| Author |
Message |
EARTHman (69.81.32.246)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 29, 2004 - 9:50 pm: | |
I posted a spec sheet for a 4106 I'm considering buying on the 17th.
Well I spoke with a guy that said he saw twon problems with this unit.
He said the VS2-8 can be a problem in that it is a 2 spd w/overdrive and is meant for city use. He indicated that it can lug the engine and cause cylinder wall scoring. I think that was the term he used.
And that is kinda sucks in the mountains as far as going up them.
Please o please bus people share your wisdom.
Thanks |
DonTX/KS (66.82.9.37)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 29, 2004 - 10:13 pm: | |
Better get another opinion, bet he never owned one. And he is WRONG that the VS2-8 was meant for city use, if you read the GMC 4905 sales literature and the Allison manual for it, you will find him very wrong. Ask him just why that "meant for city use" tranny will outrun all the other automatics and manual trannies on the highway. I think he has it very mixed up in his mind with the two speeds without overdrive, which WAS meant for city use only.
It is IMPOSSIBLE to lug an engine with a vs2-8, the darned thing shifts down wether you want it to or not! |
EARTHman (69.81.32.246)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 29, 2004 - 10:46 pm: | |
After he told me this I did look around online and found this...
http://www.coachinfo.com/Solutions/solutions_13.html
QUESTION:
I'm having a tough time deciding which automatic transmission to put in my GMC 4108. The price on the VS2 with overdrive is great, and I'm told they go in easy. Will it work? Will it travel 65 mph without overheating? What kind of problems might I encounter?
ANSWER:
I know this is a tough question for you because there are some folks out there that love their VS2-8 Allison transmissions. I am sure to catch some heat from this answer, but you wanted a second opinion! The VS-2 will go in easy, it will work, it will travel 65 miles an hour without overheating, and the problems you may encounter could be numerous! I highly recommend the Allison V-730 series transmission for a few of the following reasons: Better design—more durable easier shifts—better cooling capabilities—easier maintenance—better torque. The only negative may be slightly less fuel economy depending on your differential gearing, but this is a small price to pay for the benefits of the V-730!! |
Bill Gerrie (209.50.74.100)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 30, 2004 - 12:21 am: | |
Earthman
I have run the VS2 series and the V730 type. The final drive on the VS2 is better then the V730 but the take-off in convertor drive is the pits on the VS2 compared to the V730. I proved this to myself in a campround that had a very steep hill. I couldn't get up the hill with the VS2 but with the V730 I had to put on the brakes at the top of the hill. I am not sure what the ratio is on the VS2 on take-off but the V730 has a multiplication factor of about 5 to 1. The VS2 can be made to shift down when you want it to just like the V730 with the addition of a solenoid. This keeps the rpm just right for the hills. Hope you can understand this. Bill |
Phil Dumpster (24.16.243.37)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 30, 2004 - 4:05 am: | |
Your slow takeoff and poor hillclimbing observations with the VS2 are due to coach gearing more than anything else. The two speed Allison automatics have a very tall low gear, something the V730 design corrected.
Actually, the two speed units (including the VS2, for this discussion ignore the overdrive) don't really have gears that shift between low and high. The difference between low and high is the torque converter lock. The coach starts out with the converter unlocked, giving a gear ratio of between 2:1 to 1.5:1, and then at some pre-determined speed and throttle position the converter clutch locks the unit to 1:1. There is a set of reversing gears in the unit to allow the coach to back up. Older ones require you to shut off the engine to change from forward to reverse.
The VS2 adds a planetary overdrive gearset to this setup to allow higher speeds. It was originally designed for the New Look coaches used in suburban service, and it was also put into some of the intercity coaches as well.
The V730 is a typical 3 speed automatic transmission like the kind you'd find in a car, only bigger and designed to have the engine mounted on the side of the case instead of the front.
