Cat 775E when do you overhaul?

[MKTEF]

We got 5x Cat 775E in our fleet.
One of them has just passed 12 000h. Last report shows a increase in metal in the differental.

I know a lot of you guys have experience with fleets of theese trucks.

At what hours do you recomend to overhaul what?

How long does the engine last? Trans? diff? Other stuff?

Our Cat service guy is skeptic about the diff. He talks about doing a major overhaul of the truck to get it to hold to 20-25 000h.
My boss states that theese should last to 25 0000h.(i don't belive that!)

And as always, thanks in advance for any info!

 

[AmerIndependent]

Hey MKTEF,

It really depends on application, environment, maintenance and operator but generally major components should be pulled for pre-failure rebuild between 10 and 20 thousand hours.

Many variables can play a part in component life even when comparing the same model of machine so here are some questions that play a major role:

-How long is the haul from load to dump?
-Flat or mountainous?
-Temperature extremes?
-Haul roads well maintained?
-Maintenance intervals?

If we have this information we could probably give the benefit of our experience.

 

[MKTEF]

Ok, i forgot to give you those. And of course they play a big role.

Theese trucks work in minus 20 to plus 20C.
They usualy work in short distance from load to dump.(project work 5x together)
Haul roads vary, some times well maintained other times not so well.
Intervalls, i'm not exactly shure, but i belive 500h between service. Repair when needed.
Theese trucks work in a pakage with a 385C and some type of dozer or wheeloader on the dump.
50% rock 50% sand/gravel
High degree of low rpm hours, mostly/always one waiting for a load by the 385.(1 dumps, 2 drives, 1 loads, 1 waits by loader)
Stable operators, same guy's have been driving theese for years.

 

[Lee-online]

I just overhauled a 775E. Did a certified powertrain, It had almost 25K.
Here are some of the pics i took of it.
https://www.heavyequipmentforums.com/showthread.php?20734-Some-random-work-pictures




The idea is to do the powertrain at 20K and then a certified rebuild at 40k. Then the powertrain again at 60K Then at 80K it has reached its useful lifespan.

 

[AmerIndependent]

Based on this data I would think it safe to rebuild components at 20,000 hours as long as you have your lube guys inspect filters and screens at every service so that you can be aware of unexpected failures in progress before they cause collateral damage and contaminate other components that share oil driving repair cost through the roof. Emphasis on screens- lots of people do oil sampling but don’t inspect filters and screens!

We actually offer kits to our customers to ensure this step isn't skipped: http://www.americanindependentinc.com/downloads/TRANSMISSION SCREEN KIT FLYER.pdf