1991 D-350 A-727
to
1991.5 D-350 A-618 swap?

As you might know my transmission has finally met its maker.

The case of my A-727 is bad and needs to be replaced and of course there seems to be nothing available to replace it with.

I have a source for a complete engine and transmission but it is out of a 1991.5 (oops) intercooled and with a A-618 overdrive transmission.
I can get the entire truck less rear end

Can I swap just the transmission onto my non-intercooled engine?

A) Is the starter on the same (drivers) side? Same starter?

B) Are the transmission mount holes in the frame rails in the same location, just the rear mount is different or will I need to drill new holes?

C) Can I just swap to the newer drive shaft? entire shaft or front shaft only?

D) I will have to check the speedometer gear to match my 3.07's

How many miles average before the overdrive goes out from poor lubrication?

I am sure this an easy swap but I do not want to replace the engine at least for now.

Thanks Jim

 

Jim I think the starter is on the other side on the 2nd gen. not .sure. You would also have to use the adapter to make room for the lockup conv. Which you should have if you buy the donor rig. Also some work on the elect. But definately worth it I would say. With the 3.07 rear and lockup o/d you will have a real good highway gear!!! Great for those lonely runs up the I-5 corridor!!!!

 

I was not sure about the starter maybe it was just on the manual transmission it was on the opposite side but I am sure we will have the answer soon.

I am going to take measurements and pictures of my truck tomorrow so I can compare them.

Also what size is the turbo on the 1991.5 18cm?

Jim

 

Hey Jim let me check with my buddy I may know where a 727 trans is .

 

You mentioned a '91.5 A-618 and then the '95.5 with an A-618. Which is it? If I'm not mistaken, isn't the A-618 the 46- or 47-rh?

The start is on the driver side for all 5.9 Cummins in the Dodge trucks. Whether it's the same model starter as your '91, I'm not positive but better off to replace it with one from the same year transmission knowing it will bolt to the transmission adapter plate that bolts to the back of the block.

The '91.5 will have the larger h1c with an 18.5cm turbine housing and 3" v-band outlet.

Can't say for sure about crossmember holes in the frame, the driveshaft(s) or the VSS gear. May just have to drive it and compare it to a GPS and adjust as needed from there.

 

The starter on the 2nd gen is on the driver side. Use the starter that comes with your donor.

I'm sure youll be able to keep the rear shaft as is.

The front shaft, youll have to shorten it and with your welding skills no problem. It doesnt need balancing since it's very short.

As far as the cross member holes are concerned, i'm not sure they'll line up, but with your MacGyver skills no problem.

As for the speedo, you may have to do similar to what I did to mine - access to PCM 8 volts and VSS sense wire. Do a search here or in the Cummins forum.

 

Sorry, my mistake.
The donor truck is a 1991.5 with about 141,000 miles

Speedo is no problem for now, the only problem is it is at the trans shop in San Dimas so I want the parts to fit without too much modifications, I just want it running so I can get it home where I can finish the job.

Don't want the shop to think they are doing a big conversion job for me.

Is the OD controlled by the PCM? I want to control it using a pressure switch or maybe some ready made control module but it seems to be pretty simple.

Also does the A-618 have a lockup or non-lockup converter in it (2-wire or 3-wire) connector on the trans?

Thanks Jim

 

Just wanted to clarify. Is it for certain an A-618? What's the difference between it and the A-518? Either way, I'd say go for it. A couple of holes to drill, maybe minor driveshaft modification. Nothing YOU can't handle.

 

The A618 is the 47RH stock in 2nd gens 94 and 95, with lockup converter, 3 wire connector. The 91.5 came stock with a 518 (non-lockup) so that A618 must have been swapped in.

Yes the OD is controlled by the PCM and by the OD button.

 

Jim are you thinking it's a 46r ? not an A618, it all gets confusing to me.

i was thinking that....

727
A518 = 46r 91.5-93
47rh = 94-95 ?
47re = 96-200?

if i'm not mistaken i think an A518 is AKA 46rh.

Darwin

 

I was asking at the trans shop about the A-518 and he told me it was an A-618 if it was behind a diesel but I could been mistaken.
I will check and see what the FSM says about the trans, he also said the A-518/ A-618 had OD issues because of the pitch of the gears and the lack of lubrication but it was still a good transmission.

Jim

 

91.5 to 93 runs an A518 transmission, also known as a 46RH. OD is electric, easily operated either manually or with a pressure switch. Put in the PCM that goes with the transmission and get cruise for a bonus.

Coupla weaknesses in the OD. Full torque goes through it all the time. The gears are angled, and so thrust. You can get a square cut planetary set for them. There's a 6000 series bearing being used in thrust application, for which it isn't really designed.

Basically they hung an overdrive on the end of a 727 to get 4th gear. It'll live, though, with good oil kept cool.

I just molested mine about 2 grand worth. I expect it will stand up.

 

So why won't my 1991 cruise control work with the new trans without a PCM if it never had one?

Jim

 

It'll work fine 518 is just a lil longer. Use ur 727 vss, speedo will read the same.


Theres also quite a few threads on here of people that have done swaps and controled od

 

47RH into first gen. I think your swap would be similar:
https://www.dieseltruckresource.com/...d.php?t=114702

https://www.dieseltruckresource.com/...d.php?t=236738

I'd like to eventually swap in a 518 or 47RH. Even if I went with a 47 without using a lock-up converter.