| Author | Message | ||
| Bobh (Bobh)
Registered Member Username: Bobh Post Number: 3 Registered: 8-2006 Posted From: 204.116.186.20 Rating: N/A |
The current transmission in my bus is a ZF 6 speed. 6th is appx .75 OD. Since reverse is gone I would like to change over to a 10 or 13 speed. Is there a common procedure to move the shift linkage on the transmission so that it is on the correct side for bus operation rather than for truck use? | ||
| John MC9 (John_mc9)
Registered Member Username: John_mc9 Post Number: 86 Registered: 7-2006 Posted From: 66.217.107.154 Rating: |
Little to do with your question, but..... Why would anyone want to spend cash for gears they'll never need? In the years/miles I drove Eagles, nothing more than a simple 4-speed was ever needed... Every Eagle I drove back in the 60s, did 80+... And with 8v71s, that wasn't too bad! | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 9 Registered: 8-2006 Posted From: 207.231.82.128 Rating: N/A |
Yup, But they sure didn't do it uphill! | ||
| RJ Long (Rjlong)
Registered Member Username: Rjlong Post Number: 1016 Registered: 12-2000 Posted From: 71.195.113.23 Rating: N/A |
John - Let me see if I can answer your question: Most bus 4-spds, as used in RV Conversions, suffer from: A) Too tall 1st gear ratio to wiggle into campsites or start on steeper grades. B) Too tall reverse gear ratio for the same situations. C) Big gap between 2-3 and 3-4 for climbing RockyTop. These are not issues with line-haul or charter service. A five or six speed solves 90% of the above situations, a 10-spd solves all of them, especially if you get one of the overdrive versions. Easy to "skip shift" when intermediate ratios are not needed. A 13 or 15 is definitely overkill in a bus, even the 10-spd can fall into this category, too, but is more acceptable. Also, note that Bob's bus is a Belgian-built, two-axle Eagle 4, a very rare model. So he's got different and unique challenges ahead with his transmission choices. Bob - I think it would probably be less expensive to rebuild the transmission you already have, rather than swap it out for a different model/type. Unless, of course, that the broken parts are now made of "unobtainium"! Having said that, I can share with you that pusher Crown and Gillig skoolies from the '60s - '80s with manual 5 and 10 speed transmissions all had a "backwards" shift pattern to them. (5th/10th were in the same position as 1st on a standard 4-spd.) They took some getting used to when you first climbed behind the wheel, and could drive you nuts if you were switching often between a "normal" and a "backwards" pattern, a common thing that happens to the extra board or substitute drivers in a commercial or school bus operation. Some folk say that cab-over 18-wheelers use a linkage mechanism that keeps the shift pattern normal - but the transmission isn't turned around, like it would be in a pusher coach application. Another point here is that most buses use a couple of shift rods controlling the transmission, whereas most truck transmissions use a single rod/lever. I'm not sure what you're Eagle uses, that's something you need to look into and consider. Altho this might not be your first choice, depending on how much room you've got in the powertrain area, you might consider either an HT-740 or HT-754CR Allison automatic. Granted, fuel mileage will suffer somewhat, but the driveability, especially in RV service, will improve dramatically. Sorry if this doesn't answer your question directly, but hopefully has given you some information to work with. You might also give Luke at US Coach a call, and see if he can assist you in some way. 1-888-262-2434, M-F between 9-5 Eastern. FWIW. . . | ||
| frank-id Unregistered guest Posted From: 67.136.152.250 Rating: N/A |
Use your local Yellow pages of the phone book. The best place to get ideas are at the local trans rebuild shop or the truck salvage places. These places usually have a special guy who only works on manual trans. Frank | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 10 Registered: 8-2006 Posted From: 207.231.82.128 Rating: N/A |
Bob,, RJ said it MUCH more eloquently than I did in my first post! His comments on 4 speeds are exactly correct. I have one of the 18 MC6s that were left with the 12V71 for service in the Canadian Rockies. Power all over the place, I don't know how fast it will go, I have had it to almost 90, and just let off for fear of a ticket. The power steering pump is slightly "noisy," so you can hear engine speed in the steering wheel. At 85 plus, I'm not at "against the governor" speed pitch! BUT, this is the most miserable bus to drive in the hills there ever was! (A takeout 8V92 and a 748 Allison are in the local Detroit dealer waiting for me.) Going uphill, lots of power to top engine speed, but by the time of a double clutch between 1st & 2nd, lost so much speed that it lugs in 2nd, etc. The 10 speeds are identified by their torque handling ability, (engine size) and whether 10th is direct or over. From looking at putting one of them in my 6, I think the sizes are 710, 1110, and 13710, with the first number(s) being torque in hundreds of