The biggest problem you might have with a VS2 is parts availablity. Allison doesn't support the unit anymore. The design rights were sold to Williams Distributing, and they can get you most of the parts needed to rebuild it. |
DonTX/KS (66.82.9.60)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 30, 2004 - 8:22 am: | |
Well said Phil. One exception though, on the VS2 you said "and then at some pre-determined speed and throttle position". The VS2 has no throttle modulator, and shifts regardless of where the throttle is (uses the trannie governor only). I wish it DID have a throttle position requirement, it would have been an even better transmission.
I found that Williams supports the transmission fully (as they do many other older Allison units) I never found a part that they did not have, and they have the parts made if not in stock. |
Frank Allen (64.12.116.135)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 30, 2004 - 9:29 am: | |
Never run a vs-2 but i was told you need to change the gear in the rear end when you run this one , i put a 730 in my 06 and it has done a good job for me however be advised that the top end speed will be reduced abou 5 to 7 mph, the engine will run hotter especally climbing and high speed runs, and finally you will realize a reduction in fuel mileage of about 3 mpg, some will argue abot this but these are the facts
Frank Allen
4106 |
DonTX/KS (66.82.9.61)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 30, 2004 - 10:04 am: | |
Of course Frank, that is exactly the point and why we are comparing the two transmissions! A V730 will gear you down, about the same as running in third all the time in a manual. Of course it burns more fuel running at the higher engine speed, and unless you set the governor up you will even lose top speed..
Had you installed an over geared VS2, you would find yourself sipping fuel at only about 1700 rpm at 70, and would have increased your fuel mileage by about 3 mpg. Lets face it, MOST of the time we spend cruising the highways, NOT drag racing or contesting for speed going up hills. Most people also forget that maximum torque on a typical bus 8v71 is attained at 1200 rpm, and drops off after that. Higher rpm = less torque.
It appears most of the V730 hype is coming from people who have scrapped out transits and are trying to peddle the darned things. |
TWO DOGS (65.179.209.144)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 30, 2004 - 11:44 am: | |
shifting when you don't want it to...freewheelin' when you don't want it to....all ya' need now is about a foot of slack in the steering wheel...."standard transmissons...forever !!!" |
DonTX/KS (66.82.9.29)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 30, 2004 - 1:15 pm: | |
You and Fast Fred are a real pair. ALWAYS with stories about your knowledge of all the automatics, yet NEVER have had a bus or drove one with an automatic. Wonder where all that superior knowledge comes from anyway. |
TWO DOGS (65.179.209.99)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 30, 2004 - 1:41 pm: | |
someday you will know...when ya' have knowlege..something else too...the EXPENCE of rebuilding an automatic...but...some people just GOT to waste money... |
TWO DOGS (63.185.72.216)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 30, 2004 - 2:08 pm: | |
really...you & everybody else needs a better explanation than that...this is an opinion board...I'm entitled to my opinion...I like to have control of things...if I put it in 2nd....it stays in 2nd till I want it out of 2nd...NOT ..lurching into high & going downhill like a fat woman out of a 40 story building..everybody talks people into going to automatic....then ,since you spent 5000 on that...now ya' HAVE to install jakes..only a couple thousand more...all seems like wasted money when ya' had a good standard to begin with...now ...ya' got an automatic that shifts when IT wants..and...guess I'm old school...but an automatic that sits..seals leak...more to work on...why do you create more problems than what ya' have to start with... |
Jimmci9 (209.240.205.68)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 30, 2004 - 3:15 pm: | |
uhhh..2d??.. didn't your trans leak when it got to the valley???... and its standard???... dig.. dig....i remeber calling luke to get the numbers for the seal....and didn't don help you too???...nice try 2d....both my coaches are auto's... wouldn't have it any other way..... |
TWO DOGS (63.185.73.45)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 30, 2004 - 3:31 pm: | |
and neither one of your buses will run ...yep...had a leaky rear seal...after 918,000 miles...aren't you the guy with the wonderful winch truck...got that sideing on ? |
