Swap to manual transmission.

[Karl Larsson]

Gona make a transmission swap in my Chevy M1008 from its original TH400
to a manual NV4500 out of a 1989 6.2l diesel GMC 2500 pickup.
I Think I have sorted out the most parts needed, only Think missing is a
manual pedal assembly from a squarebody.
My question is do I need a pedal assembly from a squarebody with manual and diesel,
because of brakeboost.
to get the right on? Or am I good with a pedal assembly from just any squarebody with
manual transmission.
"My plan is to use the hydralic slave cylinder lines,ex. from the gmc-89"

Thank Karl.

 

[nvrenuf]

You'll likely want a set of pedal from an '85+, these used clutch hydraulics whereas the '84 and older had manual linkage making the clutch pedal different. I know there is a difference between vacuum and hydroboost brake pedals but I'm not sure exactly what it is, as far as I know the year break doesn't apply to the brake pedal. Hydraulic pedals are fairly sought after so expect to pay $150+ for a set, sometimes as much as $250. I would think that hydroboost style hydraulic pedals would be pretty hard to find so you might look in to getting vacuum type and then swapping the brake pedal.

 

[trukman1]

I did a hydro boost swap on a '67 and used the original brake pedal. Just had to re-drill the mounting hole for the push rod (and adjust length) so it lined up correctly.Not exactly what your doing but info none the less.

 

[obijuank5]

You can buy either set of pedals. You can just swap your brake pedal itself in place of a vacuum pedal on the hydraulic clutch pedal assembly.

 

[Karl Larsson]

You'll likely want a set of pedal from an '85+, these used clutch hydraulics whereas the '84 and older had manual linkage making the clutch pedal different. I know there is a difference between vacuum and hydroboost brake pedals but I'm not sure exactly what it is, as far as I know the year break doesn't apply to the brake pedal. Hydraulic pedals are fairly sought after so expect to pay $150+ for a set, sometimes as much as $250. I would think that hydroboost style hydraulic pedals would be pretty hard to find so you might look in to getting vacuum type and then swapping the brake pedal.

Thank you very mutch for the information

 

[campfire]

Gona make a transmission swap in my Chevy M1008 from its original TH400
to a manual NV4500 out of a 1989 6.2l diesel GMC 2500 pickup.
I Think I have sorted out the most parts needed, only Think missing is a
manual pedal assembly from a squarebody.
My question is do I need a pedal assembly from a squarebody with manual and diesel,
because of brakeboost.
to get the right on? Or am I good with a pedal assembly from just any squarebody with
manual transmission.
"My plan is to use the hydralic slave cylinder lines,ex. from the gmc-89"

Thank Karl.

NV4500 wasn't put in GM trucks until 1993. A 1989 truck should have had an SM465 4-speed (unless converted).

As stated above, pedals mix and match. You want a bracket and clutch pedal for hydraulic clutch (1986 and forward), brake pedals are easy to swap back and forth. Cut the pad down on your existing pedal and don't worry about finding a new one.

Otherwise, the swap is pretty straightforward. GM NV4500s are split into 3 groups: 93-94, 95, and 96+. Make sure you know which style you're installing so there are no surprises down the line.

 

[Karl Larsson]

NV4500 wasn't put in GM trucks until 1993. A 1989 truck should have had an SM465 4-speed (unless converted).

As stated above, pedals mix and match. You want a bracket and clutch pedal for hydraulic clutch (1986 and forward), brake pedals are easy to swap back and forth. Cut the pad down on your existing pedal and don't worry about finding a new one.

Otherwise, the swap is pretty straightforward. GM NV4500s are split into 3 groups: 93-94, 95, and 96+. Make sure you know which style you're installing so there are no surprises down the line.

NV4500 wasn't put in GM trucks until 1993. A 1989 truck should have had an SM465 4-speed (unless converted).

