I have the most popular V730 with .88 overdrive final. I remember reading on someone put a input shaft overdrive unit from a VS2-8 on the V730 and made a double overdrive out of it. Anyone know the site I can look at? Good Luck, TomC
The guy that had the info is Bill Teal He was selling a info Package. The link I have wasn't working as I typed it. Try the MSN group as his site was a MSN group
How do you tell what type of final is in a V730? Does most popular mean most common, or most desirable? Mine seems to have plenty of top end but I do not know what my rpms are. I hope to have a tach sometime in the future.
Barn owl- Mine has the .875 overdrive in it. If you knew your rear end axle ratio and tire size, it's pretty easy to figure what rpm per mph is going. For instance, I have 11R-24.5 (478rpm for my tire) 4.625 (sometimes called a 4 5/8 ratio) and the .875 overdrive. So at 60 I'm turning 1934 and at 65 just about 2100rpm. Does fine for me. Good Luck, TomC
Some clarification is in order here!
First, the V-730 is
NOT an "Overdrive" transmission. The ratio in third gear is the same as an HT-740 - 1:1.
Where the misnomer of overdrive came from is in the
bevel gearset's ratio, which in 99.9% of the V-730s is 0.875:1. If you look at a cut-away drawing of the 730, you'll see that the bevel gears are located between the engine and the torque converter, actually
before the transmission gearing.
This is the same set-up as the Manual transmission, except that the manual uses an 0.808:1 ratio.
Stock rear axle ratio for the 4106 is 4.125:1. 4.375:1 was optional, but very rare.
The
effective final drive ratio is equal to the following formula: (transmission gear ratio) x (bevel gear ratio) x (final drive ratio).
For a stick shift in 4th, this equals (1:1) x (0.808:1) x (4.125:1) = 3.333:1
For the V-730 in 3rd, it's (1:1) x (0.875:1) x (4.125:1) = 3.609:1
Supposedly there were V-730s built with a 1.04:1 bevel gearset, but I've only heard of one in over 25 years in the bus industry. Rarer than hen's teeth.
Taller tires on V-730 coaches (11R24.5s, usually in the 470 - 475 rev/mile range), will bring the coach back to almost the same top speeds as a stock stick shift w/ stock rev/mile tires (495).
HTH. . .
Quote from: Barn Owl on June 30, 2006, 10:56:42 PM
How do you tell what type of final is in a V730? Does most popular mean most common, or most desirable? Mine seems to have plenty of top end but I do not know what my rpms are. I hope to have a tach sometime in the future.
Russ- If you want to get scientific about transmissions, then many transmissions have some sort of gearing that changes the main box's ultimate ratio. For instance, take a nine speed direct Fuller Roadranger transmission and put the overdrive end unit on and now you have a 13 speed. Or take a recent Fuller Roadranger 9 speed overdrive transmission and put the underdrive end unit on and now you have either a 13 speed or an 18 speed "double overdrive" transmission. Or take an HT740 Allison transmission, take out first gear so it is like having 2nd, 3rd, and 4th only, put a .875 bevel angle input gearing and now you have the V730. How a transmission is measured is the overall ratio gearing comparing what the input shaft does compared to the output shaft. What happens inside to get that ratio really doesn't count. One side note-the Allison World transmission series only has 3 planetary gear sets that gets up to 6 speeds out of it. Just think it is very clever what they did. Previous Allisons had one planetary gear per reduction with final drive being direct. Allison does make very large off road automatics (2200hp) that are essentially a three speed main box with a two speed splitter on the back working together. Just some trivia. Good Luck, TomC
Wow Did not know back in 2004 this VS-2 v730 transmission topic was so heated..
http://www.busnut.com/bbs/messages/233/6006.html?1083517264 (http://www.busnut.com/bbs/messages/233/6006.html?1083517264)
I think I am going to go the 24.5 tire route with my 68 Fish bowl manual suburban with Allison 730 being considered for swap.
Any suggestions as to steer tires and drive tires brands and models? No power steering on my bus.
I'm a fan of toyo tires. My first set lasted 105,000 miles and 15 years. YMV
Thanks for the suggestion Brian, that's alot of miles! Guess that's why they cost so much..
I just put 6- 11R-24.5 Hankook AH37 tires on my bus. Very similar tread pattern and rating to the Michelin XZE I replaced (were 12 years old), but $1,200 less! Good Luck, TomC
Quote from: TomC on April 07, 2018, 02:53:47 PM
I just put 6- 11R-24.5 Hankook AH37 tires on my bus. Very similar tread pattern and rating to the Michelin XZE I replaced (were 12 years old), but $1,200 less! Good Luck, TomC
Thanks Tom those look like a pretty nice compromise!
TomC
I have one of only three buses in existence that have the overdrive unit in them. You need parts that are almost obsolete now. You need the following parts to even start to do it.
8V71 flywheel from a VS2-8
V730 input shaft
VS2-8 planetary gear set as well as a VS2-6 planetary gear set.
VS2-8 input shaft
VS2-8 clutch packs
A lot of machining time on a lathe
I run a 4.56 rear end and once I reach 55 mph I engage the overdrive and I am able to do over 80 mph. I normally do 60 - 65 mph and the engine turns at approx 1500 rpm. My top speed without the overdrive unit is 68 mph at 2110 rpm. My engine is DDECIV so I can't up the rpm.
