I just picked up a '58 PD4104 and drove it home from CA to NM. A couple of miles from home, it lost all drive and I coasted it onto the shoulder. There was no noise or sensation (clunk, grind, or bang)at the time and the engine ran just fine until I shut it down 20 min later.
The engine is a Detroit 6-71 mated to a V730 automatic. There's absolutely no drive in any gear (all feel like neutral) and I'm fearing the worst out of ignorance.
Can anyone offer up any would love any ideas / advice before I talk to the shop? What're my odds of sourcing a replacement trans if mine's shot?
Thanks
Clark
Does the trans stick out beyond the body on the right side a couple of inches? A V730 with a 6-71 will not physically fit inside the body on a 4104. Otherwise it would be a VS trans. I assume you checked trans oil level with engine running ning and there aren't any significant fluid leaks.
If it is a V730, about the only thing that can stop that transmission is low oil. Course the quill shaft (shaft that connects the engine to the transmission) breaking would be another-but with only a 6-71 power, I doubt it-and when it breaks, usually makes a lot of noise or vibration. Good Luck, TomC
find the gov cover on the side of the transmission it has four (4) bolts pull the cover and the gov out it probably sheared the gear. it s made out of nylon.
hope that helps
don
Evev if the governor gear is stripped, it should still move, just won't shift.
See "Stuck Eagle" post in this section!! Sounds like you guy's may be having a similar problem!!
Quote from: chessie4905 on April 12, 2016, 05:33:57 AM
Does the trans stick out beyond the body on the right side a couple of inches? A V730 with a 6-71 will not physically fit inside the body on a 4104. Otherwise it would be a VS trans. I assume you checked trans oil level with engine running ning and there aren't any significant fluid leaks.
Everything I've read agrees with you and I'm going off the word of the prior owner as to the drivetrain components. That said, it does not stick out. It's a close fit under the right side swing-out cover, but it's fully inside. This is my first step into the world of buses (motorcycles are my normal vice) so I'm 100% ignorant. When you say it'd be a "VS trans", do you mean VS730 or is there a range of possibilities?
I'm a bit embarrassed to admit it but I did absolutely no roadside diagnostics. At 1AM on a narrow I-40 shoulder (after 16 hours of driving) I was pretty much done and just called for a tow. I had to fly back east the next morning so it's in the hands of Stewart & Stevenson right now.
A picture is worth a thousand words, and the data plate would do the trick.
There's no telling what has been retrofitted in there without pics and/or the data plate.
In your discussions with S&S, get them to tell you what you've got?
And then come back and share it with us, then you'll get some good opinions!
happy coaching!
buswarrior
!
I'm waiting on S&S's "guy who works on the old stuff" to get to my bus but I'll see if he can fill me in on what I've got. In the mean time, I do have one photo of the back all opened up. Maybe it'll help...
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fpostimg.org%2Fimage%2Fvii77mclp%2F&hash=e29f6a6c2a37ee2225cbb3c7dc636cfa18cbfc5a)
http://postimg.org/image/vii77mclp/ (http://postimg.org/image/vii77mclp/)
Well-that is a V730 packed right in there. Good Luck, TomC
OK, It will all fit, when the axle from a later model with the different angle on the driveline is retrofitted along with a V730, and the adjustments made to the bulkhead.
That looks good in there!
happy coaching!
buswarrior
I guess everything I've been told about it not fitting was wrong......oh well. I think everyone assumed you needed to install it with the 4 inch spacer some used. Interesting that no one's heard of this conversion as many 4104 owners would love a automatic.
Back to your problem. What kind of shifter do you use? Have someone watch while you put it into drive. Does the linkage move at the transmission? Maybe this will help You may need a pressure gauge if it isn't something simple.
http://allisonparts.net/Allison-Transmission-Parts-B.html (http://allisonparts.net/Allison-Transmission-Parts-B.html)
Good looking rig. Bet if it was turbo-ed it would make a nice ride. Love my 6v92 but the heat is always going to be a problem.
I do not have enough sense to not think I can run with the big trucks up hills.
Can maintain 55 and 60 in high gear but the heat just keep climbing.
uncle Ned
I apologise for perpuating another myth regarding our coaches. I've been led to believe it would not fit since before the internet. Several years ago, there was a picture of one in a 4104 that showed it was sticking out about 4to 5 inches ( actually the side engine door was modified 4 to 6 inches. There were no pictures of actual trans installation.I assume he used the 4inch spacer some use.
