Transmission Oil Overflowing Into Fly Wheel of Hallison750 Transmission

[s.t Desmond]

I have a Allison 750 transmission on a HT 400 pump. Recently, the transmission oil begun to overflow into the fly wheel and then leaking out. We have checked to ensure that all parts are tight, seals are in good condition and return pump has been rekitted, but problem persist. Any assistance on what to do next?

 

[hydtools]

Over full?

Ted

 

[s.t Desmond]

No, hydtools. We have checked that too.

 

[chicopee]

If the manufacturer is still solvent, contact them. I suspect a crack somewhere, so you may have to take it apart for inspection. I just checked out E bay and there is one for $4400. If the equipment is critical to the operation it would not be a bad idea to have a spare.

 

[s.t Desmond]

Chicopee, i'll keep that as an option, mean time, we are trying to see if we can fix it.

 

[Artisi]

contacting the manufacturer Allision Transmission might be a good option.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[CWB1]

Continue troubleshooting until you resolve the issue.

 

[Mongrel]

I've come across several cracked torque convertors on these, when used in trucks. This can be quite difficult to trace. If the front seal is definitely good, and there's fluid in the bellhousing, try filling the convertor (cold) with hot oil and immediately pressurising it.