| Author | Message | ||
| carl white (Carl_mci_9)
Registered Member Username: Carl_mci_9 Post Number: 4 Registered: 1-2007 Posted From: 208.108.100.1 Rating: N/A |
This is the best site to get basic knowledge. I have to switch out my transmission in 79 mci 9 I have the opportunity to purchase a complete gillig with a 6v92 turbo ddec engine and an allision 5 speed auto with the retarder. Has any one done this switch ? Is it hard and expensive or an easy swap? am I barking up the wrong tree? I have non turbo mechanical 8v71 and a allison 740 auto transmission. I would like to have the turbo and 5 speed transmission but knot if I can do it myself. Thanks for all input carl | ||
| Mark R. Obtinario (Cowlitzcoach)
Registered Member Username: Cowlitzcoach Post Number: 130 Registered: 4-2001 Posted From: 204.245.250.46 Rating: N/A |
Hi Carl, Before you spend any $$$ measure the length of the Gillig power package. While the 6V-92 is shorter than the 8V-71, the 5-speed and retarder is longer. You may not have enough space to mount the Gillig power package in your MCI. You don't want the driveline to be much shorter than it already is. Also, if you do decide to do the swap, you need to remove the entire wiring harness from the driver's position back to the engine and transmission. Creating a wiring harness with all of the correct plugs is not easy. As it is, you still may end up having to splice in some wire to make the wiring harness long enough. Good luck. Mark O. Castle Rock, Wa | ||
| Phil Dumpster (Phil_dumpster)
Registered Member Username: Phil_dumpster Post Number: 7 Registered: 5-2005 Posted From: 71.112.104.215 Rating: N/A |
Your MCI has a 24 volt system. Most transits have 12 volt electrical systems. Account for this difference when wiring up the electronics. The Gillig engine may make less power than your current 8v71. To make more requires reprogramming the DDEC, which requires a trip to a Detroit service depot. Depending on engine serial number, build data, etc, they may not be willing to reprogram the engine to make more than a certain amont of horsepower. If this is the first repower you've ever done, bear in mind there are a million little things that need to be worked out. If you were to make a first attempt, this swap would be a good one to try. | ||
| Steveggt (Steveggt)
Registered Member Username: Steveggt Post Number: 5 Registered: 12-2006 Posted From: 71.116.87.220 Rating: N/A |
Hi Carl! A normally-aspirated 871 and 740 was a very common MC9 powertrain, so I know that these will fit with no problem or at least very minor modification. If you decide to switch to the DDEC 6-92 5-speed package, you'll be spending more $ to install the entire DDEC system (assuming your bus is currently non-DDEC). In MOST cases, if you have a DDEC engine, then your trans will be ATEC (Allison Transmission Electronic Controls)...basically computerized engine=computerized transmission which would also add more $ to install the ATEC as well. FYI, there were some buses out there with ATEC trans and regular non-DDEC engines, but thakfully there aren't too many around. The calibration of these systems required quite a bit of skill. | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 64 Registered: 3-2006 Posted From: 209.50.74.181 Rating: N/A |
Carl I made the switch from a mechanical 8V71 to a 6V92TA DDEC IV and V731 ATEC tranny. It took 3000 feet of wire to do but works great. I did one for a friend with the same engine and a hydraulic tranny. It was easier then mine as the tranny didn't have to talk to the engine. I realize your engine is right hand rotation but the electronics are the same. If it will fit let me know and I have the wireing diagram you need. Bill | ||
| Chuck Lott (Chuckmc8)
Registered Member Username: Chuckmc8 Post Number: 196 Registered: 5-2004 Posted From: 74.224.76.185 Rating: N/A |
Carl, I'm fresh from doing a repower from a 8V71 to a 8V71TA, which you would think would be an easy swap.There are a lot of issues that you will have to work out as you go. If I were going to swap, Personaly,I wouldnt use an electronic engine unles it was a 4 stroke such as a Series 50 or similar....And not then unless you are electricaly compotent to a level of evaluating/troubleshooting electrical issues such as DDEC. Wish I was! | ||
| Tim Strommen (Tim_strommen)
Registered Member Username: Tim_strommen Post Number: 264 Registered: 11-2004 Posted From: 64.186.173.26 Rating: N/A |
Gilligs are easy to take apart. My '84 Phantom is a 24-volt rig, and I'd be suprised to hear that Gillig went back to 12 for anything but lighting/instruments (DDEC started in the late '80s for the 92 series). Where was the Gillig used (east or west coast)? How much are you picking the chassis up for? -Tim | ||
| carl white (Carl_mci_9)
Registered Member Username: Carl_mci_9 Post Number: 5 Registered: 1-2007 Posted From: 208.108.100.213 Rating: N/A |
More info on the gillig. I is about 300 miles away from where I live so I have not see it as of yet. I am trying to get as much information as possible before taking the next step which would be going to check it out and if it is ok bringing it home. A little more information for you out there. It is a 1995 40 foot coach. The bus will shut down if the door is not shut just right. The bus has been set to the maximum speed of 58 mile per hour. My additional questions are should I run away? Will the door problem carry over into my bus that doesn't have this feature in it? IS the ddec set to 58 mph or would it be in the transmission gearing? If it is in the computer. Is it hard to get it switched to a faster rpm and speed and who would have to reset it? Thanks again for the addition information on this. carl | ||
| RJ Long (Rjlong)
Registered Member Username: Rjlong Post Number: 1172 Registered: 12-2000 Posted From: 71.195.127.101 Rating: N/A |
Carl - Since you live in the Rust Belt, chances are good that that Gillig will have lots of rust underneath. Not so much of a problem if you're just pulling the powertrain, but even still, things on the powertrain are going to be affected by the salt. "The bus will shut down if the door is not shut just right." Elaborate - does the engine shut itself OFF? Or does the bus just not want to move and there's no response from the throttle? Transit buses have an interlock between the doors and the brakes. If the doors aren't closed, you'll get no throttle. The engine should not shut down in this instance. If it does, there's a problem with the interlock circuitry. Max speed of 58 mph is most likely due to the rear axle ratio, not the engine RPM setting. Shouldn't be a problem if you keep your original MCI rear end. Most DDEC transit engines are set for either 275 or 300 hp. The 6V92TA can easily handle 350 hp, but it's virtually impossible to get a Detroit dealer to up the hp, based on the engine serial number. EPA/Smog rules. And Detroit is the only one who can do the reprogramming. FYI, most transits are sold at auction by the agency that's used them. Often sell for $100 > $2000, depending on condition. Tim's right - see if the bus comes with, or you can obtain, it's service records. 99% of the agencies have them, and, since they're tax-payer supported, the records are available to the public. Most often filed by fleet number, not VIN, btw. FWIW & HTH. . .  |