| Author | Message | ||
| Timnvt (67.30.237.57)
Rating: |
Anyone have info on the possibilities of swapping a two-speed rear-end into a bus? I'm asking on behalf of myself having a MCI5a and for another nut having (I think) a 4105. Being limited on transmission choices with the MCI5, maybe having a split rear-end could really help the gearing up hills. We've heard it has been done, but any info you have for how to make it successful would be appreciated. Thanks, Tim '66 MCI5A | ||
| jim mci-9 (209.240.205.60) Rating: N/A |
the idea behind a 2 speed rear-end was to give a lower set of gears....the hi end wont be any faster than what was normally available... | ||
| gary Stadler (68.7.217.217) Rating: N/A |
Hi tim, I looked into a 2 speed rear for my Crown at one time, but ended up with an overdrive tranny instead. The wisdom in this decision was given to me by a very big truck tranny place, who deals only with large semi-trucks: There are very few 2 speed rear ends out there for vehicles in our size weight class, mostly because two speed rear ends have the capability to occasionally miss splits and effectively leave you in neutral... if this were to happen while you were coming down a big grade and relying on your engine for retarding, disaster could and likely would result, because often enough the only way to reingage a 2 speed rear end that has missed a shift is to stop the vehicle and start from scratch. According to him, this reason alone is why you rarely if ever see em in big rigs. It makes sense- I've owned a mid sized truck with a 2 spd rear and experienced just that, and I'd never want it to happen on my bus! So I was instantly talked out of the idea.... Cheers gary | ||
| Phil Dumpster (67.2.18.111) Rating: N/A |
You do find them on a number of conventional school busses, but as Gary mentioned their capability to miss a shift is the number one reason why you never shift them going down a hill. Saw an RTOO913 in the Portland, OR area for $1450 surplus rebuilt unit, with no core requirement. Don't know if it will fit into an MC5 but it's a double overdrive box which would probably let you top out at over 100MPH depending on your rear end gears and level of insanity. | ||
| jim mci-9 (209.240.205.60) Rating: N/A |
as far as them being on heavy trucks, they are....several of our heavy haul trucks have 2 speed rears.. 1241 4-speed aux's..and 10 speed mains... with an air pusher axle on the tractor, a 4 axle lowboy, a 2 axle jeep, and a single axle steerable dolly, it makes quite a rig...you got 42 tires on the ground in a load.... | ||
| Peter Broadribb (Madbrit) (67.136.222.151)
Rating: N/A |
I am looking at the possibility of installing an auxilary trans (Brownie) in my Freightliner, which may be easier/cheaper than trying to get the correct rear end ratio installed for when I go to an automatic HT 740. At least I will still have the option of a lower gear set if the situation arises. I have been advised that I won't be able to change the Brownie whilst under way or maybe only if the converter is locked, anyone any info or experience of Brownies and auto mixes? Peter. | ||
| Gary McFarland (Gearheadgary) (209.128.99.14)
Rating: N/A |
I priced out the conversion for my Bird, it was about $2200, Exchange, for everything. Then I looked under my bird and realized what a job this would be and backed out. My Bird has a rockwell SQHD, which never came with a 2-speed, so I can't just swap the third member. As to Gear ratios, you have to select a ratio that is your "Highway" Gears, say 3.73, 3.90, etc... and the splitter gives you your low range, as Jim mentioned. As to other alternatives, My bird (T-Drive) has about an 18" Driveline, so there is no place for a brownie. My options are to get a different Trans (I have an Allison MT640) with an overdrive, or change gearsets. I currently have 5.57 gears, that tops me out at 60mph, when I'm standing on the governor. I don't want a more complicated (Read: Electronically controlled) Trans, so I think I am going to regear somewhere between 4.11 and 4.88. I am planning to tow heavy, so I can't affort to sacrifice pulling power for road speed. Well- that's the synopsis on my research, hope it helps. Gary | ||
| John Feld (Deacon) (204.184.224.15)
Rating: N/A |
Peter, I have never heard of a mix using both manual and auto that you refer to. My favorite was a 4X4 with air shift on the 'brownie'. That combination gave me maximum low gear power when needed (rarely), and kept the shifting of lever to a minimum. With 80,000 pounds it only required an average of thre manual lever shifts and the rest were all air shift using your finger. A streight 'brownie' uses two levers and can wear your arm out at the end of the day. Now if you really want to shift, get an old tri-plex tranny, I had one in an old Diamond T cabover, you didn't need a road to get over the mountains with that one! Oh, I just remembered, I did have a Spicer Split-Tourqe 6-speed (SST-6) that was a good one except the case was alluminum and would crack. Rockford Clutch was experimenting with Spicer on that one, they supplied us with 5 transmissions for our White tractors operateing in the mid-west for three years. After the experiment I was determined never to do that again! Let us know what you find with your proposed combination, inquireing minds want to know. John 4104 | ||
| Jose (216.229.93.51) Rating: N/A |
Back in the late 50's early 60's Eaton built a 3 speed rear end. I still have the specs. some place. Also some one mentioned a tri-plex, when we had too many drivers, we would bring a Binder demenstrator in with a tri-plex trans. Drivers would bail out like drowning rats ! Jose | ||
| jim mci-9 (209.240.205.60) Rating: N/A |
