1958 PD4104 Trans Failure
 

1958 PD4104 Trans Failure

Started by lwbclark, April 12, 2016, 12:06:22 AM

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lwbclark

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

chessie4905

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.
GMC h8h 649#028 (4905)
Pennsylvania-central

TomC

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
Tom & Donna Christman. 1985 Kenworth 40ft Super C with garage. '77 AMGeneral 10240B; 8V-71TATAIC V730.

Don Fairchild

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

chessie4905

Evev if the governor gear is stripped, it should still move, just won't shift.
GMC h8h 649#028 (4905)
Pennsylvania-central

bigred

See "Stuck Eagle" post in this section!! Sounds like you guy's may be having a similar problem!!
Rhet Raby           137 Elk Mtn Rd       Asheville N c 28804             1993 Prevost XL

lwbclark

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.

buswarrior

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
Frozen North, Greater Toronto Area
new project: 1995 MCI 102D3, Cat 3176b, Eaton Autoshift

chessie4905

GMC h8h 649#028 (4905)
Pennsylvania-central

lwbclark

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...

http://postimg.org/image/vii77mclp/

TomC

Well-that is a V730 packed right in there. Good Luck, TomC
Tom & Donna Christman. 1985 Kenworth 40ft Super C with garage. '77 AMGeneral 10240B; 8V-71TATAIC V730.

buswarrior

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



Frozen North, Greater Toronto Area
new project: 1995 MCI 102D3, Cat 3176b, Eaton Autoshift

chessie4905

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
GMC h8h 649#028 (4905)
Pennsylvania-central

uncle ned


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
4104's forever
6v92 v730
Huggy Bear

chessie4905

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.
GMC h8h 649#028 (4905)
Pennsylvania-central