How bad did I screw up?

[MDietrich]

Sunday I changed the gear lube in the rear end.

After I had the cover put back on, I realized I had purchased 75w90 synthetic BLEND!#@$%!



The stuff meets the API rating DC has in the owners manual(GL-5), but what has me worried is this printed on the back of the bottle "May be used in limited slip differentials for top off only".



Do I need to get it out now, or could I run it for a few thousand miles? The stuff was about 6 bucks a quart!



MD

 

[RonWeiss]

03's and up don't need limitied slip additives..... so that's OK. But they do recommend full synthetic gear oil.



If I were you I would leave it in for awhile maybe 5k-10k miles or so, but change it out sooner if you are going to tow or put some miles on with your camper.



Ron W.

 

[MDietrich]

That's what I was hoping to hear Ron. I would like to get a little return on my investment.



I'm taking the other 3qts for the front end back today, and getting Royal Purple lube at a local supplier. It's only 2 bucks more a quart.



Thanks Ron!



MD

 

[JBraun]

What brand did you buy? Just curious.

Jason

 

[Casey Balvert]

Rear axle problems are not uncommon in the 3rd gen trucks. Trust me, I know. If it was me, I wouldn't give DC an excuse to stick me with the bill if my axles goes. For the 25 bucks you have invested in the oil, dump it and put in the pure synthetic that DC recommends. FWIW



Casey

 

[Spooled-up]

I wouldn't take any chances either. Swap out to synthetic.

 

[Dean Upson]

I was told by AA not to use a synthetic blend. The tech told me the difference was night and day. I would dump anything that was not the full synthetic.



Dean

 

[klenger]

Consider the synthetic blend an axle flush.

 

[jungledave]

Run it and flush it like klenger said. I was told by the dealer to make very sure not to overfill it to the plug hole. Fill it ot the marks about . 75" below filler hole. He said that filling it to the hole can cause the synthetic to foam up and hurt or ruin rear diff.

 

[MDietrich]

Thanks for all the responses guys!



Next week on my days off I'm going to drain them both and put in the right stuff. Should'nt put on more than a 1000 miles in that time.



To answer JBraun's question it was Coastal brand lube. What threw me off was the word synthetic in BIG letters and the $5. 98 price tag. I said to myself 'for that price it has to be full synthetic. '



I did'nt even see the little word "blend" on the bottle 'till it was too late. :{



Again, thanks to all!



MD

 

[Ol'TrailDog]

I was told by AA not to use a synthetic blend

Gosh, I knew these guys were big into 12 step programs, but dispensing auto advice seems a bit of a stretch. :-laf



I know, you meant AAM.