| Author |
Message |
bobm (198.81.17.177)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, July 24, 2002 - 6:02 pm: | |
I have a beautifully converted 4104 and I hate to part with it but my knee has gotten to the point where the clutch and me are incompatable. Has anyone converted a 4104 to another engine/trans option with an automatic. What are the difficulties? |
Kirby (12.94.3.88)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, July 24, 2002 - 7:19 pm: | |
I replaced the original engine in my '04 with a Detroit Diesel 871 engine and installed an Allison 730 transmission, both out of a 1981 Grumman 870. Not a job for the faint of heart, but then what part of bus converting is? There are also people you can pay to do this work. Some modification of the rear bulkhead was necessary. You'll probably need a bigger radiator, I ended up putting in one from a 4905. It extends lower than the bumper now, but I don't overheat. If you want more gory details, send me your e-mail and I can e-mail you some photos. |
John Rigby (24.174.233.65)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, July 24, 2002 - 9:08 pm: | |
Kirby
We would be very interested in seeing the details.will you please post them.
Thanks
John |
RJ Long (Rjlong) (24.127.74.29)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, July 25, 2002 - 1:34 am: | |
Bob & John -
Probably the most common powertrain swap for the 4104 is the 6V92TA / V730 combo, which can frequently be found in a donor transit.
The 6V can be tweaked to 350 hp easily w/ an injector and turbo change, no teardown necessary. Gives over 100 more HP than the workhorse 6-71.
Note that you MUST change the rear axle also, as the offset of the ring & pinion are different on the 4104 vs other model angle-drive coaches. (On the 4104, the bevel gearset is after the transmission. Starting with the 4106, GM put the bevel gears ahead of the gearbox, as the bevels were not holding up during development testing to the greater torque of the V-8 when multiplied thru the lower gears of the transmission. This change also required offsetting the ring & pinion pumpkin to match the new layout.) If you don't make the axle change, be prepared for driveline vibrations and short U-joint life.
As Kirby mentions, you'll also have to upgrade the radiator to handle the additional cooling required by the higher HP engine and transmission. An interesting challenge, as the body cutout for the radiator is quite a bit smaller on the 4104 compared to later, V8-powered coaches.
This is one of those things where you have to ponder whether the expense of doing a powertrain swap is really cost-effective in relation to the shell's value. . .
Of course, the answer is no, but that would also be true nowdays with a $11K MC-9 being swapped from manual to automatic.
HTH,
RJ
PD4106-2784
Fresno CA |
Kirby (12.94.6.132)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, July 26, 2002 - 6:38 pm: | |
Too long to post, and I wouldn't know how to post a photo. If you want, I can send to individuals by e-mail. |
dave silva (208.27.31.4)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, July 27, 2002 - 7:43 am: | |
email me the pictures and i will put them where folks can see them.
dave silva |
FAST FRED (65.59.76.7)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, July 27, 2002 - 8:52 am: | |
There are also 4stroke donors that could be installed.
You need the entire coach , so you can take almost all the running gear.
Some are Cummins , some DD series 50 , all with either V730 or the Kraut ZF tranny .
These are fairly new so I dont know how many are at auction yet, but when they come in the usual oversupply , and get cheap , thats MY choice for an Xmas present for the coach.
A modern 4 stroke will get the coach at least 60 years beyond DD standards , and have it ready for the next century, 2100!.
Without the rust problems of lesser coaches , these monocoque GM will live forever.
The 4 strokers are NO way as smooth as the 8v-71 , but at cruse are easy to live with.
I'm hoping to get TCM or someone to offer a conversion cradle , so it can all just be a R&R job .
What a great way to spend a weekend!
FAST FRED |
Don Hixson (65.239.4.233)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 28, 2002 - 8:10 pm: | |
Bob
I made the 6V92/V730 conversion into my 4104 several years ago. You do not have to replace the rear axle only the carrier unit. One from a 4106 to 4905 will work fine. You will have to do a little torch work to fit in the slitly larger ring gear. I also am using the 48year old stock 4104 radiator without problems.
It is very do able and worth while for us that have nice 4104's.
4104don |
dounanpm (152.163.188.227)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 28, 2002 - 9:54 pm: | |
don
can you send me anymore details on your changeover,as i'm in need of replacing my broken 6-71.
dounan
dounanpm@aol.cm |
Kirby (12.94.2.103)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, July 30, 2002 - 10:54 pm: | |
If anyone's still interested in seeing the 8V71 in a 4104, I've got the description and photos up on my web page at http://home.att.net/~kirbybus1/ The e-mail link is broken at the bottom of the page, but it will be fixed soon. |