CACalomino

Well I just got a ton of amsoil products for diff's, tranny, T-case and 15w40 HDD&M sythetic motor oil from a local DTR member and im debating on waiting on putting them in or just doing it.

As far as the engine oil is concerned why is it bad to switch to sythetic before 15K miles on the CTD. I did a search and from what I read I gathered that it will hurt break in or slow the process down and what not. My truck is coming up on 5K on it and im going to add on a FS2500 bypass oil filter on and was thinking of switching to the synthetic at the same time but I dont want to hurt the motor. I just dont understand why u cant switch I have baught a few HP sports cars in the past that came with Mobil 1 sythetic in it from is first breath of life. So please shed some light on why changing from dino to syn with same viscosity would hurt.

As for the diffs i have some severe gear oil 75W 90 and I just ordered some mag-hytech diff covers from geno's to make changes easy and to keep the diffs cooler. Im wondering if its worth changing them early or just waiting till 15K my truck is a 06 and it sat on the lot for a year or so till I baught it two months ago and I just dont like the thaught of all that old fluid in it plus any break in particals floating in it. IM just looking for feedback to see if its worth taking out the old and putting in the new for added protection of a better lubricant.

Thanks in advance for any feedback

-Chris

dodgezilla04

you can change your gear oil early. it is just darned expensive to dump it for no real reason.
as far as synthetic in the engine, it will not properly break in with synthetics. run dino oil for about 20K, then you can switch with no worries.

Jeff in TD

I 2nd what dodgezilla04 said...

06megacabman

I did my diff's at 5K miles with RP synthetic 75W90

rockcrawler304

I might be completely wrong, and it wouldn't be the first time, but I think Cummins even says to wait until 20k before switching to full synthetic.

CACalomino

Ya I had read that from other post's when I searched the subject just could not figure out why. Basicaly why does cummins not recomend it and what could go wrong if u did use it etc.

CD in NM

I did my diffs with Amsoil 75w140 Severe Gear at 5K and also added the MagHytec covers. You will certainly like them, I sure do.

I am at 15K and still using the Valvoline Premium Blue recommended oil. I change my oil around 5K, and will keep using the VPB until around 25K, so a couple more oil changes to go before I switch to the Amsoil synthetics. I have the Amsoil Bypass BMK-11 bypass filter, just put it on the last oil change, so it's filter will go the 10K distance through my next oil change until I switch to their synthetics.

I recently noticed a bit of a jump in MPG, that's a good sign my engine is finally breaking in some. As rockcrawler304 pointed out, Cummins suggests waiting until the 20K point at least. I have never questioned WHY they suggest the wait, but I have read it in many places.

CD

RAMRODD

You are more likely to get a oil burner if you use synthetic to soon. It won't allow the rings to break in properly.
John Deere actualy uses a break in oil for the first 100 hours to break in the engine.

CACalomino

Thats the best explination I have gotten yet. Now I see full circle I guess the amsoil is gona get alittle dusty waiting for 20K better safe than sorry

coolslice

I don't buy it. I have always switched over to synth. with all my vehicles in the first 5K, including my 04.5. I have never had ANY issues nor have I ever heard of anyone else who has by using synthetics early.

CD in NM

Somewhere in one of the oil testing threads there was a discussion about one of the metal contents being a little higher and the answer had to do with break-in. That same discussion continued with seeing the number come down at a later oil change and the discussion was that it was obvious the engine was finally broke-in. I think you could use the oil testing results as good information regarding when to safely switch to synthetics. These engines are built tight, so the first 20K or so would show break-in occurring in the oil samples if you took them with every oil change. I have taken them with each of my oil changes and this is reflected in the numbers.

Oil testing has many benefits, not just for testing to determine the longest usable time you can get full life out of oil. Injectors don't go bad overnight, they slowly start leaking fuel into you oil. Oil testing can pick up this early on and save you big bucks from the other damages fuel in the engine causes. The same applies to coolant detection/head gasket problems and a faulty air filter.

CD

CRXsi

I switched to synthetic early...why? Because -40 deg in the winter and 15W40 don't make for a great combo as for engine wear either. There won't be any harm done by switching early, the only downside is it may take much longer for the break in period than normal. If it makes you more at ease why do Porsche, Mercedes, Corvette and many other high performance applications use synthetic right from the factory? There are going to be a million and one answers/replies to this post but in the end you will not hurt anything but it may take longer to break in. If you are like me and want to prevent extreme wear at extreme temps (like -40 deg) then the disadvantage of longer break in is minimal compared to the excessive wear from oil starvation when it s frozen at -40 deg. Even though it is summer now I am still running syn just because it is a better oil.

DBLR

One of the main reasons Cummins wants you to wait is becasue most people don't work the engine hard enough to seat the rings in, in under 20,000 miles. If you haul or tow heavy you could switch over before you hit 20K. I went to Amsoil at 13K and have not used any oil, but then with just over 1200 miles on the engine my wife and I did a 33 hr non stop drive and 5 days later another 24 hour non stop drive (except to fuel both times) with weight in the bed to get it broke in while on vacation so I felt my engine was broke in enough by 13K to be able to use synthetic oil.

IMHO the best way to break in a diesel engine is to either hook it up to a 3-4,000 lb trailer or load 2,000 lbs in the bed and take it for a minium of 2, 24 hour non stop except for fuel drives to help get it broke in. When I drove OTR years ago we would take a new or rebuilt engine and load up the truck to between 80,000-101,000 Lbs and drive it in the mountains states for 24-36 hours non stop to get the engine broke in.

raycarlson

Cummins 05 owners manual states it's fine to switch to syn at the first oil change.7500-15000 depending on schedule a-b.cummins customer assist says same thing, no break-in required, just don't tow or load heavy for first 500 miles(mostly for ring&pinion.About any engine made these days is 95% broke in in the first 30min of run time, don't worry about it if it makes you feel good change over at anytime you can't hurt anything, ask Cummins?

quadman20

I seen on the learning channel about Cummins engine plant inline 6. They run every motor 6 hrs before it ships to make sure it runs right. It was very interesting on how passionate about what they build. It's been a while since I seen this I've tried to arcive it but haven't found it yet.
As far as syn. I've run it after 1000 miles on truck and no problems. As stated before many manufatures are starting to run syn. strait from factory many studys have shown that either way is fine no harm from going syn. right out of the hole.
It's all what you thinks best you can't go wrong in my opion.