Fluids 8.1l

[kurt1993]

Ok i think its about time to change my transmission fluid in my 2001 Gmc Sierra 2500HD 4x4. What fluid would you recomend for:

 

Oil:

 

Tranny:

 

Rear Diff:

 

and ANY other fluid that comes to mind?

 

i was thinking ill use Mobil 1 for all 3 areas from now on but i would like to hear some opinions and maybe stories of what not to use and why or what to use and why?

 

My trucks about at the 50K mark so if anyone has some other tune up ideas that would be great too thanks, im thinking maybe plugs and wires or a K&N air filter?

 

Thanks!

 

-Kurt

[kurt1993]

um i know this may belong where you put it... but i dont want any random comments from everyone with 1500s and such... i want people with 2500HDs and 8.1s like mine answering this? so i really dont understand why you would of moved it cause the 8.1 is clearly a 'HEAVY DUTY' truck engine.... but whatever floats your boat i guess?

[tim73]

Well, theres your front axle and the transfer case. For the front axle, assuming yours is like mine, I would replace the fluid there with synthetic, the rear axle comes sith synthetic from the factory. Also, check your transfer case level, top off as necessary(Autotrak fluid)

[txab]

Ok i think its about time to change my transmission fluid in my 2001 Gmc Sierra 2500HD 4x4. What fluid would you recomend for:

 

Oil: Mobil 1 is good or any quality dino or synthetic oil of your choice. Buy high quality oil filter

 

Tranny: Dex VI synthetic edit: Double check with Allison. Prior to a certain year 2006, Allison my not recommend the use of Dex VI

 

Front Diff: Mobil 1 or Amsoil Severe Gear 75w-90

 

Transfer case: Should be synthetic trans fluid. Double check what the manual recommends

 

Rear Diff: Synthetic. Mobil 1, Amsoil Severe Gear 75w-90 If you have the G80 locker use no friction modifiers in the diff.

 

and ANY other fluid that comes to mind? Power steering fluid-synthetic. Brake fluid flush. Coolant flush if not done recently. Ditto on hoses and belts

 

i was thinking ill use Mobil 1 for all 3 areas from now on but i would like to hear some opinions and maybe stories of what not to use and why or what to use and why?

 

My trucks about at the 50K mark so if anyone has some other tune up ideas that would be great too thanks, im thinking maybe plugs and wires or a K&N air filter?

 

Thanks!

 

-Kurt

[kurt1993]

Thanks!

 

everyone else in agreeance? or does anyone feel differently?

 

-Kurt

[8.1HD/ALLISON]

I would check on the transfer case fluid. Don't think they run autotrack in the 2500's. I have 04 2500 with 8.1L/Ally and it runs dexron 6 auto tranny fluid.

 

[RyanbabZ71]

I would check on the transfer case fluid. Don't think they run autotrack in the 2500's. I have 04 2500 with 8.1L/Ally and it runs dexron 6 auto tranny fluid.

 

 

+1 the 1500 and 2500 transfer case is different (1500 has auto). Check the manual it will state what fluid to use.

[dewfpo]

If you've got an '01 Allison 1000 then you shouldn't be using DexVI. There's an incompatablity with the transmission seals prior to a certain SN cutoff in 2006 IIRC. You should be using a DEXIII (if you can find it) or, a TES-389 (standard duty service) or TES-295 (H.D. Service) compliant fluid. I'd check Allison's website for the specifics: www.allisontransmission.com

 

Someone will correct me if I am wrong on this.

 

I live in a climate that sees -20F to +100F so I use synthetic oil and lubes in everything and I highly recommend them for use in either high heat situations or very low temps. Even power steering units.

 

I'm fairly certain your H.D. rig does not use Autotrack fluid in the transfer case.

 

DEWFPO

[txab]

Here's what I was able to find. GM doesn't address it other than to say VI is backwards compatible. Two GM charts I looked at showed compatibility.

 

But, Allison does show this:

 

Effective January 1, 2007, General Motors no longer licenses DEXRON ®-III fluids.

