Wrong Fluid Put In Diffs

[kernbrian]

I had my 2004 GMC Yukon XL in for service and as part of that the front and rear differentials had the fluid changed (75k mi), only after driving 500 mi did I look at the receipt and notice that the dealer installed regular 80w90 whereas my manual calls for the synthetic fluid. Question is a)have I done any harm and b) should they do anything special when they go to change back. On this truck there is no drain plug in the rear so the cover will have to come off therefore I am not terribly concerned about not getting a full drain. I bought a rear end for my 2000 before they realized the limited slip rear ends were not holding up with the regular gear lube and I do not want to do that again! Any thoughts appreciated.

[bossier62guy]

I had my 2004 GMC Yukon XL in for service and as part of that the front and rear differentials had the fluid changed (75k mi), only after driving 500 mi did I look at the receipt and notice that the dealer installed regular 80w90 whereas my manual calls for the synthetic fluid. Question is a)have I done any harm and b) should they do anything special when they go to change back. On this truck there is no drain plug in the rear so the cover will have to come off therefore I am not terribly concerned about not getting a full drain. I bought a rear end for my 2000 before they realized the limited slip rear ends were not holding up with the regular gear lube and I do not want to do that again! Any thoughts appreciated.

 

I don't see it being an issue.....the front diff probably came w/ the 80w90, i know mine did. Was it a GM dealer that did the service?

[kernbrian]

I had my 2004 GMC Yukon XL in for service and as part of that the front and rear differentials had the fluid changed (75k mi), only after driving 500 mi did I look at the receipt and notice that the dealer installed regular 80w90 whereas my manual calls for the synthetic fluid. Question is a)have I done any harm and b) should they do anything special when they go to change back. On this truck there is no drain plug in the rear so the cover will have to come off therefore I am not terribly concerned about not getting a full drain. I bought a rear end for my 2000 before they realized the limited slip rear ends were not holding up with the regular gear lube and I do not want to do that again! Any thoughts appreciated.

 

I don't see it being an issue.....the front diff probably came w/ the 80w90, i know mine did. Was it a GM dealer that did the service?

 

 

Yes, GMC dealer did the service...surprising that they would make the mistake.

[bossier62guy]

I had my 2004 GMC Yukon XL in for service and as part of that the front and rear differentials had the fluid changed (75k mi), only after driving 500 mi did I look at the receipt and notice that the dealer installed regular 80w90 whereas my manual calls for the synthetic fluid. Question is a)have I done any harm and b) should they do anything special when they go to change back. On this truck there is no drain plug in the rear so the cover will have to come off therefore I am not terribly concerned about not getting a full drain. I bought a rear end for my 2000 before they realized the limited slip rear ends were not holding up with the regular gear lube and I do not want to do that again! Any thoughts appreciated.

 

I don't see it being an issue.....the front diff probably came w/ the 80w90, i know mine did. Was it a GM dealer that did the service?

 

 

Yes, GMC dealer did the service...surprising that they would make the mistake.

 

 

I would take it back and make them service the rear diff w/ the appropriate fluid.

[2007VictoryRed]

I think there is a drain plug on the bottom of the rear diff the very bottom. If not there going to have to replace the gasket. But I would take it back for sure. Get the right Oil in there.

[Stevens03]

Most likely, the fluid would work but I too would ask for the correct fluid.