Quote from: Bill Gerrie on April 07, 2018, 06:01:56 PM
TomC
I have one of only three buses in existence that have the overdrive unit in them. You need parts that are almost obsolete now. DDECIV so I can't up the rpm.
Hi Bill! It's George, I got your your old A730!
Hope you might be able to shed more light on this mod, if it has not been documented before. I would guess that the 3 buses that have this mod are still very reliable.
Is there a schematic somewhere or a general how to? Might be easier to manufacture these parts in the future.
Thank you! George
George
One bus was the original Bill Teal that developed the overdrive unit and the other was in FL on a 4106. Mine is the only other one. You have to get the parts I listed. They are still around but scarce. I originally bought the book from Bill Teal for $275 US. A lot of guys have tried but never completed the unit. I found a flaw and corrected it. The shaft from a V730 has to be welded to the shaft from a VS2-8. There is an oil hole that is welded off. My shaft broke about 3 years ago closing the Canada USA border for over 20 minutes. I wasn't very popular to say the least. I had the shaft remade eliminating the weak point and all is good now. The original shaft lasted 9 years but the torque of over 1000 ft lbs finally broke the shaft.
With a 4.10 rear end you can go 80 mph with a stock V730 @ 2300 rpms and 12-22.5 tires, so you get the same results as the VS overdrive unit on top end. Oh, this is on the RTS or FLX buses, so I guess the VS overdrive benefits the GM coaches. I don't know if the AM General uses the same rear end as the RTS/FLX.
Hello Bill, olebusman from fl. here. I wonder it Bill Teals bus is still around. Do you have any idea?
I have the 4:10 rear end and the stock V730 on 11R x22.5 tires and the top speed I have achieved is 69 however I usually drive at 65 MPH
I have recently changed the rear tires to 315 / 80R x 22.5 not sure how that will effect the above.
I said 12-22.5's but I actually run 315R-22.5's which are slightly wider and taller and doing the math it gets you up to almost 80 mph @ 2300 rpms, which is borne out by my speedometer.
Quote from: Bill Gerrie on April 08, 2018, 06:05:34 AM
George
One bus was the original Bill Teal that developed the overdrive unit and the other was in FL on a 4106. Mine is the only other one. 9 years but the torque of over 1000 ft lbs finally broke the shaft.
Hey Bill, you engine is turning the wrong way! You have completely voided your warranty! ;) Wow that sounds like alot of work but worth it, if doing alot of driving..
So the A730 and 731 turn different directions but does this mod care?
Was looking for the Teal modification book on google and dragged up this old post http://www.busnut.com/bbs/messages/233/19273.html (http://www.busnut.com/bbs/messages/233/19273.html)
PS. My friend from High School, Brent Teal, patented that stair-climber type bicycle. And successfully sued a Chinese knockoff company. Those Teals are crafty.
Olebusman (John)
I talked to Bill Teal awhile ago now and he said that his bus was sold a long time ago and he has no idea of where it is now.
George
The V730 and the V731 are exactly the same transmission except for the valve body. You can change the valve body from one to the other. The V730 is hydraulic and the V731 is electronic. The main modification I had to make to Bill's over drive unit was the flywheel. I run a 6V92 and the VS2-8 was for an 8V71. Different end on the crankshaft. I had to have the flywheel machined to fit the 92 series. I have been running the over drive unit for 12 years now and love it.
When Bill retired from "bussing" many years ago,,(when I owned a 4106 with a VS2-8 ),, bill agreed to send me everything he had left over from the transmission alteration effort for the cost of shipping.. I received two full pallets of gears, shafts, new clutch packs, new brake shoes, housings, gaskets sets, etc etc.. Shipping cost was $175.00...
When I sold my coach to a friend in Washington state, he inherited all this trove with the sale,,,,and I still don't think he has looked at all this stash, and I'm sure he has it stored in a shed out back.>>>Dan
Just came back from a trip to NC state to see granddaughter.
Coming down inter-state 40 I am turning 1600 rpm at 65 mph by my GPS
I am running 24.5 hankooks on Huggy
She has a 6v92 and v730.
Have no idea what the rear ratio is.
uncle ned
ps Huggy is a Jara Smith creation which a lot of old timers here will remember.
My top rpm is set by the computer to 2110. My rear end ratio is 4.56 to 1 without the over drive unit. When I engage the overdrive unit the rear end ratio effectively becomes 3.5 to 1. My fuel mileage went from 6 mpg to 8.2 mpg using the overdrive unit. That was on a 7000 mile trip.
My wish for "huggy" is a series 50 with a 731. But with the rpm range of the 50 it would need some kind of overdrive I think.
Just wishing most likely never going to happen to a Old Man.
Uncle Ned
install the 4104 3:55 rear. Buy a cv joint rated for the torque generated for one end of driveshaft to deal with the angle difference. There is an outfit in Fla. that can make big ones.
AMGeneral used the same rear end as new look GMC. With that overdrive unit, you're spinning the transmission dangerously fast. The fastest input is supposed to be 2,600rpm. Good luck, TomC
I wouldn't want anything less then a 4.10 rear end or you have no bottom end. You may go fast at the top end but the take off will suck. Soft ground forget it. I run a 4.56 to 1 and sometimes wish I still had the 5.375 to 1 when I have the overdrive unit.