1991 Allison HT-747 Transmission service question...:

[fkloster]

Cat dealer in Portland, OR told me today (Petersen CAT) that a FULL SERVICE on my transmission unit (Allison 4-speed HT-747) would cost upwards of $500. This would include the very premium Allison fully synthetic fluid, one 'interior' transmission filter and one 'exterior' transmission filter. Since i have had the coach i have just been replacing the exterior filter and doing samples which check out fine. The coach currently has 92k miles. Allison recommends only changing the 'interior' filter once every 100k miles. Coach is 20 years old. This coach is not towing toads and used for LIGHT DUTY only. Thoughts?

[FleetMan]

Are you able to change the interior filter yourself, get CAT or a local mechanic to do just that item for you? The HT-747 is a brute of a transmission. It was used extensively in the public transit buss and garbage truck for years and survived quite well in that environment. If it were mine, I'd just change the filters and continue with the pre synthetic transmission fluid instead of converting.

[fkloster]

Quote:

Originally Posted by FleetMan Are you able to change the interior filter yourself, get CAT or a local mechanic to do just that item for you? The HT-747 is a brute of a transmission. It was used extensively in the public transit buss and garbage truck for years and survived quite well in that environment. If it were mine, I'd just change the filters and continue with the pre synthetic transmission fluid instead of converting.

Great advise thank you! I call it my "Rock Crusher"