Amsoil for engine and tranny ?

Ohiozr2 · May 20, 2019

7 hours ago, 1SLOW1500 said:

Flush is good and pan drop is good I would base it on mileage and if there are trans issues you are trying to address. Issue with pan drop is the cooler and lines are blocked of and the converter holds 2 quarts also. this is why the flush is better. However the pan drop you can see if there is debris and get to the filter. If I was having issues and it was higher mileage I would do both flush till clear then drop pan and swap filter and clean it up then fill it. There is still a fill plug where a dip stick goes so it isn't hard. But truck has to be idle in neutral so the pump can move the fluid. I see people just fill and start the truck dry.

These trans are very expensive and the tcm is inside so swap with a junk yard trans isn't that simple. So the extra $90 for cheap fluid to flush is worth it.

I would rather do both, I couldn’t get either scenario to make sense in my head.

Hillwood · May 25, 2019

On 5/20/2019 at 11:11 AM, 1SLOW1500 said:

Flush is good and pan drop is good I would base it on mileage and if there are trans issues you are trying to address. Issue with pan drop is the cooler and lines are blocked of and the converter holds 2 quarts also. this is why the flush is better. However the pan drop you can see if there is debris and get to the filter. If I was having issues and it was higher mileage I would do both flush till clear then drop pan and swap filter and clean it up then fill it. There is still a fill plug where a dip stick goes so it isn't hard. But truck has to be idle in neutral so the pump can move the fluid. I see people just fill and start the truck dry.

These trans are very expensive and the tcm is inside so swap with a junk yard trans isn't that simple. So the extra $90 for cheap fluid to flush is worth it.

The 6 speed has an internal control module..

The 8 speed has an external control module..

1SLOW1500 · May 25, 2019

39 minutes ago, Hillwood said:

The 6 speed has an internal control module..

The 8 speed has an external control module..

You are very correct but he is 6 speed I thought.

I am in dozens of forums and post so it is hard to keep track all the time.

mycrowntree · May 10, 2025

On 5/18/2019 at 10:15 AM, Z45 said:

I have had AMSOIL Signature Series 0W-20 since about 5,000 miles. I also changed over to AMSOIL in the transmission (8-sp), transfer case and both differentials. Used nothing but AMSOIL for over 30 yrs. I will never use anything else, only the best if good enough for me. Even use it in my JD X738, RZR S 900, lawn mower and week wacker.

How many years did you have the Amsoil in your transmission and did it ever cause any issues?

Grumpy Bear · May 11, 2025

On 5/18/2019 at 4:21 PM, CamGTP said:

Haven't lost an engine yet running the cheapest full syn, normally the napa stuff made by Valvoline. It all has to meet spec to be sold, so it's good enough for me.

Amsoil is still great stuff though, used it before and would run it in anything I thought required some severe duty protection.

I know this is an old post.

Time is the YET in yet. In the 50's and 60's or my first 20 years on this planet I watched first hand relatives, dad and uncles, run motors on Group II oils of the period, Phillips Trop-Artic and Cen-Pe-Co to between 700K and 1 MILLION miles without issues and at end be as clean inside as the day they were built. Never stick a ring. Never rot a seal. The trick was the OCI. These were 500 to 1,000 mile OCI situations when oil was a quarter a quart and expectations were lower than a snakes belly in Death Valley. Have never seen a paraffin Group II do that at 2K OCI's.

Oil, in general, isn't the issue....the OCI is. Matching the oil to the OCI is HUGE and it is also near impossible to do as the pressure from outside is so great and the human ego so fragile that doing what is needs instead of what your told is to heavy a burden to carry. Poor motors suffer our unwillingness to be sensible.

If you are getting varnish color at your OCI it is to darn long. That isn't an opinion. Part of an oils job it CLEAN and if it can't keep it clean at your specific OCI shorten it or....don't. Neither of these are getting it done.

Edited May 11, 2025 by Grumpy Bear