foot-pounds. The 710 is too small for any thing larger than a 6v71. The RT model is direct in tenth, the RTO (we can all figure that one out!) is direct in 9th, and over in tenth. Reversing the shift patern is actually easy. These trans use a "wobble stick" instead of the two rods + solenoid shift. So, to reverse the pattern, put a pivot ball on your stick, mounted TIGHTLY ON THE FLOOR, with the same amount of stick BELOW the floor as the length of the trans shifter ABOVE the top of the trans. Hook a yoke to the bottom of the stick, the rod to the yoke, and about three feet back, a u-joint, and immediately there must be a fairly tight bearing that will let the rod slide and turn, but not flop around. Probably two more in the middle, and one in the back, then u-joint, the same distance from the trans, as the front bearing from the stick. There can't be any slack in the linkage, or you will lose feel. | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 303 Registered: 10-2003 Posted From: 69.162.3.30 Rating: N/A |
If you are going to go to a ten speed type, go with the rto 9 speed; has a better overdrive ratio, lower 1st and reverse gear and better spread between gears for a coach. Plus, if you want to get crazy; you can add a 13 speed overdrive rear section to it. That would give a double overdrive, able to split the high range gears, and a top speed of probably 90 plus if you were crazy enough to use it. | ||
| Bobh (Bobh)
Registered Member Username: Bobh Post Number: 4 Registered: 8-2006 Posted From: 204.116.186.20 Rating: N/A |
Thanks for all the information/help guys. I went over this weekend and examined the 9spd. in an old international cabover that I used to own. I think changing the top plate over might work out.What I would like to find, is the ratios of allison automatics. I've been to the web site and searched on this board but I can't seem to find them. Which automatics are overdrive? I would rather not have to chang the rear gear along with a transmission. If they have an automatic with a .8 or so overdrive then I will not have to worry about the shift linkage for a stick shift. I like a 13speed, not for the tall overdrive top gears but being able to split the top range sure is nice. My 9400 series International had an 18 speed and a 475 cat. I never had to split any of the bottom gears with the light loads that I hauled. Once again, thanks for the help | ||
| Bob greenwood (Bob_greenwood)
Registered Member Username: Bob_greenwood Post Number: 134 Registered: 7-2006 Posted From: 63.233.42.174 Rating: N/A |
Are you SURE reverse is out, and not your shift likage, I can't imagine needing more than 6 gears in a bus, I'd see if it could be put into reverse from under the bus | ||
| Bobh (Bobh)
Registered Member Username: Bobh Post Number: 5 Registered: 8-2006 Posted From: 204.116.186.20 Rating: N/A |
It's missing most of it's teeth. The trans is out now. And 3rd has a chipped tooth as well. That has damaged the countershaft cluster also.Plus, the clutch and throwout bearing are in need of some repairs. So, it's not working very well at the moment. I wanted to try to make it to the Timmonsville get together but now I don't think that's going to happen. | ||
| Bob greenwood (Bob_greenwood)
Registered Member Username: Bob_greenwood Post Number: 135 Registered: 7-2006 Posted From: 65.150.46.151 Rating: N/A |
I'd fix that trans. , sounds like the perfect trans. to me | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 306 Registered: 10-2003 Posted From: 69.162.3.30 Rating: N/A |
they make shift controllers that use 2 heavy duty morse cables to shift the roadranger trans. The cable setup makes routing much easier. | ||
| Bobh (Bobh)
Registered Member Username: Bobh Post Number: 6 Registered: 8-2006 Posted From: 204.116.186.20 Rating: N/A |
After looking around at some 10speeds I think I'll just change over to an allison. Which ones are overdrive so I don't have to change my rear end gearing. HT ??? | ||
| Ron Walker (Prevost82)
Registered Member Username: Prevost82 Post Number: 251 Registered: 11-2003 Posted From: 208.181.210.47 Rating: N/A |
You would have to go with a world series transmission B500 / B400 / 4000 / 3000 series. Depends on you HP and torque. | ||
| R.J.(Bob) Evans (Bobofthenorth)
Registered Member Username: Bobofthenorth Post Number: 102 Registered: 10-2004 Posted From: 142.165.179.130 Rating: |
I've got a 10 sp & an 8-92 in an '81 Prevost. Its a pretty good combo - auto would be nicer but there is nothing wrong with 10 gears. I hardly ever use 1st or 10th. I'm geared so I can run 65 at about 2000 in 9th. The nice thing about the 10 sp is that you always have the right gear. Usually I skip shift 2-3-5-7-8-9. The only real drawback to a 10 sp is that you end up going back and forth from high to low if you do a lot of in town driving - that can be a PITA. | ||
| Craig (Ceieio)
Registered Member Username: Ceieio Post Number: 265 Registered: 12-2004 Posted From: 206.212.230.165 Rating: N/A |
Bob - a 7 speed just popped up in the flea market: http://www.busnut.com/bbs/messages/6/14998.html?1158104849 If it will fit it may just be the ticket! Craig - MC7 Oregon |