Chris 85 RTS (66.194.150.45)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 30, 2004 - 3:32 pm: | |
I did not see where the poster was asking to be convinced to stick with a standard. Maybe next you'll be telling him why aqua is the only color to paint his coach. Give me a break. I love the standard in my Mini Cooper, it makes driving fun. Having a standard in my RTS would be pure torture. |
TWO DOGS (63.185.73.45)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 30, 2004 - 3:43 pm: | |
doesn't matter what color he paints them...they never will be roadworthy |
DonTX/KS (66.82.9.37)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 30, 2004 - 4:15 pm: | |
"and neither one of your buses will run ..." Where do you get that? Mine served me well for years, WITH AN AUTOMATIC transmission. You might take a look at the cover and centerfold story in Bus Conversions Magazine, you will see mine there, is yours? |
Jimmci9 (209.240.205.68)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 30, 2004 - 4:50 pm: | |
i drove the 5105 around storage this morning.... turned it around so i can get to the electrical connections on the rear bulkhead.....the mci starts up goood... it needs tires to make it roadworthy, they've dry-cracked in the year it's been in storage.....neither is tagged or insured, so they're not going down the highway... but i dont tag the HR motorhome i live in either.... i get a 15 day permit for it each move.... i keep insurance on it tho.... |
TWO DOGS (65.179.208.213)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 30, 2004 - 5:47 pm: | |
I was just saying I'd rather have a standard...wasn't talking about your bus Don...know you had fun in it...jim comes up & wants to argue...guess he thinks he's protecting you.. |
Dale MC8 (69.19.144.107)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 30, 2004 - 8:25 pm: | |
Uh, 2D, in regards to your comment about a fat lady out of a 40 story bldg. Remember grade school physics and the story of dropping two balls from the Tower of Pisa? Both fell at the same speed. Sooooooo, a skinny woman would be just as good an example. OK, OK not as funny!! LOL
Dale |
DonTX/KS (66.82.9.60)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 30, 2004 - 8:39 pm: | |
Well I never had a fat lady, nor did I drop one off a 40 story building, so I just have to sit back and listen to the voices of experience. |
joe shelton (68.237.128.220)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 30, 2004 - 9:55 pm: | |
Earthman, I have a v730 in my 4106. I have collected a LONG list of data & good info from good sources about the VS2 and v730 series tranies. E-mail me direct and I'll send it to you. If you-all know where'd be a good place to post it, I'll put it there as long as I don't have to jump thru too many hoops to do so.
joe |
Johnny (4.174.112.8)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 30, 2004 - 10:48 pm: | |
"You and Fast Fred are a real pair. ALWAYS with stories about your knowledge of all the automatics, yet NEVER have had a bus or drove one with an automatic. Wonder where all that superior knowledge comes from anyway"
Count me in with 2D & FF here. The count at work: 5 newer Allisons, 6 rebuilt trannies. The V730 in the Jimmy is holding up (and it should, since the 6V71 has absolutely no discernable power to hurt it), but turns the bus into a total dog that borders on "dangerously underpowered" on hills. Even the well-worn 1972 F-800 ramp truck (with a <200HP 361 gasser & a never-rebuilt Clark non-OD 5-speed) at my other job will leave it in the dust, especially on hills, & tops out a good 10MPH higher. Slushpumps are for people with one leg. |
Scott Whitney (69.35.62.177)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 01, 2004 - 12:16 am: | |
So who can tell me how much work it would be to make a VS1-8 into a VS2-8? I recently acquired a VS1-8 (thanks, Don, for the info, and thanks, Dennis, for the tranny!) and believe it or not, it is on my roof rack at the moment being hauled home. Anyone ever seen a bus transmission on a bus roof before? Haha, this trucker last night was telling me how he'd hate to be an owner operater these days, fuels prices, etc and what if your tranny goes bad etc. . . I pointed to my roof and said, "carry a spare!" He 'bout flipped.
Anyhooo, so I am dragging this thing home to use as spare parts - just in case. But would it be a monster project to rebuild it into a VS-2 in advance and keep it on hand as a ready-to-go direct swap? Or would it make more sense to just sit on it in case I need some part(s) from it someday?
