Manual swap advice... POLL

[K5dreamer]

Ok, so here's more thinking out loud. By now I've probably pounded my plan and end goal into everyones head. But heres the abreviated version.

I have an M1009 parts doner, complete. I want the 6.2 diesel, hydroboost, etc. out of it to swap into an earlier full convertible rig. Plan on a 6in lift, 1 ton axles, 37in tires on H1 beadlocks.

Here's the question. until now I've been hard set of a factory manual setup, because I didnt want to worry about that mess in addition to the diesel and brake system swap. But most of the rigs near me, that im finding in my price range, are automatics, but otherwise seem to be solid candidates, that meet my other requirements. (I seem to remember getting this advice from a helluva lot of y'all on here) Ive done some forum searching and not found an answer to this particular question.

How hard is a TH400 to manual swap really? Im sure a SM465 would be the cheapest/easiest option (keeping in mind the diesel/hydroboost part of the equation), but if I'm doing the swap should I go ahead and go full bore on a NV4500 if I'm going through the trouble? Or should I try to find an NV3500 for the better gear spacing? If I do a SM465 or NV4500 Ill do a NP205 TC, if i do a NV3500 Id use the NP208 out of the M1009.

 

[gonefishin]

I went with an nv4500 and love it but I am also running gas not diesel... There's nothing like dropping the clutch at 6 grand in the middle of a hole. But I love mine for the gas mpg too. Only bad thing is the $100 worth of fluid and adapting the hydraulics for the slave if you go with the 96 up

 

[1BEATK5]

I Think cost would be the deciding factor. You could do a 465/205 swap for. Couple hundred. A 4500 or 3500, can get expensive unless you get a good deal on the trans itself. I bet you could spend$2500 if you weren't careful.

If money isn't an issue. 4500 all the way

 

[blazinzuk]

Why a 205, its an old inefficient case. Why not a 241 much lower gearing its major weakness is its aluminum ( thats what skidplates are for).

Your always planning on running an old school 6.2/6.5 right so I doubt you will EVER overpower a 241.

IMHO a 4500 has the same problem as a 465 in a 465 its the gear split in between 3rd and 4th, in the 4500 its the split inbetween 4th and 5th.

Although that is more for towing than anything else

All the newer manual trans I want involve 6 speeds.

That said I am putting a 465/205 in my tow rig. But I have the wheelbase to be able to rock a gear vendors when I can afford it, I don't think a blazer really has the wheelbase to rock a GV

 

[80' 427]

My 6.2 with 4.10s and a 465 works great if you aren't in a hurry. I wish I could fit a taller tire to help lower the rpms. The 37s should help. My 454 with a 465 and 4.10s with 39.5s goes down the highway great.

 

[Russell]

I have run all 3 combos and would definitely go with the NV3500 again. The gear spacing flat out works with a diesel. The 4500 is nice for the OD gear but suffers the same wide ratios as the 465. The engine really struggles with the 3-4 shift as there simply isn't enough rpm to play with to keep it in it's power band.

If you get a 3500, you need to get one from a 97 - 06, with the 99 NBS truck transmissions from behind a 4.8l being he best.

 

[dyeager535]

With your gears and tires, what does 1:1 or the 4500 OD ratio (.75? can't remember) put you at for normal cruise speeds?

Honestly, if big tires and your gears put you in the sweet spot for a diesel at cruise, and you don't need the OD, I don't see the point. The gear splits on the 4500 with the low 1st has gear splits about like the 465 as I recall, so other than OD, no advantage IMO...longer, far more expensive and complex to swap, etc.

That said, I wouldn't mind a 4500, but I've got a gas motor, and honestly with my gears and tires the point where the swap paid for itself would be decades out, if ever. The good thing is it seems the 4500's price seems to be more reasonable now...but still not nearly what a 465 setup is that will bolt in.

 

[Kocher93]

SM465 to a np241? Rare combo but can be done and that's one hell of a low.

 

[K5dreamer]

I Think cost would be the deciding factor. You could do a 465/205 swap for. Couple hundred. A 4500 or 3500, can get expensive unless you get a good deal on the trans itself. I bet you could spend$2500 if you weren't careful.

If money isn't an issue. 4500 all the way

WOW!! I had no idea the price difference was that dramatic... sheesh.. and yeah, price is always an issue these days

Why a 205, its an old inefficient case. Why not a 241 much lower gearing its major weakness is its aluminum ( thats what skidplates are for).

