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So, I was under my 'Vette' yesterday, just looking at 'stuff' and saw that it looks like some gremlin was under there spraying liquid around the front of the differential. Seriously, the undercarriage around the front of the 'diff was wet/shiny like it had been sprayed with fluid, kinda like the front seal(s) are shot. Which adds a bit of clarity to my confusion about only getting approx. 2 pints of diff oil out when I changed the fluid a few days ago. So, I am pretty certain that the front seal(s) of the diff' have given met their maker. Is this something a shadetree mechanic (with a lot of wrenching experience) can correct himself, or is it better/best to send it out to a shop for servicing? What say you? BTW - it's a Dana 44 (aluminum cased diff', excessively weak structure. Should I swap in an earlier/late/stronger model cast/steel version?
In either circumstance, I will replace the U-joints, so it won't be a hyooge bummer.......
It sounds like your pinion seal is toast. It can be replaced without a lot of drama providing seal surfaces aren't damaged. With the right upgrades they can hold a decent amount of power.
apologies if you have the alum dif ( i don't remember what year they switched) .. but the answer is yes..
my iron at home AND advice i got,.
you may as well look at the axles while there..and inspect.. note also the tools needed.. https://www.corvetteforum.com/forums...-advice-3.html
edit... i see 80 was aluminum.. so not sure how applicable that thread is but should be somewhat similiar?
It will be easier to remove the Dana diff to replace the seal. It can be done on the car on a lift but unlike the iron units the bracket it part of the housing, completely different seal is used. Yet another reason I hate those diff's, regardless of who may agree or disagree.
You can replace the pinon seal while it's in the car, but it is a pain in the *** since the snubber bracket is cast into the case and is in the way. There isn't a crush sleeve to worry about. You just have to set your pinion nut back to the same exact spot it is torqued to now. Are you sure it's only your pinion seal that's leaking? If your side seals or cover/batwing seals are leaking, you're going to have to pull the differential. I'd pull the diff anyway and replace all the seals. If the side (output shaft) seals are original like your pinion seal (probably) is, they won't be far behind in starting to leak too.
I'm getting ready to do this to my '80. But I'm replacing my diff with a new unit with a better gear set than the factory 3.08. All of my diff seals have been leaking for quite some time since before I bought the car, so the underside is quite messy. Not looking forward to that cleanup job.
Before you disassemble it check the run out, if the pinion bearings are shot no need to just do the seal, a full rebuild should be considered. I also have the Bat wing aluminum Dana 44, currently doing a durability test on my 82 as I just got my 570HP LS7 running......so far up to 5500 RPM she is holding, a little concerned taking it to the 7,000 red line, tires spinning all the way through 1st and 2nd...
You can replace the pinon seal while it's in the car, but it is a pain in the *** since the snubber bracket is cast into the case and is in the way. There isn't a crush sleeve to worry about. You just have to set your pinion nut back to the same exact spot it is torqued to now. Are you sure it's only your pinion seal that's leaking? If your side seals or cover/batwing seals are leaking, you're going to have to pull the differential. I'd pull the diff anyway and replace all the seals. If the side (output shaft) seals are original like your pinion seal (probably) is, they won't be far behind in starting to leak too.
I'm getting ready to do this to my '80. But I'm replacing my diff with a new unit with a better gear set than the factory 3.08. All of my diff seals have been leaking for quite some time since before I bought the car, so the underside is quite messy. Not looking forward to that cleanup job.
No, from my cursory inspection, it only leaks in the front. BUT - I am going to delve into it a little further, to make sure I'm not over-looking something. (or imagining something that isn't there....)
OK, I've been watching TONS of Youtube vids on changing the seal - looks excessively easy once the car is high enough to slide under. I also see that the front bearing is easily accessible/replaceable during the process (as well as the rubber 'snubber' bushing....
Yes, I know it might not help/fix anything, but the cost vs. benefit ratio is on the positive side, IMO. I have fixed a lot of shiite in the past doing this, and have good results with my "Madness over method" procedures... LOL.
Unfortunately, I haven't found a 'reliable' part number for the 'front/forward' bearing. I'm going to change it, no matter what, as it will be staring me in the face, I just need a good part number. Can ya 'help a brotha out' ?
I would not get to over excited about doing this job in the car from watching videos. From a technical standpoint this job should only be done when rebuilding the whole rear end but more often than not You can "get away with it" by marking the Nut and putting it back exactly where it was. Under no circumstances should you replace the Bearing or anything else besides the Seal. I would search the information GTR1999 has given in the past and use it as real Corvette specific do's and don'ts.
I would not get to over excited about doing this job in the car from watching videos. From a technical standpoint this job should only be done when rebuilding the whole rear end but more often than not You can "get away with it" by marking the Nut and putting it back exactly where it was. Under no circumstances should you replace the Bearing or anything else besides the Seal. I would search the information GTR1999 has given in the past and use it as real Corvette specific do's and don'ts.
Thank you for your input. I truly appreciate it. But - Do you have the part # for the outer bearing?
I'm going to change it, no matter what. If I end up having to rebuild the whole diff, then ok, I'm good with that eventuality. I just need a good part # for the outer/front bearing.
Sometimes, it seems that folks on here tend towards suggesting that something 'Can't be done'. I've spent my life looking at "How can I do it?"
I'm pretty new here, so I don't have the whole story, but - Damn.
It's bad enough doing the seal in the car, but the bearing, only a masochist would attempt what you were planning to do.
In the words of Grandmaster Flash, don't do it.
So, I just 'Might" be a masochist. I've been accused of worse in my 57 years on this rock.... :-) Bearing part #, please... :-) and "Thank You".
In my life, there hasn't been nothing that was "Easy".
my question to you would be.
If you can’t even figure out the bearing PN by yourself, how do you figure that you are able to do what others are advising you not to do?
it’s like this: a straight line is always the shortest path. But only if there isn’t a mountain in the way. Having done what you are attempting to do with the rear completely out of the car, there’s no freakin way I’d pacify myself into thinking it’s somehow less work or hassle to do this with that greasy pig in place.
leaking seal, front bearing replacement, opens the door to low gear oil, which opens the next door to neglect as a result..which leads to other bearing damage, and worn stub shafts .
Drop out that center, and fix it easy. Stop bumping your head.
1980 C3 Differential question.......