BTW, I like my VS2 just fine. I can climb the steep hills, slowly, and cruise about 62-65mph on flats all day. (6-1/7 rearend, 8V71, 32K Lbs)
Scott |
Gary Carter (68.25.23.10)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 01, 2004 - 12:27 am: | |
Looked at automatics when we had our 4106. V730 was a nice box, but slower with more fuel burn kept me from doing it. Was getting serious about the VS2-6 when we sold the bus. With the VS2-8 there were 2 overdrive ratios. They were about .6:1 and .7:1 and the VS2 was about .8:1. The .6 was about worthless in a 4106 because unless you were going downhill it was geared to tall for the engine. With .7 it is marginal and will need to downshift on the slighest hill. The .8 gives you a slightly better top end than the 4 speed spicer with no reduction in MPG.
I belive, but may be wrong, that the VS2-6 also has a little better gear multiplication in the torque convertor. With a 4 1/8 rear end a little really helps.
You can add skinner valves to the VS to totally control shifts I have been told. Keep in mind you can use the jakes in direct drive, but this should give you better than 55mph. |
DonTX/KS (66.82.9.12)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 01, 2004 - 1:37 am: | |
You are correct on the VS2-6 having different angle drive ratio. One was running on a 8V71 just fine for years in a 4106, the guy did it for the ratio it afforded. He never had a problem with it for years (even though technically overpowered), yet when he changed to a V730, he is now on his third one in as many years.
I am not sure what you are saying about the "better than 55mph" The jake works perfectly until that last downshift into "hydraulic", at10-15 mph. I could always handle it from there on to a stop, gotta use the brakes a little to keep them functional anyway. |
BrianMCI96A3 (65.40.117.27)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 01, 2004 - 1:56 am: | |
Sheesh, we have this argument time and time again...
It's the guys with manuals that hate automatics, but the guys with automatics don't really care if you like manuals or not, They just really love their automatics... especially once they have switched over to one.
The fact is, at our shop, with dozens of Allisons over the last 15 years, we have had one Allison tranny that needed to be repaired, it had been installed in an overloaded 45,000 lb. paint striper and it lasted 10 years.
We have had at least two manual transmissions we've had apart during that time, an omigod number of clutches replaced during the same time period and one tranny that came apart by itself.
About four years ago a truck came in on a hook, in the bed of the truck was the transmission, a manual tranny.
The driver of the truck said that the engine lost power and he started to pull over the next thing he knew all h*** broke loose.
Examining the remains of the Clark Transmission
was looking at the single most amazing and destructive failure I have ever seen.
After a bunch of us looked at the pieces a while we determined that one or more PTO bolts had worked themselves loose at some point and was ignored or missed long enough that one bolt fell out and all, or most, of the gear oil went away.
In looking at the inside of the pieces of the tranny afterwards, they were bone dry, we believe it got to be dry when the rear main shaft bearing, running without oil, began to turn cherry
red, then after that the main shaft...
At that point we figure that the red hot tranny had boiled off any oil residue and the driver finally noticed the "loss of power"
What happened at that point, we believe, either the deceleration was the last straw, or perhaps the mainbearing chose that moment to seized on the shaft, in any case, the red hot mainshaft twisted like a piece of soft-serve ice cream, the whizzing internals of the tranny bunched together and blew the tranny apart like a pinata...
Then like a hairball, it coughed the entire tranny in a thousand pieces out from under the truck.
I'd have loved to have seen the face of that driver when the stick shift ripped out of his hand and literaly beat the crap out of the inside of the cockpit as it tore it's way through the floor boards and tied itself into a pretzel.
The case of the tranny was in four large pieces, and who knows how many small ones and the hardened steel solid mainshaft was twisted in two at a point where it was 'only' 1 3/4" in diameter.
I mention this because it was amazing to witness the aftermath, and because by comparison our striper was driven to the tranny shop when it began to develop problems.
I really like driving with a stick shift in my car, I'm really glad I swapped out the four speed manual in my coach for an electronic shift HT748 Allison.
