Transmission rear mount

[rayshound]

Well I'm on vacation, my engine & transmission on a cart in the garage being painted and have been wondering for a long time & soon after paint job it will be to late, anyways thats an awlful big assed transmission hanging from the engine bell housing with no support other than the bell housing motor mounts. This is an ATEC HTB748 about the same as a ht-740 except electric plus this big assed retarder. Would a rear upper tailshaft mount help? Do you think a extra motormount would cause problems? two bell housing mounts plus front mount. This is a series 60. I had kept my original clearances and driveshaft. MCI-8.  Ray

[TomC]

Most do not have a rear transmission mount.  With the smooth ride of buses, it probably isn't necessary.  I like to put them on big rigs, but they ride considerably rougher, and the constant torquing of the manual transmission makes for a jumping transmission.  The smooth Allison isn't a problem.  Good Luck, TomC

[NJT5047]

My HT748R isn't hanging on the bell housing...it has the rear motor mounts on the transmission.   This subject just came up on another board.    Don't know whether  the trans mounts as used with a 6V92 could take the additional weight, idle chatter,  and torque of an S60.   Or whether the correct dampening biscuits  are available for the S60/HT mounts since the S60m moves around much more than a 2 stroke.  The tail of the trans/retarder are going to move around considerably.  Limiting that movement with an additional rear motor mount (4 point mounts?) would seem  complicated... 
Sounds like a ton of weight hanging on a bell housing?   
How do others do it?   Bernhard (sp?) had a pix of an S60 with an HT series trans pictured in their website...along with their proprietary engine cradle.   Forgot how they did it.   
JR

[luvrbus]

If you have a cast iron bellhousing you can use it with out mounts but not on the the aluminum bellhousing

[rayshound]

I have the aluminum bell housing. I have never seen a cast iron bell housing for a S-60 in the wrecking yards and there is a ton of them in the yards. That doesn't mean there is not any. I had purchased for my first bus a md 643 with a retarder that I put on my 3208 cat and it had a cross brace that bolted accross the rear of the retarder and a mount on each end. Thanks Ray

[Sammy]

The B500R that is mounted behind a Series 60 in a Prevost H3-45 only uses the aluminum bellhousing for support. No rear mount of any kind.
Some transit buses with Series 50's and a B500R use the side mounts on the trans bellhousing and the front bellhousing bolts to support it (New Fllyer 60 foot articulated bus)
I've only seen an Orion transit bus with a Series50 and a B500R use a rear top mount and the front bellhousing bolts .
Hope this helps. Good luck with your repower.
Sammy 

[rayshound]

Thanks Sammy, I appreciate all of your help. Ray