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Fluids

4K views 24 replies 11 participants last post by  oscyjack 
#1 ·
Hey Guys,
I'm looking to replace my tranny and differential fluids on my 02 LB7. Wondering what brand is best and quantities are needed for the job.
Any info would be great.
 
#2 ·
Hey Guys,

I'm looking to replace my tranny and differential fluids on my 02 LB7. Wondering what brand is best and quantities are needed for the job.

Any info would be great.


Transyd (best IMO) for your trans and transfer case
Amsoil (I prefer) 75w-90 synthetic gear oil for the front and rear diffs


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#3 ·
Mobile Delvac ATF is a little cheaper than transyd stuff and is synthetic and is certified for our trucks. I also use Mobile 1 gear oil 75-90 because you can find it just about anywhere these days
 
#5 ·
For just a regular trans, transynd is the best you can use, but expensive. In my built trans i use just a standard dex VI as per the builders. Im sure you can use just a standard dex VI as well, i think the key is a proper maintenance schedule if you dont use the best fluids.
 
#6 ·
If you have a actual Allison authorized dealer in your area you should get a better price compared to places like Kenworth, Peterbilt, etc. that sell the Allison TS295.

Even the spin-on filter is a much better price @ Allison.
 

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#10 ·
You'll need 2-3 qts for the front diff, 3-4 qts for the rear diff, & a drain a fill on the trans 7.5 qts.
 
#11 ·
75/90 gear oil, I use syntethic. Amsoil for me but any name brand is good.

For trans dex3,dex6 or transynd (also torque drive or any te295 equivalent).

Tranny pan flush is approx 2 gallons. I think 3.5 qts on rear diff but just fill til it weeps out the fill hole. Do this on level ground.

Remember to fill trans with engine on.
 
#13 · (Edited)
NO Fill trans with engine OFF

You'll burn up the trans when low on fluid with eng running.
After you get the approx amount of fluid back in then yes start the engine run to operating temp then check fluid level.

No on DEX 3 unless you don't care about a good long life on the trans.
DEX 3 is NOT a synthetic trans fluid, these trans require a synthetic.

I had a local Allison dad and son trans shop do my TransGo Jr for me, requested Transynd, paid for Transynd, he put in DEX 3.
After a couple of days I noticed crappy shifting and 20* hotter trans temps.

Found out what the but head did, I did the double drain method with Transynd.
Lucky for me I fingered it out quick.
 
#14 ·
Dex 3 was originally used in early Allison's if I'm not mistaken. Dex 6 would eat the seals if it was used in its place, needed vitron seals which were swapped when they started running Dex 6.

If your manual asks for dexron3, look at the shell spirax s6 atf a295. It's a Dex 3 replacement. I run the s3, but my trans was built and I talked to a reputable builder about the fluid before I used it.
 
#15 · (Edited)
It would help knowing what year truck ca2500 has.
Maybe you can run s3 in your built trans which from what I read that's ok.
But I did have a few issues with DEX 3 in my stock (not built) Allison synthetic suggested, 2 different animals between stock and built with clutches used.
 
#17 ·
Ca2500 didn't ask the question. The op has an 02 lb7 which I'm pretty sure fell in the dex3 group. My 06 stock used Dex6, your truck is newer again so it would be the same. I want to say the seals didn't get changed until the 6-speed was released, so guys with a 5-speed Allison would want to check there owners manual.

I realize the differences between built and stock clutches, no need to get into fluids and such for those. I was mearly pointing out a Dex 3 atf that was a295 approved for his stock truck, and that I was running a similar fluid myself.
 
#16 · (Edited)
Procedure is to fill with engine running. The 5 seconds low on fluid won't hurt anything, the tc is still full. For those who use the hoot method, the engine must be run, so what is better there than here? Nothing. This is assuming the OP is doing a drain/fill procedure and not a full flush.

Dex3 is what Evan recommends for his builds. So that's what's in mine and what I'll continue to use.

Transynd is good for those wanting to extend their maintenance intervals. Both are appropriate for the Allison. I used transynd (torque drive actually) on my stock Allison for the pst 30k miles, I put it in when I bought the truck.

Dex3 is a standard, not an oil. Not all dex3 is Dino oil, some is indeed syntethic. Synthetic doesn't automatically mean best fwiw, though typically they are in many applications. You won't be short changing yourself with dex3, but you should be with any fluid changing spin on Allison filter with every oil change, and doing an pan drop every 30-40k depending on usage and tranny health. Transynd could allow for longer intervals
 
#19 · (Edited)
Whatever do as you want.
If you know so much about the clutch differences and the recommendations,
Built trans uses a different type material clutch which DEX 3 is usually recommended.

In the stock trans DEX 6 / transynd is the recommended fluid for long clutch life.

Put in DEX 3 in a trans that recommends DEX 6 / transynd you WILL shorten the clutches life.
Plain and simple facts.

Has anyone noticed the ones suggesting using DEX 3 on a stock trans that came with DEX 6 all have built trans, not stock.

One easy way to get a good answer for the ones that depend on good suggestions on these forums would be to check with Allison or a actual trans shop to clear up these suggestions before you do something you'll regret.

Oh ya, it will take longer than 5 seconds to refill the fluid, so scrap that idea.
 
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#20 · (Edited)
http://www.duramaxforum.com/forum/a...ramax-fluid-types-capacities.html#post1604515

http://www.duramaxforum.com/forum/transmission-shop/46434-dex-3-dex-6-a.html#post554678

Notice the 01-05 Allison 5 speed used DexIII. Hence why I mentioned the specific DexIII I'm using and the one I recommended he could run which was TES-295 rated, perfectly fine for him to run. Yes, he can run Transynd. He needs to avoid DexVI however.

If you ever build your own transmission, I hope you do some research and talk to builders like Mike L, which I did.
 
#21 ·
OK, after listening to all of you I think I have a very basic understanding of this issue. Please correct me if my thoughts are incorrect:

1. Dex III and Dex VI are not interchangeable
2. Transynd is acceptable replacement fluid for either Dex III or Dex VI

If that is all correct my conclusion is to use Transynd, Period! It may cost a bit more but it will always be correct?

Someone please let me know if this rational is correct. Im not debating the relative merits of one fluid over another just wish to know if my reasoning is flawed or not.

Thanks
 
#24 ·
:thumb
Back a few years when I bought my Transynd from my local (main) Allison dealer I paid $30 a gallon, when Peterbilt and Kenworth other Allison dealers was as much as $40 gallon.
 
#23 ·
I did talk to Mike L told him about the temp increase bad shifting excessive slippage monitoring by my CTS (TCC SLIP) and the seat of my pants, he said that's ok, that won't hurt anything. rightt:
I then contacted another big name trans shop and went to my local Allison where they drove it both said get that CHIT out of there.

The response was a sure sign of job security when it breaks there will be 50/50 chance I'll choose him for a re-build.

Once again you have a built transmission with different material clutches that dex3 is required.

Anyone that wants to fall for this chit on a stock Allison that dex6 or better is suggested, that's your choice. 'uhNo

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