| Author | Message | ||
| erik (66.214.76.36)
Rating: |
i have recently fallen in love with a 1957 4104 with a 671 DD and 4 speed. i am unsure as to the rear axle gear ratio. i need to be able to pull my 10k lbs enclosed car trailer behind my bus. will the 4104 handle this task ? what can i expect from her as far as speeds go ? are there engine mods i can do to help? what about a 2 speed rear axle? any of you folks pull a trailer with your 4104? | ||
| RJ Long (24.127.74.29) Rating: N/A |
Erik - This question comes up periodically, here's your answers: ~ Rear Axle ratio: Majority are 4.125:1. There are a few 3:53:1s out there, but they're very, very rare. ~ Yes, the 4104 will pull the trailer, but: Because of the powertrain & cradle design, you cannot have a lot of tongue weight on the hitch, most folk say not much over #300. The majority of the engine and transmission's weight actually hangs from the roof of the coach! For best results, a custom hitch that ties together the rear radius rods, engine bulkhead and rear bumper is recommended. Much easier on the coach to flat tow a toad, but it sounds like you might not be in that situation. See the pics at Daris Bouthillier's site of his 4106 hitch for an excellent example of a custom hitch for the GMCs: http://home1.gte.net/res07rfl/ (Click on "Exterior" under Conversion Articles in the LH menu for the link to the pics.) ~ Top speed for most 4104s is about 65 mph, but it will take a long time to reach that pulling a 10K trailer. Remember, this is a bus that first hit the highways back in 1953, long before the Interstate system of freeways was even thought of, and 60 mph was considered really moving. This speed is limited by the governed engine rpm, the bevel gear ratio, and the rear axle ratio. You can pick up a few mph by using 11R24.5 tires, but that has an effect on hill-climbing ability. (A compromise, one of many when operating a 4104.) ~ Engine mods: Are you interested in longevity or hot rodding? Another compromise. Set up stock, at 235 hp, you'll get over 500,000 miles out of the engine. Turn the governor up to 2400 rpm, slap N80 or N90 injectors in it with advanced timing, you'll bump the HP to about 255 or 260, and get 200,000 out of it. Other options include the 6-71T turbo at 275 hp, or a complete powertrain $wap to a 6V92TA/V-730 out of a transit, pumped up to 350 hp - an expensive option to only go 5 mph faster. (OTOH, Mama will like it, 'cause now it will be an automatic!) ~ Two-speed rear axles are not available for the angle-drive GMCs. Period. Think of this fable - "The Tortoise and the Hare". The 4104 is the Tortoise. Treat it as such, and you'll have a ball. But if you want to "run with the big boys", you'll be miserable with a 4104. It's all a compromise. . . HTH, RJ PD4106-2784 Fresno CA | ||
| erik linker (Erik) (66.214.76.36)
Rating: N/A |
RJ thanks for the info and link. the bus i have in mind has a hitch similar to that already installed. BONUS. i live in atascadero so i assume you are you are familar with the area. we go to the mojave desert several time a year so tehachapi and highway 58 are my main concerns. flat towing is not an option since we have an enclosed trailer with a 4wd and quads and motorcycles we take to play in the desert. sounds like if i can address the tounge weight issue with a load distributing system then i may be able to pull my trailer at the 55mph limit for trucks with trailers. i am not to worried with keeping up with the "big boys " as long as i get there with out having to keep the flashers on the whole time. LOL i could live with the hot rodded 671 life span since i am currently only traveling about 10k per year. since you live in the area, do you happen to know a long time converter named Red Smith who lives on the central coast ? it is one of his buses. he also has a 4106 with the 8v71 which is probally a better choice but i just seem to like the 04. Erik | ||
| RJ Long (24.127.74.29)
Rating: N/A |
