Transmission mount dimensions...
 

I'm looking for some kind of a source..on-line, or catalog, that list transmission mounts and their...Height, length, bolt spacing, etc. I've been scouring the internet for weeks now and can not find anything. I have found a few dimensions here and there...but nothing that gives me a wide enough range of mounts to try and find the one I need to make the transmission cross member for the crewcab, work with the NV4500.

Closest I've got solving my problem was an E-mail I sent to Advanced adapters asking if they carried a conversion mount, or cross member for this kind of a swap...Getrag 360 to a NV4500. I received a response, and a small PDF file that showed some slight modification to the stock cross member, and the running a GM TH350/400 tranny mount. I tried this but the mount it too short.

Anyone have a source?

I'm pretty sure advanced adapters also puts a piece of square tubing in between the gm mount and the crossmember, I think it's 2.5". Check on their site and it should tell you, try mounts or kits, can't remember exactly where it's located there, but I did read it with the size of it.

I just looked on AA's site and it's a 3" square tube. Download the instructions on the Getrag conversion kit and it gives you dimensions of everything.
And the tube goes against the trans then the mount.

Those square tube adapters are for 4wd conversions...not the 2wd conversion I'm working on. But thank you anyway for your replies.

They also have instructions with pics for the 2wd install. Try part# 712585 and download the install instructions. It says the gm mount sets into the dodge crossmember channel.

Yup that is the file I was sent from AA...showed the slight modification, and GM mount. I tried this already and the GM mount...while it does bolt up to the NV4500...it puts my tranny at too low and angle. I need this same mount...about an inch taller.

What if you modify the crossmember? 1 inch flat stock, sq tubing or angle drilled through...Or longer bolts w/ bushings spacing the tranny mount higher. Or even welding the bushings in w/ gusseting for strength.

....../I I\....... <-----like this.

Was considering doing that...but I'd really like to find a drop in mount that I don't need to modify. I'm thinking more for others doing this swap down the road...make it off the shelf parts...with minor mods to your current cross member.

I hear ya...Sometimes it's either gas, time, shipping and money looking for the parts you need. Or just end it and build it yourself.

I'm thinking about just ending it...since I've decided to convert to 4x4 I'm really not seeing any reason to pursue this.

I would kind of like to see it through to the end though...more for the fact I've vested so much personal time on trying to find the perfect combo.

I have decided to post what I have learned as it pertains to our 1989-1993 First Generation Cummins trucks, with regard to TRANSMISSION CROSSMEMBER & ISOLATION DIFFERENCES.

Wonder of Wonders, I will also be illustrating this WITH PICS!!!

Please note! This does NOT cover the 727 automatic OR 1991 Overdrive 518 arrangement!!!

Picture 1, below, depicts both the automatic crossmember (closest) and the 5 speed crossmember (farthest).
You'll note, by careful examination, that the closer crossmember, the automatic version, appears taller on the front edge, which it actually is.
PLEASE NOTE, the TAPERED side of the crossmember is located to the DRIVER'S SIDE of the truck, for reference.

Attachment 54957

Picture numbers 2 and 3 show the crossmember center areas.
You will note the difference in heights in the isolator mounting area, the more varied difference is the early 5 speed version.
Automatic:
Attachment 54958

5 speed:
Attachment 54959

Picture number 4 depicts the whole of the mount arrangement, in a dis-assembled state.

Attachment 54960


Of particular note is that the isolator ITSELF, 3rd part from the end, is the SAME isolator used in ALL applications, automatic, 5 speed Getrag, 5 speed NV4500 (Gas) and even in the A-535 found in the 6 cylinder D-150s! Very universal part!
Also note the 4th part, which is unique to certain 2WD Getrag applications.
Why "CERTAIN Getrag Applications" you ask?
Because I just recently have found that there are actually TWO separate stock arrangements for the Getrag 2WD mount and the break point in years, near as I can ascertain, is 1992.

In 1992 Dodge, along with General Motors, got together to create the NV4500, which Dodge then used in the 1992 and 1993 Dodge trucks from 1/2 ton through 1 ton. It was used with ONLY the GAS engines in Dodge's line up, the 3.9, 5.2 and 5.9 360 V-8.
Why even mention the GAS engines? Because the parts DO exist to make a clean install of an NV4500 into a 1st gen chassis.

It is interesting to note that the mount and cross member arrangement for both the LATE getrags and the NV4500 use a hybrid of parts between the automatic arrangement and the early getrag arrangement.
Essentially the "NV4500", or late G-360 arrangement, uses the AUTOMATIC crossmember and isolator with the isolator support bracket garnered from the manual transmissions (1st item in pic 4).

Moving on, we see pics 5 and 6 showing bolt hole arrangements.
This will be more for ease of identification, than anything.
You'll note that pic 5 shows a crossmember with 5 holes drilled into it, 3 fore and 2 aft. This is the early Getrag crossmember.
Pic 6 shows 6 bolt holes, 3 fore and 3 aft. this is the automatic, NV4500 and Late Getrag crossmember.

5 speed (early) holes:
Attachment 54961

Auto/NV4500/Late G-360:
Attachment 54962

The following 3 pics are various angles of the early 5 speed mounting arrangement;
Rear:
Attachment 54963
Side:
Attachment 54964
In place:
Attachment 54965

I hope you enjoyed the pics and my ramblings![roll]

Mark.

Thank you Mark!! I appreciate your contribution to my saga..[laugh]

So I need one of the U-shaped brackets and I can try again. But I still think it will put my transmission too high.

I don't understand what you mean by "too high"?
The crossmember is designed so that there is a significnt "drop" to it, so if you use what works for you, the orientation should be correct.

Keep in mind, the 2WD cross members all orient off the TOP of the framerail, which is always oriented the same no matter the frame height, unlike the 4WD crossmember that mounts to the BOTTOM of the frame rail, which can change the height due to the frame rail being taller or shorter.

I think if you have the first part in pic 4, you should be able to properly orient the transmission with the isolator and cross member you just bought.

Mark.

My too high I mean that my transmission will be pushing against my floor boards. Right now with the cross member in place, tight against the top of the frame like it's supposed to be, I have maybe 1" between the cross member and the flat mounting pad on the NV4500.

Is there more then one source for that U-shape bracket? Other years and tranny configurations?

Not sure if this is any help, but here is a photograph of the OEM transmission mount setup for a 1993 automatic:
https://www.dieseltruckresource.com/...nny_Mount3.JPG

The steel saddle riveted to the crossmember is apparently for the later model first gens only, those with 7" frame rails. The part number for the four rubber tranny mounts is the same for the manual and automatic transmissions, but the steel plate (roughly 3/8" thick) part number is different for the manual and automatics.