crown 1959 trans

[BJ]

friend of mine that has a 59 crown 35 footer with a Cummings just blew his trans for the second time. It seems the main brg has let go twice and he thinks it was the rebuilders fault since after the 1st time 2nd gear jumper out when you let off the accelerator pedal. Any way he is looking for a trans and wants maybe a 9 or 10 speed or maybe an automatic. can anyone HELP him? He has no computer so you will have to email me at mc8driver@aol.com in the subj line put transmission to keep it out of my spam folder..thanks in advance.

[TomC]

First off it is a Cummins (no G).  The standard 220 put out about 650lb/ft of torque.  This leaves a whole lot of choices available.  You could install either a 5 spd direct or a 6 spd overdrive which will give enough gearing especially with the overdrive-advantage being, many of these transmissions are synchronized so that anyone can drive the bus.
Going to a 7spd or more, all are unsynchronized.  So that you have to either double clutch or be good with timing.  Transmissions of 8spd or more will have air operated splitters and/or range selectors.
Allison automatics- because of the power you could use the 600 series. Advantage-they're smaller and don't hang down so much like the HT740 does-considering the pancake engine and the fact the engine is in the middle of the bus (worse for ground clearance).
Personally-I'd go with the 6spd Eaton overdrive-many available since many are installed in U-haul sized trucks. Good Luck, TomC

[BJ]

TomC
thanks for all the info  I got to bed at 3am after wk and Rick called me at 8am..I had only been up about 10 min when I entered the question.. Still stumbling around.

[Jerry W Campbell]

Hi BJ,
   You need to go to the crowncoachjunkies.
The source of most of the Crown knowledge on the internet.
Jerry

http://autos.groups.yahoo.com/group/crowncoachjunkies/

[HB of CJ]

What is the road gearing?  If he already has around 70-72 mph at 2100 rpm, there is no need of installing a tall overdrive tranny.  The old 220 MAY not have the power to pull it.

However, if the Supercoach is limited to about 58 mph at 2100, then an overdrive would be super cool as those old mills seemed to run best between 1600 and 1800.

My old 1974 Crown (VIN 37317) had the infamous RTO-910 10 speed Roadranger. .82, 1.00, 1.26, 1.59, 2.00// 2.57, 3.14, 3.95, 4.98 and 6.27.

The 910 series Fullers are now getting hard to find.  All been scraped out.  If you find one, installing it would require some fabricating as probably right now the Crown has a Spicer.

Another choice would be a 7 speed Fuller .75, 1.00, 1.37, 2.04, 3.22, 5.35, 9.24.  No air lines required.  This box would work if the Crown is geared very short.  HB of CJ (old coot)