Changing fluid on front and rear end

[broncoeddie1970]

Ok so a couple of questions. I need to check and rather just put in new fluid in the dana 44 and rear end. I just ordered some breather bolts for both front and rear.

1. Can this be done easy enough with simple tools?
2. How to flush out what's in there now?
3. What kind of fluid to use? weight? brand?
4. How do you know the right amount of fluid?

5. What about the 3 speed tranny? same questions as above.....

Thanks. I want to do this over a weekend and hope its easy enough to do it on the drive way.

Thanks so much for your help.

 

[BigBlueBronco71]

1. Can this be done easy enough with simple tools?
Yes I did this in a day in the garage with simple tools when I first got the bronco

2. How to flush out what's in there now?
I used a simple pump from Horrible Freight and it worked but was a bit of a pain and you'll get most but not all the fluid http://www.harborfreight.com/gear-oil-and-fluid-pump-61746.html
There are other ways people will comment or you could crack the diff and let it drain and clean everything up with new gaskets but thats a little more work

3. What kind of fluid to use? weight? brand?
Per the advice of the veterans on here I used 75-90w full synthetic gear oil (I think I used valvoline) in both diffs, the 3 speed, and the transfer case, it's nice to have the same fluid all around and it works well for me and many others

4. How do you know the right amount of fluid?
You can look up the spec or you can just fill them up until fluid comes out the fill hole like many others do, that way you're sure theres enough in there

5. What about the 3 speed tranny? same questions as above.....
The three speed has a drain plug and a fill plug I believe but everything else above applies

Good luck and have fun!

 

[blubuckaroo]

broncoeddie1970,
What do you know about your car's history?
The reason I ask, is if you don't know, your differential housings may have been in deep water sometime. The oil floats on top and the water can't get out unless you drain the diff. That's not a problem for the front diff, but the rear didn't come with a drain plug. You're not going to be able to suck the crud out of the bottom.

Why not do this?
Pull the axles and differential out of the rear housing. That way you can inspect the axle bearings and clean up the housing.
It's an easy job, and something you'll need to know how to do anyway.

I always use a major brand 80W-90 GL-5 gear oil. I don't invest in synthetic because I have to change the gear oil annually. I drive regularly in deep water to get to my trout fishing spot.

 

[broncoeddie1970]

1. Can this be done easy enough with simple tools?
Yes I did this in a day in the garage with simple tools when I first got the bronco

2. How to flush out what's in there now?
I used a simple pump from Horrible Freight and it worked but was a bit of a pain and you'll get most but not all the fluid http://www.harborfreight.com/gear-oil-and-fluid-pump-61746.html
There are other ways people will comment or you could crack the diff and let it drain and clean everything up with new gaskets but thats a little more work

3. What kind of fluid to use? weight? brand?
Per the advice of the veterans on here I used 75-90w full synthetic gear oil (I think I used valvoline) in both diffs, the 3 speed, and the transfer case, it's nice to have the same fluid all around and it works well for me and many others

4. How do you know the right amount of fluid?
You can look up the spec or you can just fill them up until fluid comes out the fill hole like many others do, that way you're sure theres enough in there

5. What about the 3 speed tranny? same questions as above.....
The three speed has a drain plug and a fill plug I believe but everything else above applies

Good luck and have fun!

Thanks so much sir. I will look into what you have told me.

 

[sykanr0ng]

Most recommend not to use the same oil in the transfer case as the differentials, the additives for the hypoid gears are not compatible with the brass thrust washers in the Dana 20.

GL5 is for hypoid gears.
GL4 is for transmissions and transfer cases.

 

[broncoeddie1970]

broncoeddie1970,
What do you know about your car's history?
The reason I ask, is if you don't know, your differential housings may have been in deep water sometime. The oil floats on top and the water can't get out unless you drain the diff. That's not a problem for the front diff, but the rear didn't come with a drain plug. You're not going to be able to suck the crud out of the bottom.

Why not do this?
Pull the axles and differential out of the rear housing. That way you can inspect the axle bearings and clean up the housing.
It's an easy job, and something you'll need to know how to do anyway.

I always use a major brand 80W-90 GL-5 gear oil. I don't invest in synthetic because I have to change the gear oil annually. I drive regularly in deep water to get to my trout fishing spot.

Thanks so much sire. As far as history, i don't know too much about it. I got it from a guy who lives in Round Rock TX. It does not have too much rust and I don't believe the guy did anything too major like going thru mud or rivers but that's just my guess. As far as me, it going to be a weekend driver going around town and cruising.. I will look into the different brands of oil and wait for more folks here to tell me what they use. I didn't know that the rear end didn't have a drain plug. I will do more research on that part (youtube).

Thanks so much for your time and responses.

 

[1strodeo]

I changed mine a few months ago it's all in this thread, not a very long read

http://classicbroncos.com/forums/showthread.php?t=272770

 

[broncoeddie1970]

I changed mine a few months ago it's all in this thread, not a very long read

http://classicbroncos.com/forums/showthread.php?t=272770

Thanks so much..i read over that thread..so did you end up going with 75w/90 fully synthetic gear lube ???

 

[1strodeo]

No Sir, this stuff here works just fine, made a noticeable difference too, but I only used it in the trans and rear end. I plan to do it again this summer because they both need cleaned out better. The cheapo HF tool mentioned above did a good job on the rear end, but I could tell from the 'fudge' that came out it needed cleaned out better.

 

[DirtDonk]

Most recommend not to use the same oil in the transfer case as the differentials, the additives for the hypoid gears are not compatible with the brass thrust washers in the Dana 20.

Correct enough, but there are gear oils (especially in the synthetic world) that are compatible with the soft metals like the bronze bushings.
The bottom line is to read the label of course. Just saying there are ways around the multiple oil types in the same vehicle issue.

The difference in weights is kind of a non-issue when they're that close. A 75w/90 is not going to be much different than an 80w/90 for most of us. There might be advantages to the way one particular brand is made over another, but I have no idea what those might be.

I've used the 75w/90 synthetic in mine for years and probably 60k miles or more, with no trouble and no noticeable wear and tear on the inner components that I could tell.
But no matter whether you use dinosaur oil, fully synthetic or a mix of both, read the label to make sure that particular version doesn't have the wrong additives, and is compatible with what you're using it in.

Or when in doubt, suck it up and use what the factory says and put 50wt motor oil in the transfer case. Hard to go wrong that way.
I just liked how things worked out with the right gear oil.

Paul

 

[broncoeddie1970]

Correct enough, but there are gear oils (especially in the synthetic world) that are compatible with the soft metals like the bronze bushings.
The bottom line is to read the label of course. Just saying there are ways around the multiple oil types in the same vehicle issue.

The difference in weights is kind of a non-issue when they're that close. A 75w/90 is not going to be much different than an 80w/90 for most of us. There might be advantages to the way one particular brand is made over another, but I have no idea what those might be.

I've used the 75w/90 synthetic in mine for years and probably 60k miles or more, with no trouble and no noticeable wear and tear on the inner components that I could tell.
But no matter whether you use dinosaur oil, fully synthetic or a mix of both, read the label to make sure that particular version doesn't have the wrong additives, and is compatible with what you're using it in.

Or when in doubt, suck it up and use what the factory says and put 50wt motor oil in the transfer case. Hard to go wrong that way.
I just liked how things worked out with the right gear oil.

Paul

Thank you Paul for your comment. Looks like i will play it safe with the transfer case and use 50wt motor oil. I think i will use 75-90w full synthetic gear oil for rest of stuff.