T5 Tranny Fluid & Rear End Fluid

[ZachMorris]

Good morning,

I used the search function but i got alot of conflicting answers and nothing very recent. My 92 Notch hasn't had the fluid changed in probably 8+ years so I'm going to change the transmission fluid and the rear end. Rear end is an 8.8 Auburn HD 31 spline and the t5 is just a stock WC with a King Cobra clutch and FMS Billet steel fly wheel.

What do you guys recommend?

 

[Dan02gt]

My T5 is going to need a rebuild or replacement soon. Main problem is notchiness down shifting into 2nd and it's noisy. Upon trying to find the best fluid to limp it along I found that Royal Purple Syncromax was far better than anything else. I also tried Amsoil, Mobile 1, and standard Dextron 3. The Royal Purple made a big difference in noise and smoothed out the shifts.

I run Mobile 1 in the rear end. It comes with the limited slip additive so you don't have to add friction modifier.

 

[Mustang5L5]

I use regular Castrol D3 ATF in mine after I rebuilt it. It shifts like butter and is silent.

 

[fredfifty]

i went to the ford dealer and bought ford motorcraft synthetic 75w-90 rear axle lubricant, cant go wrong with ford fluids

 

[RaggedGT]

I use Super S 75w140 synthetic gear oil-has the modifier in it.
Been a while since I’ve had a manual trans-I think last time I used parts house branded atf with no issues

 

[ZachMorris]

Is there any filter that needs to be changed??

 

[Mustang5L5]

In manual trans or rear diff? No. Just magnets on the drain plugs.

 

[revhead347]

Any brand of syncromesh is going to improve your transmission. I wouldn't go as heavy as gear oil (80W-90) in the transmission, they really aren't built for it. Honestly, I'd just get the parts store brand. I'm sure Royal Purple is the best, but I personally can't justify putting super expensive oil in a T5. Lots of different opinions on the gear oil for the axle. I put 80W-90 in mine. It's self changing, because the pinion seal leaks, and I just top it off every few years. Make sure you put the friction modifier in it.

Kurt

 

[General karthief]

I am a big fan of synthetic rear gear lub. My truck has over 550k and no issues, just replaced the wheel bearing but honestly they still looked good.
I use royal purple in my t5 but if you change it every 25k or so it is likely a little overkill.

 

[ZachMorris]

I grabbed some Royal Purple Syncomax for the transmission and some Valvoline 80w-90 for the rear end. What are your thoughts on the Valvoline 80w-90? The reason I went for this is because I have an Auburn diff and I heard they require 80w-90....also the gentleman at Napa told me I did not require the friction modifier because the Valvoline 80w-90 states Limited Slip right on it.

 

[General karthief]

Go to ford and get the friction modifier, the gear lube is 'compatible' with limited slip I don't belive it has any friction modifier in it.

 

[revhead347]

They sell the friction modifier at the parts store too. Doesn't HAVE to come from Ford. If buying OEM is stuff is your game, I don't blame you though.

Kurt

 

[General karthief]

I guess I have a relationship with my local ford dealer, have had bad experience with parts stores.
When your dealing with a 97 sd, with the body change for the f150 and not the sd always got wrong parts, f350 parts instead of sd (they didn't call it a f450 just f super duty)