Engine/Transmission (1994 - 1998) Synthetic oil in a Dana 70 differential

[RVnwithRAM]

I changed my oil out in my Dana 70 limited slip differential several thousland miles ago with a synthetic lube plus the additive and after a few thousand it makes a popping sound I added some more additive and it still does the same thing . Should I change back to the original type lube? Has any one else had this problem ?

 

[JR]

The synthetic fluid is not your problem, it's actually the preferred fluid to use especially if you haul/tow frequently.
Are you sure it isn't a universal or possibly a carrier bearing going bad? It may be time to pop the rear cover and do an inspection.

 

[RustyJC]

I ran Royal Purple 85W-140 synthetic in my 2002 dually's Dana 80 since I towed a heavy 5th wheel. The RP already has the friction modifier for clutch-type limited slips, and I never had any chatter or noise problems from the differential while using it. Are you sure your problem is a limited slip clutch chatter issue??



Rusty

 

[RVnwithRAM]

I do tow with the truck , it only chatters while making a sharp turn like driving in to the drive way . It vib

rates the truck some but that is the only time it does it.

 

[JR]

That is a clutch pack issue. The clutches get gummed up and you are effectly running a posi full time hence the chattering in the corners. I've been able to pull the R&P assembly, LIBERALLY spray the clutch packs with brake clean, blow dry with compressed air, and had great results. I did that on my former 00 and I drove it another 20k before selling to a friend who has put many thousands of miles on it since with no issues. As long as your not seeing a bunch of metallic colors in the gear oil when you drain it, you can most likely clean them and be fine.

 

[LHastings]

I also put RP in my rear end and not to long after that I with experiencing chattering when turning and backing up. Wound up having to replace the clutch pack. I ordered a set from Randy's Ring and Pinion. I went back to Diff. Grease and after 159000 mi no problem.

 

[JR]

Running synthetic oil has no bearing on clutch pack problems. It comes with the territory of high mileage vehicles, vehicles that are either run at close to max gvw or hot rodded, and not changing the oil frequently enough when one or more of the first 3 apply. Most of the time a good cleaning like I mentioned above is all that is needed but they do wear out. Synthetic will not break down as quickly as regular gear oil. The main thing to watch out for is whether or not the additive is needed. Some synthetics still require it while others do not. I am a firm believer in running synthetic in my rear diff. The front is not so important I feel because of it's limited use and 95% of the time if I am in 4 wheel drive I am not towing therefore the front is not subjected to the same torque and heat as the rear.

 

[GAmes]

The differential is the only part of my drivetrain that is original. I've used RP for the last 800k, and change it every 50k. No problems with the LS so far. Lots and lots of towing trailers over 10k pounds.