Allison Transmission Leak

[RussWhite]

1999 Model Newell with Allison HD4060 transmission.



I noticed fluid on the ground at the end of my 1000 trip from Florida back to Tennessee. I observed fluid dripping from the drive shaft end of the transmission. I was at my final destination so have not needed to travel since.

I will perform a COLD LEVEL check and be sure I have sufficient fluid before moving, even to go to a repair facility. I am within 50 miles of an authorized Allison dealer in Knoxville Tennessee.



I am posting in the hopes that some other member may have experienced a similar situation and might comment on what may be ahead for me.



There was never any warning light or unusual transmission operation. If I had not seen the leak, I would never have know anything was not normal.



Thanks,
Russ White - Greenback, Tennessee

[truk4u]

Russ,

I would guess it's the rear seal, but could be a hose, fitting, etc.

[Jon Wehrenberg]

Russ,

Glad to see another POG member from east TN. Covington has a guy that is really good on the Allison. If there is any way you can get beneath the coach and clean up all crud and traces of fluid from your transmission and other related items in the area the drive from Greenback to Knoxville will show the tech where the leak is. It will make his job easier and save you a bunch of time and money. They do not have a pit but they can and will raise your coach up, so if you have cleaned things off they won't have to, then drop it down and run it on the roads for a while and then put it back up in the air before doing the repair.

Assuming you have Transynd this is a good leak to cure because the price of Transynd is approaching the price of gold per ounce.

[RussWhite]

Thanks Tom and Jon,

I have confirmed sufficient fluid to operate the transmission. It was actually slightly above the full cold line when tested - that's good.

I will clean what I can get to, but it is pretty clean as it is. I was able to read the S/N and Model tag without even wiping it off.

I have attached a picture of the drive shaft end of the transmission which is toward the front of the bus, but may be called the rear of the transmission according to Tom's reply. If you look closely at the bottom of the flywheel looking donut you will see a drop of fluid getting ready to fall off. This is the only location that seems to be leaking.

Thanks for your thoughts and I will followup on this thread with the results of the repair.

Russ

[Jerry Winchester]

Gotta be a rear seal. What else is near it that can leak?

[BoaterAl]

What I miss seeing is oil on the trans and appears to be completly dry. With the forward movement of the bus oil would be coating the output shaft area. Need to look above as Tom posted.
I would not be at all concerned with driving to the shop with the very minor wetness.

[Larry W]

2 years ago the output shaft seal started to leak on mine. Took it to Stewart Stephens in Grand Junction, CO for repair. The bill us under $250. After the tech replaced the seal the service manager rode with me for a 15 mile road test. When we returned to the shop the tech was under the bus again checking the new seal for leaks. Was pleased with the service.

[billbunch47]

From the picture it looks to be the inner shaft seal not the main seal. It's not a problem for an allison guy. Had the same problem recently it only leaked with the engine running and in netural no spray on the white tow truck and the tranny was just as dry as your picture.