D/A break-in period

[BillTex]

If I pull the trigger on a new 3/4 ton D/A this weekend-how many miles am I "supposed" to put on it before I tow next week?

[jcanavera]

On my '03 GMC 3/4 ton 6.0 liter gas Savana van, the recommendation was 500 miles before doing any towing. Then for the next 500 miles, to not exceed 50 mph while towing.

Jack

[CanoeStream]

Woo-hoo BillTex! Looks like you'll have long distance, all terrain towing performance for just about any Airstream you like.

Jack is right on. You cannot tow the first 500 mile break-in and should stay at 55mph or under. Then your first 500 miles of towing are supposed to be 50mph or less and no rapid acceleration.

I bought mine in early February, so was able to do the preliminary break-in without my Safari tugging at my heart. I didn't complete the 500 mile towing break-in until driving to the Midwest Rally the weekend after Memorial Day. That was o-n-e l-o-n-g d-a-y driving from just west of Minneapolis to Madison, Wisconsin (350 miles).

Enjoy!

[BillTex]

Thank you-are those numbers for the diesel/Allison combo or just gas?

Bill

[Silvertwinkie]

It's not so much for the engine, but the gears in back. True, it's nice to be kind to a nice, new, tight engine, but it's the gears. New gears run far more hot than broken in gears.

Make sure that you drain, flush and refill the differentials after a few thousand miles, even though there is a magnet to get the metal shavings that will come off the new gears during the break in period, it's great preventive maint. I also change the gear oil in front and back every 6-7k after the initial, particularly if I've been towing a bunch.

[davidz71]

Originally Posted by Silvertwinkie

It's not so much for the engine, but the gears in back. True, it's nice to be kind to a nice, new, tight engine, but it's the gears. New gears run far more hot than broken in gears.

Make sure that you drain, flush and refill the differentials after a few thousand miles, even though there is a magnet to get the metal shavings that will come off the new gears during the break in period, it's great preventive maint. I also change the gear oil in front and back every 6-7k after the initial, particularly if I've been towing a bunch.

Better yet, replace that rear diff cover with a Mag-Hytec cover which gives you extra lube capacity, a screw-in dip stick that is magnetic and last, a drain plug at the bottom of the cover which is also magnetic. Gear lube drains are a breeze afterwards. I run Amsoil Severe Gear 75-90 synthetic and plan on changing every 35,000 miles or so. I check the dip stick monthly to wipe off filings. Go to www.mag-hytec.com

[Silvertwinkie]

Originally Posted by davidz71

Better yet, replace that rear diff cover with a Mag-Hytec cover which gives you extra lube capacity, a screw-in dip stick that is magnetic and last, a drain plug at the bottom of the cover which is also magnetic. Gear lube drains are a breeze afterwards. I run Amsoil Severe Gear 75-90 synthetic and plan on changing every 35,000 miles or so. I check the dip stick monthly to wipe off filings. Go to www.mag-hytec.com

I totally agree. The mag-hytec is on my list of items, but I've put the severe gear lube in the front and the specified lube visc for the front as well (Amsoil syn too).

Did you know that if you pay something like $20 to be an Amsoil Preferred Customer that you can save that and more annually for everything Amsoil sells? I bought motor oil, trans, diff and 2 cycle for the boat. Personally I think Amsoil makes great stuff, so far I've saved about $40 ($60 minus the $20 the prefferred customer thing cost me) compared to their online list prices and what the local guy sells it for.

[TIMEMACHINE]

A few other basic break in rules.

1. No hard acceleration. ( This goes for braking too, not good for the new brakes)

2. No long idling.

3. No constant speed for long periods of time, in other words, vary you speed even on the hiway.

4. No hard downshifts.

I didnt realize till I wrote this....its has a whole bunch of NOs.

Here is a Yes

5. Yes, drive it like you have a drivers test examiner in the truck.

[BillTex]

Pulled the trigger Saturday, LT3/LBZ/6 spd Ally-with the 4th Holiday, I probably won't take delivery till Wed. The truck is probably 200 miles away, by the time it gets here, I would guess it could have 300 miles on it.
We are leaving on a 300 mile tow Friday 7/7, by the time I leave it will only have 300-400 miles on the odo.

Of course I will take it easy on our trip, but I won't have much choicde but to leave with only 300/400 miles on the clock... I know this is splitting hairs, but I have never owned a diesel before.

Bill

[pmclemore]

BillTex,

It is hard to spend the extra $, but I trust you will be as glad as I am - every day that I did.

Buy what you want, once, then be happy with what you buy.

Pat

[CanoeStream]

Originally Posted by TIMEMACHINE

A few other basic break in rules.
......
2. No long idling.
......

As a matter of fact, the ol' diesel habit of leaving it running for extended times while you're in a store or finishing off a pint has fallen prey to the more complex machinery and pollution control gear of a modern diesel. Do NOT do this as a habit with the newer diesels.

A good browsing website (but no replacement for ASForums!) is http://www.dieselplace.com/forum/index.php

[wahoonc]

Originally Posted by BillTex

If I pull the trigger on a new 3/4 ton D/A this weekend-how many miles am I "supposed" to put on it before I tow next week?

I always heard that it took 50,000 miles for a diesel to fully break in

Enjoy your new diesel truck!

Aaron

[davidz71]

The only reason to let the modern trucks idle for a period of time is to let the turbo cool down. There are plenty of soccer moms running diesel Excursions who probably weren't even told this.

[wahoonc]

Originally Posted by davidz71

The only reason to let the modern trucks idle for a period of time is to let the turbo cool down. There are plenty of soccer moms running diesel Excursions who probably weren't even told this.

According to my EGT it takes less than 2 minutes of idling after a hard Interstate run. Most of the time in city stop and go driving it doesn't get hot enough to need to cool down. I typically drive 200 miles at a time without stopping, usually by the time I hit the end of the exit ramp, wait to make my turn and get the 1/4 mile to the stop, it has cooled down. They make kits with an automatic shut off that will handle the cool down for you too.

Aaron

[Pick]

The LB7 Duramax has a water cooled turbo, so the cool down period is not necessary. I am not sure if the LLY and LBZ are water cooled as they have the variable vane turbo.

[TIMEMACHINE]

Every manufacturer is a little different regarding turbo cool down periods, Ford recommends 7 to 10 minutes " after extended high speed or maximum GVW operation". Unless I am running real hard, I usually shut down in about 3 to 5 minutes. I know you are looking at buying a D/A, but who knows, maybe you will defect.

[Pahaska]

Originally Posted by Pick

The LB7 Duramax has a water cooled turbo, so the cool down period is not necessary. I am not sure if the LLY and LBZ are water cooled as they have the variable vane turbo.

I do a cooldown on my LB7 anyway after a major climb such as up Kimichi Mountain in eastern Oklahoma. We like to stop at the crest and enjoy the view for a while anyway.

Any other time, I figure that by the time I get the trailer parked, my LB7 turbo should be cooled enough.

I never do a cooldown when not towing or when towing on relatively flat terrrain.

I get 14-15 mpg towing my Classic 28 at 60-62 mph; even better when in a caravan rolling along at 55.