Your always planning on running an old school 6.2/6.5 right so I doubt you will EVER overpower a 241.

IMHO a 4500 has the same problem as a 465 in a 465 its the gear split in between 3rd and 4th, in the 4500 its the split inbetween 4th and 5th.

Although that is more for towing than anything else

All the newer manual trans I want involve 6 speeds.

That said I am putting a 465/205 in my tow rig. But I have the wheelbase to be able to rock a gear vendors when I can afford it, I don't think a blazer really has the wheelbase to rock a GV

The desire for the 205 is purely a preference for gear driven as I feel its more reliable. I don't think I'd ever overpower a chain driven TC with the diesel, but If I'm swapping drive trains, going for bulletproof reliability is the goal. The gear ratio would be addressed later down the road with a set of lomax 3:1 gears.

I have run all 3 combos and would definitely go with the NV3500 again. The gear spacing flat out works with a diesel. The 4500 is nice for the OD gear but suffers the same wide ratios as the 465. The engine really struggles with the 3-4 shift as there simply isn't enough rpm to play with to keep it in it's power band.

If you get a 3500, you need to get one from a 97 - 06, with the 99 NBS truck transmissions from behind a 4.8l being he best.

Oh yes, If I go 3500, you will quickly become very annoyed with how many questions I start asking you The only concern I had was reading up years ago there were concerns with the strength of a 3500, with a 5000lbs rig, and big tires (obviously 37's arent big to everyone). so while the gear spacing is better, I always had that little thing in the back of my head saying eventually something would break.

With your gears and tires, what does 1:1 or the 4500 OD ratio (.75? can't remember) put you at for normal cruise speeds?

Honestly, if big tires and your gears put you in the sweet spot for a diesel at cruise, and you don't need the OD, I don't see the point. The gear splits on the 4500 with the low 1st has gear splits about like the 465 as I recall, so other than OD, no advantage IMO...longer, far more expensive and complex to swap, etc.

That said, I wouldn't mind a 4500, but I've got a gas motor, and honestly with my gears and tires the point where the swap paid for itself would be decades out, if ever. The good thing is it seems the 4500's price seems to be more reasonable now...but still not nearly what a 465 setup is that will bolt in.

The 4500 isnt necessary by any means, you can see in the options above, the addition of the OD option transmissions allow deeper gears (4.88's). but the 465 and 4.10's would do just fine on the road with the 37in tires, buzzing about 2048 rpms at 55mph. the 4500 or 3500 with 4.88's and 37in tires would spin 1779 rpms at 55, and 2038rpm at 63mph.

To throw even more monkey wrench in the equation. the 4500 and 3500 with 4.56 gears and 37's would let me run 65 on the highway at 1965 rpms, and 60mph at 1814 rpms. right around the sweet spot for fuel economy on these diesel engines.

At the end of the day, the 465 trumps the 4500 in my eyes, the crawl ratio (sm465/4.10 vs nv4500/4.56) is 80:1 vs 89:1, and as long as I behave on the highway (55mph) and only give up 10mph for fuel economy. for the huge price difference thats a no brainer.

the question now would be sm465 vs 3500. and basically its price vs better driveability.

but this is gonna be a toy, driven every once in a while, and used to pull people out of ditches in bad weather. but will be expected to do alot of highway driving to get to camping areas and concerts.

 

[gonefishin]

Hmm let's see I bought the trans used for 900 then a new clutch and slave cylinder for about 300 then I think I gave 150 for the pedals and then about 100 for all the fittings and an line for the hydraulic clutch and the master was like 30 I think so that's about 1500 give or take still its probably 700 more than the 465 swap

 

[Russell]

I still say NV3500!

I ran my NV3500 in my K5 with 1 tons, 37" boggers, lockers front / rear and a lead right foot flogging every last ft lb of torque I could coax out of my hopped up & turbocharged 6.2L diesel. I dropped the clutch, power shifted and generally abused that poor little transmission for years without so much as a wimper.

The NV3500s from the 99+ 4.8L trucks are not the same as the weenie Getrag 290s of the late 80s and early 90s. Those transmissions sucked, and broke easily. The new ones have much improved cluster gears, shift rails and main shafts and will take a genuine butt kicking. Definitely not on par with an NV4500, but it is not something to stick your nose up at.

