to close machining tolerances during manufacture". This is on page 3-100 of my '96 Dodge service manual talking about replacing the "spider gears. I would send you a scan of it , but my scanner is O. D. Maybe somebody else can if you would like to see. Also, a picture may be worth a thousand words and E-mails. Let us know how it all comes out! Herb

 

[Roger rodbolt]

Opps....

Sled Puller,

I posted on your other thread before I read this one. Glad that you only broke the spider gears. The advice above from TDR friends is better then the "howling" mentioned by the shop. I use a magnetic base with a dial indicator and do set the preload on the carrier bearings. You have to remove the differential side bearing to shim the preload which is a pain, I do have a set of "dummy" bearings for set up if you need them. Hang in there, Larry

 

[Extreme1]

Don't worry about preload and shims if you replace the braeings. Bearing tolerances are WAY tighter than the amount required to change the shim stack. I installed a LSD in my driveway in cold weather, my only regret is I didn't replace the pinion bearings.



PM me for more...

 

[HoleshotHolset]

I've put new spiders/clutches&steels inside a few Dana 70's and 80's by just taking it apart and putting it all back together with new parts. No noticeable howl..... and these rearends were in ambulances that are at GVW 24/7/365.



If the ring & pinion were toast... I'd leave it up to a prof. Since all that you ate up were the spiders (common failure... ) replace 'em & keep on pullin'! Usually when the spiders go... they eat away at the pins that keep 'em in check... . you might want to take a closer look at those... .



Be sure to refill with AMSOIL!!





Matt :-laf

 

[LSMITH]

Rebuilding a diff completely is not hard, just take your time and follow the book. I would NEVER have a diff rebuilt at a shop, paying them $600 for what I can do in the driveway in a long afternoon is just not my style. Even if you do not have the tools you can afford to buy them and still come out ahead. Go for it Gene.

 

[HoleshotHolset]

I agree with you LSMITH, but for competition use consistancy is the key... . I may have the ability to rebuild a rearend... . but my quality assurance is lacking compared to a prof. shop.



Someone who rebuilds something everyday of their life is surely more likely to be better qualified than someone who occasionally does a rebuild.



No flames... just observations/replies... .

 

[Roger rodbolt]

Originally posted by Extreme1

Don't worry about preload and shims if you replace the braeings. Bearing tolerances are WAY tighter than the amount required to change the shim stack. I installed a LSD in my driveway in cold weather, my only regret is I didn't replace the pinion bearings.



PM me for more...

The importance of preload has little or nothing to do with bearing tolerances or in the case of the Dana 80, bearing wear. I've found little bearing wear or need for bearing replacement unless water contaminated. What I do know is that the differential will slide out with no resistance or case spreader installed. Not sure why Dana is no longer putting preload at the factory or if the banjo is stretching but differential preload has been around for years, is recommended in the service manual and I prefer it. HTH's Larry

 

[Sled Puller]

Thanks guys!!



I tore it apart, damage is isolated to the spiders, have my feelers out now looking for a good price.

I was, however, informed by another puller, they will KEEP on breaking, so it looks like a temp. fix for now.



Gene

 

[Snow man]

Gene,just order the arb,or detroit locker now,or figure out how to swap in the dana 135 out of the F550,that wouls solve that problem for good.

 

[jstarnes]

it might be worth a shot to

check with a diff shop to find out if you have a new or old stile power lock (not sure about dodge) but the 99and up F450 POS/PSD have dana 80's with the new stile power lock also a nice finned alum. cover that can be swaped in PM me I can put you in contact with a guy who might be able to help you!

 

[Extreme1]

Originally posted by Roger rodbolt

The importance of preload has little or nothing to do with bearing tolerances or in the case of the Dana 80, bearing wear. I've found little bearing wear or need for bearing replacement unless water contaminated. What I do know is that the differential will slide out with no resistance or case spreader installed. Not sure why Dana is no longer putting preload at the factory or if the banjo is stretching but differential preload has been around for years, is recommended in the service manual and I prefer it. HTH's Larry

A few points for clarification:



1) There are worn/damaged parts in the differential in question.



2) This forgien material will likely have already damaged the bearings.



3) High milage, high loads, etc. will accellerate bearing wear.



4) If you have the differential disassembled and decide to replace the bearings, it is not necessary to refigure any shimming or preloading. This is because the bearing manufacturing tolerances are usually +/-. 0003" or so. The smallest shim incriment is (usually) . 001". Replacing a worn bearing with a new one will return the preload and backlash to "as assembled" conditions.



5) You will be able to slide the carrier assembly out by hand with . 002-. 003 preload. I've varified it with a dial indicator more than once.



I would have put this all in the original post but I'm typing wrong-handed and it takes a while!

 

[HoleshotHolset]

Gene,



It's time for a spool!!



Matt

 

[Roger rodbolt]

Originally posted by Extreme1





A few points for clarification:



1) There are worn/damaged parts in the differential in question.



2) This forgien material will likely have already damaged the bearings.



3) High milage, high loads, etc. will accellerate bearing wear.



4) If you have the differential disassembled and decide to replace the bearings, it is not necessary to refigure any shimming or preloading. This is because the bearing manufacturing tolerances are usually +/-. 0003" or so. The smallest shim incriment is (usually) . 001". Replacing a worn bearing with a new one will return the preload and backlash to "as assembled" conditions.



5) You will be able to slide the carrier assembly out by hand with . 002-. 003 preload. I've varified it with a dial indicator more than once.



I would have put this all in the original post but I'm typing wrong-handed and it takes a while!

Extreme1,



I don't disagree with your clarification but if a differential is . 003 loose (many are) then they should be preloaded by shimming. I believe Joe Donnelly did an article on this in TDR some time ago.



Dana 60 and 70's seem to be tight while I've noticed the 80's being loose after little use. My service manual recommends . 010 preload on NEW bearings but certainly each to his own. Sled Puller launchs sleds weighing 30,000 to 45,000 lbs quickly and drags them as fast as his little 5. 9 will go. If I were setting up his rear end it would have a little differential preload in an attempt to keep the ring gear steady in contact with the pinion. All it takes is a dial indicator and a little patience. After all, there is a whole lot of pullin' goin' on