Thoughts on Time v Mileage

Messages
3,082
A look at my sig shows the reason I ask. I have a 15 F150 5.0 that turns 5 the first Week of September. Only have 38k miles that are high percentage highway. Contrast my DD 17 Subaru 3.6 with over 60k. My question concerns the F150. I did the front and rear diff along with a trans pan drop and transfer case drain/fill at 30k. Front/rear diff's have Mobil 1 75/90 in them. I would like to change them again at 100k. That would be around 8 years of that fluid in the locker. I don't think any issues with the diff's but wanted to ask your thoughts. Transmission will get a pan drop and fill every 30k that's easy peasy. I assume it's a good idea to do transfer case same time as trans. Plugs is a big shrug Going to 100k miles is going to be a 10 year timeline. That's a long time for a plug to be in there. Might be an ordeal to get them out. I have nightmares over this as I had a 04 F150 with the 2piece plugs in the 5.4 3V. Yes I know it's not that disaster of a plug anymore. So, change em out early? And if so when? 50k? 75k? The truck runs great and no mechanical issues to date.
 
Messages
19,686
Location
Sunny Florida
I run plugs to far past 100k miles in our duty cycle. We are almost all city mileage which is much harder than yours, so it seems plug life is not an issue for you at the suggested interval. All our fleet trucks are late model LS style V-8's with aluminum heads and I have never had any issues with getting plugs out except in our vans due to tight packaging. I always spray them with penetrating oil a few days ahead of time and then they just come right out. Diffs we do at 50k miles so you seem well covered there. We service our trans at around 30k miles, changing pan and filter first and then a complete fluid exchange. Do you have electric power steering? If not, there's a fluid that needs attention occasionally, too.
 

BISCUT

Thread starter
Messages
3,082
Originally Posted by SteveSRT8
I run plugs to far past 100k miles in our duty cycle. We are almost all city mileage which is much harder than yours, so it seems plug life is not an issue for you at the suggested interval. All our fleet trucks are late model LS style V-8's with aluminum heads and I have never had any issues with getting plugs out except in our vans due to tight packaging. I always spray them with penetrating oil a few days ahead of time and then they just come right out. Diffs we do at 50k miles so you seem well covered there. We service our trans at around 30k miles, changing pan and filter first and then a complete fluid exchange. Do you have electric power steering? If not, there's a fluid that needs attention occasionally, too.
Yes Sir, power steering is electronic.
 
Messages
5,295
I thought maintenance schedule for F150 said differentials at 150,000 miles then every 50,000 thereafter. Why so early?
 

BISCUT

Thread starter
Messages
3,082
Originally Posted by LoneRanger
I thought maintenance schedule for F150 said differentials at 150,000 miles then every 50,000 thereafter. Why so early?
Get the wear metals out. I dont thoroughly trust any car brands to give me the most beneficial information. They have an incentive to get me in a newer model as well as seek to keep maintenance costs low for sales reasons. Many say lifelong fluid but I have yet to see any written definition.
 
Messages
10,001
Location
Waco, TX
Seems everything I hear about plugs is leave them alone until you get a misfire code. I have 197,000 miles on the original plugs in my 4.6 (2008) F150. I never detect any audible misfire ever.
 
Messages
17,881
Location
Silicon Valley
My dad's Taurus came with plugs with no plating, so they surface rusted into the head and took a while to get out. If your F150 is anything like that do them at 10 years regardless of miles. However, my Corolla and Integra came with plated plugs and they don't get stuck, I'd just go by miles in that case.
 

BISCUT

Thread starter
Messages
3,082
Originally Posted by jjblbi
Why not pull the plugs and put a dab of ant-seize on the threads? Performance wise they should go 100k miles.
Pretty sure anti seize on these are not recommended.
 
Messages
3,463
Location
Coastal South Carolina
you said Transmission will get a pan drop and fill every 30k that's easy peasy. I assume it's a good idea to do transfer case same time as trans. my last two toyotas went 200k before trading them, with only one change, 30k seems excessive
 
Last edited:

BISCUT

Thread starter
Messages
3,082
Originally Posted by edwardh1
you said Transmission will get a pan drop and fill every 30k that's easy peasy. I assume it's a good idea to do transfer case same time as trans. my last two toyotas went 200k before trading them, with only one change, 30k seems excessive
Apples to coconuts right? And in stating pan drop not flush. If all you did in 200k miles was a pan drop and fill I'd ask why ???
 

BISCUT

Thread starter
Messages
3,082
Originally Posted by edwardh1
you said Transmission will get a pan drop and fill every 30k that's easy peasy. I assume it's a good idea to do transfer case same time as trans. my last two toyotas went 200k before trading them, with only one change, 30k seems excessive
Apples to coconuts right? And in stating pan drop not flush. If all you did in 200k miles was a pan drop and fill I'd ask why ???
 

BISCUT

Thread starter
Messages
3,082
Just saw your location....as I write this im at Sticky Fingers coastal grand circle SC location.
 
Messages
19,686
Location
Sunny Florida
Many trans experts seem to like an early filter change over a fluid exchange as the typical slushbox generates most of its debris in the early stages of its life. 30-50 k miles seems good to me based on what I've read here and elsewhere. Once you get a filter change you can switch to fluid exchange for the next service. You can also safely extend the intervals as the trans ages...
 
Top