I am always here to help you with the swap man! Heck, give me enough notice and I'll come down for the weekend and help put it in

 

[blazinzuk]

The gear ratio would be addressed later down the road with a set of lomax 3:1 gears.

Well those might be a bit hard to find as they don't make them anymore.

 

[Richcz28]

I'm running a 6.2 sm465 208. I have 33s and 3:08s. Yes it is slow. I would never use 5th on the highway and rarely get my truck over 55mph. Be realistic with how you are going to drive it. I drove to pennsylvania from mass at 55mph and speed didn't matter because the 6.2 got 22.5mpg With my tsls my truck gets wobbly above 55 anyways.

I got all my manual swap parts from a donor truck thanks to help from 496truck. It was the way to go. When you see everything come out it is much easier to put back in.

 

[K5dreamer]

Ok, so If I can find a factory setup, Ill go with the SM465/205, because it will obviously be cheaper that way as no swap equals no dollars, and my axles already have 4.10 gears. making it even less expensive. and it will certainly get the job done even if its not "perfect".

If I find a solid truck that happens to be slush box equipped, and I have to do the swap, Then Im gonna go with the 3500/208 combo and put together the "perfect" setup for me if I'm gonna go through the trouble of the swap.

Simply because Im not likely to use the truck as a serious Rubicon style rig, bouncing it off tree's and boulders. And its more likely to be hauling people and coolers to campsites, and national park trails far from home, some mild mud and stream crossings, and I dont have a tow rig. And given the fact that lo max gears are no longer available the crawl ratio with a SM465/205/4.10 setup is only marginally better (52.64:1) than the NV3500/208/4.88 setup (51:1), and is still buzzing above the optimal 1800rpm highway speed (1936rpm) at 52mph, not even 55mph (where its 2048rpm). When I seriously look at what I'm going to be using the rig for, driveability becomes more of a priority.

The NV3500/208 setup leaves me with two options to decide between.

4.88 gears will give me cruising speeds of...
55mph @ 1779rpm
60mph @ 1941rpm
65mph @ 2103rpm

and a crawl ratio of 51:1

5.13 gears will give me cruising speeds of...
55mph @ 1870rpm
60mph @ 2040rpm
65mph @ 2211rpm

and a crawl ratio of 53.6:1

The tree hugger in me is leaning towards the 4.88's because of the roughly 100rpm lower speed across the board. But I will be putting a turbo on the diesel, and running a turbo'd diesel below 1800rpm on the highway for extended periods is usually no bueno. and for a geared truck, 2040rpms at 60mph isnt too bad, my diesel jetta runs around 2000rpms at 60mph....

guess that means im going 5.13's now that Ive gone and typed all that out...

 

[K5dreamer]

so... assuming Im starting with a rig equipped with a TH400/TH350 and an NP205... Im thinking Ill need....

NV3500 out of a late model 4.8L chevy full size
(does it have to be a 4x4 model? or can 2wd models be converted?)

NP208
(already have in the doner M1009, does that have the right spline count to mate to the NV3500?)

Clutch and flywheel assemblies to mate the 6.2 to the NV3500

Slave and master cylinder assemblies

clutch pedal assembly for that truck body style

lines to connect master and slave cylinders

Is a manual trans steering column required?

Ill need the ring gear assemblies for the D60 and D70HD axles

Ill need the 4.56 and up carriers for both axles as they currently have 4.10's.

for the swap, Ill obviously need to cut a hole in the floor for the shifter, and drill the holes for the shift pedal assembly...

how much am I missing here???

 

[K5dreamer]

and because i have an unhealthy love of numbers crunching....

The 5.13 option is further solidified by the driving characteristics...

1st gear - drive 10mph @ 1873 rpm, shift point 14mph @ 2622rpm
2nd gear - drive 17mph @ 1837 rpm, shift point 24mph @ 2594rpm
3rd gear - drive 28mph @ 1826 rpm, shift point 39mph @ 2544rpm
4th gear - drive 39mph @ 1817 rpm, shift point 55mph @ 2562rpm
(and 45mph @ 2096rpm)
5th gear - drive 55mph @ 1870rpm
(and 60mph @ 2040rpm)
(and 65mph @ 2211rpm)

Thats a nearly perfect layout of common speed limits, of 10, 15, 25, 35, 45, 55, 60, and 65 mph respectively, all (except 45, 60, and 65) at slightly above the optimum 1800rpm cruise for this engine. especially when you consider we all drive a few mph over the posted limit in the real world.

