Auto to Manual trans.

[dodjh]

727 has been leaking fluid and need to deal with it.

I have a 4speed from an '84' Dodge pickup with the granny Low.

Mine has the 318 and 203 TC. What would be involved to swap the 727 with N435 or 455 ( not sure which it is as I'm typing but it is the granny Low)?

 

[nattieleather]

727 has been leaking fluid and need to deal with it.

I have a 4speed from an '84' Dodge pickup with the granny Low.

Mine has the 318 and 203 TC. What would be involved to swap the 727 with N435 or 455 ( not sure which it is as I'm typing but it is the granny Low)?

Lots would be involved, but not impossible. You would need the transmission, clutch, flywheel, bell housing, throw out bearing, clutch linkage, peddle, and all that goes with it. The shift lever. You would need to see what is needed to adapt the manual trans to the 203 transfer case (sorry I don't remember if it is divorced or not). You'd have to cut a hole in the floor for the shift lever and adapt everything for the clutch peddle and then you would have the old gear shifter on the column that would just be hanging out. Plus you may have to change both front and rear driveshafts as the location of the transfercase may change which may also lead to changing brackets etc.

Personally I would just put the time and money into fixing the 727 and keep on driving it as is. In MHO that is less work than trying to convert to manual. But that's just me. If you do this post lots of pictures.

 

[dodjh]

Good advice....I have everything ......You would need the transmission, clutch, flywheel, bell housing, throw out bearing, clutch linkage, peddle, and all that goes with it. The shift lever. ......... Would be much more problematic to swap out to the manual trans.

Thank you for your reply and advice.

 

[michigandon]

NP435 would be the correct transmission.

 

[dodjh]

 

[deathrowdave]

NP 435 has 2 output shaft lengths , one for a 203 case and one for the 205 , 208 , 241 . All are 23 spline . Do not loose the coupler between the trans output and case input , they are no longer available and are reaching untouchable costs to purchase . I recently sold a complete change over for 600.00 , that was everything and 2 axles , I have everything from the knuckle out to convert to lockout hubs if you need it also remaining .

 

[dodjh]

Thanks again deathrowdave for a reply...not sure if I have the coupler between trans output and case input.

 

[deathrowdave]

Switch it to later NP435 and 205 , 208 or 241HD , all are good . 205 is all gears , 241 is the lowest ratio . I switched mine to 4BT and NV4500 , it took me 5 years to locate all the parts to swap it over . The diesel had to have OD or only drive 55 MPH . I’ll contact a few Buds and see what parts are floating about for you .

 

[dodjh]

Thanks!

 

[msgjd]

not really a big deal if you have everything on hand and ready .. There is only one thing that will stop you from doing this conversion, some 318's with automatics do not have a pilot bearing hole machined into the crank...

I did one muscle car tranny conversion in the 1970s and three mopar truck tranny conversions somewhere between 1985 and 2005, all 1970's vehicles and components. .. The flywheel will bolt up in place of the TC.. You can grab the floor pan from a Std truck or just neatly cut your own holes, the xfer case hole is an oval... I kept the original NP203 xfer cases just because they had no issues ... I forget which model tranny I stuffed in them but they were 1970's dodge/plymouth Dana OEM with the non-synchro 1st .. the manual tranny bolts right up to the same existing xfer case adapter .. And to assist in lowering/raising , I always kept the tranny and xfer case together as a set coming out and going back in, keeping the crossmember attached to the set.. As long as the tranny/xfer package you are using has the same lengths as the original 1970's set, your existing driveshafts fit just fine... I think what was hardest was changing out the brake/clutch pedal assemblies , not exactly a comfortable position to work . . the good news is the existing A-frame for the pedals works for either setup, you don't have to R/R it. .. I did the tasks alone, but now at my age , well, I would probably still be stubborn enough not to ask for help

 

[dodjh]

Good information, the 318 is a '76' so not sure if the crank has been machined with a pilot bearing hole or not.