the eaton 3 speeds were very common in ford trucks.... not really 3 actual speeds, but by shifting the 2 speed axles, you could get the following combos::: low/low= low on selector... hi/lo= 2nd on selector... hi/hi= 3rd on selector... what happened was the rear axle stayed in low, the front axle went to hi and the power divider on the front axle made up the difference...so you actuall got 3 differnt ratios...... the cotton module truck company in lubbock texas (reynolds) used 2 speed rear ends.... 8341 air-shifted auxilaries, and allison auto transmissions.... all on an underpowered international chassis....we used autocar, mack and internatioal chassis later on in manufacturing....but stayed with the allison auto/spicer aux setup..... | ||
| Peter Broadribb (Madbrit) (67.136.222.151)
Rating: N/A |
Gary, You might want to search out an Allison HT-70. This is a 6 speed auto which is found in some MC-7 and various other applications, behind 8v71 and 92s. The 6th gear is an overdrive. I would use it but my Series 60 produces too much torque for what it is rated for and although it may well survive, I don't want the grief of finding out. It was considered a bullit proof trans and Stephens and Stephens can supply info etc. John, I did consider just using the 9 speed Rockwell I already have and locking out all gears apart from 8 and 9, effectively giving me 1:1 and 0.72:1. I would have to work out how to connect the input shaft to the output of the HT 740, any ideas anyone? Peter. | ||
| TWO DOGS (158.254.225.27) Rating: N/A |
I'm kinda interisted in that transmisson,when you go to automatic | ||
| madbrit (67.136.222.151) Rating: N/A |
I will bear that in mind. | ||
| Tony (64.215.196.142) Rating: N/A |
Posted by Doug on November 30, 03 at 09:00:56: drdoug@viclink.com Go To this link and this guy had one about a month ago. Tony In Reply to: Allison HT-70 transmission...got one? posted by C.J. Haunz on September 24, 02 at 17:39:57: : Hey all! : I have a good used Allison HT-70 automatic transmission. Taken out of a custom Maxim firetruck. Reverse gear ring broken. Can provide more details, but case is perfect, forward gears perfect. Looks new. Asking $2,000 for whole transmision.. in Kansas. | ||
| Peter Broadribb (Madbrit) (67.136.222.151)
Rating: N/A |
Sounds a little expensive for a tranny which is in need of repair and very out of date, especially as you can often buy the whole firetruck for that money or less. Make sure it will connect up without having to spend a fortune in bellhousings, flexplates, etc. | ||
| BrianMCI96A3 (65.40.145.233) Rating: N/A |
I wouldn't call a tranny with reverse gear gone out of it "good". And $2000 sounds a little steep to me too. I was very fortunate, but my electronic shift HT748 cost me $2500... Swaping out the manual transmission, and installing the allison, INCLUDED. Brian | ||
| Gary McFarland (Gearheadgary) (209.128.99.14)
Rating: N/A |
Yeah, I was thinking a $2K Trans that needed a rebuild a little....Opyimistic for the seller. I have a couple of questions--what is the difference between MT and HT Allison transmissions? Does the HT-70 use electronics? Thanks all, Gary | ||
| Peter Broadribb (Madbrit) (67.136.222.151)
Rating: N/A |
Gary, MT is for Medium Duty applications and HT is for Heavy duty applications, it is all down to the horsepower and torque the tranny can handle. The HT-70 is a non-electronic tranny, will just need a modulator hook up, as far as I know. But do remember it is an old unit so check with a rebuilder for parts availability. Peter. | ||
| Tony (64.215.196.187) Rating: N/A |
If a MT Is Medium duty and a HT Is a heavy duty how much weight Is a MD supposed to be able to carry and how much Is a HT able to carry without having problems. Tony | ||
| Peter Broadribb (Madbrit) (67.136.222.151)
Rating: N/A |
Tony, From what I have observed, the Allison 500 and 600 series is used upto an MC-5 and anything beyond seems to have a 700 series or World trans. If you want specific info, then I suggest you call Allison's Indiana Tech line at: 1-800-252-5283 They were very helpful to me and should be able to answer questions on their older models. Their website offers little, apart from current trans info and info booklets you can order on the older ones. Peter. | ||
| Rodger Manecke (64.70.24.171) Rating: N/A |
FWIW: My 35', 35k GVWR Prevost with an 8V71N has an MT644 transmission. Dean's Coach did the retro fit in the mid '90s for the former owner. It works just fine and is holding up well. As explained to me, the MT 600 series is ample for my 8V71's torque and GVWR and would be very adequate for a 40'er with an 8V71 when used as a motorhome but a bit light for commercial use. For 8V92s and 40K LB plus coaches, HD series trannies are a better choice. Rodger | ||
| dmkite (65.40.180.114)
Rating: N/A |
Brian, Where did you have your tranny work done? We would like to convert our 4 sp spicer to a ht-740. We are located in Oregon. | ||
| BrianMCI96A3 (198.81.26.45)
Rating: N/A |
dmkite, on the opening page is a list of sponsors to Bus Nut Online, on that list you will see RWFULKERSON, that is who did my tranny swap... He is now in Missouri, he was in Arizona then... I believe two things contributed to the exceptional price I paid, 1. he was trying to sell me the bus, and the swap became part of the deal, and 2. he was not only readying for his move to Missouri, he was moving out of one of his yards in Arizona and had a couple dozen engines and trannys plus a half dozen busses that needed to be moved. At the time he had a neoplan transit FILLED with literally, dozens of heads, pistons, rods and injectors by the bucket. Having said that, I believe Randy will still give you the best price you will find for a tranny swap. Brian |