Brian |
Frank Allen (205.188.116.135)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 01, 2004 - 12:03 pm: | |
Ok Don, what ever you say, i only talk about what i know, i thought that was what this board is all about, and i was telling the man what happened to my bus when i put the 730 in it, it is not like running in third as you said, it would run 53 in third gear before runs 76 now so how is that like running in third gear?? this board is how you learn things , people are willing to share, but some think theres is the only OPINION worth listening to, now ive said my peace i will try to stay off the board and let you guys have it
Frank Allen
4106 |
Johnny (4.174.70.26)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 01, 2004 - 12:06 pm: | |
At work, we have NEVER gotten more than 100,000 miles on an Allison slushpump (we have one bus on its third Allison--at something like $5000 a pop--at 91,000 miles). The longevity record is the one in my bus, a 1997 Freightliner-chassis snubnose with a Cummins 5.9 & Allison 500 lockup 4-speed. It has 83,000 miles, & if it hits 90K, it will be a miracle, considering it's current status (hanging up, lurching, shifting with a loud BANG).
At my other job, one of the wreckers (1986 F-350 diesel) has over 530,000 miles on an unrebuilt T-19 4-speed. The only repair it's needed (along with a couple of clutch replacements) was replacing the 3rd gear synchro at just over 500K. Another (1972 F-800) has the Clark 5-speed unrebuilt in 32 years of abuse. A third (2001 F-550 diesel rollback) has 165,000 miles on the untouched ZF 6-speed. A fourth (1968 Chevy C-30) has the original, unrebuilt SM465 with over 200,000 miles & 30 years of use. A fifth (1974 GMC C-35 rollback) has almost 450,000 miles on the unrebuilt 3-speed (though on its third clutch & second engine). |
Derek (24.85.245.203)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 01, 2004 - 12:51 pm: | |
I must say, if you're going through a transmission at less than 100k intervals, you're doing something wrong. There are allison B500's here with well over that amount with no problems. |
DonTX/KS (66.82.9.22)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 01, 2004 - 2:01 pm: | |
I wasn't trying to put a bee under your bonnet Frank, just trying to use your experience as an example of what changing to a V730 does to a GM, as opposed to a VS2-8. Without exception, you will increase fuel useage, decrease top speed, and complain about it. Many people do not even start to comprehend the differences in gearing and transmission styles, and tend to take YOUR experience as some sort of gospel for ALL automatic transmissions in ALL applications.
As Brian said, this has come up time and time again, always with the same partial misinformation from so called experts that never even got close to a bus with an automatic, let alone drove one or owned one.
I was merely describing your gear down situation to illustrate what happens when you put a V730 in a standard GMC, and used the third gear example for clarity, not that you get the EXACT gearing that you had in third, but in that direction.
I have had the pleasure of driving 4106's with standard, V730, and VS2/8 for some distances. Give me the VS2/8 over the other two any time, except if I were in CONSTANT mountains, I would go for the V730 since top speed would never be appreciated anyway, and the stump pulling gearing would better suit the conditions. |
Johnny (4.174.91.73)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 01, 2004 - 5:52 pm: | |
"I must say, if you're going through a transmission at less than 100k intervals, you're doing something wrong."
You're right: it's called "100% city use", and "not spec'ing a manual grearbox". |
BrianMCI96A3 (65.40.117.27)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 01, 2004 - 10:26 pm: | |
Well, it seems to me that massive amounts of hard city driving are simply not remotely what any of us will be doing with our coaches.
A properly used and maintained Allison will last in a coach for years with no trouble.
Brian |
Scott Whitney (69.35.62.177)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, May 02, 2004 - 2:29 am: | |
Yeah, but that is the thing. The VS2 will withstand decades of city driving as well as run the highways. . .
Scott |
Henry van de Graaf (Hcvdg) (172.194.223.242)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, May 02, 2004 - 10:15 am: | |
I like this option. Bill's documented a way to use the vs-2 overdrive on a V730.
http://groups.msn.com/billteal/allisonv730overdrive.msnw |
Johnny (4.174.103.64)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, May 02, 2004 - 1:01 pm: | |
"Yeah, but that is the thing. The VS2 will withstand decades of city driving as well as run the highways."
So will a Spicer or Clark. |