Spark plugs

[PK from KY]

I own a 2019 Laramie 2 wheel drive. I have 113,000 miles on it. The miles are about 85% highway miles at speeds of 65 - 75 mph. I know the book states to change the plugs at 100K miles, but never a misfire and I still get 22.5 mpg - 24 mpg as long as no strong headwind. If all is good do I really need to change the plugs ? Also what is the consensus on rear differential & Tranny fluid changes as there are no leaks and no problems at all.

 

[danielmid]

I just did my spark plugs 2015 at 110k and they looked fine, I viewed it more as preventative, replace before a problem comes up. Worth doing but not an emergency.

Rear diff is super easy and should be done if you've never done it. Amsoil SG or Red Line is my recommendation.

Transmission you'll get 50 different opinions on, I haven't done mine but it's on my list.

 

[turkeybird56]

Rear diff way overdue. When you change it, you will see. Tranny: Well FCA says lifetime fluid??? How comfortable are you with that? IMHO only, I say get tranny done. If you DIY, best look up procedures, very definitive way and steps to follow. But I am no mechanic, just my thoughts. If you do change, no flush, just fluid pan/filter setup.

Plugs: 113K, preventative, something to think about.

 

[GTyankee]

If you did much towing up to now
I will say that you may be pushing your grins allotment

 

[kdoublep]

I would start working my way through fluids and plugs as advised. Preventative maintenance. Rear diff is really simple if you're just doing a fluid change and not opening it up.

 

[BadHemi2014]

Agree with other responses, preventive maintenance. You change plugs, fluid, hoses, etc BEFORE they become a problem.

 

[Rebel4Mo]

I would do the maintenance.

If you have the transmission serviced it could be costly.
The lowest estimate I got was $750 from an independent transmission shop.The dealership wanted $75 more!