Im almost finding myself feeling like I SHOULD look for an automatic truck to convert although a factory manual would already have many of the parts I'd need.

 

[Russell]

Ok, here is what you'll need to pull off a clean swap.

NP208 must be 32 spline 6 bolt round bolt pattern (think TH400 or SM465)
NV3500 must be a 4x4 model, 2wd cannot be converted.
You'll need an 85-87(91) hydro clutch pedal & brackets with a master cylinder and clutch hose for an SM465.
Get the clutch hose and internal slave cylinder with the NV3500
You can use the auto column if you want
Use a flywheel and clutch for a 6.2L / SM465 truck.
Get the reverse light wiring for a manual transmission truck from 78-87(91)

Bolting the transmission in is easy. Put the clutch on the engine, and bolt the transmission up like you would an SM465. The slave cylinder is also the throwout bearing. It uses the same pilot bushing as an SM465 does. You can re-use the stock transmission crossmember from your automatic with the NV3500. Transmisison mount too (still hasn't changed all the way up to 2012!). You need to make sure you cut the shift tower opening up in the floor ahead of time as it sticks through the floor a bit.

To hook the clutch up, buy an appropriate sized compression fitting (I very highly recommend Swagelok if you can get ahold of it down there) and splice the two clutch hoses together where appropriate. Another option is to purchase the adapter fittings required to convert the clutch hose to AN fittings (they exist for both the master and the slave).

Hooking the reverse lights up is a matter of unplugging them from the switch at the base of the steering column and plugging them into the extension harness you'll pick up for the manual truck. Pass it through the firewall and plug it into the transmission. The SM465 and NV3500 use the same reverse switch connector at the transmission.

The transfer case bolts directly up to the back of the transmission with no adapters. You'll hook up your speedometer like normal. You will need to move the NP208 shifter back towards the center console a few inches to make room for the NV3500's shifter boot (or just find a different shifter boot for the transmission). If you do relocate the shifter, you'll need to take the shift rod out and add some threads to it to shorten it down the same amount you move the shifter back. Your driveshafts will still fit as the NV3500 is the same length as your automatic is.

Voila, NV3500 swap complete

If you need a hand sourcing a compression fitting (don't use the junk they sell at home depot) I'll go snag one for you and pop it in the mail. The stuff I use is made of 316 stainless, is rated for 22 000 PSI operating pressure without letting go of the tubing (plastic or metal) and will not crush the tubing either (ID stays the same unlike the cheap stuff)

 

[K5dreamer]

That is all

 

[Richcz28]

Has the hydraulic setup been tried and tested using a master from a sm465 and a slave from a nv3500? Does the amount of fluid travel match up? If the slave is smaller you could break a seal and if the slave is larger you could not disengage the clutch...

You do not need to swap steering columns. I kept my original, because it matched the wiring under the dash. You may need wiring and column from the M1009 to match the 6.2, but I do not know that. There is a pin that is pressed into the auto shifter lever that can be pressed out to remove. I also took my gauges out and removed the auto shift indicator pattern. Maybe someday I will mount something interesting in there.

I noticed Russel said you may have to cut the floor to fit the nv3500. A small body lift may be another solution?

 

[Russell]

Has the hydraulic setup been tried and tested using a master from a sm465 and a slave from a nv3500? Does the amount of fluid travel match up? If the slave is smaller you could break a seal and if the slave is larger you could not disengage the clutch...

You do not need to swap steering columns. I kept my original, because it matched the wiring under the dash. You may need wiring and column from the M1009 to match the 6.2, but I do not know that. There is a pin that is pressed into the auto shifter lever that can be pressed out to remove. I also took my gauges out and removed the auto shift indicator pattern. Maybe someday I will mount something interesting in there.

I noticed Russel said you may have to cut the floor to fit the nv3500. A small body lift may be another solution?

Yup, I have personally tested and confirmed that the displacement of the hydraulics match. GM still had the same displacement even for the ZF6 Used behind the Duramax.

The floor cutting is for the shift tower, which is located a few inches further back on the transmissions from the newer body styles.