| Author | Message | ||
| carl white (Carl_mci_9)
Registered Member Username: Carl_mci_9 Post Number: 1 Registered: 1-2007 Posted From: 24.154.148.105 Rating: N/A |
I need a new transmission in my MCI 9. As I have looked at different options I have found that there are several different 700 transmissions. Can some one tell me the difference between a 740 ht 740 rs and a 741. I can get a 741 at a really good price. Can all of these fit in my mci 9? Thanks in advance. carl | ||
| Ray Lala (Rayshound)
Registered Member Username: Rayshound Post Number: 84 Registered: 8-2003 Posted From: 68.201.216.135 Rating: N/A |
The 740 HT is more than likely your best bet for your mci9. It is the most common & is a manual control automatic you would use a cable or air feedback for the modulator control.Also a shift tower and mech cable to shift or an "air shifter" If your mci has ddec controls on the engine the 741 ht has a few advantages as it is basically the same transmission but is the electric version but you will need the transmission computer and wiring harness.. Not sure about the 740 rs but I believe it is a low geared transmission for speciality vehicles. | ||
| RJ Long (Rjlong)
Registered Member Username: Rjlong Post Number: 1158 Registered: 12-2000 Posted From: 71.195.127.101 Rating: |
Carl - The HT-740 is the non-electronic workhorse of the bus industry. A four-speed transmission with a lock-up torque converter that makes it feel like a five-speed. Practically bulletproof with normal maintenance, have been known to go a half million miles in Greyhound-type line-haul or charter service. The HT-741 and 748 are electronically controlled versions of the same transmission. If you have a non-DDEC engine, having an electronic transmission complicates the installation moreso than installing a mechanically-controlled 740. Might also seriously look for an HT-754CR Allison. This is basically the same gearbox as the 740, except it's a five-speed with the lock-up torque converter. This one REALLY works well in the MC-9, gives that extra gear between 3rd & 4th of the 740, where it comes in very handy in many situations. The CR stands for Close Ratio, they make the same in a Deep Ratio, which has a stump-puller low gear, designed for concrete mixers, garbage rigs, dump trucks, etc. Not necessary in a coach. Not as common as the 740s, but well worth it if you can find one. Not sure what a HT-740RS is, but an HT-740R has a hydraulic retarder built-in. These work OK, but a Jake brake on the engine is better - less risk of overheating the transmission fluid in retardar mode on a long downgrade. FWIW & HTH. . .  |