Erik - I wouldn't worry about 58 over Tehachapi. Just figure you'll be pulling the grade sittin' on the governor in 2nd gear at about 30 mph. Even w/o the trailer. . . But that's an '04! Remember, over 5,000 of these coaches pounded the pavement in revenue service for Greyhound and others for over 20 years safely and dependably with the stock powertrain. . . Don't know Red Smith. Do know Gary Nickerson, who's since moved to Lake Havasu. FYI, the 4106 will easily run 70+ mph, due to the higher hp and greater torque of the 8V71, as well as the overdrive bevel gear ratio. (Which cannot be swapped into the 4104, btw.) But there really is a certain amount of charm to the Tortoise. . . If you can get the VIN on both coaches, I'll let you know who originally purchased them from GMC. Email me directly if you'd like. Just click on my name in the header above. RJ | ||
| erik linker (Erik) (66.214.76.36)
Rating: N/A |
30 mph..............thats great news. my class A motor home would only do 15 mph over the hill. ( it also went thru 2 brand new crate motors in 3 years.) hence my quest for a real road machine. i will try and stop by today and get vins today. i don't know gary but i have heard red speak of him. thanks | ||
| Geoff (Geoff) (64.1.2.143)
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With all do respect for the 4104 if you are looking for a "real road machine" for the mountains and towing you better keep looking! It's a buyer's market out there on seated and converted buses, don't limit yourself-- there are a lot more modern machines available with the power you need. --Geoff '82 RTS CA | ||
| erik linker (Erik) (66.214.76.36)
Rating: N/A |
geoff thanks for your input. in your opinion what bus/motor combo should i be looking at ? as i stated i was using a class a with a 454 chevy. it got us there but blew up several times and got 4 mpg. i am not to worred about mpg but would like more than only 20k miles from a motor. LOL my main use of the bus is to get our race car to the races out in the barstow area. aprox 700 miles round trip that we do 10 times per year. we dry camp out in the desert for 3 to 4 days at a time. some of the use peramiters i have are : because we are in the desert i really only need a rig that looks OK. given the fact we get caught in sandstorms once or twice per year i would hate to take a very nice paint job out and ruin it. also the interior can be older due to the fact i have 2 small kids and kids in the desert are dirty. i would hate to see a perfect interior trashed. | ||
| Johnny (67.241.224.132)
Rating: N/A |
OK, I expect to get flamed here, but there is sopmething very wrong if you managed to grenade 2 NEW crate 454s in 3 years. Even the leadfoot drivers at work only managed to grenade one 454 (actually, it still ran, just had 2psi of oil pressure) in a tow truck that's been used (read: beaten like a rented mule) since December of 1986. This truck has ~350,000 miles (~80K on the rebuild), & is still going (it finished a 12-hour shift at 8pm, in fact). It still guzzles the gas (5-7MPG), but has NEVER broken down on a call. If you managed to grenade 2 engines in 3 years, either there was an inherent problem with the vehicle (like inadequate cooling), or you should take a hard look at your driving and maintainence habits. I'm sure I'll get flamed for this, but there it is. | ||
| Geoff (Geoff) (64.1.0.85)
Rating: N/A |
Eric-- you asked me what you should be looking at and you have to realize I am bias towards my bus-- a GMC RTS. To me the best "all-around" engine is the 6V92TA @ 350 HP-- it gets the best fuel milage for the power, and still has enough ump to pull a trailer. If you like the looks of the RTS, you can get one in a 35-40', 96-102" shell with the 6V92TA and 3 speed automatic. There aren't too many converted ones around for sale but this might be better for you-- build it for you needs (paint and interior) and enjoy it. Come join our RTS Yahoo group at http://groups.yahoo.com/group/RTS-bus-nuts if you want more information. The RTS is a great shell-- you can spend a little or spend a lot, depending on your needs and taste. --Geoff '82 RTS CA | ||
| John Rigby (24.174.234.92)
Rating: N/A |
Erik The guys talking MC9 or later models they make a good point. However I have owned a 4104 for 16 years now and due to the way the 04 is layed out,it has been easy to do my own trouble shooting and repairs.i.e. the engine is mounted in a way that allows you to access easily the starter,blower,water pump,fuel pump radiator,transmission cluch,everything.The 04 is a pleasure to drive, Watch your gauges closely. I have stampco staight through mufflers on my 671,makes that DDA really purr. If I can help in any way e-mail me. John |
