Let Me Know if You Have Allison Transmission Fluid Questions

Jarlaxle wrote:

hzjcm8 wrote:

Jarlaxle wrote:

hzjcm8 wrote:
Hi all,

I've just joined Good Sam Club. I was the former Transmission Fluids Engineer at Allison Transmission. I held that position from 1990 until my retirement in 2009. Let me know if you have questions about TranSynd, the TES-295 specification or just anything to do with automatic transmission fluids. I'm here to help.

My Genesis has an MT643 trans behind a DT466 engine...Dexron III, right?

Nope !!! I no longer recommend anyone use DEXRON-III. Use TranSynd or another TES-295 for the best possible performance and durability. DEXRON-III is an obsolete spec so anything these days is being manufactured under the label D3/M meaning DEXRON-III/MERCON. These fluids are manufactured and sold but have no license and are no longer approved by either GM or Ford. I used to sit on the GM DEXRON-III committee and I can tell you that these fluids are no longer evaluated by anyone at GM. So, it's sort of like "buyer beware" when it comes to any DEXRON-III (D3M) products on today's market. Also, do not use DEXRON-VI due to possible seal issues with your older MT transmission.

PS: D3M fluids (DEXRON-III) tend to lose viscosity so cooling won't be as good due to lower cooling circuit flow. Unless you change it every 25,000 miles. So, just put in TranSYnd adn you should be good for at least 100,000 miles. Don't forget to change the filters too.

It's wound up 307,000 miles (filters changed annually, roughly 25K) on D3...honestly, I'm leery of switching it at this point! Is TranSynd compatible with D3? Flushing all of the old fluid out at this point is just not feasible short of component replacement. (This thing has the biggest trans cooler I have ever seen!)

Also, what (if anything) can you tell me about the oddball AT500?

If you've had success with DEXRON-IIIH, it's because you've been changing it and paying attention to the filter changes too. However, these fluids are no longer licensed products and I'm leary of them. The AT500 is an older Allison automatic with 4 speeds. It has hydraulic controls. Most every school bus in America had an AT500 at one time. It's a good transmission but a little low on cooler flow at idle. No electronics and it has a mechanical governor (no speed sensors).

If a person doesn't know which trans fluid his coach has. Is their a way to tell what fluid is in the coach???? Color?

Tom, having you here is amazing! Thank you. I have read all the posts so far....wow!

I recently purchased an 07 Mountain Aire 45' with an Allison 4000 with Transynd. It had been repo'd so I'm missing most documentation and have no maintenance history.

I assume the 4000 requires the first primary filter change at 5K like my last 3000 did???

You have stated a 4000 could go 100K+ miles between fluid changes provided proper filter changes and oil analysis. But, not knowing if filter changes have been done, what steps would you recommend I take? Should I go ahead and change the fluid and filters so I have a good starting point? Or just change filters?

Can you take the original Transynd to 100K+ miles? Or is this done after the first complete change?

I read the whole thread and if I missed this, I apologize.

Let's say there is a drain interval of 150,000 miles or 48 months, whichever comes first. Or 50,000/48, whatever.

And let's say in 48 months the vehicle is actually only driven 20,000 miles. I understand that sampling and testing can be employed to extend the drain interval. But...

What is the reasoning behind specifying a calendar time? What happens to the fluid as it sits in the transmission in a low mileage situation? ie How does it go bad?

Thanks!

Reference to the 4000MHR transmission, using the Detroit TranSynd oil, What would the max safe temp allowed when decending a mountain using the retarder ?
So far, have not let it go above 220F.
Many thanks

hzjcm8 wrote:

Jarlaxle wrote:

hzjcm8 wrote:
Hi all,

I've just joined Good Sam Club. I was the former Transmission Fluids Engineer at Allison Transmission. I held that position from 1990 until my retirement in 2009. Let me know if you have questions about TranSynd, the TES-295 specification or just anything to do with automatic transmission fluids. I'm here to help.

My Genesis has an MT643 trans behind a DT466 engine...Dexron III, right?

Nope !!! I no longer recommend anyone use DEXRON-III. Use TranSynd or another TES-295 for the best possible performance and durability. DEXRON-III is an obsolete spec so anything these days is being manufactured under the label D3/M meaning DEXRON-III/MERCON. These fluids are manufactured and sold but have no license and are no longer approved by either GM or Ford. I used to sit on the GM DEXRON-III committee and I can tell you that these fluids are no longer evaluated by anyone at GM. So, it's sort of like "buyer beware" when it comes to any DEXRON-III (D3M) products on today's market. Also, do not use DEXRON-VI due to possible seal issues with your older MT transmission.

