V731 to V730

[Cary and Don]

We considered changing our V730 out for a V731.  The answers here made that sound like a lot of work and we would have to live with an electronic controlled transmission. So the next question is,  can the V731 be transformed into a V730?  We pulled the pan on the V730 and there were signs of wear in the bottom,  a few metal shavings, like sand. It may be good for years, but we have this nice new transmission just sitting here.

Don and Cary
GMC4107
Neoplan AN340

[Cary and Don]

On another note,  does anybody know of an oil pan, the filter that sits inside the oil pan, and a new gasket for it.  It looks like the idiot that installed the transmission jacked it into place from under the oil pan.

Don and Cary
GMC4107
Neoplan AN340

[PSmith]

I would bet you can swap out the valve body, shift arm assy and other obvious pieces from the 730 to the 731 ( new ).  The real difference is the 731's valve body is 'electronically shifted' .  Investigate the differences and I'll bet you can move the pan as well.  I believe the cases are the same.  Since you have both, why not make the 731 into a 730 with the best pan,filter,etc.

I've had mine all apart and back again with new hard parts,clutches,bearings,etc. successfully.  It's just a BIG automatic.  Applying standard practice's for rebuilding anything and you'll be just fine.  Listen not to the Nay Sayer's or you'll never get anything done !!  NO FEAR !

[TomC]

Going from a 731 (electronic) to a 730 (mechanical) is a relatively easy switch since you're not concerned with all the sensors.  The actual internals, like the clutches, gears, etc are the same on both.  Just the valve body is different.
Now changing from a 730 to a 731 is just about impossible, as state because of the additional sensors.  Good Luck, TomC

[CraigC]

You also have to change the rear cover of the V731. The 731 has a electronic governor sensor a small round hole for the gov. sensor.
I know you are familiar with the mechanical governor. I delivered you the new gear on I-5 a couple of years ago.  As you know the mech. gov. has a cover with 4 bolts.
The output shaft will have to be swapped. The 731's shaft does not have the spiral gear cut in it to drive the governor's nylon gear.
You have all of the parts to do this except the gaskets. If you decide to not do this I might be interested in your 731.

[Cary and Don]

We thought it would be pretty easy to do the swap.  We were wondering how hard it would be to change the V731 unit into a V730.  It appears that the only difference is that control unit on the bottom of the V731.  That would have to be replaced with the shift control used on the V730.  Not sure if that is possible.

Don and Cary
GMC4107
Neoplan AN340

[CraigC]

I assume you do not have the service manual or a parts book. My e mail address is under my profile. I will happy supply some copies of a few pages that might help clarify your question.
The shift mechanism is in the value body that would already be change out.
The rear cover can be pulled with the output shaft, 2 brgs., governor assy complete, speedo assy complete & driveline ( output ) flange as a complete unit. If you swapped this out you would have 2 old brg's. from your V730 unless you take this assy. apart.

You have to change BOTH the the value body & the rear trans cover.

I had one of the parts men at the local DD / Allison parts house state they do not have a V730 parts book any more. If you run into this I have an old parts book that I will get the gasket part numbers for you. The numbers will more then likely have to update, DD calls it superseded.

Good luck

[Cary and Don]

Thanks for the information Craig.

Now for the decision as to just getting the rest of the parts to install the V731 as is or do we really want to turn it into a V730 or just wait until the V730 quits at some point.   We can see from the book and the V731 there wouldn't be any "fix it yourself" on the road.  Everybody seems to think that the V731 is less reliable.

Don and Cary
GMC4107
Neoplan AN340

[Cary and Don]

Craig,  your email isn't listed under your profile.

Don and Cary
GMC4107
Neoplan AN340