It's time to change the fluid in the Tranny and the Diffs. How hard is it to do the Tranny myself? I have done this on a Chevy 4L60E? What are some good fluids to run in the truck? Lucas, Royal Purple, Red Line?

 

No drain plug on the transmission pan. Remove bolts from one side and loosen on the other. Let drain from one-side and then carefully lower and dump. Get a big drain pan and plenty of rags and dry sweep. You might want to put on an aftermarket trans pan with a drain plug for future changes.

Differential is about the same except the pan is vertical.

I used the recommended fluid types in my manual. I think the brand was Valvoline in the trans and Mobile 1 Syn in the diff.

Good luck.

 

For Trans fluid & diff's I use Amsoil fluids in all of my trucks & cars and have been very happy with there products for the last 7 years. Yes it cost a bit more but then I want my truck to last a long time so I buy top quality fluids and not fake synthetics that some sell. I've been told Redline also has some very good fluid and gear oil but I have not used it my self. It's all up to what you want as far as the fluids to install, go with what makes You feel good, not what anyone thinks you should use.

 

My purpose is modifying the truck is to mildly improve performance and increase the longevity and durability. I next mod will most likely be a bypass filtration system. I am looking for a fluid that will help the transmission/diff stay healthy. I want to run a high quality fluid not a cheap off brand tranny/diff fluid .

 

My self I like Amsoil products a few others here use it in their trucks including Drew. I have 75/90 sever gear oil in my diff's now and am very happy with it and they say its good for 50K under sever use. If you do much towing then you can use 75/110 or the even heavier weight 75/140 gear oil. I have used AmsoilATF in my last 4 Dodge products and it has held up very well and I’ll be installing it in my 06 shortly. IIRC Steve360 has the Amsoil MK11 by pass in his truck and I think he is happy with it so far.