Dana 70 will it hold up??

[drives mopars]

will my dana 70 hold up?

whats the kind of abuse you've given it

and does it still hold up?



i really want a disc 80 but not that lucky

to get one so for now its the 70



whats the hp they can take?

 

[Bad340fish]

I don't think the 80 or the 70 needs to be worried about at all. Both are very heavy duty. The Dana 60 is a very popular rear end for drag racers. I would say go for it

 

[Dieselnerd]

I fried the carrier bearings in my Dana 70 at 37,000 miles towing a 7500 pound trailer (Tow bigger one now) using Mopar synthetic oil as called for in the owners manual. The problem? Manual said to fill about 1/2 inch below the fill hole. Wrong! If you use the stock cover, point the nose down hill and fill until it runs out or better yet get a Mag Hytec cover and keep those bearings running in oil. With new bearings, Mag Hytec and Amsoil series 2000 75-140 I have had no problems whatever. The Dana 70 is a very strong axle and when properly lubricated will last a long time. The problem is just the bottoms of the bearings touch the oil at stock oil level and considering the crown of most roads your left hand carrier bearing only gets splash oil and fails right around the time your warranty expires.

 

[Texas Diesel]

I agree completely with filling it to the top. The MagHytec has a small plug in the cover that is supposed to be where the factory fill plug would be. We filled it to the full line on the dipstick which took considerably more oil than where the little plug let some start draining out. Wonder if this is enough to keep the carrier bearings submerged. How would you know for sure?

 

[HoleshotHolset]

Good observations!!

I never thought of it like that.....

Hrmmm... maybe we could have reduced the # of Dana-70 failures on ambulances with the Mag-Hytec rear diff covers installed... . interesting.



Matt

P. S. It's usually the carrier bearings that get eaten... then the magic fairy dust from them goes through the pinion bearing and eats that (doesn't happen ALL the time... but sometimes... ). BTW, most of our failures have been on trucks that are at or near full rated GVW 24/7/365.



P. P. S. Now for the real question... . will all this added oil help to mess up our already bad relationship with our hub seals??!!

 

[Dieselnerd]

Holeshot, I have never had a seal leak in my rear axle and the people at Mag Hytec told me that the seals last longer with plenty of oil on them. I am on my third right front seal but it hasn't failed again since I started using Amsoil and keep it full to the top.

Texas Diesel, when the Mag Hytec is full, the level is slightly higher than the axle tubes. That way plenty of lube gets to the hubs and the lower part of the carrier bearings are submerged.

 

[HoleshotHolset]

[Just a few observations, no flames intended. ]



Mag-Hytec is in the business of selling rear-end covers and deep transmission pans (and maybe a few other things that I don't know of... . )... . it would be in their best interest to NOT say that the installation of their product will harm or further accelerate the wear of any part as a result.

I'm always in pursuit of the cold-hard-facts, whether the results are good or not... . I don't care, just give it to me straight.



My concern is that the OEMs did not intend these hub seals to be under this added stress of the extra oil capacity... . see what I mean?



I'm not discounting anyone else's work/product, nor am I against anyone who owns or may be purchasing the product... . I'm just doing all my homework.



Matt

 

[LarryB]

You have a point HH, but then again the OEM has to pay for the extra oil that may be unneeded to carry the product through the warrantee period. All adds up.



Larry

 

[Texas Diesel]

One thing to consider, my Dakota (170,000) rear diff says the same thing about filling 1/2 to 1/4" below the opening. I asked the service writer about it when I first serviced it and he said it was because a few seeped oil that DC lowered the level, so that no oil was "sitting" on the seals. He suggested filling it to the top. It has been filled as full as possible and changed annually for 7 years. No leaks or failed bearings. Just a thought.

 

[HoleshotHolset]

Nice thread!

As for the Dakota... well, without full-floating axles it's not quite the same... . but it looks as if the little extra fluid didn't hurt it yet.

Cool.



Matt

 

[Bill Lins]

Has anybody tried this?

I've thought about installing a pipe "ell" in the fill hole and capping it. Has anybody tried this?

 

[LarryB]

That will work. Use a street el. You could even put a 2" nipple on it and make a little dipstick right in the cap. Then find a big magnet and stick it to the back cover. Poor mans MagHytec.

 

[Roger rodbolt]

For what it's worth..........

While preparing to install a limited slip carrier, I noticed the following in a '98 Dodge service manual;



Caution: Overfilling the differential can cause lubricant foaming and overheating.



The caution was the same for both Dana 70 and 80 and is listed under lubricant change. I run 3/4 inch over stock level with the MagView cover.

 

[Extreme1]

I fill mine about midpoint on the Maghytek dipstick which is above the stock cover fill hole level. I have checked it several times just after driving and it isn't foaming.



There is always oil against the seals in the hubs. When you fill to the stock level, it stays in the hubs. When you fill above that, it circulates with the other oil.



The left hub bearing thought is a good one. Guess what? When I dissassembled my brakes this summer, the left bearings were gone. Guess what else? I was a dumba$$ and followed DC instructions when filling the rear axle after first change.



If you really want to do it right, add a drain/fill plug to your hubs so when you change the oil, you get all of it.

 

[baby.driver]

Foamy

I really think you would have to get the oil high enough to submerge part of the pinion gear before danger of foaming is reached.



Jay

 

[Sled Puller]

Lorretta Mitchell twisted her Dana 70 yoke off.



She is kind of hard on parts fetching groceries.

Gene