PS: D3M fluids (DEXRON-III) tend to lose viscosity so cooling won't be as good due to lower cooling circuit flow. Unless you change it every 25,000 miles. So, just put in TranSYnd adn you should be good for at least 100,000 miles. Don't forget to change the filters too.

It's wound up 307,000 miles (filters changed annually, roughly 25K) on D3...honestly, I'm leery of switching it at this point! Is TranSynd compatible with D3? Flushing all of the old fluid out at this point is just not feasible short of component replacement. (This thing has the biggest trans cooler I have ever seen!)

Also, what (if anything) can you tell me about the oddball AT500?

Count me in as interested!!!!

hzjcm8 wrote:

J Walker wrote:
A great thread. The 100,000 and 150,000 miles between changes recommended by Tom I assume requires fluid analysis to be sure it is ok to extend the change interval, right? Something I learned or was reminded of is to change my filter every two years even though the fluid is still good in my Allison 1000. I'll bite, what is the fluid that is $10 cheaper per gallon that can give 100,000 miles between changes?

J Walker,

This new fluid doesn't exist yet .... but, it could if I get enough interest. It's very possible to produce such a fluid. I'm just throwing out the idea for consideration to see if there's sufficient interest.

J Walker wrote:
A great thread. The 100,000 and 150,000 miles between changes recommended by Tom I assume requires fluid analysis to be sure it is ok to extend the change interval, right? Something I learned or was reminded of is to change my filter every two years even though the fluid is still good in my Allison 1000. I'll bite, what is the fluid that is $10 cheaper per gallon that can give 100,000 miles between changes?

J Walker,

This new fluid doesn't exist yet .... but, it could if I get enough interest. It's very possible to produce such a fluid. I'm just throwing out the idea for consideration to see if there's sufficient interest.

krivanj wrote:
Okay, here is my question. My service guys just changed both filters inside the transmission and used Amalie TES-389 to fill it last month. This is a 2001 Allison 3000. It does not have an external filter. So if I change it next time to transynd, then I will have to change the fluid at short intervals whenever I open it up to change the filters, right?

Krivan,

Put in TranSynd and change the filters according to the recommendations, you'll still be money ahead compared to the short TES-389 change intervals. I wrote the original "Value Analyzer" that Allison uses to run a long term comparison on non-TranSynd vs. TranSynd fluids. Taking the drain interval differences into account, the math always so you're money ahead to change to TranSynd when you factor in the labor charges (which is written into the program). Your Allison dealer/distributor should have this program and can run it for you. I'll see if I can get a copy of the latest program and post it so everyone can run it themselves.

Mr. TranSynd

bobschultz wrote:
Fom what Ive been told Allison Trans Co. approved Dextron III for many years before the introduction of Transyd. Dont know of any documented failures of the transmissions due to fluid type. I know that lack of normal maint and overloading the trans. has caused more problems than anything else. Correct me if Im wrong. Bob S.

Bob,

Allison did approve DEXRON-III ATF for many years until I saw a need to change that. The problem was always viscosity loss in DEXRON type fluids. They were good fluids from every other aspect but they tended to lose viscosity (some could lose as much as 50-60%). So the problem we had was keeping the drain intervals low enough to avoid significant viscosity loss that could affect transmission durability. If you use a TES-389 fluid (DEXRON-IIIH) you need to drain it per recommendations. These fluids lose viscosity and could result in wear if you run them too long. Also, cooling efficiency drops due to reduced flow in the cooling circuit because the fluid is thinner. So, as long as you're following recommended TES-389 drain intervals, you'll be OK. However, unless you're changing it yourself, the labor to change fluid will eventually be more than the TranSynd since you can run it 150,000 miles in the 1000/2000 Series and 300,000 miles in the 3000/4000 Series.

PS: That's why I'm on this forum. I'm here to settle all the arguments concerning Allison fluid recommendations and specs since I'm the guy that wrote all of them.

PSS: TES-389 fluids are all DEXRON-IIIH fluids. That's why the drain intervals are so short compared to TranSynd and TES-295 fluids. We launched the TES-389 specification because some folks just could not bring themselves to spend the extra money for TranSynd or another TES-295 fluid. But, it's false economy .... TranSYnd and the other TES-295 fluids are worth it (by a large margin).

Hope this addresses all of your concerns !!