DEXRON ®-VI fluids may be used in the 1000 and 2000 Product Families transmissions

beginning with S/N 6310670488 and 6320784373

 

So other serial numbers would be recommended to stay with away from VI. Mobil has their Delvac synthetic trans fluid that is Allison approved

 

 

If you have questions regarding fluid or filter change intervals, or models

not listed, contact the Allison Technical Assistance Center

at 1-800-252-5283.

[kurt1993]

intresting well i can say its a 2500 so it must have a 2500 Tcase and it is an 01' Allison so i guess it would use the DEX III.... im gonna look into if DEX IV is okay to use.... If anyone knows for sure what to use or what is best/preferred that would be great

 

thanks,

 

-Kurt

[kurt1993]

so lets get this straight....

 

Oil: Mobil 1 w/ Purolator One or Fram tough guard X6

 

Tranny: Mobil 1 Synthetic not so sure on which DEX to use?

 

Front Diff: Mobil 1 75-90? or is 75-140 better?

 

Transfer case: Synthetic obviously but DEX 3 DEX 4 DEX 6(wich one is/isnt OK to use)? or autotrack (is this gm's smurf stuff?) most likely i wanna stick with mobil 1 but whatever is considered to be best is fine

 

Rear Diff: Synthetic. Mobil 1, 75w-90 or 75-140? i dont think i have a G80 i dont believe 01's got the G80 no matter how much you paid idk?

 

Dot 3 or 4 brake fluid?

 

synthetic power steering recommendation ?

 

Also why not its only one more question.... preferable coolant?

 

and just to throw a random one what can i get for really blindly bright High/Low beam headlights?

[txab]

so lets get this straight....

 

Oil: Mobil 1 w/ Purolator One or Fram tough guard X6

 

Tranny: Mobil 1 Synthetic not so sure on which DEX to use?

 

Front Diff: Mobil 1 75-90? or is 75-140 better?

 

Transfer case: Synthetic obviously but DEX 3 DEX 4 DEX 6(wich one is/isnt OK to use)? or autotrack (is this gm's smurf stuff?) most likely i wanna stick with mobil 1 but whatever is considered to be best is fine

 

Rear Diff: Synthetic. Mobil 1, 75w-90 or 75-140? i dont think i have a G80 i dont believe 01's got the G80 no matter how much you paid idk?

 

Dot 3 or 4 brake fluid?

 

synthetic power steering recommendation ?

 

Also why not its only one more question.... preferable coolant?

 

and just to throw a random one what can i get for really blindly bright High/Low beam headlights?

 

75w-90 will be just fine for your diffs

 

I use Amsoil power steering fluid. Any good quality dino or synthetic will be fine.

 

If your truck has Dexcool in it, stay with it.

 

Brake fluid: Dot 3. Whatever good quality brake fluid your local auto part store sells

 

I'll stay away from a "blinding bright" bulb recommendation, because I don't believe in blinding other drivers.

 

Again, I'd call Allison's hotline # and ask their recommendation for fluid

[kurt1993]

haha okay i guess your right about the lights but i dont know i kinda like those sylvania Ultras 50% brighter

 

is 75-140 that much better cause i dont mind spending a few more $$ for something that can elongate my trucks lifespan.

 

is the dexcool the stock GM stuff? and would i have to go to them for more?

 

and i guess ill do what you say and give Allison a call or just go read my manual

 

thanks a biggie

 

-Kurt

[txab]

haha okay i guess your right about the lights but i dont know i kinda like those sylvania Ultras 50% brighter Sylvania's will be ok. I run them. What I hate are the HIDs that are improperly installed and shining light all over the place blinding oncoming traffic.

 

is 75-140 that much better cause i dont mind spending a few more $$ for something that can elongate my trucks lifespan. I doubt you're gaining anything with 75w-140 Thicker is not always better.

is the dexcool the stock GM stuff? and would i have to go to them for more? Dexcool is sold at parts store, Wally world etc.....

 

and i guess ill do what you say and give Allison a call or just go read my manual Your manual is going to have information from 2001. Talking directly with the manufacturer you'll know for sure.

 

thanks a biggie

 

-Kurt

[kurt1993]

i appreciate all your help!

 

Thank you very much!