Cost of total Service

[chessie4905]

Mobil used to advertise series 60 going 1 million miles before overhaul using Delvac 1300 super 15w40.

[DoubleEagle]

One justification for a 5-40 synthetic is better cranking ability in cold weather, but if you are in the hot south or west, that virtue does not have much value. For the Allison, any TES 295 spec oil will be good enough, and will usually be cheaper than Transynd. There are Allison bulletins that recommend TES 295 fluid over the older Dexron's, and 15-40 motor oil, even for the HT 740. 15-40 oil used to be recommended for severe service situations, like garbage trucks, I wonder why they changed their mind about that. For our kind of use, which fluid we use might not make a noticeable difference.

[luvrbus]

Allision doesn't support the old 700,600 or 500 series transmission anylonger and haven't in years, you cannot even buy Allison parts only after market stuff,they are just trying to sell Transyd it doesn't make the 700 series last anylonger,I have rebuilt transmmisson that used Transyd and with 15/40 both had the same wear with the same miles   

[Boomer]

Allison won't warranty a new transmission that does not run Transynd so they have operators by the balls.  For a busnut to run it is crazy. Extending an oil change interval when you don't put on any miles does not make sense.  ATF is just as good whether electronic or hydraulic trans based on my fleet experience and private experience.

[luvrbus]

Allison won't warranty a new transmission that does not run Transynd so they have operators by the balls.  For a busnut to run it is crazy. Extending an oil change interval when you don't put on any miles does not make sense.  ATF is just as good whether electronic or hydraulic trans based on my fleet experience and private experience.

This is from a Prevost manual about oil specs in the B500 from 1997 to prove your point Mark   

[Boomer]

Another point on changing to Transynd is that it takes 3 oil changes @ 25K miles ea to get up to the 50K mile service level with Transynd.  This is to flush out all the old oil.  Makes zero sense with motorhomers who only run 8-10K miles per year.  I'll never forget paying $1,500 for my first barrel of Transynd back in 1999, that frosted me, but had to for the Allison warranty.  Wonder what a barrel costs now.

[luvrbus]

The mileage level is up from the 50.000 miles now Boomer, I won't mention names but a former Allison employee at a FMCA convention told people they could use it and never worry about it for 350,000 miles I just shook my head and walked off.I found these specs for the Allison 4000 in a 2007 model I going with a different fluid the specs are from Allison and I live where it is warm