As stated above, pedals mix and match. You want a bracket and clutch pedal for hydraulic clutch (1986 and forward), brake pedals are easy to swap back and forth. Cut the pad down on your existing pedal and don't worry about finding a new one.

Otherwise, the swap is pretty straightforward. GM NV4500s are split into 3 groups: 93-94, 95, and 96+. Make sure you know which style you're installing so there are no surprises down the line.

Ok, I bought a wreckt truck just for the 6.2 Engine, the manual trans, unseend the guy sade that it was a nv4500 in it but how nows!
I have not seen the truck yet, how do I tell the diffrence!?

 

[campfire]

Ok, I bought a wreckt truck just for the 6.2 Engine, the manual trans, unseend the guy sade that it was a nv4500 in it but how nows!
I have not seen the truck yet, how do I tell the diffrence!?

Look up pictures of what they look like. The 465 is a 4-speed cast iron case with a cast iron transfer case adapter. The 4500 is a larger 5-speed cast iron case with an aluminum tail housing and no adapter needed.

Count the total number of forward gears. Some shift knobs are numbered 1-5, some are numbered L,1,2,3,OD. Kinda confusing when second gear is labeled '1.'

Physically they both will fit, but the shifters are in different places.

 

[Karl Larsson]

Look up pictures of what they look like. The 465 is a 4-speed cast iron case with a cast iron transfer case adapter. The 4500 is a larger 5-speed cast iron case with an aluminum tail housing and no adapter needed.

Count the total number of forward gears. Some shift knobs are numbered 1-5, some are numbered L,1,2,3,OD. Kinda confusing when second gear is labeled '1.'

Physically they both will fit, but the shifters are in different places.

I Think I can get my hands on a NV4500 out of a -99 Chevrolet 3500 4WD, would that be a good match!?

 

[campfire]

I Think I can get my hands on a NV4500 out of a -99 Chevrolet 3500 4WD, would that be a good match!?

That's fine. Have you read through my M1009 thread yet? I did a very similar swap, except mine was a blazer, and I used a 92-94 NV4500. A late-model will have an internal slave cylinder and a removable shifter column. Otherwise it's exactly what I did. Adapt the hydraulic line from the stock 1999 slave to a stock squarebody hydraulic master cylinder (1986-1991 R/V series truck, not the newer body style trucks).

Note that CUCV trucks were built to 1984 spec. In 1985 the civilian trucks changed cross member heights, but the military trucks continued to use the flat-style cross member. Older 1/2 and 3/4-ton trucks had this crossmember:

While later trucks have this "W"-shaped cross member:

(1-ton crossmembers have a different frame height offset, but you get the idea). The center section is raised up on the newer style of cross member, and that is the height that an 85+ GM transmission expects (including all varieties of GM NV4500). You can raise your transmission mount up with a block, or you can obtain a different crossmember. (There's also an "S"-shaped crossmember, but the center height is the same as the "W").

Otherwise...Length, height, width, bell housing, input/output shafts and transfer case flange are all identical or compatible with a late-model stock SM465 configuration. You will need a 6.2/6.5 diesel flywheel and a compatible clutch set. They are dimensionally the same as a 350 flywheel, but with a significant amount of extra balance weight (which you need for your unbalanced engine). Avoid the dual-mass flywheels used on early 6.5 engines. They are nice while they last, but have longevity issues. A stock 6.2 flywheel will work just fine.

 

[Karl Larsson]

That's fine. Have you read through my M1009 thread yet? I did a very similar swap, except mine was a blazer, and I used a 92-94 NV4500. A late-model will have an internal slave cylinder and a removable shifter column. Otherwise it's exactly what I did. Adapt the hydraulic line from the stock 1999 slave to a stock squarebody hydraulic master cylinder (1986-1991 R/V series truck, not the newer body style trucks).