Probably the best way to do that, for that reason, is to pull the engine. I think dropping Tans, and TC would be a lot more work.
By doing the latter though, if it is machined for PB I could continue on with the swap.

The Transmission shop that rebuilt my 727 in an '89' Dodge RC, is no longer in business, so have no idea what it would cost to rebuilt the 727 in the M880.
Thank you for the reply and I'll have to determine which route to take. I'm still, periodically adding transmission fluid to keep it going.
That stuff is expensive compared to years ago but I guess, what isn't.

 

[msgjd]

Good information, the 318 is a '76' so not sure if the crank has been machined with a pilot bearing hole or not.

just to be clear, it doesn't matter which 70's year the 318 is.. some of the ones mated to automatics had the PB holes, others don't .. It's a crapshoot... I think the same for the 360's as well, but I don't remember. I converted a 360/auto truck to std once, but I also had had that engine rebuilt previously with a forged crank and forged rods etc.. It's very likely I had planned ahead and requested it done with a crank with PB hole for a standard although at the time the truck would stay an automatic for several more years before I eventually did the conversion . that particular swap was done around 1987, too many experiments before and since then

 

[msgjd]

Probably the best way to do that, for that reason, is to pull the engine. I think dropping Tans, and TC would be a lot more work.
By doing the latter though, if it is machined for PB I could continue on with the swap.

If you have a smooth floor and a tranny jack, or at least a large floor jack, you can safety-chain the tranny/xfer assembly to it, unhook the driveshafts, unbolt the bottom half of the rear-mount crossmember, and roll the entire thing back just enough to get at the TC and see if there is a PB hole .. But you shouldn't forget to place blocks at the rear oil sump of the motor for support else you could get a fan blade in your radiator or at least a bent distributor shaft.. (don't ask how I know, teenage mistake from my very first transmission rebuild) .. If I remember right, the balance point was right under that crossmember/mount, but check it out. It's been a long time. That xfer case weighs more than that tranny, but all together it's still much lighter than the motor . whatever you want to do

 

[msgjd]

have no idea what it would cost to rebuilt the 727 in the M880.

a top mechanic at a dealership (now a retired brigade LTC) told me in the early 80's the small-block 727 was designed as a car tranny and should not have been put in any of the trucks that would be doing real work, especially the full-time 4x4's. .. that was his opinion... But the 727 was also in certain muscle cars and it took quite a beating .. He defended his opinion by saying muscle cars would break traction and the damage would be prolonged, they would hold up longer to it. But the full-time-4x4 trucks were much heavier thus the tranny got all the inertia and stresses.. I have no opinion other than I have never been sorry swapping out for standards in my muscle car or any of the dodge/plymouth trucks I had/have, especially if it's going to be a hard-working truck. My M890 still has its original (low-mileage) 727 but it always springs a leak somewhere, especially when it sits a few months, and it came direct from DRMO with a cracked valve body (creeps forward in neutral) .. Not the first time I have seen a cracked one,. The last time I had a 727 rebuilt was in the mid-80's in my '77 TD. Cost $900 (when a great paycheck was $400/wk).. It didn't last 4 years towing a 4T-rated trailer and extensive snowplowing. Never again.

 

[dodjh]

Good information...the NP 203 is around 200lbs. and hadn't thought about rolling TC and Trans. back...sure have plenty of room under it w/ the 36" Hummer run flats on it. The original one I bought had no issues until the right side tire turned all the way in one time while driving it. Bought another M880 complete except TC and swapped out the front right assembly...a few weeks later truck did the same thing. So I parked it and drive the one I have now. (3rd one)
I like the orginal one better but hasn't been cranked in 5-8 years so Trans. is probably not usable. Oh well.

 

[Bob H]

I like the orginal one better but hasn't been cranked in 5-8 years so Trans. is probably not usable. Oh well.

If the trans worked 5-8 years ago when parked, it should still work now.

 

[dodjh]

Didn't think it could be that easy, except for the actual change over. I would be really stretching it to think the carb. is okay too...right?