So after seeing posters picture, I measured my 4905 for trans projection from Bell hsg to outermost end and measured brothers 4104. The V730 will easily fit and sticks out to the right no more than the manual trans in that coach. There would still need to be a fair amount of body clearance through the bulkheads for the body of the trans and slightly different driveshaft angle, but probably no worse than installing one into a 4905. BTW, the distance from radiator to engine bellhousing flange is within one inch between the 4905 and 4104 models.
Now back to the posters 4104 picture...it appears blower air intake points to bottom of engine. I think it is tuboed also. Also notice where air filter is. Probably short pipe from it to turbo air inlet, turbo would be mounted directly to exhaust manifold like our was. Removing horizontal factory muffler/s gives plenty of room. Our inlet pipe to the blower went over top of engine with a notch in bulkhead for clearance.
I believe the turbo-ed one that I saw had the blower on the coach side and the turbo on the back side.
Will have to check with Boomer or Gene Russell to see how Gene did theirs.
I notices how the air was ran and could not figure out why.
uncle ned
Gene put his exhaust manifold on the bulkhead side and mounted the turbo and bracket to the cylinder head on the front side. On mine the exhaust manifold and turbo are both on the front side.
That pictured setup wouldn't work well on the 4104. Lots of room on bulkhead side for turbo mounted directly to exhaust man. That picture..pita to remove valve cover, but I don't know how the spaces available on a 3751. Looks like lots of room on top. Nice clean looking seup. Is that actually a silver 6-71?
The pictured engine without the spacer under turbo is the same as mine, just different air intake, and exhaust. Pictures used to be on this board. All the Phoenix transit motors were the same on cradles with radiator, exhaust, and v730..S50's were just little longer package. Rdw
Chessie, you would think that would be the case but I have seen so many of the Allison and gm autos loose a governor and just stop.
Don
Well at least it would be a simple check.
If I had a 4104 and wanted to turbo it, I would mount the turbo above the transmission. Just change the bulkhead side exhaust manifold to a single outlet (rather than the twin 3 cylinder some have) with the outlet at the rear. Then on the right transmission door mount the air to air intercooler with an electric fan blowing from engine compartment out (the big engine radiator fan is too powerful for an electric fan to overcome-as I found out with my aux transmission cooler with electric fan). Good Luck, TomC
Clark, the same thing happened to me some years ago in Wisconsin, with my 4104 running an 8V71 with V730 trans. The cause was, all the bolts with threads pulled out of the bevel gear carrier from the case. Fortunately, I had a spare transmission in the custody of a good friend who shipped it out to the shop where I landed after the failure. Good luck, Kirby
They are terrible about shearing the fly wheel bolts if they have not been updated
The V730 flywheel I have in the shop is one heavy sucker. Hope it isn't the problem.
I just spoke to S&S and it looks like the flywheel has sheared so (at a minimum) an engine rebuild is in order. He also said that there may be another driveline issue at work here that's the root cause (bound trans or driveline vibration). The ballpark for a repair could be $30k, leading me to wonder if replacing is a better option than repairing. S&S will install but won't get involved in sourcing used drive components. Does anyone have any ideas on where to go from here? Since this seems to be an oddball drivetrain combo, I don't expect that I'll find a complete package. Is going used even a good option? Where would I start looking?
Quote from: lwbclark on April 27, 2016, 09:19:24 AM
I just spoke to S&S and it looks like the flywheel has sheared so (at a minimum) an engine rebuild is in order. He also said that there may be another driveline issue at work here that's the root cause (bound trans or driveline vibration). The ballpark for a repair could be $30k, leading me to wonder if replacing is a better option than repairing. S&S will install but won't get involved in sourcing used drive components. Does anyone have any ideas on where to go from here? Since this seems to be an oddball drivetrain combo, I don't expect that I'll find a complete package. Is going used even a good option? Where would I start looking?
I was afraid of that but was hoping it wasn't the case for you
Wow, did you say 30 grand for repair?? Hope it works out.
Please forgive my ignorance here. But why would he need an engine rebuild? I always thought that flywheels are replaced all the time and it sounds like his engine is fine otherwise. That is a rare combo indeed for the 4104. I wonder what could have gone wrong unless a problem was building for awhile.
