[Wickedsprint]

how many of ya'll actually took the time to break your engine in..IE not getting into the throttle for 500 miles or extended interstate driving, I have always been religious about this, although it is hard keeping this thing under about 3k and no full throttle for that long...it's torture!!!

 

[hoot]

I bought mine at a dealer 300 miles from home, It had 300 miles on it already.... I was easy on it on the way home.

After that I forgot about breakin.

 

[Mr X]

Some say these engines aren't fully broke in uintil about 20,000. Mine's at over 16,000 and still seems to be getting stronger and smoother all the time.

 

[CS-Dmax]

I did my best to follow the guidelines....

I am at 5300 miles and it is getting better every day!

 

[Mcfly]

The truck service manager at the dealer where I get all my service done had 100000 mile engine apart. He said that you could still see the crosshatching on the cilinder walls. Apparently these things never break-in.

 

[geno]

It had 43 miles on it and i was approx 200 mi from home, first of all i checked the speed limiter at 97 m.p.h. never held it at a steady rpm all the way home. few miles around town. had approx 400 loaded 1500 lbs and went to st louis mo 1030 mi round trip almost time to change the oil (5000) oil level still full. this truck was ordered for the owners father in law to pull a 5er and i feel it has been set up a little cause it runs and pulls like crazy. as far as breakin drive hell out of them, i am a old man and done it this way all my life and never had a problem, but you guys do as you chose and dont let me influence anybody, its just the way ive done it and untill i blow one ill continue this. my co truck is a 99 3/4 gmc 5.3 with 272k still goin with no engine or trans problems.


Geno

 

[Tsckey]

I bought my truck in Idaho and live in Sacramento. I fully intended to drive like a church lady all the way home, but by Spokane I was starting to itch and somewhere south of there lost all self control. I did vary my speed religiously, though

By the time we got home I was holding 75 and averaging 18.5 mpg. Now at 20,000 it runs like a big noisy watch, burns no oil and gets even better mileage (after an anomolous period of low numbers). I'm not sure what the message is here.

TC

 

[cloudytown]

This has been covered on PUTC several times. No where did I see in my manual about breaking the engine in. The weak spot on these trucks are the rear differentials. This is "Expierence" speaking. I now know of 4 people who have had to have their rear ends replaced, mine was one of them. The first 500 plus miles I kept it below 50 mph. Enjoyed driving around in it, not a problem. Also mentions the first 500 miles of towing keep it under 50 mph. Much harder to do. By 780 miles on the odometer, I had such a howl in the drive train I could not stand to be in the truck. Rear ring and pinion out. Parts back ordered...took 8 days to get the gears in and put in. Then the dealership told me to again use the stated break in period listed in the manual, first 500 under 50, first 500 towing keep it under 50 mph.


The rear ring and pinion gears need to wear in and seat themselves against themselves. When towing a different wear pattern needs to be wore in. Extreme heat is generated in the break in process. My differential housing was so hot, I could not hold my hand on it.


Broker describes the trucks he uses for towing 53 ft long trailers loaded as having a system he sets up which is a differential oil cooler mounted in the bed of his trucks.


I have also talked to two D/A owners who told me they drove their trucks from day one in the way they would use them as long as they own them, and have not had any differential problems. Just my opinion. (The differential repair was covered by the warranty and not listed on the repair ticket, but I saw a ticket listing the repair cost at over $1800. .)

Edited by: cloudytown

 

[jesshd]

I did not baby my truck when new. Took delivery of it at 10 miles. Bought it on Thursday, towed with it Saturday. 10K 5r. Did not go much above 60 or 3/4 throttle. Changed the oil at 2500K to Rotella Syn and then the rear diff at about 3500 with Mobil 1 syn. No problems with anything so far. I have also towed with the 40 hp Predator and Juice on level 2. No oil use, no strange noises and getting 16 mpg in town and 19-21 on the highway.





Jess

 

[k1xv]

Gee Jesshd...


You waited to 2500K to change the oil for the first time? That's about 5 round trips to the moon!!!

 

[GMC-2002-Dmax]

I kept mine under 60 for the first 500 miles, drove mostly back raods and a lot of stop and go to keep speed an RPM variable.


At 27K miles all is good.


No oil usage, strong as can be.


T

NY

 

[hdmax]

Gee Jesshd...


You waited to 2500K to change the oil for the first time? That's about 5 round trips to the moon!!!

Or one trip back home!

 

[jesshd]

Everybody's a wise guy

Jess

 

[Frank Blum]

What is the definition of broke in? If it is what we used to call seating in the rings, I think they are seated by the time we drive it off the lot. Many years ago there were no moly rings. The rings were not round and had to wear the high spots down before they made a good seal. It was not uncommon to use two quarts in the first 500 miles. The rings today are pre-lapped to make them perfectly round before they go into the cylinders. I built a few engines over the years.I can remember it took a 2' long breaker bar to turn a 327 over by the time I got the cast iron rings on the last piston. The last 350 I used moly rings. It took a 12 box end wrench to turn it over. A cross hatch pattern in the cylinder at 100K is great. I am sure there are a few guys on this forum as old as I. Later! Frank