Auto to manual 98 Sierra 5.7

[PatGlocks]

So I joined the forum a few days ago and I've been on here day and night I've come to the point of wanting to do a manual swap into my truck.

Now, I've spent hours on google an different forums looking for my specific truck with a manual swap, not sure if I'm looking up the wrong thing or what but I can't find the answers that I need.


So, I've come to y'all for help:

1. 1998 GMC sierra SLE with the 5.7 in it, 2WD, which tranny do I have ? ( I'm assuming 4l60e from what I've read but no idea)

2. Will a NV3500 bolt up? Will it be strong enough to handle the V8? Or should I go with the NV4500?

3. Driveshaft? Can I use my current one or...?

4. Will clutch assembly(pedals, master, etc) work from any GMT400?

5. Wiring, will I need a reture or something like that?


All of the write up's I've seen have been on 4x4's so I'm a little lost here.


Sorry if this stuff has been covered before, I've tried using the search bar and google and I'm still stumped!


Link to a write up would be nice if someone knows of one.





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[98_k1500]

Welcome to the forum. I know this is not exactly what you are looking for, but im sure someone with more info will chime in soon. I ended up buying a truck that had a nv4500 already in it, and swapped my vortec 350 to it. I know both transmissions will physically fit. The trans mount/crossmember will need to stay with the trans. Other than that, I am not much help to you. Mine is in a 4x4. In my opinion, the nv3500 is pretty weak, and having a full aluminum case is not worth the weight savings. That bein said, if you did'n rod on it, it would probably last a very long time. There are alot of 5 speed folks on here, Im sure someone has the answers to your questions.

 

[PatGlocks]

Guess I should have posted my plan for the truck haha. It's just a DD so being a 2WD I want to put it on the floor and have a nice cruiser with a 5 speed.


You bring up a good point tho, what about trans x-member? Do I use the one out of an s10 if I grab a nv3500?


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[98_k1500]

An s10 cross member won't fit. You really need to find a donor truck where you can get the flywheel, pressure plate, transmission, clutch pedal, cross member, drive shaft, computer, wiring harness, steering column, and gauge cluster all from one place. It will make the swap easy, and could be done all with factory parts. You could then part out what you don't need on the donor truck and make most if not all of your money back on it. I realize finding a donor for this type of thing is not easy, but it would take most of the headache out of doing the swap.

 

[SCOTTYINWV]

Look for a doner 96-98 c2500 or 3500. That will give you a stronger rear end, correct driveshaft, stronger nv4500 transmission with all the wiring and bits to do the swap. I seen you mentioned towing your 240, this will all help.

 

[K15 Blazer]

i have the NV3500 in my truck =)
but its 4WD
yeah, it will absolutely bolt right up. even the 4.3V6s are the same for 2WD.




1. 1998 GMC sierra SLE with the 5.7 in it, 2WD, which tranny do I have ? ( I'm assuming 4l60e from what I've read but no idea)

yup- 4L60E

2. Will a NV3500 bolt up? Will it be strong enough to handle the V8? Or should I go with the NV4500?

Yup! NV4500 is SUPER heavy duty though... are you towing a battleship or installing a 400+ HP motor?

3. Driveshaft? Can I use my current one or...?

yes if you find a GMT400 manual as a parts vehicle. doesn't hurt to upgrade though.

4. Will clutch assembly(pedals, master, etc) work from any GMT400?

yes. the only thing they changed was the slave cly. one model is external with a fork, one is an expanding throwout bearing. pedals and stuff, all the same.

5. Wiring, will I need a reture or something like that?

speed sensor?... maybe?... reverse switch wires?... easy easy stuff.



I really torture mine climbing sand dunes and DD traffic so yeah... NV3500 will be totally fine. but do upgrade the 10-bolt to something else with posi-traction if you can.
having a manual frees up about 50 HP so your MPG will go up too.

 

[mudtruck89]

This is a swap i've been looking into for my 89 extended cab long bed 4x4. im pretty new here but I have done my home work and for what I wanna do; towing a lawnmower, mostly highway cruising and maybe towing some larger stuff, an NV4500 seems like the most cost effective and easy swap to do.I do have one question though is there any way to possibly have a mechanical clutch instead of a hydraulic clutch? im no transmission genius so that's why im asking

 

[michael hurd]

By far the easiest / cheapest method would be to find the truck with what you want, buy it and be happy.

 

[PatGlocks]

See, only thing is where I'm at it's a lot harder to come by a 5spd gmt, and if I do chances are it's probably fubared or cleaner than my truck and an arm and a leg. I was hoping to just grab a junkyard trans grab some pedals slap it all on and give'r but the donor truck is gettin out of budget and I don't have space for another vehicle at my home


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[blazin8556]

By far the easiest / cheapest method would be to find the truck with what you want, buy it and be happy.

where is the fun in that? your one of those pple that just drive the truck. like my father in law. does it run and drive? yes leave it alone. im one of those pple that can't leave crap alone and want to make it better. if someone wants to build the vehicle i say let him. if they want it to look like and drive like the truck next to them at the red light. thats fine too.