46RH overdrive / transmission query

Jon Connolly · Post by **Jon Connolly** » Fri Jan 10, 14 8:07 am

I have a 46RH transmission I am looking to use. It is not the later electronically driven box but the standard hydraulic 3 speed with electric overdrive. I have 2 questions.

1 - Can the electric overdrive be operated by a simple driver operated switch so it is either on or off ???

2 - Is overdrive a straight percentage of 3rd gear. i.e. if I had a 4 10 ring and pinion is overdrive 0.69 x 4.10 = 2.83 giving me an equivalent of a 2 83 gear when overdrive is engaged ??

Or have I got completely the wrong idea ?????????

Thanks in advance

Cannonball · Post by **Cannonball** » Fri Jan 10, 14 8:20 am

yes you can use a regular flick switch i think you may also need a switch for the lockup converter and a tip switch on brake or throttle to knock it back off you wont want it locked up as your slowing down,, no idea on the ratio but 3rd gear is 1 to 1 so its deff a overdrive ie 4th gear,

Jon Connolly · Post by **Jon Connolly** » Fri Jan 10, 14 8:26 am

Nice one Dunc

Be a bit quicker next time

( Specs say 3rd gear is 1 to 1 and overdrive is 0.69 which seemed alot to me ? )

Dave-R · Post by **Dave-R** » Fri Jan 10, 14 8:39 am

Trying to remember what the ratio was on my Gear Vendors.

0.78 springs to mind.

Dave-R · Post by **Dave-R** » Fri Jan 10, 14 8:45 am

Looked it up. Yes it was 0.78:1. I think typlically overdrives are in the 25% region. So yes that ratio you have does seem a bit strong.

Birdman · Post by **Birdman** » Fri Jan 10, 14 8:47 am

Jon,
Wikipedia search shows od to be 0.69:1
Link to HodRod mag article
http://www.hotrod.com/howto/43323_mopar ... sion_swap/
PATC have quite a bit of info / parts on the A518/46RH trans
Chris

Jon Connolly · Post by **Jon Connolly** » Fri Jan 10, 14 9:07 am

Looks like it could be simple answer to the road legal strip car trade off.

Dave ... I was thinking it would be more like 15 - 20 percent not 31 percent ?

Thanks all

Six-pack Speedshop · Post by **Six-pack Speedshop** » Fri Jan 10, 14 10:39 am

Yes it's a 31% so drops the revs nicely.

We are in the process of installing a new build (with bb bellhousing) one behind a Hemi and include a throttle positioner and pressure sensors to make it do the overdrive / lock up fully automatic. Still in the process of trying to set it perfect so no real world experiences to share yet.

These are nice transmissions.

Jon Connolly · Post by **Jon Connolly** » Fri Jan 10, 14 11:18 am

Six-pack Speedshop wrote:Yes it's a 31% so drops the revs nicely.

We are in the process of installing a new build (with bb bellhousing) one behind a Hemi and include a throttle positioner and pressure sensors to make it do the overdrive / lock up fully automatic. Still in the process of trying to set it perfect so no real world experiences to share yet.

These are nice transmissions.

Nice one 6 pack ... I`ll let you do the research and let us know when you have it working correctly

Cannonball · Post by **Cannonball** » Fri Jan 10, 14 1:56 pm

i have built severall for the jensen boys and one fitted to a facel vega.
they are a 904 with lockup and overdrive . or 727 with lockup and overdrive, they also do a 48re that goes behing the cummins and the v10 mtr that is well upgraded

Pete · Post by **Pete** » Fri Jan 10, 14 2:03 pm

Cannonball wrote:i have built severall for the jensen boys and one fitted to a facel vega.
they are a 904 with lockup and overdrive . or 727 with lockup and overdrive, they also do a 48re that goes behing the cummins and the v10 mtr that is well upgraded

Interesting stuff.
Do you have to cut the bellhousing off like you were using an ultrabell so you can get it to marry up with the back of the B R/B Block???

How much bhp and torque can it take???

Cannonball · Post by **Cannonball** » Fri Jan 10, 14 2:11 pm

Pete wrote:
Cannonball wrote:i have built severall for the jensen boys and one fitted to a facel vega.
they are a 904 with lockup and overdrive . or 727 with lockup and overdrive, they also do a 48re that goes behing the cummins and the v10 mtr that is well upgraded
Interesting stuff.
Do you have to cut the bellhousing off like you were using an ultrabell so you can get it to marry up with the back of the B R/B Block???

How much bhp and torque can it take???

the customers purchased there own converters and the adapter kit for the small to big block patten i think some firm stateside may have cast the case to suit a b/rb not sure though

Pete · Post by **Pete** » Fri Jan 10, 14 2:16 pm

Good thread:
http://www.dippy.org/forum2/index.php?topic=231.0

Pete · Post by **Pete** » Fri Jan 10, 14 2:24 pm

Reading a bit more suggests that 500bhp is the limit before reliability goes out the window....

Pete · Post by **Pete** » Fri Jan 10, 14 2:31 pm

Adapters:

http://www.transmissioncenter.net/dodge.htm

#56XXX. Chrysler Big Block (361, 383, 400, 413, 426, 440) to Dodge Small Block 518 transmission. This is the adapter everybody is looking for. 6 bolt crank Cost $689.00, 8 bolt crank Cost $730.00