Posted By: Wedgeman
keep the 904 or go with 46RH ? - 03/11/09 02:07 PM
Swapping for a magnum engine in my A-body...should I be going with the 46RH or will my 904 be enough ? Bog difference in strenght between the 2 ?
Dan
Dan
keep the 904 or go with 46RH ?
Posted By: DaytonaTurbo
Re: keep the 904 or go with 46RH ? - 03/11/09 03:05 PM
I thought the 46RH was the 727 based o/d trans and the 42RH was the 904 based one. There is a big difference between the 904 and either of the two o/d's in terms of size and the amount of tunnel 
needed.
needed.
Posted By: 70AARcuda
Re: keep the 904 or go with 46RH ? - 03/11/09 06:03 PM
the OD units on a 42rh and 46rh are the same size...they only difference is the number of clutches and steels inside..
so on that end of the trans is not going to make any difference in trans tunnel surgery...
46rh is based on the 727
42rh is based on the 904
so on that end of the trans is not going to make any difference in trans tunnel surgery...
46rh is based on the 727
42rh is based on the 904
Posted By: MoparMarq
Re: keep the 904 or go with 46RH ? - 03/11/09 08:17 PM
Don't know about 904s (and very little about the later ones), but the trans designations say something about trans. 42RH decodes as 4 forward speeds, level 2 torque capacity, (something), hydromechanical actuacted. 46RH is 4 forward speeds, level 6 torque capacity. I'd go with the 46RH, if it becomes a choice of 42RH or 46RH.
As for the choice between 46RH and 904, I'd go 46RH as that gets you a tidier way of getting the overdrive.
Plus, though I may be out of left field here, some of the 42s have torque converter issues. My sister has a Jeep Grand Cherokee with the 42RE that will occasionally not stay in torque converter lockup driving on the highway (above 48 mph). I believe this is a known problem among dealers (yes, she had the TSB flash to the control unit). They refuse to look at the trans "because it hasn't thrown a code". (Whatever happened to good old-fashioned diagnosis?) My Durango had the same problem for a while (46RE trans) until I changed the fluid to Amsoil and put in a new filter. Problem solved in the Durango. Fluid and filter change in the GC helped a little, but didn't solve the problem. Maybe electrical, maybe the TC, maybe something weird about the Grand Cherokee version of the trans, I don't know.
As for the choice between 46RH and 904, I'd go 46RH as that gets you a tidier way of getting the overdrive.
Plus, though I may be out of left field here, some of the 42s have torque converter issues. My sister has a Jeep Grand Cherokee with the 42RE that will occasionally not stay in torque converter lockup driving on the highway (above 48 mph). I believe this is a known problem among dealers (yes, she had the TSB flash to the control unit). They refuse to look at the trans "because it hasn't thrown a code". (Whatever happened to good old-fashioned diagnosis?) My Durango had the same problem for a while (46RE trans) until I changed the fluid to Amsoil and put in a new filter. Problem solved in the Durango. Fluid and filter change in the GC helped a little, but didn't solve the problem. Maybe electrical, maybe the TC, maybe something weird about the Grand Cherokee version of the trans, I don't know.
Posted By: Wedgeman
Re: keep the 904 or go with 46RH ? - 03/11/09 09:17 PM
Good info to know...
thanks
Dan
thanks
Dan
Posted By: gdonovan
Re: keep the 904 or go with 46RH ? - 03/11/09 09:28 PM
Quote:
Swapping for a magnum engine in my A-body...should I be going with the 46RH or will my 904 be enough ? Bog difference in strenght between the 2 ?
Dan
You will have to do a bunch of slicing and cutting to the trans tunnel to fit a 46R in there.
Posted By: Wedgeman
Re: keep the 904 or go with 46RH ? - 03/12/09 03:31 AM
That's what I thought too...
Thanks
Dan
Thanks
Dan
Posted By: 36PLYM
Re: keep the 904 or go with 46RH ? - 03/12/09 11:36 AM
Quote:
Don't know about 904s (and very little about the later ones), but the trans designations say something about trans. 42RH decodes as 4 forward speeds, level 2 torque capacity, (something), hydromechanical actuacted. 46RH is 4 forward speeds, level 6 torque capacity. I'd go with the 46RH, if it becomes a choice of 42RH or 46RH.
As for the choice between 46RH and 904, I'd go 46RH as that gets you a tidier way of getting the overdrive.
Plus, though I may be out of left field here, some of the 42s have torque converter issues. My sister has a Jeep Grand Cherokee with the 42RE that will occasionally not stay in torque converter lockup driving on the highway (above 48 mph). I believe this is a known problem among dealers (yes, she had the TSB flash to the control unit). They refuse to look at the trans "because it hasn't thrown a code". (Whatever happened to good old-fashioned diagnosis?) My Durango had the same problem for a while (46RE trans) until I changed the fluid to Amsoil and put in a new filter. Problem solved in the Durango. Fluid and filter change in the GC helped a little, but didn't solve the problem. Maybe electrical, maybe the TC, maybe something weird about the Grand Cherokee version of the trans, I don't know.
The something designation you are looking for is R for rear wheel drive