Allison Transmission

Blaster Man wrote:
If you have Transynd, and have your oil tested, it's good for 300k.

yep, to bad the rest of the motorhome wont last that long

I am a FIRM believer in Trans-Synd

If you have Transynd, and have your oil tested, it's good for 300k.

It takes TWO complete trans fluid changes to be able to go to the EXTENDED interval according to Allison. The reason is that there is quite a bit of fluid left in the torque converter and other lines when you drain the fluid so the result is that there is not enough Transyn fluid in your transmission after the first change. The change interval after the first change is the same as it was with conventional trans fluid. After the SECOND change with Transynd fluid, then you can go with the extended interval for your next fluid change.
Of course all of the change intervals are based on normal circumstances. IF you get the transmission fluid very hot on a long climb, this can drastically reduce your change interval, even with Transynd fluid.

FFCC told me 75K between changes on SYN, except the first time syn added, regular interval still applies. I think unless you get your RV new with syn oil or plan on driving 150K it's not necessary or worth the added cost. I've had my RV 10 plus years, 68K miles to date.

Far too often.... Wow!

you change your transmission oil every 6K miles? waste of money. waaaaaay to often, read your manual.

Ed Manifold wrote:
My motorhome has the 3000 series Allison transmission and I am going to have the oil changed to a synthetic oil. How long will be between changes and how many miles can I expect. My motorhome has around 35000 miles on it. I have had it changed approx. every 6000 miles since new.

Ed,
I'll have to go dig his user name up but, on both RV.net and, IRV2, there's a gent who was involved with the research and development of many tranny fluids, test runs and much more for Allison Transmissions. He's answered many questions on this subject. I followed his explicit instructions for the change-over to the Transynd synthetic fluid for my MH3000.

His instructions were:
1. Drain existing Dexron from your transmission
2. DO NOT remove or change the filters at this time.
3. Install required amount of Transynd for this type of fluid change
4. Drive for approximately 1/2 hour or more.
5. Drain brand new Transynd out.
6. Remove and discard filters
7. Install new filters.
8. Install NEW Transysnd and, amount for filter replacement.

According to this gent, he states that, that method above is approved by Allison. There is absolutely NO NEED for any transmission flush, of any type. He stated that this method of change replaces enough of the Dexron that, full benefits of the Transynd will be achieved.

Now, there are other approved synthetic transmission fluids for the Allison trans. I used Transynd because it was available and, I purchased it through my sons work, an RV Repair center. But, it's been a while, about 10,000 miles since it's been done so, I'll have to look up what I paid for it.

One thing, it's real depressing to watch BRAND NEW TRANSYND be drained out and thrown away. But, it's the approved method by Allison so, I followed it and, got over the depression.
Scott

On edit: I just cruised on over to IRV2 and found his posts about it. He's by far, the reigning authority of the subject. Your manuals were most likely contributed to by him. Check his posts out, tons of good info on this subject and, your transmission.
Scott
Allison Tranny Expert

Allison's recommendations (requirements) have changed over the years. I suggest that you find a manual from the time frame of your coach's manufacture.

My own coach from the late 90's said that the first change to TranSynd didn't count; the next change was as if you hadn't switched. After the second change, follow the change intervals for TranSynd.

For my current coach, which came with TranSynd, the change intervals are:
Fluid: whichever comes first
150,000 miles
6000 hours
48 calendar months

Main and Lube Filter: whichever comes first
75,000 miles
3000 hours
36 calendar months

Tom

Ed- "My Allison" website, enter the serial number for your transmission, it will list service interval, approved lubricants, manuals and pubs for free download, service locations and tools.

MY ALLISON