Still a lot of 6l71ta ddec's floating around, complete with 730's. Plus S50 reverser packages are still out there. just late 90's transits. Easy swap.rdw
The friggin flywheel for a 730 weighs a couple hundred pounds at least it seem like it does,you are supposed to remove the dowels and tap the holes for extra bolts to hold it in place DD makes special raised head bolts for the modification. I went through this with Scott Crosby on a GM bus that sheared the bolts he got it going
Milton when the bolts shear it destroys the holes.If it was mine I would insert the bad holes and tap the dowels. 30 grand it is a lot of cash to dump into a 4104.What location is the S/S shop I would think Tom at the Albuquerque location would work with you unless Houston won't allow it.I would tap it, insert it, install a new 600 buck vibration damper or DDEC it with a 730 and go
Good luck
Quote from: gg04 on April 27, 2016, 01:09:33 PM
Still a lot of 6l71ta ddec's floating around, complete with 730's. Plus S50 reverser packages are still out there. just late 90's transits. Easy swap.rdw
Any advice on where I'd start looking? I ran into this on my first day with my first bus so I'm starting flat footed.
The DDEC 6L71TA was found in Flxible Metros with the V731 fwiw LACMTA had those 90 and 91 some with air starters the last 1 I purchased was air start, if you go that way you are going to be all electronic do you want that ?
Last 3 I had were air start. Reli-bilt replacement sets out of mid 90s shortened RTS's. Haven't looked for one since Karina.rdw
They are hard to find now the shrimpers along the Gulf bought up every one they could find.I bought a new one in Louisiana at a good price without the ECM,so I had to have a ECM from a 6V92 reprogrammed for the 6L it took him 3 shots till he made it work.
If I am not mistaken I recall Don Fairchild telling me he had some mechanical 6L71 all with the Clean Cam Technology upgrades, dyno tested ready to for around 15k
Thanks that explains it. I'm quiet surprised that they 6-71 was still available as late as the early 1990's in transits.
All of the buses around here like RTS's and NEOPLANS in the 1980's had the 8V-71 and 6V-92. Must have been exclusive to FLXIBLE.
Only 2 of the 671's I had were from Flexi's both from Phoenix. The others and S50's were from remanufactured RTS's..rdw
Quote from: CrabbyMilton on April 27, 2016, 12:58:18 PM
Please forgive my ignorance here. But why would he need an engine rebuild? I always thought that flywheels are replaced all the time and it sounds like his engine is fine otherwise. That is a rare combo indeed for the 4104. I wonder what could have gone wrong unless a problem was building for awhile.
Crank thrust.... maybe.
Can eat lots of money.
After a day of reading, it sounds like rebuilding is not an option. That set me down the replacing path. Is there any way to identify the left-turning engine I need from a photo or do I need to ask? There seem to be a million flavors of 6-71s. How interchangeable are they?
You want the most current block and go from there,the 6-71 is not that difficult to change direction from R to L shop around and check with Western GM group they keep the old Gm's going and know where the parts are ? how close to Albuquerque are you
good luck
Can the right to left conversion be done without disassembling the engine? I'm finding running 6-71s from between $2k and $6k but if I have to pay labor on disassembling an engine to change the rotation, I may as well stick with rebuilding mine.
I'm actually stationed in Maryland until June, then I'll be at White Sands, NM. My plan was to leave the bus with my wife in Albuquerque and pick it up this summer.
Many rebuilding jobs on a 6-71's are relatively easy. Changing which side the blower on the block is and which side the exhaust manifold on the head is one of those jobs. Along with that is the rotation of the engine. Just a matter of tearing into the rear gear train and switching the idler pulley to the opposite side. Then flipping the camshaft and idler cam around, and changing the oil pump to a left handed pump. This is very simplified, but if you have any engine experience, it would be a fun experience to do yourself. Good Luck, TomC
The later 6L71 blocks have no front or rear it is the same on both ends for left and right applications
I know where you can find a DDEC II 6L71TA, left hand, if you need one. May or may not still have a ECM.
Boomer, At this point, I'd love any options that are out there! Where's it at?
Clark
I know a guy in Mesa Az that has a left hand mechanical turbo 6L71 I can call and ask if it's for sale or not.Mikey drove all the Wa to pickup what he thought was 8v71 lefty and it turned out to be a 6L71 left handed engine he bought anyways and I don't know if he sold it or not.They are out there just keep on looking
Luvrbus, I'd appreciate it if you could find out!
Clark