1958 PD4104 Trans Failure

[luvrbus]

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    

[lwbclark]

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.

[luvrbus]

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 ?

[gg04]

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

[luvrbus]

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      

[CrabbyMilton]

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.

[gg04]

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

[eagle19952]

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.

[lwbclark]

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?

[luvrbus]

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

[lwbclark]

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.

[TomC]

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

[luvrbus]

The later 6L71 blocks have no front or rear it is the same on both ends for left and right applications

[Boomer]

I know where you can find a DDEC II 6L71TA, left hand, if you need one.  May or may not still have a ECM.

[lwbclark]

Boomer,  At this point, I'd love any options that are out there! Where's it at?
Clark