Note that CUCV trucks were built to 1984 spec. In 1985 the civilian trucks changed cross member heights, but the military trucks continued to use the flat-style cross member. Older 1/2 and 3/4-ton trucks had this crossmember:

While later trucks have this "W"-shaped cross member:

(1-ton crossmembers have a different frame height offset, but you get the idea). The center section is raised up on the newer style of cross member, and that is the height that an 85+ GM transmission expects (including all varieties of GM NV4500). You can raise your transmission mount up with a block, or you can obtain a different crossmember. (There's also an "S"-shaped crossmember, but the center height is the same as the "W").

Otherwise...Length, height, width, bell housing, input/output shafts and transfer case flange are all identical or compatible with a late-model stock SM465 configuration. You will need a 6.2/6.5 diesel flywheel and a compatible clutch set. They are dimensionally the same as a 350 flywheel, but with a significant amount of extra balance weight (which you need for your unbalanced engine). Avoid the dual-mass flywheels used on early 6.5 engines. They are nice while they last, but have longevity issues. A stock 6.2 flywheel will work just fine.

Thank you for lot of useful inforamtion, I will defently read your tread about M1009.
I will use the flywheel and clutch set from the 2500 -89 pickup so I Think I be fine there.
Thanks Karl.

 

[campfire]

Thank you for lot of useful inforamtion, I will defently read your tread about M1009.
I will use the flywheel and clutch set from the 2500 -89 pickup so I Think I be fine there.
Thanks Karl.

Yes, that's fine. A note to anyone else considering this swap...if your truck currently has a 700R4 or TH350, your output shaft is smaller than what the TH400 and manual transmissions have (27-splines vs. 32 splines). In this case you would need a 32-spline input shaft for your transfer case. @Karl Larsson won't have this problem, because he's replacing a TH400.

 

[diesel4me]

That's fine. Have you read through my M1009 thread yet? I did a very similar swap, except mine was a blazer, and I used a 92-94 NV4500. A late-model will have an internal slave cylinder and a removable shifter column. Otherwise it's exactly what I did. Adapt the hydraulic line from the stock 1999 slave to a stock squarebody hydraulic master cylinder (1986-1991 R/V series truck, not the newer body style trucks).

Note that CUCV trucks were built to 1984 spec. In 1985 the civilian trucks changed cross member heights, but the military trucks continued to use the flat-style cross member. Older 1/2 and 3/4-ton trucks had this crossmember:

While later trucks have this "W"-shaped cross member:

(1-ton crossmembers have a different frame height offset, but you get the idea). The center section is raised up on the newer style of cross member, and that is the height that an 85+ GM transmission expects (including all varieties of GM NV4500). You can raise your transmission mount up with a block, or you can obtain a different crossmember. (There's also an "S"-shaped crossmember, but the center height is the same as the "W").

Otherwise...Length, height, width, bell housing, input/output shafts and transfer case flange are all identical or compatible with a late-model stock SM465 configuration. You will need a 6.2/6.5 diesel flywheel and a compatible clutch set. They are dimensionally the same as a 350 flywheel, but with a significant amount of extra balance weight (which you need for your unbalanced engine). Avoid the dual-mass flywheels used on early 6.5 engines. They are nice while they last, but have longevity issues. A stock 6.2 flywheel will work just fine.

The 6.2 flywheel is a one of a kind version--though it has the same crankshaft bolt pattern as a gas engine,as noted above,the 6.2 is externally balanced (flywheel has a balance weight on it),and another difference is it has only 139 teeth vs 153 or 168 for a gas engine,the starter drive also has a different tooth count..
The overall diameter may be different also,I'm unsure about that..

I've heard about guys trying to use a gas flywheel by adding the balance weight,but then they discovered the starter wouldn't engage the flywheel,after everything was bolted up and they went to start it for the first time...

 

[campfire]

The 6.2 flywheel is a one of a kind version--though it has the same crankshaft bolt pattern as a gas engine,as noted above,the 6.2 is externally balanced (flywheel has a balance weight on it),and another difference is it has only 139 teeth vs 153 or 168 for a gas engine,the starter drive also has a different tooth count..
The overall diameter may be different also,I'm unsure about that..

