The switch from tranny fluid to 15/40 Rotella cured my transmission slippage

[RickB]

On some sound advice from a long term bus repair guy here in Minneapolis (JD at C &J Coach) before I went through rebuilding my 754 Allison he recommended I try a last ditch possible cure for my very intermittent 2nd gear start slippage. It would only happen when i had my foot in it and was on an incline, it was not chronic slippage at all. I talked to the guys at interstate diesel and Brian Diehl they all agreed it was worth a try and so I bought the oil on sale at sam's club and switched it over today and it worked great. From a complete stop on an incline with my foot in it there was no shudder or noise. Feels pretty darn good to at the least buy some time or maybe this will cease to be an issue altogether. It shifted better both upshifting and downshifting to tell the truth. I am quite happy about the outcome...I will make sure to warm it up well before taking off in cold weather so i don't blow the filter off the motor.

It was a good day to own my bus!

Rick

[Hartley]

I had a couple of RTS buses with V730 Allisons and they were tagged for
using 15w40 oil only. Never had a problem with them.

Truth about fluids??? Who knows.. I guess some shops have a preference
for maintenance reasons.

[Busted Knuckle]

We run 15/40 in all our 700 series transmissions and have been for a while now!

But word of advice that was given to me by a well know and super smart bus nutwho will be forever missed on this board!
Sammy warned me against using it in the B500 (or B400 for that matter). He said that when used in those series trans mission it causes the trans to fail at around 100,000 miles from a fresh, or possibly less on a used one after after switching over.
FWIW   BK 

PS when I first heard of this practice I was skeptical too, but after talking to Sammy and Rick @ G & W Diesel (large Detroit and Allison shop in Memphis that works on many 2 stroke fire trucks, buses, dump trucks and has a crew of service guys who work on the river boats as well!) I tried it and we were impressed with the improvement of performance of the transmission!

Rick first told me "well ya we use it for Fire Trucks and equipment that see's severe service conditions." When I asked him if a bus wasn't just as severe he looked at me funny. When I asked him if he'd ever seen a bus driver who didn't have his foot either buried in the floor with either the gas pedal or the brake he laffed and said "well you are right and in that case I suppose you are right!"

[muddog16]

Masking a problem is not a cure!

[Busted Knuckle]

Masking a problem is not a cure!

Well in Ricks case it maybe masking the problem. (but it may not be either, could be just a better way! But either way this gives him more time to save up for the tow bill & a trans rebuild, or a replacement trans )
But in our case it was looking to improve performance while extending useable life & it is doing a great job!

[luvrbus]

Guys the 15/40 has been in use for years with good results, I have a friend in Mesa that owned a charter co that ran 11 Eagle buses and all the hype about not using 15/40 in the 2 strokes this guy used 15/40 in the engine and transmission.
The 1st engine he lost was a 6v92 and it went south with 397,000 miles on it because of heat and the first 740 was 788,000 miles. I am not telling you guys to use 15/40 in your engine I don't but he did  fact not fiction   good luck

[ttomas]

Okay guys, help me understand this thread. I have a 740 auto trans in a '83 mci 6v92 that came from NJT. it had a clear trans oil when I got it and I assumed was syntetic. I spent the cash and installed ams oil synthetic trans fluid.
It somtimes chatters when it down shifts.
  would this be an application to use the 15/40?
   what is the proper oil to use according to allison?

[luvrbus]

Here is a site that gives you the names,types and weights for the Allison  www.utxchange.com    

good luck

[RickB]

I'm not sure if this is "masking" a serious problem or not but with it being such an intermittent problem my thinking was a little more pressure in the system might provide that little extra to make the 2nd gear clutch pack hook up a little better. It seems to have worked at least temporarily. If my transmission was acting really bad, slipping badly, tranny fluid dark and smelling burnt/sweet and metal or shavings in the fluid I would agree that anything I would do at that point would be masking really serious issues. My tranny exhibited none of those chronic issues.

Time will tell I guess. But it sure was worth the $100 if it lasts just until winter which considering it was only doing this once in a great while I feel fairly confident it will...

Famous last words right???

To the post asking for specifics: I used 15/40 Rotella. I was told NJT put it in all their 700 series buses.


I am hopeful heading to the Black Hills next weekend.

Rick