93 auto to nv4500 conversion

[Stoner93]

I've got a 93 w250 extended cab with the piece of crap auto. had a buddy rebuild it for me and less then 500 miles it lost 3rd 4th and reverse so I'm going with the nv4500 swap. I just put a rebuilt one in my father in laws 91 and kept the core to rebuild. I just ordered the parts for the rebuild, had to get a new input shaft and cluster shaft. Still need bell housing and master/slave, shift tower, 23 to 29 spline coupler, clutch pressure plate flywheel,and to fab a cross member tranny support. I have a peddel assembly. Tranny is out of a 98 and newer dodge so it has the square shift tower with the updated main shaft/fifth gear nut. All together the swap will cost right around $2100. Can't buy a "good" rebuild auto for that not one that will hold up...
The truck has a small lift with 35" tires. I put pods in it cause I was at runaway with my stock auto injectors and the pods were free... turned pump back down to compensate for auto rebuild but that obviously didn't matter. Will turn it back up for the NV4500 wanting to put better injectors and a 3" intercooler already have the three inch intake to install. Stock from 01 cummins hope it works... Also free...
If you guys have any advice about any of this let me know. I have thought about going the other way with it and converting it to a duelly for all the towing I do but we'll see need some money for all that plus that's six tires. Feel free to blow up my board and tell me what I am doing wrong. I appreciate any feedback.

[Stoner93]

Tearing into the tranny today ordered all but 23 to29 spline coupler and shift tower / boot.

[Stoner93]

Got it torn down today will continue the build tomorrow

[coolhand_luke]

very nice truck

[Stoner93]

I'm still waiting on a small parts kit for the tranny so I'm kind of at a stand still on the build. I went ahead and put the clutch and break peddle with the clutch master support, it went in fairly simple. Had all my wires running through the firewall right where the master cylinder goes so I had to move all those.
I'm looking at getting new tires soon but haven't settled on a brand I will be doing a lot of on road driving but will take it in the mountains where I could see mud snow rock and any other mountain terrain. I'm getting into hauling logs for fire wood so will probably be towing a trailer a lot on and off road. Only experience I have with tires are the KM2s. just thought I would get someone else's opinion. Considering now sizes 255/85r16 or staying with the 35/12.50r17s unless they make a size equivelant to a 35/10.5.

[Stoner93]

Does anyone have a 23 to 29 spline coupler I tried contacting SHS diesel but they have yet to get back to me. And wile I'm asking I'm looking for a shift tower for the 98 and newer nv4500

[Mark Nixon]

If you can weld worth a damn, you can make your own coupler.
If you have access to a lathe, or can otherwise cut 2 couplers, take one 23 spline and 1 29 spline coupler and cut them in half.
Make sure it's cut straight, take 2 tapered cones and bolt the 2 together, then 'V' them out, grab a sticker, or a hot mig, and buzz them together.

Even just butt welded, they'll hold enough to break a 23 spline input.

BTW, the parts are available to make a 23 spline t-case into a 29 spline, just know a machinist and use a SINGLE LIP seal, instead of the typical OEM suggested DOUBLE LIP seal, in the bearing retainer bowl.
The single-lip seal is 1/3rd shorter on the casing height and will seat in the re-machined auto bowl.

The 29 spline input, front bearing and splined sleeve set me back ~$160 SHIPPED from Zumbrota.

FYI, parts wanted ads go in the "parts wanted" forum.

Mark.

[Stoner93]

Thanks for the info on zbag. Galen told me to get the parts number or measure the input shaft bearing because some have a smaller one and you can't do the swap... Is this why you said that I need to have a machinist re machine the auto bowl?
Would much rather go this route would be better in the long run... Plan on giving this truck to my kids some day and want it to last.
Sorry for posting those things here I tried to go to the parts section but I don't have access yet. Trying to get my posts up to 25. Hope you can bear with me and my inexperience. Thanks for helping me figure out where the right place to address this type of discussion is located. Maybe soon I will be able to access the parts page.

[CumminsPower59]

For machining the adapter "bowl", you will also need the specs for the input bearing snap ring that goes around the circumference of the input bearing...

[Mark Nixon]

Thanks for the info on zbag. Galen told me to get the parts number or measure the input shaft bearing because some have a smaller one and you can't do the swap... Is this why you said that I need to have a machinist re machine the auto bowl?

The auto bowl needs to be machined to clear the input, regardless of how much and where it needs machined.
The 29 spline input just will NOT go through the hole, seal or not.
It's been said that some will accept a seal when re-machined, some won't, but if you're stuck on the OEM double-lip type seal, bank on it NOT working.
I will have the number for the shorter single lip seal sometime to-day.

For machining the adapter "bowl", you will also need the specs for the input bearing snap ring that goes around the circumference of the input bearing...

I'll have that dimension as soon as I can borrow another set of dial calipers, since I have a bowl that's already machined.

Other thoughts:
Another option is to simply bore the bowl to clear the input, minus the seal, then use a gasket, or have an 'O'-ring groove cut into the bowl face to seal it to the tranny and allow the bowl to fill with the transfer case's lube
This will be fine with a Getrag, since it's output is actually sealed off from the transfer case.

An NV4500 is a bit harder to seal off, since you'd need to step the splined coupler for the seal and then seal the inside of the coupler so the splines don't leak.
A narrow, tight fitting rubber disc with some gray silicone around the edge, fitted into the center of the sleeve would likely perform that function adequately.

In all honesty?
Other than buying the PROPER t-case, the 23/29 spline coupler is the least trouble for the $$ spent, if you don't plan on 1000 pds/ft of torque.

Mark.

[Stoner93]

Humm a lot to think about I wouldn't have the slightest idea where I am at torque wise...stock turbo stock intercooler "but plan on putting the power stroke or equivalent intercooler in within the next year" pod injectors 4" exhaust nothing really special yet. So if I thought about it I would say I'm probably not even close to 300 horse 600 torque "yet" 300 to 350 would be my goal. Maybe one day!! Just need a truck right now might start looking for a np205 with 29 spline after I get the build done and have some money.

[Mark Nixon]

Cut and dried, whether you buy a "real" 29 spline, or build one, plan on anywhere from $500 to $1000 for one.
Anyone can luck into one dirt assed cheap, but it's like anything else, just being in the right place at the right time.

Beware of the reman Ebay units!
I've tried contacting a couple of the guys on there about whether the "bowl" is included with theirs, one told me "no", the other refused to reply twice now.

Mark.

[CumminsPower59]

Seen that one bowl on eBay...$280

[Mark Nixon]

Seen that one bowl on eBay...$280

I did too.
Called and did some asking and I SUSPECT it's a re-machined 23.

Mark.

[CumminsPower59]

It's hard telling without a detailed interior shot of it....