I've heard about guys trying to use a gas flywheel by adding the balance weight,but then they discovered the starter wouldn't engage the flywheel,after everything was bolted up and they went to start it for the first time...

Could you simply use a 350 starter for that? I know it would be underpowered, but I think the bolt pattern is also different.

 

[diesel4me]

I'm not sure if the bolt pattern in the 6.2 block is the same as gas engines,it appears to be by eye,but I've never tried matching up a diesel starter to one off a gasser..if the gasser starter would bolt up,maybe one of the gear reduction mini starters might be powerful enough to crank the diesel over fast enough..(in summertime at least!)..
Best to use the right parts,that way you know everything should work..

 

[Karl Larsson]

That's fine. Have you read through my M1009 thread yet? I did a very similar swap, except mine was a blazer, and I used a 92-94 NV4500. A late-model will have an internal slave cylinder and a removable shifter column. Otherwise it's exactly what I did. Adapt the hydraulic line from the stock 1999 slave to a stock squarebody hydraulic master cylinder (1986-1991 R/V series truck, not the newer body style trucks).

Note that CUCV trucks were built to 1984 spec. In 1985 the civilian trucks changed cross member heights, but the military trucks continued to use the flat-style cross member. Older 1/2 and 3/4-ton trucks had this crossmember:

While later trucks have this "W"-shaped cross member:

(1-ton crossmembers have a different frame height offset, but you get the idea). The center section is raised up on the newer style of cross member, and that is the height that an 85+ GM transmission expects (including all varieties of GM NV4500). You can raise your transmission mount up with a block, or you can obtain a different crossmember. (There's also an "S"-shaped crossmember, but the center height is the same as the "W").

Otherwise...Length, height, width, bell housing, input/output shafts and transfer case flange are all identical or compatible with a late-model stock SM465 configuration. You will need a 6.2/6.5 diesel flywheel and a compatible clutch set. They are dimensionally the same as a 350 flywheel, but with a significant amount of extra balance weight (which you need for your unbalanced engine). Avoid the dual-mass flywheels used on early 6.5 engines. They are nice while they last, but have longevity issues. A stock 6.2 flywheel will work just fine.

Have I understand it right if I said that a crossmember from a civilian -85 or -86 would be the right on for me!? or do i still have to raise the NV4500 with block to get it right?

 

[campfire]

Have I understand it right if I said that a crossmember from a civilian -85 or -86 would be the right on for me!? or do i still have to raise the NV4500 with block to get it right?

Yes, a civilian crossmember from those years would have the correct offset. HOWEVER...your truck has a 1-ton frame, which is taller. 1-ton crossmembers have less frame offset. So if you found an '85-'91 1-ton crossmember, you would not need any block. The first time I did this swap, I simply built a block. The second time, I bought a crossmember. Looking back I think I'd just use a block, unless a crossmember dropped in my lap.


Side note about the dates... 1/2-ton and 3/4-ton squarebody trucks were discontinued after 1987. 1988 was the start of the GMT400 trucks. But squarebody Blazers, Suburbans, and 1-ton trucks continued production until the end of 1991 model year. So you can find parts for squarebodies after 1987, as long as you're looking at an R/V-series truck, rather than the C/K series which by that point used the newer body style. These middle years gradually phased in some pieces of the newer tech, like EFI, electric fuel pumps, serpentine belts, and eventually the 4L80 heavy-duty transmission.

So...you can find the parts you need in an 85-87 C/K10 or C/K20 truck, or also in an 85-91 Suburban, Blazer, or C/K30 truck.

Make sense?

 

[obijuank5]

85-91 crossmembers were all the same. 1 tons were mounted inside the frame rails and others were mounted under the rail.

These are 88-91. Not entirely sure what year these started. W crossmember was 85-87 ish. Something like that.

 

[Bowtiek10]

If you need help figuring out how to adapt all the hydraulic lines let me know. Theres an easy way to use AN/adapter fittings