4104's

[artvonne]

I know of one 04 that has a two speed rear end installed.  He said it is really nice in the mountains.

   That is something I would like to pursue, can you find any more info on it?

[RJ]

I know of one 04 that has a two speed rear end installed.  He said it is really nice in the mountains.

That is something I would like to pursue, can you find any more info on it?

Art -

I believe what 4104GA is talking about is the option between 1958 > 1960 known as the Hydrashift.  Basically a planetary gearset controlled by a push-pull knob on the gearshift lever.  It was mounted in the clutch area on the 4104s.  The results, when used properly, was an 8-speed gearbox.

Unfortunately, they are VERY, VERY, VERY rare, and also not the most reliable, per various industry sources.

As for the common "two-speed axle" that others have been talking about, I've never seen or heard of one being built by Timkin (early) or Rockwell/Meritor (late & current) for the V-drive configuration used by GMC. 

FWIW & HTH. . .

 

[Len Silva]

There was indeed a two speed axle, made by an unknown builder in California in the fifties.  I have what little info there is posted here;
http://autos.groups.yahoo.com/group/gmc-busnuts/files/GM%20Two%20Speed/

[artvonne]

  I think I will just stick to the winch idea. Cheaper, simpler, less to go wrong

[steve wardwell]

OK so you will need 2 of the same buses, a long cable and pulley all attached togather...so when you want to go up you just drive the extra bus down the hill while wifey drives the good bus up

[bevans6]

Art, if your overhangs allow the bus to approach the grade in the first place, why not consider a tractor to tow it up?  Low gear, 3 mph, lots of traction, those things just don't stop.  I  have in mind a fabricated tow bar that could almost be permanent on the tractor if you wanted, connected to fabricated mounts on the bus.  The tractor would be able to  steer the bus, you  wouldn't need anyone in the bus to steer but you might still want someone in the bus to work the brakes if it started back down the hill.  It would almost be like docking an airplane...

I was just thinking of how to work a winch in that situation, how heavy it would have to be, how much cable you would need, two people minimum needed, and a tractor seemed a lot easier.  Unless  it was snowing,, I guess...

Brian

[gus]

This think is getting crazier by the minute, but I admire your tenacity!!

[steve wardwell]

Well we are afterall "nutz"

[RJ]

Art -

Art, if your overhangs allow the bus to approach the grade in the first place, why not consider a tractor to tow it up? 

A D-9 Cat should do it!

Nice hefty tow rope attached to the towing eyes underneath the front bumper, and away you go!

FWIW & HTH. . .

[Barn Owl]

You need to make a compromise that works. Look for a 4104 that has been converted to a V730 or go to a 4106 with the same. If you find one with a 6v92 all the better. I have  a very steep driveway and the v730 is the only practical solution that I can think of that one could live with. Raised on a farm in the hills I have towed and winched a few things in my life, and don't understand how that could be considered.

[Hard Headed Ken]

My 4104 came with a Hyradrashift. It was a reliable transmission after I discovered the service manual that had the updates for the clutch plates in the plantery gears. The updated metal plates were thinner allowing one more metal and one more friction plate to be used in the stack. If I remember correctly the update was for the high side (overdrive) clutches only. Of course no plates were available, but I did have some extra stock plates. Using those as a pattern and the thickness specs from the manual I had new metal plates (drive and driven)  laser cut and harden. Then I sent the metal plates that needed the friction coating to a company that used Kevlar on their clutch plates. Now after all that it worked like it should.  Impossible for anybody to drive but me and still under powered. Then I installed a 6V92 and V730. It really made driving more of a pleasure than a chore.  I'm in agreement Mr Barn Owl. If you find something with a V730 don't forget to check the top speed or diff ratio. The ratio should be 4.125 or 8/33 I don't think you would happy with any lower gearing.

Ken

[artvonne]

   If a GMC Bus cant make an 11% grade, I may not have to keep thinking about this much longer. Nothing is posted anywhere that ive seen, but there are a few grades coming out here I believe may exceed 11%, and in the next few days I will try to measure some of them. Its a state highway, I just assumed if a road had grades that certain vehicles couldnt pass, they would post it?? No signs anywhere saying no Busses.  

 As far as getting up the driveway, provided I can get this far, a 10 or 20 ton winch will be the cheapest option.

[artvonne]

You need to make a compromise that works. 

  No kidding. This discussion has really opened my eyes to these busses capabilities. I never would have thought a GMC Bus with a Detroit couldnt climb a reasonable grade. My Uncle has a place in NC with a road up to his place that exceeds 15% for about 1500 feet. Hes had 4 S&S motorhomes make it up there, Ive had two of mine up there, no problem. I doubt he would believe me if I told him a Greyhound couldnt make it. My Parents rode a Bus from Minnesota, through Colorado out to Cali in 1942 that followed what is now I 70. My Father cant believe me telling him a Bus would not only not make it up this driveway, but probably not even make it out the highway this far.

  Glad I found this forum and asked about this before I jumped in with both feet. I wont drive an automatic. If a GMC cant climb the grades around this part of the country, I'll look into something that will.

[happycamperbrat]

My gmc rts has the 6v92 and 730 allison (automatic). I would NOT want to try your driveway...... but Im a big chicken too! I can do steep grades though. I did one in virginia city nevada! This was a side residential street and only about 20 or 25 feet from a stop sign it became VERY STEEP (almost straight uphill). I tried going up hill to the stop sign from a 5mph speed and the bus actually rolled BACKWARDS before finally getting enough umph to make it!!! NOT good, but can be done

[Barn Owl]

My bus will climb grades greater than 11% but that is only possible with the v730. Remember an automatic transmission gives you what is known as a torque multiplying effect. "The torque multiplier effect means that a vehicle equipped with an automatic transmission and torque converter will output more torque to the drive wheels than the engine is actually producing." If you are going to do it for any length of time you have to be able to keep it cool. That means an oversize radiator.